Seminar Programme
We encourage visitors to give a research seminar while on La Palma. Please contact your support astronomer or ING's Head of Astronomy if
you would like to give a presentation. We invite staff from other institutions on site to attend. These seminars usually take place in our sea-level base in Santa Cruz de La Palma, on the 6th floor of
Mayantigo building. Some of these seminars are organised together with NOT or Mercator telescopes.
Other institutions at the Roque de Los Muchachos Observatory organise seminars, and these can take place at CALP, Fundación Galileo Galilei, or even broadcasted from the IAC headquarters in La Laguna (Tenerife),
using online streaming video or videoconferencing facilities (more can be read here: seminars of the IAC programme).
Seminars in 2013
| Date:
04 July (Thu)
| Time: 15:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Star forming sites around HII regions and supernova remnants
| | Speaker (Affiliation):
Dr. Sergio A. Paron (Instituto de Astronomia y Fisica del Espacio (IAFE) - Buenos Aires, Argentina)
| Abstract:
Nowadays it is well known that massive stars in our Galaxy are born predominantly within the dense cores of giant molecular clouds. They usually form and evolve in clusters,hence it is expected to observe several HII regions in different evolutionary stages and probably also supernova remnants (SNRs) in a same Galactic neighbourhood. Moreover, it is usually observed large amounts of molecular gas in the surroundings of HII regions and SNRs. The shock and ionization fronts from these objects, which compress and sweep up the gas, can trigger the formation of a new generation of massive stars. In this talk I will show some results from our multiwavelenth studies towards several star forming sites around both SNRs and HII regions.
| | Slides:
| | |
| Date:
17 Jun (Mon)
| Time: 15:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
How to submit a successful observing proposal
| | Speaker (Affiliation):
Dr. Marc Balcells (ING Director and IAC, Spain)
| Abstract:
The talk will cover recommendations for writing observing proposals, including:
organising preparatory work; giving your proposal a good structure; clues on a good
title and a good abstract; recommendations on figures and figure captions; recommendations
on latex; and suggestions on how to learn from proposals that did not get time.
| | Slides: PDF
| | |
| Date:
10 Jun (Mon)
| Time: 15:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Ultracompact AM CVn binaries and their progenitors
| | Speaker (Affiliation):
Drd. Thomas Kupfer (Department of Astrophysics, Radboud University Nijmegen, The Netherlands)
| Abstract:
AM CVn systems are a small group of mass transferring ultracompact binaries
with orbital periods between 5.4 and 65 min. They consist of a white dwarf (WD)
primary, and a WD, or semi-degenerated helium star secondary. AM CVn systems are
important as strong low-frequency Galactic gravitational wave sources and will act as
verification sources for upcoming space based gravitational wave detectors like
eLISA/NGO. They might also be the source population of the proposed Ia supernovae. An
open question is still at which number WD donors or helium star donors contribute to
the population of AM CVn systems. We have started a project to search for AM CVn
binaries and compact binaries which might evolve into AM CVn type binaries. I will
report on the discovery of an interesting progenitor system which is a good candidate
to explode as an underluminous supernova and present a project to find these
interesting compact binaries using the UVEX database. I will also present the results
of phase-resolved spectroscopy of four AM CVn systems obtained with the William Herschel
Telescope and the Gran Telescopio de Canaries (GTC). We measured orbital periods and
used flux ratios of different helium lines to estimate the temperature of the accretion
disc and the bright spot where the accretion stream hits the accretion disc.
| | Slides: PDF
| | |
| Date:
17 May (Fri)
| Time: 15:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Evolution in galaxy cluster cores since half way back to the big bang
| | Speaker (Affiliation):
Dr. Claire Burke (Astrophysics Research Institute, Liverpool John Moores University, UK)
| Abstract:
Galaxy clusters are the densest regions of matter in the Universe and their cores were formed from the first density peaks to collapse after the big bang, as such they are ideal regions for studying the buildup of large scale structure in the Universe. The cores of galaxy clusters are usually dominated by a massive brightest cluster galaxy (BCG). Sitting at the centre of mass of galaxy clusters, BCGs are the most massive, most luminous galaxies observed. Studies of the mass assembly of BCGs provide a major challenge for current cosmological models as they are observed to have assembled the majority of their present day mass by z>~1, equivalent to half way back to the big bang. This indicates an assembly which is much more rapid than current models predict. BCGs are surrounded by diffuse, faint intracluster light (ICL) which pervades the whole cluster and extends beyond its visible limits. Whilst faint, the ICL contains a large fraction of the stellar mass of nearby clusters (as much as 80%), however its origins and assembly history are unknown.
I will present our recent observational studies of the assembly and evolution of BCGs and the ICL since half way back to the big bang. Our results show very little evolution the for half-light radii of BCGs, highlighting them as a population distinct from normal or field ellipticals; however we find that BCGs should undergo a large number of mergers, both major and minor over this time. We also find a rapid and large growth in the ICL over the same time. The large number of expected mergers onto BCGs their along with the observed lack of growth in mass and radius indicates that the majority of the stellar mass from mergers must end up in the ICL rather than centrally on the BCG. These results point to a rapid early assembly of massive galaxies in clusters followed by passive evolution, with interactions between galaxies in clusters mainly occurring by stripping to build up the ICL at later times.
| | |
| Date:
14 February (Thu)
| Time: 15:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Gamma Ray Burst Polarimetry with the Liverpool Telescope
| | Speaker (Affiliation):
Drd. Doug Arnold (Liverpool John Moores University and ING student)
| Abstract:
Gamma Ray Bursts (GRBs) are the most high energy events in the
Universe since the big bang. First discovered in the 1960s it
was not until this century that GRBs could be reliably followed
up at other wavelengths by ground based facilities. In the SWIFT
era, ground based follow-up from robotic telescopes, such as
the Liverpool Telescope, enable early time (less than 5 minutes
post burst) observations which aid us in understanding the progenitors
of these events. Early time polarimetry has been an exceptionally
valuable tool in confirming models of emission within gamma ray
bursts. The talk will present an overview of GRB theory, detail
the Liverpool Telescope capabilities and present new results
of the polarimetry of six bursts.
| | Slides: PDF
| | |
| Date:
25 January (Fri)
| Time: 11:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
A 3D view of the nova remnant of GK Per
| | Speaker (Affiliation):
Dr. Tiina Liimets (Tartu Observatory, Estonia)
| Abstract:
Due to the high expansion speed, the apparent growth of the
nearby nova remnant GK Per can be easily resolved from ground-based
optical imagery on a timescale of months. For that reason, starting on
2004 we embarked in a program of frequent imaging monitoring of the
expansion of the GK Per remnant with the Isaac Newton Telescope
and Nordic Optical Telescope. The expansion in the plane of the sky
coupled with Doppler shift velocities allowed us to obtain a unique
3D view of the ejecta and carry out a detailed kinematical and
dynamical study. The main results of our work are discussed
in this presented.
| | |
| Date:
24 January (Thu)
| Time: 15:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Does every large spiral galaxy contain a classical bulge?
| | Speaker (Affiliation):
Prof. Dr. Reynier Peletier (Chair of Kapteyn Instituut Groningen, Netherlands)
| Abstract:
It has become clear in recent years that bulges of galaxies come in two
flavours: classical bulges, that are very similar to small elliptical galaxies,
and so-called pseudobulges, that are very similar to disks. In this talk I try
to show that it is possible that spiral galaxies do not contain a classical
bulge or a pseudobulge, but that they always have a classical bulge, together
with possibly a pseudobulge. This has strong consequences about the build-up
of galaxies. In the end, I will also talk about scientific interests in the
Netherlands for the WHT and INT.
| | |
Seminars in 2012
| Date:
11 December (Tue)
| Time: 15:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
The EURONEAR project and its successful collaboration with students and amateurs
| | Speaker (Affiliation):
Dr. Ovidiu Vaduvescu, Isaac Newton Group, IAC and IMCCE associated
| Abstract:
I will present the European Near Asteroid Research (EURONEAR), a project
dedicated to Near Earth Asteroids (NEAs) and Potentially Hazardous Asteroids (PHAs).
Founded in 2006, EURONEAR currently joins 17 collaborating nodes and more than 50
astronomers from eight countries interested in the orbital properties (via astrometry)
and physical properties of NEAs and PHAs (using photometry, spectroscopy and polarimetry).
Following a brief overview about NEAs and their possible risk posed to Earth, I will
list 10 projects/papers completed mostly in collaboration with students and amateur
astronomers, including few other projects related to EURONEAR. These papers include
data from 14 telescopes (0.3-4m) accessed by the EURONEAR network in Chile, La Palma,
France, Germany and Romania, in addition with data mining of wide field archived
images from 2-8m telescopes. The future of EURONEAR will be finally resumed,
including the need of at least one 2m class telescope dedicated to NEA work.
| | Slides: PDF
| | |
| Date:
26 November (Mon)
| Time: 15:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
WEAVE: The next generation wide-field spectroscopy facility for the WHT
| | Speaker (Affiliation):
Prof. Dr. Gavin Dalton, STFC-RAL, WEAVE PI, United Kingdom
| Abstract:
I will describe the major scientific motivation and outline design concept
for a new 2 degree field, 1000 fibre multi-object spectroscopy facility for the WHT.
WEAVE is expected to be completed by early 2017 and will be capable of addressing a
wide range of Galactic and extra-Galactic goals, covering the redial velocity
follow-up to the full depth of the Gaia astrometric catalogue, stellar abundances
and chemical labelling in the Galactic halo, galaxy evolution from integral field
studies and from the identification of the LOFAR source population, and Cosmology.
The instrument is complex, but not necessarily challenging, and will provide a major
resource for the whole ING community for the next decade. I will try to include some
details of the operational implications for the telescope.
| | |
| Date:
19 November (Mon)
| Time: 15:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Core-collapse supernovae: progenitors and dust production
| | Speaker (Affiliation):
Dr. Rubina Kotak, Queen's University, Belfast, Northern Ireland, United Kingdom
| Abstract:
Recent years have witnessed a flurry of studies that have emphasised
the important role that dust plays in our understanding of the near
and distant Universe. The short time-scales required for dust enrichment
make core-collapse supernovae rather natural candidates for dust producers
in the early Universe. Yet, direct evidence that grains condense in
such supernovae is rather sparse. Here, I will discuss recent results,
and attempt to put the role of core-collapse supernovae as dust producers
into perspective. I will also review what is currently known about the
progenitors of core-collapse supernovae, and how this ties into the
observed properties of core-collapse supernovae, including
their ability to produce dust at relatively early epochs in
their evolution. I will discuss how such studies might evolve
in the light of current and future surveys / facilities.
| | |
| Date:
21 September (Fri)
| Time: 15:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Large-scale Galactic massive star surveys
| | Speaker (Affiliation):
Dr. Jesus Maiz Apellaniz, Instituto de Astrofisica de Andalucia - CSIC
| Abstract:
In the last decades, large-scale surveys have become a dominant mode of doing astronomical
research, as e.g. 2MASS, SDSS, or Hipparcos evidence. In this talk I will describe several
ongoing spectroscopic and imaging massive-star surveys in the Galaxy, including three that
are being carried out from La Palma. Such surveys are interesting because of the enormous
impact that massive stars have on galactic evolution in terms of radiative, kinetic energy,
and chemical evolution effects. A large effort is needed to do them because studying massive
stars is complicated by their scarcity, extinction, spatial distribution, and a nasty habit
of hating loneliness. Our final goal is to study at least 5% of the O stars in the Milky Way
in order to build for the first time a high-quality complete database of massive stars in
the solar neighborhood. I will discuss our ongoing studies on the multiplicity, spatial
distribution, and IMF of the massive stars in the solar neighborhood and of the imprint of
the ISM on their colors and spectra.
| | |
| Date:
14 September (Fri)
| Time: 10:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Red supergiants in the Milky Way: Massive clusters and supernova progenitors
| | Speaker (Affiliation):
Prof. Ignacio Negueruela, Universidad de Alicante
| Abstract:
Red supergiants represent a decisive phase in the evolution of high-mass stars. The recent
identification of several supernova progenitors in nearby galaxies has shown that most
supernova explosions are type II plateau, occurring in red supergiants. Surprisingly, these
observations suggest that most explosions happen in stars with 7 to 10 Msun, unexpectedly
low values. In contrast, the population of well-characterised red supergiants in the Milky
Way is dominated by rather more massive objects, typically with >=15 Msun, in sharp contrast
with expectations based on the shape of the IMF. In this seminar, I will present the first
results of our search for red supergiants in regions of high reddening, which has led to
the discovery of several massive clusters near the base of the Scutum arm. I will also
present preliminary results of our ongoing observational campaign aimed at providing
accurate parameters for a sample of open clusters with ages in the 30-60 Myr range,
containing sizeable numbers of K-type supergiants.
| | |
| Date:
13 August (Mon)
| Time: 11:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
The early Universe just around the corner: Fornax dSph
| | Speaker (Affiliation):
Dr. Andrés del Pino Molina, Instituto de Astrofísica de Canarias, Spain
| Abstract:
We present the full Star Formation History as a function of radius of the Fornax dSph galaxy.
We also present the preliminary results of the spatial distribution of the stellar populations.
We found significant differences in the populations as a function of the galactocentric radius,
which may be the result from interactions between Fornax and other systems. The implications of
the obtained results on the dwarf spheroidal galaxies evolution are also discussed. This study
is based on FORS1@VLT photometry as deep as I ~24.5 and the IAC-star, IAC-pop and MinnIAC codes.
| | Slides: PDF
| | |
| Date:
31 July (Tue)
| Time: 15:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Nuclear stellar disks as tracers of galaxy merging history
| | Speaker (Affiliation):
Hugo Ledo, Isaac Newton Group of Telescopes and University of Hertfordshire
| Abstract:
The current hierarchical paradigm for galaxy formation predicts early-type galaxies to have
been formed through the merging of galaxies of similar mass. During this process, old nuclear
stellar disks (NSD), if present, will be destroyed and new ones can be formed.
We can therefore use the age of the stars in the nuclear disks to constrain the look-back time
since the last major merging event. We present the first NSD census together with a study of
some of the disks' properties and a new technique to deal with the degeneracy between age and
mass to better constrain the age of disk stellar populations which we have applied to the case
of NGC4458.
| | |
| Date:
27 July (Fri)
| Time: 11:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Characterizing exoplanet atmospheres with ground-based telescopes
| | Speaker (Affiliation):
Dr. Ernst De Mooij - Department of Astonomy and Astrophysics, University of Toronto, Canada
| Abstract:
In the 16 years since the discovery of the first planet outside our
solar-system, the field of exoplanet research has made a lot of progress.
Not only has the number of known exoplanets increased to almost 800, it
has also become possible to detect the atmospheres for several dozen of
these exoplanets. For transiting planets we can study their atmosphere
both in transmission (during the transit), as well as in
emission/reflection during the secondary eclipse (when the planet passes
behind the star).
Until a few years ago, the characterization of exoplanet atmospheres was
only possible using space-based telescopes. However, I will show that
ground-based telescopes can be used to reach the high precision required
to detect the atmospheric signatures and can provide complementary
information to space-based observations. In addition, I will also discuss
some of the challenges we encounter when doing these observations.
| | |
| Date:
23 July (Mon)
| Time: 16:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
High-redshift proto-cluster radio galaxies and the search for molecules in the early Universe
| | Speaker (Affiliation):
Dr. Bjorn Emonts - CSIRO Astronomy and Space Science / ATNF, Australia
| Abstract:
Millimeter astronomy with the Atacama Large Millimeter Array (ALMA)
will take a prominent role in astrophysical research this decade. A key
topic will be the search for molecular gas -- the raw ingredient for star formation --
in the early Universe. I will give an extensive introduction on some of the
successes and limitations thus far in the search for molecular gas in the
distant Universe, focussed on the commonly used tracer carbon-monoxide or
CO. I will address how the Australia Telescope Compact Array (ATCA) has
overcome some of these limitations and is now a world-class open-access
southern millimeter-facility and excellent compliment to ALMA in the search
for distant molecules. We used the ATCA for a survey for molecular CO(1-0)
gas in a sample of 14 high-redshift proto-cluster radio galaxies. These high-z
radio galaxies are among the most massive and active galaxies in the early
Universe and believed to be the progenitors of current day giant ellipticals in
the cores of rich clusters. I will highlight results of two fascinating sample sources
(the Spiderweb Galaxy and MRC 0152-209), which show evidence for widely
spread reservoirs of cold gas that have not (yet) been depleted by star formation
or radio source feedback. Results of our survey provide insights into the co-evolution
of active black-holes and their massive host galaxies in the early Universe.
| | Slides: PDF
| | |
| Date:
06 July (Fri)
| Time: 16:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Ultracool KIS
| | Speaker (Affiliation):
Dr. Eduardo Martín Guerrero de Escalante - INTA-CSIC Centro de Astrobiología, Spain
| Abstract:
The Kepler INT survey (KIS) is an ongoing imaging survey of NASA's Kepler mission field of view.
A search for ultracool dwarfs, very low-mass stars and brown dwarfs, in the KIS using the Spanish
Virtual Observatory will be presented. The scientific prospects of Kepler observations of
ultracool dwarfs using GO time will be presented.
| | Slides: PPT
| | |
| Date:
04 July (Wed)
| Time: 15:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Ground-Based Follow-Up Observations of the Kepler Asteroseismic Targets
| | Speaker (Affiliation):
Dr. Joanna Molenda-Zakowicz, Astronomical Institute - University of Wroclaw, Poland
| Abstract:
The NASA space mission Kepler has been providing high-precision time-series photometry in
a single, broad-band filter for thousands of stars since March 2009. As in April 2012 NASA
approved the extension of the Kepler mission, those observations will be continued for another
four years.
The Kepler data allowed to discover more than 60 exoplanets, and to study new or
already known but poorly investigated astrophysical phenomena in stars of different kinds.
However, the full use of the Kepler observations is possible only if they are completed
with ground-based spectroscopic and photometric data. Keeping that in mind, an enormous
observational effort has been undertaken by the astronomical community which aims at deriving
the atmospheric parameters of the Kepler targets, computing the cluster membership of the stars
falling into the open clusters in the Kepler field of view, and classifying the variable stars
to the types of variability.
In this talk, I give an account of the present state of the photometric and spectroscopic
monitoring of the Kepler field, the results which have been already obtained, and the progress
of the on-going work.
| | Slides: PDF
| | |
| Date:
20 June (Wed)
| Time: 12:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
The Planck Mission: Early Results
| | Speaker (Affiliation):
Dr. Jose Alberto Rubiño-Martín, Instituto de Astrofísica de Canarias, Spain
| Abstract:
The European Space Agency's Planck satellite was launched on 14 May 2009, and has been surveying the sky stably and continuously since 13 August 2009. Its performance is well in line with expectations, and it will continue to gather scientific data until the end of its cryogenic lifetime. I will present the first scientific results of the mission, which appeared as a series of 26 papers at the beginning of 2011, covering a variety of astrophysical topics. In particular, I will focus on the results on galactic diffuse emissions, as well as the first results on galaxy clusters detected by means of the Sunyaev-Zeldovich effect.
| | |
| Date:
31 May (Thu)
| Time: 12:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Dwarf Galaxies
| | Speaker (Affiliation):
Dr. Ovidiu Vaduvescu, Isaac Newton Group of Telescopes and IAC Associated
| Abstract:
I will present my research interests in dwarf galaxies, specifically dwarf
irregulars (dIs), blue compact dwarfs (BCDs) and dwarf ellipticals (dEs).
First, I will explain my preference to observe galaxies in the near
infrared (NIR), sharing some experience in the difficult task of imaging,
reducing and measuring extremely faint surface dwarfs observed with many
facilities (2MASS, IRSF, OAN-SPM, INT, NTT, TNG, CFHT, Blanco, Gemini and
VLT). Second, I will list some main science results, such as the new "sech
law" to fit surface profiles of dIs and BCDs and the "dwarf
fundamental plane" (FP) that recently lead to some insights in some
fundamental physics linking star forming dwarfs. Third, I will present
some spectroscopical and chemical results about star forming dwarfs
located in the Local Volume (LV) and nearby clusters (Virgo, Fornax,
Hydra, Antlia, Perseus). Finally I will present some recent and future
projects including dwarfs and giants in different environments, where
I gladly welcome students or new collaborators.
| | Slides: PPT
| | |
| Date:
09 May (Wed)
| Time: 16:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Young, massive, and poweful ...
| | Speaker (Affiliation):
Dr. Cecilia Farina, Isaac Newton Group of Telescopes
| Abstract:
Massive stars (M > 10 Ms) constitute a small fraction of the whole stellar
population of a galaxy and the time scales involved in their evolution are
short (in the order of a few million years). Nevertheless, these objects
play a fundamental role in the dynamical and chemical evolution of
galaxies. During all their evolutionary stages, massive stars interact
violently with the interstellar medium: injecting kinetic energy through
their strong stellar winds, providing most of the ionizing photons in the
galaxies as well as the heavy chemical elements that will be recycled in
the new stellar generations. Whereas in the last few decades, knowledge of
the physical processes involved in massive star formation has greatly
increased, both from theoretical and observational points of view, there
are still basic issues in the field which are not clearly understood.
These uncertainties originate from the complexity of the environments
where massive star formation proceeds, which makes observational studies
of massive star formation regions a challenging task. In this talk I will
give a brief summary of massive stars and massive formation regions at
different scales, from an observational perspective. I will also review
the fundamentals of studying these regions at infrared wavelengths. This
will provide the context to present a near infrared study of the youngest
and more massive stellar population of NGC 604, the second major giant HII
region in the Local Group after 30 Doradus.
| | Slides: PDF
| | |
| Date:
04 Apr (Wed)
| Time: 16:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Kepler's treasure chest of eclipsing binary stars
| | Speaker (Affiliation):
Dr. Steven Bloemen, Institute of Astronomy, Leuven University, Belgium
| Abstract:
While the Kepler satellite was designed to hunt for planets, its precise
photometric observations of about 150 000 stars have also proven to be of
immense value to the binary star community. More than 2000 previously
unknown eclipsing binary stars have been found, which can all be studied in
detail thanks to the nearly continuous Kepler datasets that will span at
least 3.5 yrs. During this talk we will dig into Kepler's treasure chest of
eclipsing binaries. We will discuss scientific highlights such as the first
discoveries of circumbinary planets, binaries with components that show
tidally excited oscillations, and compact binaries in which the detections
of Doppler beaming and Rømer delay allowed us to measure the components'
radial velocity amplitudes directly from the photometric data.
| Date:
19 March (Mon)
| Time: 16:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Status of the NAOMI upgrade
| | Speaker (Affiliation):
Dr. Jure Skvarc, Issac Newton Group of Telescopes
| Abstract:
NAOMI, the adaptive optics system at the WHT, is undergoing several upgrades
in last three years in order to improve reliability and stability. I will
present an overview of the work done on environmental control, optical
components, detectors, software at the user level and the real time system,
as well as the hardware upgrades of real time system. First results of the
on-sky tests of the new real time system will be presented, both for
infrared imaging with INGRID and optical imaging with the Andor EMCCD
camera. In addition, some results obtained with lucky imaging technique will
be shown. Although some more on-sky tuning is necessary to get the optimal
performance, the initial results show that the upgrade is progressing well
and that the work to replace the entire NAOMI real time system can continue
with the goal to further improve reliability and performance, as well as to
simplify the system.
| Date:
14 March (Wed)
| Time: 15:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
The formation of S0 galaxies
| | Speaker (Affiliation):
Prof. Dr. Alfonso Aragon-Salamanca, School of Physics & Astronomy, University of Nottingham, UK
| Abstract:
Evidence is mounting indicating that S0s were once spiral galaxies that
ceased forming stars and subsequently changed their morphology. Studying
the timing, location and physical mechanism(s) involved in this
transformation is not only interesting in itself, but it can also provide
very useful clues on how galaxies evolve and the possible role of the
environment. During the last few years we have been following several
lines of research to test whether this transformation is indeed taking
place, find out where it happens, and look for the physics driving it. At
low redshift we have studied in detail the final products of the
transformation - the S0s themselves - while at intermediate redshifts
(z~0.5) we have concentrated on the putative progenitors - spiral galaxies
- and the galaxies caught in the act of transforming. In this talk I
present some of our more interesting results. Although there are still
some loose ends, a coherent picture may be emerging.
| | Slides: PDF
| | |
| Date:
14 March (Wed)
| Time: 12:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
INO340 project; status and future plans
| | Speaker (Affiliation):
Dr. Habib Gharar Khosroshahi, Institute for Research in Fundamental Science, Iran
| Abstract:
Iranian National Observatory (INO) project aims at construction of a
3.4m optical telescope currently being designed. The observatory site is
located at an altitude of 3600m in the central Iran mountains benefiting
from very good observing conditions. This general purpose optical telescope
demanded to offer high resolution imaging over a relatively large field of
view. Imaging and spectroscopic follow-up observations of ground and space
based surveys are among the key science objectives of this telescope. Given
its longitude, it can also be efficiently used for the time domain
observations. Just a few days after the CoDR, I
will report on the progress in different areas, optical design, mechanics,
infrastructure and many more. The INO340 is more than a telescope!
| | Slides: PDF
| | |
Seminars in 2011
| Date:
14 Dec (Wed)
| Time: 16:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
New Insights into the Galaxy Morphology-Density Relation
| | Speaker (Affiliation):
Dr. Peter Erwin, Max-Planck-Insitute for Extraterrestrial Physics, Garching
| Abstract:
Galaxy morphology is known to be directly related to galaxy environment, but how
this varies outside of dense clusters is poorly understood, and whether hierarchical
formation models can correctly predict this is also unclear. I present the recent
work on relating the detailed morphology of local galaxies to group environment
on a variety of scales, from single-galaxy halos to the most massive groups, and
compare these empirical findings with modern semi-analytic models which account
for the full merger history of galaxies. We find contrasting trends for elliptical
and S0 galaxies, which suggests two different formation channels for the latter.
| Date:
28 Nov (Mon)
| Time: 16:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Double white dwarfs and the connections between hot subdwarfs, R,CrB stars and extreme helium stars
| | Speaker (Affiliation):
Prof Simon Jeffery, Armagh Observatory and Trinity College Dublin
| Abstract:
The proposal that the merger of two white dwarfs would form a major channel for the
formation of hot subdwarfs has been current for over two decades. Naturally, such a
merger would result in a single star, rather than a binary. The consequences for
frequency, mass distribution, rotation velocity, surface composition, and so on are
less obvious.
This talk will review the general picture of double white dwarf mergers, including
links between white dwarf mergers and various classes of evolved star.
It will present recent work on: a) links between main-sequence binaries and double
white dwarf merger progenitors, b) stellar evolution calculations following the
merger of two white dwarfs, and c) the correlation between predicted and observed
surface abundances of post white-dwarf mergers.
| Date:
28 Sep (Wed)
| Time: 16:00
| Place:
6th floor meeting room, Mayantigo building |
| Title:
The Telescopes, Instrumentation and Operations of the AAO
| | Speaker (Affiliation):
Dr. Chris McCowage, Former staff member of AAO Australia and ING La Palma
| Abstract:
The Australian Astronomical Observatory (AAO), formerly the Anglo-Australian Observatory, operates the 3.9 metre Anglo-Australian Telescope (AAT) and the 1.2 metre United Kingdom Schmidt Telescope (UKST) at Siding Spring Observatory which is operated by the Research School of Astronomy & Astrophysics, Australian National University. The telescopes and instrumentation will be described together with the operations model. There will be a particular emphasis on the development of the use of optical fibres in AAO astronomical instrumentation including 2dF, 6dF and AAOmega. Other topics to be touched on include future instrumentation and technology developments including the use of photonics, changes to AAO governance with the withdrawal of the United Kingdom and external instrumentation projects for other observatories.
| | Slides: PDF
| | |
| Date:
10 June (Fri)
| Time:
12:00am
| Place:
6th floor meeting room, Mayantigo building |
| Title:
The Myth of Haumea
| | Speaker (Affiliation):
Mike Brown, CALTECH, USA
| Abstract:
Haumea is perhaps the strangest object in the Kuiper belt. It has a faster rotation, greater
elongation, and higher density than almost anything in the Kuiper belt. It is surrounded by
a pair of moons and has a family of much smaller objects in nearly identical solar orbit
which appear to have the composition. I will discuss the causes of these strange properties
and show the latest observations on trying to unravel the history, physics, and chemistry of
this odd dwarf planet.
| | Slides: PPT
| | |
| Date:
17 February (Thu)
| Time:
11:00am
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Time-Resolved Properties of the White Light Continuum During Stellar Flares
| | Speaker (Affiliation):
Adam Kowalski, Astronomy Department, University of Washington
| Abstract:
The primary mode of radiative energy release in stellar flares is in the
optical and near-ultraviolet (NUV) continuum. This white light radiation
carries a large fraction of the total radiated flare energy. However,
radiative hydrodynamic models of stellar flares using a solar flare
paradigm and the sparse observations of solar and stellar flare continua
are all seemingly in disagreement over the type(s) of emission that
contribute to the optical/NUV continuum during flares. We have begun a
long-term spectroscopic flare monitoring campaign to fully characterize the
optical/NUV white light continuum emission on short timescales for large
and small flares. To date, our most significant results come from
spectroscopic (3350A - 9260A) and photometric (U band) observations during
1.3 hours of the decay phase of a megaflare on the dM4.5e star YZ CMi,
where we have detected multiple continuum components that contribute to the
white light. I will present the continuum and emission line properties of
this flare and initial phenomenological modeling of the flaring atmosphere.
I will also compare the continuum properties to ultra-high speed
observations of smaller flares.
| | Slides: PDF
| | |
| Date:
9 February (Wed)
| Time:
11:00am
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Gravitational wave sources and the (future) use of the La Palma telescopes
| | Speaker (Affiliation):
Prof. Paul Groot, University of Nijmegen, The Netherlands
| Abstract:
The gravitational wave domain remains the last completely unopened
window on the Universe. Ground-based high frequency detectors are already
operational, but lack known sources. The low-frequency domain will be
opened by the LISA space interferometer. The only known LISA sources are
ultracompact white dwarf binaries. In a campaign involving many of the
La Palma telescopes we are uncovering and characterizing the Galactic
population of these ultracompact binaries, with orbital periods as short
as 5.6 minutes. In the talk I will give an overview of the current state
of affairs, our use of the La Palma telescopes, and the (possible)
future (combined) use of the telescopes.
| | Slides: PDF
| | |
| Date:
21 January (Fri)
| Time:
11:00am
| Place:
6th floor meeting room, Mayantigo building |
| Title:
Accelerating Universe, Dark Energy or Modified Gravity
| | Speaker (Affiliation):
Shant Baghramian (Department of Physics, Sharif University of Technology Tehran, Iran)
| Abstract:
First, I will give a very brief description of the accelerating
universe state and its cosmological evidence like SNIa, CMB and the
LSS. Then I propose the Cosmological constants (LCDM-model) and its
alternative Dark energy (DE) and Modified gravity (MG) models as
plausible candidates for describing the accelerating Universe. Some
cosmological observations, especially large scale structure probes
such as matter power spectrum, the ISW effect and growth index are
discussed later, as useful tools to distinguish between viable DE
and MG models which are equivalent in predicting the background
dynamics of Universe. Finally, the reconstruction of the dynamics
method as a probable way for investigating the problem is introduced,
and the future prospects on the issue is discussed.
| | Slides: PDF
| | |
Seminars in 2010
| Date: 10 December (Fri) |
Time: 11:00am |
Place: 6th floor meeting room, Mayantigo building |
| Title:
Filter Measurements for ACAM
|
| Speaker (Affiliation):
Annemieke Janssen (Rijks Universiteit Groningen & ING student)
|
Abstract:
During the last three months the Transmitted Wavefront Distortions (TWD)
of almost all 50-mm filters have been measured. These distortions are
important to know since they affect the image quality of ACAM
observations. For other instruments the TWD is less critical since filters
are usually placed in the focal plane, where they only affect the image
quality locally. ACAM is a bit of an exception having the filters placed
near the pupil plane, where wavefront distortions over the whole filter
area affect the image quality.
We started analysing the results, partly with Zemax and partly with
pinhole experiments. In the last case, calibration lamps and a pinhole in
ACAM create a very tiny spot on the CCD. The effect of a filter placed in
the beam can now be compared with the measured TWD. The first results will
be discussed in an half-hour presentation.
|
| Slides: PDF |
| |
| Date: 9 December (Thu) |
Time: 11:00am |
Place: 6th floor meeting room, Mayantigo building |
| Title:
Dark matter in galaxies
|
| Speaker (Affiliation):
Marc Balcells (ING)
|
Abstract:
This seminar is part of an initiative coordinated from SISSA to present the phenomenology of dark matter in galaxies at seminars in as many
institutes as possible, in a single 'Dark Matter Awareness Week' (http://www.sissa.it/ap/dmg/index.html ). Over 150 institutes have listed up to hold such seminar.
La Palma is of course represented. The ING makes a special invitation to astronomers from all ORM institutions to attend this event at Mayantigo, where the evidence for DM in galaxies
will be reviewed. Below is the official abstract proposed by the DMAW organisers.
We discuss the details of the mass discrepancy phenomenon in galaxies usually accounted by postulating the presence of a non luminous component.
In the theoretical framework of Newtonian gravity and Dark matter halos we start by recalling the properties of the latter as emerging from the state-of-the-art
of numerical simulations performed in the current LCDM scenario of cosmological structure formation. We then report the complex and much-telling phenomenology of the
distribution of dark matter in spirals, ellipticals, and dwarf spheroidals. Care will be given to show that such a coherent observational framework is obtained from different
and large samples of galaxies and by means of very different methods of investigation and by exploiting different tracers of the gravitational field. These include rotation curve
and dispersion velocities mass fitting, X-ray gas property analysis, weak and strong lens signal mass decomposition, analysis of halo and baryonic mass functions! We will
then highlight the evidence that the distribution of dark and luminous matter are closely correlated. Hints on how the empirical scenario of the mass distribution in galaxies,
including the Milky Way and the nearby ones affects the cosmological investigations are given throughout the talk. Among them, the theoretical constraints on the elusive nature of
the dark matter particles and its direct and indirect searches.
|
| |
| Date: 16 November (Tue) |
Time: 11:00am |
Place: 6th floor meeting room, Mayantigo building |
| Title:
Using AF2/WYFFOS (and Spitzer) to investigate terrestrial planet formation around young stars
|
| Speaker (Affiliation):
Rob Jeffries (Astrophysics Group, Keele University)
|
Abstract:
Our own terrestrial planetary system is thought to have formed during
the first 5-50 Myr of the solar system, but direct evidence for
terrestrial planets around other stars is hard to obtain. I will
describe a joint program of WHT spectroscopy and Spitzer photometry
that seeks indirect evidence for the formation of terrestrial planets
in the form of 24 micron excesses from young (~25 Myr) solar-type
(F-K) stars in the IC 4665 open cluster. Membership of the cluster and
stellar parameters have been obtained using optical photometry and a
WYFFOS spectroscopic survey. I report on oddly effective lithium
depletion in the cluster, casting doubt on the use of this diagnostic
as a reliable age indicator in very young stars. The membership list
is combined with a Spitzer survey to identify stars with mid-IR
excesses. We determine that 42(+18-13)% of the solar-type (F5-K5)
cluster members have excess emission at 24 microns indicative of
debris discs, the highest frequency of the clusters studied with
Spitzer to date. The majority of these discs have intermediate levels
of excess and no source is found to have extreme levels of excess
indicative of a recent transient event (like the collision that formed
the Earth-Moon system) as opposed to steady-state collisional
evolution.
|
| |
| Date: 22 October (Fri) |
Time: 11:00am |
Place: 6th floor meeting room, Mayantigo building |
| Title:
Dynamical Studies of the Globular Cluster Systems
around the Giant Elliptical Galaxies
NGC4636 and NGC1399
|
| Speaker (Affiliation):
Ylva Schuberth (Argelander-Institut fur Astronomie, Bonn, Germany)
|
Abstract:
Dark matter (DM) studies in elliptical galaxies were long hampered by the
lack of suitable dynamical tracers. The advent of 8m-class telescopes
equipped with multi-object spectrographs has made it possible to use
globular clusters (GCs) as dynamical probes constraining their host
galaxy's gravitational potential. I will present results for the two
largest samples of globular cluster velocities obtained for giant
elliptical galaxies to date: The galaxies studied are NGC4636 located in
the very outskirts of the Virgo cluster of galaxies and NGC1399, the
central galaxy of the Fornax cluster. Owing to its unusually bright X-ray
halo, NGC 4636 has a reputation of being extremely dark matter dominated.
The Jeans Models for its GC system, however, require significantly less DM
than suggested by the X-ray studies. The extremely populous GC system of
NGC1399 has an extent of at least 250 kpc, which is comparable to the core
radius of the Fornax cluster itself. Here, the mass estimates obtained
from the combined analysis of the GCs and the stellar velocity dispersion
profile agree with the values from X-ray studies in the inner 100 kpc. At
larger radii, however, we do not find any evidence for a transition from a
galaxy to a cluster halo, as suggested by X-ray work.
|
| |
| Date: 16 September (Thu) |
Time: 03:30pm |
Place: 6th floor meeting room, Mayantigo building |
| Title:
Early time GRB follow-up with BOOTES
|
| Speaker (Affiliation):
Martin Jelinek (IAA-CSIC Granada)
|
Abstract:
BOOTES is a robotic telescope/observatory network primarily
designed for follow-up of Gamma-Ray Bursts (GRB). Telescopes
are relatively small but fast and their "specialization" is
the first hour after the GRB explosion. The operation of the
telescopes is automated up to the high degree so that the
observatory can work unattended for weeks.
I will discuss observational properties of GRBs. What and how
we observe, what is needed and what is not.
|
| |
| Date: 2 July (Fri) |
Time: 11:00am |
Place: R. Pallavicini Tesi meeting room, FGG-INAF (Rambla J.A. Fernandez Perez 7, San Antonio) |
| Title:
CoRoT and its rich exoplanet harvest
|
| Speaker (Affiliation):
Davide Gandolfi (Research and Scientific Support Department, ESA/ESTEC)
|
Abstract:
Studies of transiting extrasolar planets are cornerstones for
understanding the nature of planets beyond the Solar System since a
wealth of precious information can be gained. The space telescope CoRoT
is the first space mission devoted to the discovery of extrasolar
planets via the transit method using photometric measurements of high
accuracy. The transiting extra solar planets recently detected by CoRoT
show the capability of the instrument to enlarge the parameter space of
extra-solar planets and explore the transition regimes between gaseous
giant and terrestrial planets, and gaseous giant planets and brown
dwarfs. In this talk I will review the recent results from CoRoT
observations and complementary ground-based photometric and
spectroscopic follow-ups. The physical parameters of the new transiting
planets and their host star discovered so far by CoRoT, will be
presented and discussed.
|
| |
| Date: 22 June (Tue) |
Time: 15:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title:
A Lucky Imager System for the WHT
|
| Speaker (Affiliation):
Craig Mackay (Cambridge Institute of Astronomy, UK)
|
Abstract:
A new method of imaging in the visible has given the highest
resolution images ever taken anywhere. It needs a natural guide
star of only 18.5 mag (I band) and delivers a corrected field
over almost 1 arcmin. This talk will show how it can be
done on the WHT, the VLT and even on the GTC.
|
| |
| Date: 24 May (Mon) |
Time: 11:00am |
Place: 6th floor meeting room, Mayantigo building |
| Title:
Space weathering mechanisms insight Near-Earth Objects
|
| Speaker (Affiliation):
Mirel Birlan (Institut de Mecanique Celeste et de Calculs des Ephemerides (IMCCE), Observatoire de Paris)
|
Abstract:
Space weathering is influencing in a very important manner the
atmosphereless bodies. The consequence of this effect to the surfaces in
the visible and near-infrared domains is the reddish slope of the spectrum
corroborated with a decreasing of the albedo, and (if exists) the decrease
of absorption bands. However, the spectral response of the surfaces of a
class of Near-Earth Objects (Q-type taxonomic class) shows physical
properties of surface minerals less affected by space weathering. This
result is intriguing while these objects are closer to the Sun, thus
exposed to an important interaction with the solar wind. The close
encounters of these bodies with telluric planets seem to be the most
probable mechanism of such phenomenon. I will present some recent results
concerning NEOs and I will place these researches in the global context of
small solar system bodies.
|
| Slides: PDF |
| |
| Date: 13 May (Thu) |
Time: 11:00am |
Place: 6th floor meeting room, Mayantigo building |
| Title:
Chemical abundances in the polar disk of NGC4650A: implications
for cold accretion scenario
|
| Speaker (Affiliation):
Marilena Spavone (Università di Napoli Federico II)
|
Abstract:
The aim of the present study is to test whether the cold accretion of
gas through a "cosmic filament" (Maccio' et al. 2006) is a possible
formation scenario for the polar disk galaxy NGC 4650A. If polar disks
form from cold accretion of gas, the abundances of the HII regions may
be similar to those of very late-type spiral galaxies. The deep spectra
available allowed us to measure the Oxygen abundances (12 + log (O/H))
using the "Empirical method" based on intensities of the strongest
emission lines, and the "Direct method", based on the determination of
the electron temperature from the detection of weak auroral lines. The
low metallicity value in the polar disk NGC 4650A and the flat
metallicity gradient are both consistent with a later infall of
metal-poor gas, as expected in the cold accretion processes.
|
| |
| Date: 6 April (Tue) |
Time: 15:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title:
Photometric and structural properties of dwarf galaxies in the Coma cluster
|
| Speaker (Affiliation):
Mark den Brok (Kapteyn Astronomical Institute, University of Groningen)
|
Abstract:
The formation of dwarf galaxies in clusters is still an unsolved
problem. Models of galaxy formation underpredict the number of
observed dwarfs. Additionally, it is not clear which of the mechanisms
that have been proposed to remove gas from dwarf galaxies dominates.
In this talk, we present results from the Coma Cluster ACS Treasury
Survey on photometric properties of dwarf galaxies, for which we have
studied colours, colour gradients and structural parameters. Owing to
the high sensitivity and resolution of our data, we are able to
separate out the nuclear and the remaining components of dwarf
galaxies and study the stellar populations of each component separately.
Our results on colour gradients show that metallicity gradients in
dwarf galaxies form a continuous sequence with elliptical galaxies,
becoming shallower for fainter galaxies. I will discuss the relation
between colour gradients and other photometric and structural
properties, such as the presence of and stellar populations of
nuclear star clusters.
|
| |
| Date: 10 March (Wed) |
Time: 15:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title:
Heavy element abundances in the second parameter globular
cluster pair NGC288 / 362
|
| Speaker (Affiliation):
Paul Anthony Wilson (NOT Student, University of Oslo)
|
Abstract:
I will present the results from my master thesis where I measured and
assessed the relative abundance ratios of heavy elements (Si to Eu)
in the second parameter pair NGC 288 and NGC 362. This is needed in
the context of the 2nd parameter problem which, as of yet, does not
have a satisfactory solution.
Studies such as this one are important for providing constraints upon
the uniformity of mixing in the protocluster environment and for
constraining the role of heavy element abundance as a 2nd parameter
candidate.
|
| |
| Date: 26 February (Fri) |
Time: 15:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title:
Variability and stability in optical blazar jets:
photopolarimetric monitoring of OJ287 in 2005-2009
|
| Speaker (Affiliation):
Carolin Villforth (Space Telescope Science Institute, USA)
|
Abstract:
Blazars are a subclass of AGN with jets pointing almost directly towards
the observer, making them perfect object for studying the properties of
AGN jets. We present photopolarimetric monitoring of the blazar OJ287 and
discuss implications for jet physics. Additionally, this particular object
is of special interest as it has shown regularly appearing double-peaked
bursts and is therefore suspected to host a supermassive binary black
hole. Our data can also be used to assess different binary black hole
models.
|
| |
| Date: 12 February (Fri) |
Time: 15:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title:
SHARDS: Understanding the mass assembly of galaxies at 0 |
| Speaker (Affiliation):
Pablo G. Pérez-González (Universidad Complutense de Madrid)
|
Abstract:
We will present the main results of our research about the assembly of
galaxies at z<4 based on observations obtained by the deepest surveys,
noticeably including mid- and far-IR data taken with Spitzer. Analyzing
SFR and stellar mass functions in several redshift bins at 0 |
| |
| Date: 9 February (Tue) |
Time: 11:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title:
The faint extragalactic radio source population
|
| Speaker (Affiliation):
Chris Simpson (Liverpool John Moores University)
|
Abstract:
With LOFAR and e-MERLIN about to start taking data, and SKA on the
horizon, I will describe what we know about the composition of the
extragalactic radio source population and, in particular, the advances
that have been made in understanding the microJansky sources. I will then
look to the future to discuss what progress is likely to be made in
addressing the existing uncertainties in our current picture.
|
| |
| Date: 5 February (Fri) |
Time: 11:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title:
The making of planetary embryos
|
| Speaker (Affiliation):
Cornelis Dullemond (Max Planck Institute for Astronomy, Heidelberg)
|
Abstract:
Making planets out of dust is one of Nature's tricks that we still haven't
understood well. This is remarkable, because modern science has struggled
with this question for many decades. Recent developments in observations
of protoplanetary disks and exoplanetary systems, new developments in
numerical models of the planet formation process, as well as over a decade
of laboratory experiments of colliding dusty bodies, have shed new light
on this issue. But this new information is cryptical: it is not obvious
how to derive an answer to the above question from it. I will talk about
various theoretical modeling efforts that try to synthesize these various
crytic pieces of the puzzle to obtain a full picture, though I will focus
my talk on the growth process from dust to "planetary embryos", i.e.
thousand-kilometer size planetary building blocks. I will show that while
some answers are found, new questions are raised. Most importantly, I will
show how current and future observations of various kinds (can) put
constraints on these models.
|
| |
| Date: 15 January (Fri) |
Time: 11:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title:
Developing global observatory network - the software environment of the Bootes observatories and other
|
| Speaker (Affiliation):
Petr Kubanek (Image Processing Laboratory, Universitat de Valencia, and IAA, Spain)
|
Abstract:
I will present an open source system we are developing for control of
various, usually fully autonomous, observatories. The system is capable
taking care of the weather, selecting targets for observations, and
doing basic image image processing. The system is called RTS2 and is
being developed for almost a decade, and controlling more then 10
observatories. It primary task was a quick follow ups observations of
Gamma Ray Bursts fields, but it is now making progress towards a generic
observatory control environment. It design philosophy, lessons learned
during development, as well as some of the results obtained will be
presented.
|
| Slides: PDF |
| |
| Title:
Abell 41: Nebular Shaping by a Binary Central Star?
|
| Speaker (Affiliation):
David Jones (Jodrell Bank Centre for Astrophysics, Univ. of Manchester, UK)
|
Abstract:
Although the theoretical link between bipolar planetary nebulae and binary
central stars is long established, there is little observational support
for this hypothesis. Here, I will discuss some of the observational tests
being employed to evaluate the validity of the hypothesis, before
focussing on one particular 'test-case' object.
Abell 41, one of a small percentage of planetary nebulae known to contain
a central binary system, in this case the well-studied, close-binary MT
Serpentis. As such, Abell 41 represents an ideal object to test the
so-called 'Binary Hypothesis'. I present detailed spatio-kinematic
modelling, based on deep narrow-band WHT-ACAM imagery along with high
resolution MES-SPM longslit spectroscopy, in order to determine the
relationship between the plane of the central binary and any nebular
symmetry axis. Thus, testing one of the fundamental predictions of all
theories of binary-induced nebular shaping, that the nebular symmetry axis
will be perpendicular to the plane of the central binary.
|
| |
Seminars in 2009
| Date: 17 December (Thu) |
Time: 12:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title:
Integral Field Spectroscopy of Star-Forming Regions in M33
|
| Speaker (Affiliation): Jose M. Vílchez (IAA-CSIC, Granada, Spain)
|
Abstract:
We present an ongoing project of Integral Field Spectroscopy (IFS)
of the giant star-forming regions of M33. These observations are
intended to study the variations in 2D of the main physical and
chemical properties across the HII region complexes, selected to
sample the metallicity gradient of M33.
IFS is a powerful technique: at each position of the observed field,
the full optical spectrum from 3650 to 6990 A was obtained. We have
created maps of the most relevant emission lines and line ratios for
all the giant HII regions of the sample.
Among these regions, a detailed study of NGC595, the 2nd brightest HII
region in M33, is presented. The extinction map and the fraction of the
absorbed Halpha luminosity were derived and compared to the Mid Infrared
emission measured by Spitzer. In addition, the total census of Wolf-Rayet
stars, the ionisation structure and star clusters of the region as well
as its shell morphology and the density distribution have been analysed.
Finally, our IFS has provided a simple way to examine the reliability of
some popular metallicity calibrators currently used to characterize the
most distant emission line galaxies.
|
| Slides: PDF
|
| |
| Date: 14 December (Mon) |
Time: 17:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title:
RaTS and the search for Ultra-Compact binaries
|
| Speaker (Affiliation): Gavin Ramsay (Armagh Observatory, UK)
|
Abstract:
Ultra Compact Binaries are predicted to be the strongest known sources of
gravitational waves in the LISA pass-band. Since they are at the short
period end of the orbital period distribution (<70 mins), their number is
a sensitive test of binary evolutionary models. The best method to detect
these short period systems, whose optical light is dominated by an
accretion disk and show optical intensity variations on timescales close
to their orbital period, is through deep, wide-field, fast-cadence
photometric surveys. The RaTS (Rapid Temporal Survey) project is unique
in that it is sensitive to variability on timescales as short as 2 mins
and systems with V~22. Our strategy and initial results will be presented.
|
| Slides: PDF
|
| |
| Date: 30 November (Mon) |
Time: 15:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title:
Observational studies of gas in protoplanetary disks
|
| Speaker (Affiliation): Andres Carmona Gonzalez
(Astronomical Observatory, University of Geneva) |
Abstract:
Circumstellar disks are essential in the process of star and planet
formation. Early in the star's life they permit the inflow of material
from the primordial cloud to the star and the outward transport of angular
momentum. During the pre-main sequence, also known as the T Tauri phase,
these reservoirs of dust and gas are the sites of planet formation.
Although protoplanetary disks are composed of 99% gas and only 1% dust,
our physical understanding of these disks has been based mostly on the
study of dust emission. The dust dominates the opacity, therefore, it is
much easier to observe. However, as the gas is the dominant mass
component, to derive observational constraints of gas properties in the
disk is fundamental for our understanding of disk physics, therefore,
planet formation. Several fundamental questions about planet formation
remain unanswered: How much material is available for forming planets? How
long is the disk life-time? How does the disk dissipate? What are the
dynamics of disks? The answers to these questions will require direct
observational constraints of the gas, especially from the region where
planets are expected to form (R<10AU). The advent of high-resolution
spectrographs in the IR opened the way to the observational study of the
gas in the inner disk. In this talk I will review I discuss several
observational diagnostics in the UV, optical, near-IR, mid-IR, and
(sub)-mm wavelengths that have been employed to study the gas in the disks
of young stellar objects. I will concentrate in diagnostics that probe the
inner 20 AU of the disk, the region where planets are expected to form. I
will discuss the potential and limitations of each gas tracer, what we
have learned and present prospects for future research. In addition, I
will discuss briefly our current project with NOTCAM: NIR spectroscopy of
candidates to young stellar objects in Taurus. Reference: Carmona, A. 2009 http://arxiv.org/abs/0911.2271
|
| |
| Date: 24 November (Tue) |
Time: 15:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title:
Optical and NIR studies of short period low mass X-ray binaries
(LMXB)
|
| Speaker (Affiliation): Pasi Hakala (Tuorla Observatory, University of Turku, Finland) |
Abstract:
I present some recent results from our Optical and NIR studies of five
short period LMXB's (X1822-371, X1957+115, UW CrB, X1916-05 and
X0614+091). Optical photometry and spectroscopy reveal some surprising
results on the geometry and evolution of accretions discs in LMXB's.
Based on our data, it is increasing clear that accretion discs in
these systems are far from being stable and must undergo substantial
precession and/or warping behaviour on timescales less than a day in
case of the shortest period systems.
|
| Slides:
|
| Presentation: |
| |
| Date: 20 November (Tue) |
Time: 15:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title:
Star-forming Galaxies in the Hercules Cluster: Spectroscopic Properties
|
| Speaker (Affiliation): Vasiliki Petropoulou (IAA) |
Abstract:
I will present preliminary results of the spectroscopic follow-up of a sample of star forming galaxies in the Hercules cluster,
performed with INT/IDS and WHT/ISIS. The sample was defined by the Halpha imaging survey in the central region of the A2151 cluster, performed by our group (Cedres et al. 2009).
The central goal of this project is to study the impact of the cluster environment on the evolution of these galaxies and search for observable imprints on their photo-chemical evolution.
|
| Slides: PDF
|
| |
| Date: 23 October (Wed) |
Time: 15:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title:
A new review of accurate stellar masses and radii
|
| Speaker (Affiliation): Johannes Andersen (NOT) |
Abstract:
A new review of accurate stellar masses and radii has been performed. We
find 95 detached binary systems in which the components have basically
evolved as single stars and have mass and radius determinations to 3%
accuracy or better. 21 systems have spectroscopic metallicities as well.
Effective temperatures, reddening, rotational velocities and approximate
ages are also provided when possible. We discuss the use of the data to
test models of stellar structure and evolution, the properties of mildly
active stars, and the tidal evolution of the stars and their orbits,
including the implications for general relativity.
|
| Slides: PPT | PDF
|
| |
| Date: 21 October (Wed) |
Time: 11:00am |
Place: Fundación Galileo Galilei; Rambla José Ana Fernández Pérez, 7; Breña Baja |
| Title:
Analysis of asteroid Steins resolved surface from Rosetta spacecraft
|
| Speaker (Affiliation): Sara Magrin (Dipartimento di Astronomia, Padua University) |
Abstract:
On September 5th 2008 the Rosetta spacecraft had a fly-by with the
main belt asteroid Steins, at a distance of about 800 Km from the
body. OSIRIS WAC and NAC (Wide Angle and Narrow Angle Cameras)
observed the 5 Km sized object at different phase angles with
different filters.
To analyze the possible color variegation of the surface of Steins we
developed an IDL tool to produce pixel per pixel (rough) spectra, by
using values of albedo in three different filters at a time.
The results of this analysis performed on the data obtained by the NAC
camera will be shown.
|
| Slides:
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| |
| Date: 13 October (Tue) |
Time: 16:30 |
Place: 6th floor meeting room, Mayantigo building |
| Title:
Overview of the European Extremely Large Telescope
|
| Speaker (Affiliation): Isobel Hook (Dept. of Astrophysics, Univ. of Oxford) |
Abstract:
The European ELT is now in the detailed design phase, leading to a proposal for construction that will be presented to ESO Council in late 2010. If approved, the ELT will see first light in around 2018. In this talk I will present a summary of the science case, which ranges from studies of exo-planets to the most distant galaxies and cosmology. I will show some recent results from science simulations developed as part of the Design Reference Mission. I will also give an overview of the telescope and the ELT instrument studies that are currently underway.
|
| Presentation: On DVD, please contact Javier Méndez. |
| |
| Date: 9 October (Fri) |
Time: 15:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title: The 6.5 m MMT's f/5 instruments - with a focus on high-resolution multi- and single-object spectroscopy
|
| Speaker (Affiliation): Gabor Furesz (Smithsonian Astrophysical Observatory Cambridge, MA, USA) |
Abstract:
In this talk I briefly review the f/5 wide field optics and instruments
built by SAO for the 6.5m MMT telescope: the 1.7m diameter f/5 secondary,
the f/5 corrector lens and ADC prism, wavefront sensor, the 1/2 deg imager
Megacam, the multi-slit NIR imaging spectrograph MMIRS, the NIR camera
SWIRC, the low and high res multi-object spectrographs Hectospec and
Hectochelle, and Binospec, the dual-beam high throughput VIS multi-slit
imaging spectrograph. I'll discuss some of the technical details in
optical mounting and design, which were the results of SAO's internal R&D
work, and potentially can be very benefitial for future instrument
developments by other groups.
During the second part of the talk the focus will be on high resolution
spectroscopy. I'll discuss the Hectochelle instrument in more detail, the
pros and cons of this multi-object echelle in comparison of other similar
instruments, and in the light of measuring precision radial velocities
(PRV).
After showing some of the scientific results of Hectochelle on cluster
dinamics we will shift to PRV measurements on single stars, as the key
tool for exoplanet research. In this 3d part I'll summarize SAO's
instrumental and scientific experience on some of the important
instrumental and scientific aspects of PRV work, based on our involvment
in the HAT-Net, Kepler, HARPS-Nef and GMT projects.
|
| Presentation: On DVD, please contact Javier Méndez. |
| |
| Date: 23 September (Wed) |
Time: 11:00am |
Place: Fundación Galileo Galilei; Rambla José Ana Fernández Pérez, 7; Breña Baja |
| Title: Deep LBT photometry of VV124: an isolated dwarf galaxy falling into the Local Group |
| Speaker (Affiliation): Michele Bellazzini (INAF - Osservatorio Astronomico di Bologna) |
Abstract:
VV124 == UGC4879 has been recently recognized as a dwarf galaxy lying in
the outskirts of the Local Group (Kopylov et al. 2008). I present the
preliminary results from our very deep LBT observations of this galaxy.
We derived a
Color-Magnitude diagram reaching r=26.5, down to ~4 mag below the RGB
Tip and more than two magnitude deeper than previously available
photometries. We obtain a very clean detection of the RGB tip, deriving
a distance of 1.3 Mpc.
Our CMD reveals that the galaxy is dominated by an old and metal-poor
population, and it displays a metallicity gradient; a tentative
detection of and extended HB and RR Ly population is also obtained.
Coupling surface photometry and star-counts we are able to trace the
Surface Brightness profile of the galaxy out to ~5' (=2 kpc), that is 5
times more extended than previous studies. We provide some interesting
evidences suggesting that VV124 is a good representative of the pristine
status of dwarf Spheroidal galaxies, before that close interactions with
the main galaxy they are orbiting around transformed them into the very
Low SB system we observe today.
|
| |
| Date: 21 August (Fri) |
Time: 12:00am |
Place: Fundación Galileo Galilei; Rambla José Ana Fernández Pérez, 7; Breña Baja |
| Title: CTA: toward the next generation of Cherenkov Telescopes |
| Speaker (Affiliation): Angelo Antonelli (INAF - Osservatorio Astronomico di Roma) |
Abstract:
Very-high-energy gamma-ray astronomy has witnessed a major breakthrough
with the physics results obtained by ground-based instruments during the
last few years. These results have demonstrated impressively the huge
potential of this field, not only in the area of astrophysics, but also
in particle physics and cosmology. However, it also became apparent that
the performance of current instruments is not sufficient to
tap the full physics potential. The answer of the European VHE energy
community to that challenge is the Cherenkov Telescope Array (CTA). In
this talk I will shortly review the CTA project.
|
| |
| Date: 8 July (Wed) |
Time: 12:00 |
Place: Fundación Galileo Galilei; Rambla José Ana Fernández Pérez, 7; Breña Baja |
| Title: An overview to the interacting binary class of Symbiotic Stars
and the ongoing 2008-09 outburst of the system CI Cyg |
| Speaker (Affiliation): Bryce Croll, PhD Student (University of Toronto, Canada) |
Abstract:
We present an overview to the interacting binary systems knows
as the name of Symbiotic Stars, in which a hot compact object (very
often a White Dwarf) accretes material from a late type giant via
stallar wing or Roche overflow. In particular we discuss about the early
phases of the ongoing outburst that CI Cyg, a prototype of this class,
is currently undergoing after thirty years of flat quiescence. The
outburst started while the accreting WD was being eclipsed by the
Roche-lobe filling M giant companion, and it was discovered during the
egress phase on the second half of August 2008. The outburst reached
peak V-band brightness in early October 2008 and has been characterized
by amplitudes up to 1.9, in B band. At maximum V-band brightness, the
outbursting WD had expanded to closely resemble an F3 II/Ib star, with
M_V=-3.5, T_{eff} ~ 6900 K and R=28 R_{sun}. The high ionization
emission lines ([NeV], [FeVII], HeII), so prominent in quiescence,
disappeared, and only lower ionization lines (Balmer, HeI, SiII, FeII,
[OI]) were visible. During the outburst, Balmer and HeI emission lines
declined in equivalent width but increased in absolute flux. The output
radiated by the hot component during the outburst corresponds to
nuclear burning proceeding at a 2.10e{-8} M_{sun}/yr rate.
|
| Date: 11 June (Thu) |
Time: 15:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title: Exploring the Diversity of Planets in other Solar Systems |
| Speaker (Affiliation): Bryce Croll, PhD Student (University of Toronto, Canada) |
Abstract:
I will discuss preliminary results from three ongoing observational
projects that will form my thesis on extrasolar planets. I will present
preliminary results from very recent CFHT WIRCam observations of the
secondary eclipses of two of the hottest of the hot Jupiters in the
near-infrared. We hope to detect the secondary eclipses of a number of hot
Jupiters in the J, H and K near-infrared bands. I will touch upon progress
from my ongoing project using GMOS on Gemini-South & North to search for
atmospheric absorption from various chemicals in the transmission spectra
of hot Jupiters. Lastly, I will discuss the preliminary results from our
Spitzer IRAC 8.0 micron observations of the thermal phase curve of the
eccentric (e~0.67) hot Jupiter HD 17156. Our observations are the first to
probe more than one pseudo-spin period of an eccentric exoplanet. The goal
of these observations is to detect the variation in thermal emission of
the planet as a single face of the planet is flash-heated as it makes its
"Big Swing" into periastron and then this flash heated face rotates in and
out of view as the planet cools as it swings out towards apastron.
|
| Slides: PDF
|
| |
| Date: 11 June (Thu) |
Time: 15:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title: Exploring the Diversity of Planets in other Solar Systems |
| Speaker (Affiliation): Bryce Croll, PhD Student (University of Toronto, Canada) |
Abstract:
I will discuss preliminary results from three ongoing observational
projects that will form my thesis on extrasolar planets. I will present
preliminary results from very recent CFHT WIRCam observations of the
secondary eclipses of two of the hottest of the hot Jupiters in the
near-infrared. We hope to detect the secondary eclipses of a number of hot
Jupiters in the J, H and K near-infrared bands. I will touch upon progress
from my ongoing project using GMOS on Gemini-South & North to search for
atmospheric absorption from various chemicals in the transmission spectra
of hot Jupiters. Lastly, I will discuss the preliminary results from our
Spitzer IRAC 8.0 micron observations of the thermal phase curve of the
eccentric (e~0.67) hot Jupiter HD 17156. Our observations are the first to
probe more than one pseudo-spin period of an eccentric exoplanet. The goal
of these observations is to detect the variation in thermal emission of
the planet as a single face of the planet is flash-heated as it makes its
"Big Swing" into periastron and then this flash heated face rotates in and
out of view as the planet cools as it swings out towards apastron.
|
| Slides:
|
| |
| Date: 26 May (Tue) |
Time: 12:00 |
Place: Fundación Galileo Galilei; Rambla José Ana Fernández Pérez, 7; Breña Baja |
| Title: Nine years of Solar System research using TNG |
| Speaker (Affiliation): Javier Licandro (IAC)
|
Abstract:
In this talk I will present the major results of my research on surface
properties of trans-neptunian objects and related minor bodies using TNG
started in 2000. Results include the characterization of large TNOs like
Eris, Makemake and, in particular, Haumea and the family of objects
related with it; the determination of the surface characteristics of
asteroids in cometary orbits; the mineralogy of Near Earth Asteroids and
the relation with meteorites and main belt asteroids.
|
| |
| Date: 19 May (Tue) |
Time: 12:00 |
Place: Fundación Galileo Galilei; Rambla José Ana Fernández Pérez, 7; Breña Baja |
| Title: |
| Speaker (Affiliation):
|
Abstract:
Several astrophysical and cosmological tests demand a more accurate
knowledge of the morphological distribution of clusters of galaxies. I
will show how multi-wavelength observations allow to obtain information
on the intrinsic three-dimensional shape of galaxy structures, and
present results of our ongoing work on the subject and future applications.
|
| |
| Title: Post Common Envelope Binaries from the Sloan Digital Sky Survey
|
| Speaker (Affiliation): Stelios Pyrzas, (ING & University of Warwick)
|
Abstract:
While the majority of (wide) binaries evolve as if they were single
stars, a fraction of them is expected to undergo a common envelope phase
(CEp), giving birth to close binaries. The classes of objects affected
by the CEp include supernova Ia progenitors, low mass X-ray binaries,
ultracompact binaries and progenitors of short gamma ray bursts. Thus,
Post Common Envelope Binaries (PCEBs), i.e. binaries that have undergone
a CE phase during their evolution, play a key role in our understanding
of close binary systems. Despite the clear importance, the current
theoretical understanding of the CE phase is rather poor and underconstrained
by observations. In this talk, I will present an ongoing project, aiming
to build a large, well-defined sample of PCEBs, identified in the Sloan
Digital Sky Survey (SDSS), with observationally determined stellar
parameters. I will refer to the current status of the project, focus on
the methods and techniques used and present important first results.
|
| |
| Date: 13 April (Mon) |
Time: 15:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title: CSI: PN (CircumStellar Investigation:
Planetary Nebula) - SuWt 2 and its mysterious central stars
|
| Speaker (Affiliation): David Jones (ING & Jodrell Bank Centre for Astrophysics)
|
Abstract:
It is generally believed that binary systems play a major role in the
shaping of planetary nebulae (PNe), although to date there is little
observational evidence linking PN morphologies to the parameters of their
central star systems. In the case of SuWt 2, the star observed at its
centre is a double A-type eclipsing binary with a period of 4.9 days, and
as such contains no star considered old enough to have been the nebular
progenitor. This represents a major challenge not only to current
theories linking PN and binary star evolution, but also to standard
theories of intermediate-mass stellar evolution.
In April 2005, as part of a continuing programme to study the morphology
and kinematics of PNe with known close-binary central stars, spatially-
resolved high-resolution longslit profiles of SuWt 2 were acquired using
EMMI on the ESO-NTT. Here, I present the analysis of these position-velocity
(PV) arrays, and the subsequent spatio-kinematic modelling performed in an
attempt to replicate these results in synthetic spectra, hence determining
the nebular morphology of SuWt 2. I will also discuss my findings in
relation to the A-type binary and, most importantly, the various
evolutionary scenarios that have been put forward for SuWt 2.
|
| Slides: PDF
|
| |
| Date: 1 April (Wed) |
Time: 11:00am |
Place: 6th floor meeting room, Mayantigo building |
| Title: LUCIFER - the LBT NIR spectroscopic Utility with Camera and Integral-Field Unit for Extragalactic Research
|
| Speaker (Affiliation): Jochen Heidt (ZAH, Landessternwarte Heidelberg, Germany) |
Abstract:
LUCIFER is a NIR spectrograph and imager (wavelength range 0.9 to 2.5
micron) for the Large Binocular Telescope (LBT) on Mt. Graham,
Arizona, working at cryogenic temperatures of less than 70K. Two
instruments are built by a consortium of five German institutes and
will be mounted at the bent Gregorian foci of the two individual
telescope mirrors. Three exchangable cameras are available for imaging
and spectroscopy: two of them are optimized for seeing-limited
conditions, a third camera for the diffraction limited case will be
used with the LBT adaptive secondary mirror working. Up to 33
exchangeable masks are available for longslit or multi-object
spectroscopy (MOS) over the full field of view. At present, the
commissioning of the first LUCIFER instrument at the LBT is almost
complete. In this talk, I will give an overview about the LBT
organisation and the operation of the LBT followed by an description
of the instrument and the first results obtained during commissioning.
|
| |
| Date: 20 March (Friday) |
Time: 10:00am |
Place: 6th floor meeting room, Mayantigo building |
| Title: Young stars in Lupus: not as expected, not where expected |
| Speaker (Affiliation): Fernando Comeron (ESO) |
Abstract:
Most studies of the stellar and substellar populations of star forming
regions rely on the identification of the signatures of accretion,
outflows, circumstellar dust or activity characteristic of the early
stages of stellar evolution. However, the decay of these observational
signatures with time limits our ability to understand the complete star
forming history of young aggregates, and to obtain unbiased samples of
young stellar objects at different stages of disk evolution.
I will present the results of a wide-area study of the stellar population
of selected clouds in the nearby Lupus star forming region, initially
defined to complement the data obtained by the Spitzer Space Observatory
Legacy Program "From molecular cores to planet-forming disks". When
combined with 2MASS photometry, our data allow us to fit the spectral
energy distributions of well over 150,000 sources seen in that direction,
and to identify possible new members based on their photospheric fluxes
alone, with independence of the display of signposts of youth. In this way
we identify a very clear signature of the existence of a surprisingly
numerous and thus far unrecognized population of cool members of Lupus 1
and 3, which is absent from Lupus 4.
The approximately 130 new members that we identify show that Lupus 1 and 3
have been forming low mass stars in numbers comparable to, or even
exceeding in Lupus 1, those revealed by recent sensitive surveys based on
the signposts of youth. We hypothesize on several possibilities for the
origin of this population that may account for its puzzling properties of
general lack of disks, coevality with the disk-bearing population, and
preferential off-cloud location, which hint at a picture more complex and
interesting than the quiescent formation inside dense molecular clouds.
|
| Presentation: PPT | PDF |
| |
| Date: 9 March (Monday) |
Time: 16:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title: A rate study of Type Ia supernovae with Subaru/XMM-Newton Deep Survey |
| Speaker (Affiliation): Yutaka Ihara (Institute of Astronomy, University of Tokyo, Japan) |
Abstract:
I will talk about my study, a measurement of the rate of high-z Type Ia supernovae (SNe Ia) using multi-epoch observations of Subaru/XMM-Newton Deep Field (SXDF) with Suprime-Cam on the Subaru Telescope.
Although SNe Ia are regarded as a standard candle, progenitor systems of SNe Ia have not been resolved yet. One of the key parameters to show the progenitor systems by observations is the delay time distribution between the binary system formation and subsequent SN explosion. Recently, a wide range of delay time is studied by SN Ia rates compared with an assumed cosmic star formation history. If SNe Ia with short delay time are dominant, the cosmic SN Ia rate evolution should closely trace that of the cosmic star formation.
In order to detect a lot of high-z SNe Ia, we repeatedly carried out wide and deep imaging observations in the i-band with Suprime-Cam in 2002 (FoV~1 deg^2, m_i<25.5 mag).
We obtained detailed light curves of the variable objects, and 50 objects are classified as SNe Ia using the light curve fitting method at the redshift range of 0.2 |
| Presentation: PPT |
| |
| Date: 17 Feb (Tuesday) |
Time: 12:00 |
Place: Fundación Galileo Galilei; Rambla José Ana Fernández Pérez, 7; Breña Baja |
| Title: Globular Clusters - Some simple, some complicated, all interesting! |
| Speaker (Affiliation): Alistair Walker, (Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory) |
Abstract:
Galactic globular clusters have for several decades been highly
useful as examples of single stellar populations of stars almost as old as
the Universe, and as such have been critical to calibrating models of
stellar evolution for low mass stars, and for understanding galaxy
formation and evolution. However, explanations for puzzles such as
differing distributions of stars on the Horizontal Branch, and
element-element abundance anomalies in individual clusters, have been
elusive. Recent, mostly HST-ACS, observations of some globular clusters
have complicated the picture but also give strong clues for resolving the
remaining issues. After a short overview, I will describe a wide-field
imaging program for a selected sample of clusters designed to provide
complementary information to the HST and spectroscopic studies, and show
some of the first results.
|
| Date: 13 Feb (Friday) |
Time: 15:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title: Status and Plans for the ASTRONET Initiative |
| Speaker (Affiliation): Johannes Andersen (NOT & ASTRONET Board) |
Abstract:
The ASTRONET consortium aims to establish a comprehensive, long-term planning for all of European astronomy. Three years old, it has matured substantially: Nearly all significant European communities are involved;
the Science Vision and Infrastructure Roadmap have been completed and published; and we are moving into the phase of implementing their recommendations.
The talk will summarise the current status of ASTRONET and outline some of the options for the future.
|
Seminars in 2008
| Date: 8 Jul (Tuesday) |
Time: 15:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title: Astronomy in real time |
| Speaker (Affiliation): Tiina Liimets (Tartu Observatory and ING) |
Abstract:
The objects of our project: the light echo of V838 Monocerotis, nova
remnant GK Persei,
nebulosities of R Aquarii, are exceptional stellar outflows which give
as a very rare opportunity
in astronomy to investigate the structure and kinematics of
circumstellar matter in real time.
For that we analyze the multi epoch images which are able to resolve the
apparent expansion of
the outflows, and thus provide the information of the velocity component
in the plane of sky.
This allows a detailed dynamical and morphological study to understand
the geometry and
physics of the ejection, outflows or light echoes.
|
| Date: 8 Jul (Tuesday) |
Time: 15:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title: Who is this girl and what is she doing here?
|
| Speaker (Affiliation): Sarah Barker (University of Sheffield and ING) |
Abstract:
As part of my masters degree in Physics and Astrophysics with the
University of Sheffield, I was lucky enough to be given the opportunity to
apply to spend my final year here at the ING. For the past 10 months I
have been working as a Support Astronomer at the Isaac Newton Telescope,
whilst simultaneously studying for my degree. This talk gives an overview
of the work I have done, and projects I have been involved with during
this time.
Particular attention is paid to Broad Absorption Line Quasars, my main
research interest this year. By using the level of ionisation of these
BAL QSOs, I have estimated the distance to which high-velocity outflows
extend from the centre of these quasars, and the results will be discussed
in this talk.
|
| Presentation: PPT |
| |
| Date: 8 Jul (Tuesday) |
Time: 15:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title:
ARCS: the Asiago Red Clump Spectroscopic Survey and its applications
|
| Speaker (Affiliation): Marica Valentini (Astronomical Observatory of Padova and ING) |
Abstract:
My PhD project is about a further investigation and characterization of local Red Clump Stars, in order to use them as distance indicators and tracers of Milky Way structure and kinematics.
The project started in 2006 with ARCSs (Asiago Red Clump Spectroscopic survey), and then it will be fulfilled with data from Rave survey.
Now ARCS survey is ended, and I personally observed about 500 local Red Clump stars with the Echelle spectrograph, mounted in the Asiago 1.82m telescope. The data reduction and analisys ended in these days, at last. The result of this work will be the publication of one of the biggest Red Clump stars catalogue, containing radial velocities and atmospherical parameters of the selected sample.
The analysis of this data also led to a calibration of a reliable function of Mv dependent on [M/H], log(g) and Teff, useful for using RC stars as distance indicators.
In the next future my project will continue with the application of the ARCSs and Rave data on classical problems of Milky Way structure and cinematics, as streams detection, local velocity escape calculation and detection of dark matter.
|
| |
| Date: 16 Apr (Wednesday) |
Time: 16:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title: AGN feedback in compact radio sources |
| Speaker (Affiliation): Joanna Holt (Sterrewacht Leiden) |
Abstract:
Over the last decade or so, it has become clear that
AGN feedback plays a key role in galaxy evolution. However, due to the
lack of observational results, feedback is often inserted into the models
as a black box. Theroetical analyses by e.g. Silk & Rees and Fabian give
good descriptions of the feedback process, although these scenarios
assume the feedback process is dominated by quasar-induced winds. Whilst
this may be true for radio-quiet AGN, in radio-loud AGN the expanding
radio jets may also provide a significant contribution to the overall
feedback of the AGN.
In this talk I will discuss our recent study of the emission line
outflows in compact radio sources. Compact radio sources are ideal objects
in which to study AGN feedback as i) the compact radio source highlights
the presence of a young, recently triggered AGN which still retains
it's natal cocoon and ii) these sources contain all of the possible
outflow driving mechanisms (AGN winds/starburst winds/radio jet activity)
and are therefore the only objects in which the relative importance of all
of the different feedback effects can be studied.
|
| Slides: PPT Additional material: movie and
movie player
|
| |
| Date: 27 Mar (Thursday) |
Time: 16:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title: Galaxy formation - the fossil record of nearby stars |
| Speaker (Affiliation): Klaus Fuhrmann (ING) |
Abstract:
High-resolution spectroscopy of nearby solar-type stars implies that
the Galaxy became reality 13 Gyr ago with the implementation of a
massive, rotationally-supported population of thick-disk stars. The
very high star formation rate in that phase gave rise to a rapid metal
enrichment and an expulsion of gas in supernovae-driven Galactic winds,
but was followed by a star formation gap for no less than three billion
years. In a second phase, the thin disk -- our "familiar Milky Way" --
came on stage. Nowadays it traces the bright side of the Galaxy, but it
is also embedded in a huge coffin of dead thick-disk stars that account
for a large amount of baryonic dark matter and that particularly
challenge the hierarchical cold-dark-matter-dominated formation picture
for our parent spiral.
|
| Slides: Tar file
|
| |
| Date: 19 Mar (Wed) |
Time: 12:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title: Galaxies with star-forming satellites: How typical is the Milky Way
system? |
| Speaker (Affiliation): Phil James (Astrophysics Research Institute at Liverpool John Moores University) |
Abstract:
|
| Slides: PPT | PDF
|
| |
| Date: 13 Mar (Thursday) |
Time: 12:00 |
Place: 6th floor meeting room, Mayantigo building |
| Title: Sigma Orionis: A New Hope |
| Speaker (Affiliation): José A. Caballero (Universidad Complutense de Madrid) |
Abstract:
The sigma Orionis cluster is very young (about 3 My) and relatively nearby (a
bit less than 400 pc). It takes the name from the Trapezium-like star system
sigma Ori, which illuminates the mane of the Horsehead Nebula and is the fourth
brightest star in the Orion Belt. The cluster is a well-equiped laboratory to
investigate the stellar and substellar formation. It contains OB-type stars,
Herbig-Haro objects, strong X-ray sources, peculiar multiple systems, Class I
object candidates, highly photometric variable brown dwarfs, and the largest
known population of isolated planetary-mass objects. I will give a general
review on the sigma Orionis cluster, describing from the O9.5V star in its
centre (M ~ 18 M_sun), to S Ori 70, that is to date the less-massive isolated
body directly imaged out of the Solar System (M ~ 3 M_Jup).
|
| Slides: PPT
|
| |
| Date: 18 Feb (Monday) |
Time: 12:00 |
Place: Meeting room, Fundación Galileo Galilei (Rambla José Ana Fernández Pérez, 7; San Antonio - Breña Baja)
|
| Title: CTIO and the US System of Telescopes |
| Speaker (Affiliation): Alistair Walker (CTIO, NAO) |
Abstract:
I will describe the present status of the telescopes and
instrumentation at CTIO, and then explain how the US National Optical
Observatories (CTIO, KPNO) plan to evolve over the next decade, in the
face of the competing demands of the new 'super projects' for both funding
and support observations. This has led to the concept of the 'US System
of Telescopes', designed to optimize the range of facilities available for
US astronomers.
|
| Slides: PDF | PPT
|
| |
Previous seminars
Seminars in 2007, 2006, 2005, 2004, 2003, 2002, 2001, 2000.
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Contacts:
(Seminar organiser)
(Deputy seminar organiser)
Last modified: 01 July 2013
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