PN.S - Manual - operation

PNS MANUAL: operation / filter tuning

Tuning the filter

Access to the filter is easiest via the square hatch on the flat side of the PN.S. Under no circumstances touch the filter with bare hands. If touching is necessary, use the gloves in the PN.S cupboard. Take the tuning dial and carefully place it over the filter. It will only locate in one orientation. You should be able to read the angle off the dial (see the small marker near the hatch opening). With gentle downwards pressure so that the dial does not slip or jump, rotate the dial to the desired angle in degrees (maximal 6^o), using that half of the scale on which the 3^o symbol is marked with a sticker.

!! UPDATE THE PNS HEADER CREATER GUI !!

Email John Hart 11.8.2001: The offset angle of the filter in its cell is equal to the offset angle of the cell. As the cell is rotated, at one extreme these cancel to give zero filter tilt, and at the other they sum to give a tilt of twice the offset angle. If A is the azimuth angle, B is the filter tilt angle, and C is the offset angle, then
sin B/2 = mod(sin C x sin A/2).
For small tilt angles (as we have), the plot is a rectified sin wave.

Computed velocity ranges

These are computed by first fitting the best constant value of n_eff to the manufacturer's data on central wavelength versus tilt for tilts up to 10.3 degrees; in some cases minor adjustments are made to the central wavelength in order to get a good fit. The formula Wavel = Wavel₀ * sqrt(n² - sin²(theta))/n is then used ... it is asumed that the FWHM obeys the same relationship, i.e. the bandwidth gets smaller with tilt angle. Actually the FWHM of Filter C does not change (according to manufacturer's curves) while that of the rejected Filter A gets smaller more rapidly than calculated. Not known for Filter B yet.

FILTER AND N_eff ANGLE WAVEL (Å) MIN VEL CENTRE MAX VEL

Filter C 0.0 5058.10 2002.04 3059.05 4116.06
5058.1/35.4 0.5 5058.05 1998.82 3055.82 4112.81
1.887 1.0 5057.88 1989.17 3046.13 4103.09
1.5 5057.61 1973.08 3029.98 4086.89
2.0 5057.23 1950.56 3007.38 4064.21
2.5 5056.75 1921.61 2978.34 4035.06
3.0 5056.15 1886.25 2942.85 3999.45
3.5 5055.45 1844.48 2900.93 3957.38
4.0 5054.64 1796.30 2852.59 3908.87
4.5 5053.73 1741.74 2797.84 3853.93
5.0 5052.70 1680.81 2736.69 3792.57
5.5 5051.57 1613.51 2669.16 3724.80
6.0 5050.33 1539.88 2595.26 3650.64

Filter B 0.0 5034.30 703.18 1637.76 2572.35
5033.9/31.3 0.5 5034.25 700.20 1634.78 2569.36
1.959 1.0 5034.10 691.28 1625.83 2560.38
1.5 5033.85 676.42 1610.92 2545.42
2.0 5033.50 655.62 1590.05 2524.49
2.5 5033.05 628.88 1563.23 2497.58
3.0 5032.50 596.21 1530.46 2464.71
3.5 5031.85 557.62 1491.75 2425.88
4.0 5031.11 513.11 1447.11 2381.10
4.5 5030.26 462.71 1396.55 2330.38
5.0 5029.32 406.42 1340.08 2273.74
5.5 5028.27 344.26 1277.72 2211.19
6.0 5027.13 276.23 1209.49 2142.74
PRELIMINARY!!

Filter A 0.0 5004.20 -1231.7 -159.75 912.19
5004.20/36 0.5 5004.13 -1236.0 -164.08 907.84
1.62? 1.0 5003.91 -1249.0 -177.09 894.79
1.5 5003.55 -1270.6 -198.76 873.03
2.0 5003.04 -1300.8 -229.10 842.59
2.5 5002.39 -1339.6 -268.09 803.46
3.0 5001.59 -1387.1 -315.73 755.64
3.5 5000.65 -1443.2 -372.01 699.16
4.0 4999.56 -1507.9 -436.92 634.02

FILTER AND N_eff	ANGLE	WAVEL (Å)	MIN VEL	CENTRE	MAX VEL

Filter C	0.0	5058.10	2002.04	3059.05	4116.06
5058.1/35.4	0.5	5058.05	1998.82	3055.82	4112.81
1.887	1.0	5057.88	1989.17	3046.13	4103.09
	1.5	5057.61	1973.08	3029.98	4086.89
	2.0	5057.23	1950.56	3007.38	4064.21
	2.5	5056.75	1921.61	2978.34	4035.06
	3.0	5056.15	1886.25	2942.85	3999.45
	3.5	5055.45	1844.48	2900.93	3957.38
	4.0	5054.64	1796.30	2852.59	3908.87
	4.5	5053.73	1741.74	2797.84	3853.93
	5.0	5052.70	1680.81	2736.69	3792.57
	5.5	5051.57	1613.51	2669.16	3724.80
	6.0	5050.33	1539.88	2595.26	3650.64

Filter B	0.0	5034.30	703.18	1637.76	2572.35
5033.9/31.3	0.5	5034.25	700.20	1634.78	2569.36
1.959	1.0	5034.10	691.28	1625.83	2560.38
	1.5	5033.85	676.42	1610.92	2545.42
	2.0	5033.50	655.62	1590.05	2524.49
	2.5	5033.05	628.88	1563.23	2497.58
	3.0	5032.50	596.21	1530.46	2464.71
	3.5	5031.85	557.62	1491.75	2425.88
	4.0	5031.11	513.11	1447.11	2381.10
	4.5	5030.26	462.71	1396.55	2330.38
	5.0	5029.32	406.42	1340.08	2273.74
	5.5	5028.27	344.26	1277.72	2211.19
	6.0	5027.13	276.23	1209.49	2142.74
PRELIMINARY!!

Filter A	0.0	5004.20	-1231.7	-159.75	912.19
5004.20/36	0.5	5004.13	-1236.0	-164.08	907.84
1.62?	1.0	5003.91	-1249.0	-177.09	894.79
	1.5	5003.55	-1270.6	-198.76	873.03
	2.0	5003.04	-1300.8	-229.10	842.59
	2.5	5002.39	-1339.6	-268.09	803.46
	3.0	5001.59	-1387.1	-315.73	755.64
	3.5	5000.65	-1443.2	-372.01	699.16
	4.0	4999.56	-1507.9	-436.92	634.02

Larger tilt

Here is the situation if we can tilt to 10 degrees:

0.0	5058.10	2002.04	3059.05	4116.06
2.0	5057.23	1950.56	3007.38	4064.21
4.0	5054.64	1796.30	2852.59	3908.87
6.0	5050.33	1539.88	2595.26	3650.64
8.0	5044.32	1182.26	2236.39	3290.52
10.0	5036.64	724.84	1777.37	2829.89

0.0	5034.30	703.18	1637.76	2572.35
1.0	5034.10	691.28	1625.83	2560.38
2.0	5033.50	655.62	1590.05	2524.49
3.0	5032.50	596.21	1530.46	2464.71
4.0	5031.11	513.11	1447.11	2381.10
5.0	5029.32	406.42	1340.08	2273.74
6.0	5027.13	276.23	1209.49	2142.74
7.0	5024.55	122.68	1055.45	1988.23
8.0	5021.58	-54.09	878.13	1810.35
9.0	5018.22	-253.91	677.69	1609.29
10.0	5014.48	-476.57	454.34	1385.24

Measured Curves

Line IDs with Filter A (angle 0) - see also the CuAr/CuNe linelist (pnspipe$data/linelist)
Profile of Filter A (angle 0) measured in corner of field (Oct 2002)

Profile of Filter A (angle 0) measured in centre of field (Oct 2002)

Profile of Filter B measured with the PN.S in the centre of the field at tilt angles 0 and 6

Proposed Filter "B-flat"

Before specifying a new filter, it is important to check that the existing filters are behaving according to our theoretical expectations (bandpass equations above).
The empirical bandpass function over the field for Filter B at 6° looks like this: left arm | right arm (dotted lines show location of 5017Å line.)
The FWHM velocity cutoff values are shown here. The red line shows the theoretical prediction for comparison. The agreement is pretty good. Note that the bandpass is a strong function of y and a weak function of x.

The specs of Filter B-flat have been now optimised to allow the 6 PN.S main programme galaxies to be targeted that could not be otherwise done.
Here is a plot illustrating this. The bandpass ranges of the existing filters are shown as a function of tilt angle, and the new filter shown with dotted lines. The symbols show the wavelength range of individual galaxies (v_central ± 2.68*sigma_central gives 99% PN recovery). The black and green symbols are PN.S main programme galaxies; the green ones are better done with Filter B, or have already been done with it; the black ones are better done with Filter B-flat. Other potential targets of interest are shown in cyan.
The filter params are: n=1.96, wavelength range = 5000.5 -- 5043.1 Å (0°).

Name	v_h (km/s)	sigma_c (km/s)	R_eff (arcmin)	Filter: angle	Avail chip frac	# R_eff	Notes

Primary programme
NGC 3379	879	206	0.59	B: 6.0° D: 0.0-4.5°	0.56 1.00	4.8 8.5	used B-6.0°
NGC 4494	1302	158	0.82	B: 0.0-4.7° D: 0.0-2.7°	1.00 1.00	6.1 6.1	used B-6.0° (0.81 frac = 4.9 R_eff)
NGC 4374	901	297	0.92	B: 6.0° D: 0.0-2.9°	(0.57) 1.00	(3.1) 5.4	B: 1.9-sigma cutoff
NGC 4552	307	264	1.0	D: 4.3-6.0°	1.00	5.0
NGC 4649	1126	339	1.37	B: 6.0° D: 0.0°	(0.45) 1.00	(1.7) 3.6	B: 2.0-sigma cutoff
NGC 4267	1020	168	0.69	B: 6.0° D: 0.0-4.3°	0.90 1.00	6.5 7.2
NGC 4339	1270	114	0.52	B: 0.0-5.5° D: 0.0-3.7°	1.00 1.00	9.6 9.6	used B-6.0° (0.92 frac = 8.8 R_eff)
NGC 4203	1084	158	0.33	B: 5.2-5.8° D: 0.0-4.1°	1.00 1.00	15.2 15.2
NGC 3607	915	217	1.10	B: 6.0° D: 0.0-4.2°	(0.76) 1.00	(3.4) 4.5	B: 2.0-sigma cutoff
NGC 4365	1224	266	1.11	B: 4.4-5.0° D: 0.0-1.1°	(0.91) 1.00	(4.1) 4.5	B: 2.1-sigma cutoff
NGC 4636	1071	211	1.95	B: 5.1-6.0° D: 0.0-3.4°	0.67 1.00	3.4 5.1	4 pointings
NGC 4589	1953	222	0.64	B: 0.0°	(0.51)	(4.0)	2.3-sigma cutoff

NGC 4278	627	252	0.78	B: 6.0° D: 5.2-6.0°	(0.35) 0.82	(2.3) 5.2	B: 2.0-sigma cutoff
NGC 4621	2180	245	0.67	B: 0.0-1.9° C: 0.0°	(0.43) ?	(3.2) ?	B: 1.2-sigma cutoff
NGC 4660	1072	191	0.20	B: 5.4-6.0° D: 0.0-3.6°	0.80 1.00	20.0 25.0
NGC 2549	1080	150	0.29	B: 4.7-5.9° D: 0.0-4.2°	1.00 1.00	17.2 17.2	used B-6.0° (0.99 frac = 17.0 R_eff)
NGC 2768	1424	189	1.07	B: 0.0-3.5° D: 0.0-1.1°	1.00 1.00	4.7 4.7
NGC 3115	658	265	0.54	B: 6.0° D: 4.9-6.0°	(0.36) 0.76	(3.3) 7.0	B: 2.0-sigma cutoff
NGC 3384	728	141	0.42	B: 6.0° D: 0.0-6.0°	0.59 1.00	7.0 11.9
NGC 3377	692	136	0.57	B: 6.0° D: 0.0-6.0°	0.56 1.00	4.9 8.8
NGC 1023	626	209	0.66	B: 6.0° D: 3.4-5.7°	(0.44) 1.00	(3.3) 7.6	B: 2.0-sigma cutoff
NGC 4406	-288	255	1.74	A: ?°	?	?	4 pointings
NGC 7457	773	75	0.54	B: 6.0° D: 0.0-6.0°	0.91 1.00	8.4 9.3	used B-6.0°
NGC 7332	1293	135	0.24	B: 0.0-5.0° D: 0.0-3.2°	1.00 1.00	20.8 20.8	used B-0.0°
NGC 821	1739	208	0.83	B: 0.0-0.9°	1.00	6.0	used B-0.0°
NGC 5866	739	142	0.67	B: 6.0° D: 0.0-6.0°	0.58 1.00	4.3 7.5	used B-6.0°

Spirals
NGC 7013	779	90	0.44	B: 6.0° D: 0.0-6.0°	0.85 1.00	9.6 11.4	used B-6.0°
NGC 2683	427	143	0.93	D: 4.7-6.0°	1.00	5.4
NGC 5907	667	?	2.04	B: 6.0° D: 0.0-6.0?°	0.65? 1.00?	1.6? 2.5?
NGC 7339	1337	??	??	B: 0.0-5.4?° D: 0.0-3.6?	1.00? 1.00?	~15? ~15?	used B-0.0°
M51	463	100	2.08	D: 0.0-6.0°	1.00	2.4	multiple pointings
M101	240	96	5.74	A: ? D: 6.0°	1.00	0.9	multiple pointings
M94	308	146	1.3	A: ? D: 6.0°	0.87	3.3

About this Document

We need your input to keep these notes up-to-date. Please add to this document, or create new ones which can be linked from it. Send your input by email. Last updated 22-08-2003.

Documents of this background colour are part of a set linked from the manual

	Line IDs with Filter A (angle 0) - see also the CuAr/CuNe linelist (pnspipe$data/linelist)
	Profile of Filter A (angle 0) measured in corner of field (Oct 2002)
	Profile of Filter A (angle 0) measured in centre of field (Oct 2002)
	Profile of Filter B measured with the PN.S in the centre of the field at tilt angles 0 and 6