Title:
Probing Outflow Activity in Very Low Mass Objects and
Brown Dwarfs
Authors:
Emma Whelan, Tom Ray, Francesca Bacciotti, Antonella Natta, Ray Jayawardhana
Abstract:
Stellar nurseries are the birth places of not only
low to high mass stars but very low mass (VLM)and sub-stellar objects
such as Brown Dwarfs (BDs), also. Numerous studies have shown that VLMOs
and BDs are strong accretors and that in some cases they have a
T Tauri like accretion phase. To date any hint that outflows may also
be a feature of VLMOs or BDs has only come from the detection of optical
FELs in their spectra. That the outflow phenomenon should be a common
occurrence amongst protostellar and sub-stellar sources, or that this
phenomenon should manifest itself in a similar manner for all objects,
is not obvious a priori. Hence a fundamental question that must be
answered deals with whether outflows are also launched by newborn
objects in the very low mass to sub-stellar regimes and the possible
forms in which this phenomenon may manifest itself. These questions
ultimately address the universality of the outflow phenomenon and any
discovery that BDs for example, too are associated with outflows, would
extend the mass range, over which the jet mechanism operates to nearly
10 orders of magnitude. Here I shall review what is known to date about
the forbidden emission line (FEL) spectra of VLMOs and BDs and in
particular discuss how the important technique of spectro-astrometry
is used to probe the FEL regions of newborn objects in the low mass to
sub-stellar regimes. Integral Field Spectroscopy and adaptive optics
can also play a vital role when it comes to resolving the FEL regions
of objects not as yet proven to drive outflows and indeed there is
potential for developing spectro-astrometry to a 2D form using an IFU.