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 6o), using that half of the scale on which the 3o 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 neff 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.

Filters A and B have the same wavelength engraved on the side (503.2) but they have different codes - filter A has the code 2002
Filter AB has the edge marking "502.66/4.32".


Filter C "506.2/3.6"
MANUFACTURER'S DATA:
Theta=0 Lambda = 5058.1 BW = 35.4
Theta=4.3 Lambda = 5054.1 BW = 35.4
Theta=7.0 Lambda = 5047.6 BW = 35.6
Theta=10.8 Lambda =5033.0 BW = 35.6
CALCULATED CHARACTERISTICS:
Best fit neff=1.89
      Theta     Lambdac     Vmin     Vc         Vmax
0.0 5058.10 2012 3072 4131
1.0 5057.88 1999 3059 4118
2.0 5057.24 1962 3020 4078
3.0 5056.16 1899 2956 4012
4.0 5054.65 1811 2865 3919
5.0 5052.72 1699 2749 3800
6.0 5050.36 1561 2608 3655

Filter B 5033.9/31.3
MANUFACTURER'S DATA:
Theta=0 Lambda = 5033.9 BW = 31.3
Theta=4.3 Lambda = 5030.6 BW = 30.6
Theta=7.0 Lambda = 5024.8 BW = 31.0
Theta=10.8 Lambda =5010.7 BW = 30.6
CALCULATED CHARACTERISTICS:
Best fit neff=1.96
      Theta     Lambdac     Vmin     Vc     Vmax
0.0 5033.90 686 1623 2560
1.0 5033.70 674 1611 2548
2.0 5033.10 638 1575 2512
3.0 5032.11 578 1515 2452
4.0 5030.71 495 1432 2368
5.0 5028.92 388 1325 2261
6.0 5026.74 258 1194 2129
7.0 5024.16 104 1039 1975
8.0 5021.19 -73 862 1797
9.0 5017.84 -273 661 1595
10.0 5014.10 -496 437 1371
11.0 5009.99 -742 191 1124

Filter AB "502.66/4.32"
MANUFACTURER'S DATA:
Theta=0 Lambda = 5026.0 BW = 44.0
CALCULATED CHARACTERISTICS:
Assume neff=1.88
      Theta     Lambdac     Vmin     Vc     Vmax
0.0 5026.00 -168 1150 2467
1.0 5025.78 -181 1137 2454
2.0 5025.13 -219 1098 2415
3.0 5024.05 -284 1033 2350
4.0 5022.54 -374 942 2259
5.0 5020.60 -490 826 2142
6.0 5018.23 -631 684 1999
Assume neff=1.96
0.0 5026.00 -168 1150 2467
1.0 5025.80 -180 1138 2455
2.0 5025.20 -215 1102 2419
3.0 5024.21 -274 1042 2359
4.0 5022.82 -357 959 2275
5.0 5021.03 -464 852 2168
6.0 5018.85 -594 721 2037

Filter A "500.3/3.6"
MANUFACTURER'S DATA:
Theta=0 Lambda = 5002.2 BW = 36.5
Theta=4.3 Lambda = 4998.3 BW = 36.1
Theta=7.0 Lambda = 4991.6 BW = 35.9
Theta=10.8 Lambda = 4977.2 BW = 34.9
CALCULATED CHARACTERISTICS:
Best fit neff=1.88
      Theta     Lambdac     Vmin     Vc     Vmax
0.0 5002.20 -1368 -275 817
1.0 5001.98 -1381 -288 804
2.0 5001.34 -1418 -327 764
3.0 5000.26 -1481 -392 698
4.0 4998.76 -1568 -482 605
5.0 4996.82 -1681 -597 486
6.0 4994.46 -1818 -739 341

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 AB, center of field, tilt angle 0 (measured Apr 2005). Four strongest lines are 5009.3, blend near 5017, 5031.4, 5037.8.
Profile of Filter B measured with the PN.S in the centre of the field at tilt angles 0 and 6

Filter C was characterized in April 2004, unfortuantely with badly defocussed spectrograph arms. Nevertheless the lines are clearly identifiable (to be done). See plots for C-0 L, C-0 R, C-6 L, and C-6 R.

Historical reasoning that led to Filter AB

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 half-max lower-limit relative to median value over the field is here, while the FWHM velocity cutoff values are shown here.
See notes for how this was done.
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 bandpass for different tilt angles is illustrated here. Note that the local bandpass does not change in width, but the global bandpass (wavelengths transmitted everywhere in field) shrinks with tilt. If the entire field is not needed, shorter wavelengths can be accessed by tilting. Note that additional x-dependence of the bandpass is not plotted.

For Filter B at 0° the bandpass looks like this: left arm | right arm (dotted lines show location of 5038Å line.)
The half-max lower-limit relative to median value over the field is here, while the FWHM vs y is shown here.

The specs of Filter AB have been now optimised to allow the 6 PN.S main programme galaxies to be targeted that could not be otherwise done:
n=1.96, wavelength range = 5008.0 -- 5044.2 Å (0°, field centre).
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 black dotted lines. The symbols show the wavelength range of individual galaxies (vcentral ± 2.68*sigmacentral gives 99% PN recovery). The solid lines show PN.S main programme galaxies; the dotted are secondary targets. The green ones are better done with Filter B, or have already been done with it; the black ones are better done with Filter AB.
To illustrate how the galaxies fit in the spatial and velocity range, see plots for Filter B and Filter AB, where the colours and line-styles are the same as before.
Note the galaxy ellipticities have not been allowed for! Also, these are from estimated filter AB specs, not yet real specs.



Name vh (km/s) sigmac (km/s) Reff (arcmin) Filter: angle Avail chip frac # Reff tint (hrs) for 50/100/200 PNe, > 2 Reff Notes

Primary programme
NGC 33776921360.57B: 6.0°
AB: 0.0-6.0°
0.56
1.00
4.9
8.8
AB: 1.5/4.2/21.8
NGC 33798792060.59B: 6.0°
AB: 0.0-4.8°
0.56
1.00
4.8
8.5
B: 0.7/1.5/6.0used B-6.0°
NGC 36081233?1930.56B: 0.0-4.6°
AB: 0.0-3.8°
1.00
1.00
8.9
8.9
B:8.0/?/?
AB:10.5/?/?
NGC 42786272520.78B: 6.0°
AB: 0.0-3.6°
(0.35)
1.00
(2.3)
6.4
AB: 9.9/?/?B: 2.0-sigma cutoff
NGC 433912701140.52B: 0.0-5.5°
AB: 0.0-4.1°
1.00
1.00
9.6
9.6
B: 3.8/11.9/?used B-6.0° (0.92 frac = 8.8 Reff)
NGC 436512242661.11B: 4.4-5.0°
AB: 0.0-1.6°
(0.91)
1.00
(4.1)
4.5
AB: 5.9/11.7/?B: 2.1-sigma cutoff
If D=15 Mpc, then tint=1.8/3.6/10.9
NGC 43749012970.92B: 6.0°
AB: 0.0-3.3°
(0.57)
1.00
(3.1)
5.4
AB: 3.4/5.5/11.4 B: 1.9-sigma cutoff
NGC 447322421790.44C: 2.5-3.0°
B: 0.1-1.7°
(0.43)
(0.49)
(4.9)
(5.5)
C: (2.5/5.2/?)
B: (2.2/4.7/15.6)
C: 1.7-sigma cutoff
B: 1.6-sigma cutoff
NGC 449413021580.82B: 0.0-4.7°
AB: 0.0-3.1°
1.00
1.00
6.1
6.1
B: 1.4/2.1/3.7used B-6.0° (0.81 frac = 4.9 Reff)
tint=12.5 to get 500 PN > 2 Reff
NGC 45523072641.0AB: 6.0°(0.67)(3.4)B: 2.3/4.6/?
A: 2.6/5.4/?
AB: 2.0-sigma cutoff
used A-0.0°+B-6.0°
NGC 456411521590.33B: 0.0-5.4°
AB: 0.0-4.0°
1.00
1.00
15.2
15.2
B: 2.8/7.4/?used B-6.0°
NGC 474212701070.46B: 0.0-5.8°
AB: ?°
1.00
?
10.9
?
B: 5.8/21.2/?
NGC 584618142401.04B: 0.0°(1.00)(4.8) B: 12.4/26.9/?2.3-sigma cutoff
used B-0.0°

NGC 58417982050.42B: 0.0-0.2°1.0011.94.7/9.8/?
NGC 59618821560.46B: 0.0-0.7°1.0010.98.0/?/?
NGC 72017322420.60B: 0.0-0.6°1.008.315.5/?/?
NGC 82117392080.83B: 0.0-0.9°1.006.0B: 16.4/?/?used B-0.0°
NGC 10236262090.66B: (6.0°)
AB: 0.0-6.0°
(0.44)
1.00
(3.3)
7.6
AB: 1.2/2.3/7.0B: 2.0-sigma cutoff
NGC 105214892160.56B: 0.0-2.6°
AB: 0.0-0.3°
1.00
1.00
8.9
8.9
B: 4.8/10.2/?
NGC 254910801500.29B: 4.7-5.9°
AB: 0.0-4.6°
1.00
1.00
17.2
17.2
B: 2.9/8.1/? used B-6.0° (0.99 frac = 17.0 Reff)
NGC 276814241891.07B: 0.0-3.5°
AB: 0.0-1.6°
1.00
1.00
4.7
4.7
B: 8.4/?/?
NGC 277820411620.26B: 0.0-0.6°0.8015.4B: 27.1/?/?
NGC 295013721820.25B: ?°??B: 4.3/11.6/?
NGC 297418952270.41B: 0.9-1.1°0.668.0B: 8.0/?/? Use B-0°
NGC 31156582650.54B: 6.0°
AB: 0.0-6.0°
(0.50)
1.00
(4.7)
9.3
AB: 1.5/3.3/11.2B: 1.5-sigma cutoff
NGC 322613301940.57B: ?°??B: 10.6/?/?
NGC 33847281410.42B: 6.0°
AB: 0.0-6.0°
0.59
1.00
7.0
11.9
AB: 1.0/2.1/6.9
NGC 3605668960.35B: 6.0°
AB: 0.0-6.0°
0.68
1.00
9.7
14.3
B: 15.8/?/?
NGC 36079152171.10B: 6.0°
AB: 0.0-4.5°
(0.76)
1.00
(3.4)
4.5
?B: 2.0-sigma cutoff
NGC 361017701620.26B: 0.0-2.1°1.0019.2B: 8.8/?/?
NGC 364013181810.54B: ?°??B: 16.2/?/?
NGC 39621841?2230.59B: 0.0-0.1°0.968.1B: 12.5/?/?
NGC 412513612270.97B: 0.0-3.7°1.005.2 B: 7.1/?/?
NGC 420310841580.33B: 5.2-5.8°
AB: 0.0-4.4°
1.00
1.00
15.2
15.2
?
NGC 426710201680.69B: 6.0°
AB: 0.0-4.6°
0.90
1.00
6.5
7.2
?
NGC 43875581060.26B: 6.0°
AB: 0.0-6.0°
0.52
1.00
10.0
19.2
B: 37/?/?if D=15 Mpc, tint=30 (dominated by HSB)
NGC 4406-2882551.74A: ?°??A: 7.6/12.8/?4 pointings
NGC 447813861380.22B: ?°??B: 18.6/?/?
NGC 4489947530.47B: 0.0-6.0°1.0010.6B: 8.0/?/?
NGC 455111831070.22B: 0.0-5.9°
AB: 0.0-4.6°
1.00
1.00
22.7
22.7
B: 12.1/?/?
NGC 458919532220.64B: 0.0°
C:?
(0.51)(4.0)B: 6.5/13.6/? B: 2.3-sigma cutoff
NGC 46214302450.67AB: 0.0-4.4°1.007.5AB: 4.7/9.5/?
NGC 463610712111.95B: 5.1-6.0°
AB: 0.0-3.7°
0.67
1.00
3.4
5.1
B:7.8/11.2/?
AB: 6.8/16.4/?
4(B) or 6(AB) pointings
NGC 464911263391.37B: 6.0°
AB: 0.0°
(0.45)
0.91
(1.7)
3.3
AB: 4.0/8.9/?B: 2.0-sigma cutoff
NGC 466010721910.20B: 5.4-6.0°
AB: 0.0-4.0°
0.80
1.00
20.0
25.0
B: 3.2/12.0/?
NGC 469712341731.20B: 0.0-4.8°
AB: ?°
1.00
?
4.2
?
B: 1.6/5.8/?used B-0.0°?
NGC 4733949720.49B: 0.0-6.0°1.0010.2B: 8.3/?/?
NGC 52731108660.51B: 0.0-6.0°
AB: 0.0-6.0°
1.009.8B: 6.3/25.1/?
NGC 536311391950.60B: 5.4-5.7°
AB: 0.0-4.7°
0.95
1.00
7.9
8.3
B: 3.0/6.0/19.0
NGC 557614861841.04B: 0.0-3.2°1.0016.7B: 16.8/?/?
NGC 558214401390.55B: 0.0-4.6°1.009.1B: 21.1/?/?
NGC 563816671640.47B: 0.0-2.8°1.0010.6B: 14.5/?/?
NGC 581219492000.43B: 0.0-0.8°0.758.7B: 25.7/?/?
NGC 583116661640.43B: 0.0-2.8°1.0011.6B: 11.1/?/?
NGC 583813662660.38B: 3.5-4.1°0.719.4B: 17.5/?/?
NGC 58667391420.67B: 6.0°
AB: 0.0-6.0°
0.58
1.00
4.3
7.5
AB: 2.5/5.5/19.3used B-6.0°, improper offset
NGC 670322641800.37C: (3.6-4.1°)
B: (0.0-1.3°)
(0.36)
(0.44)
(4.9)
(6.0)
B: 29.4/?/?C: 1.9-sigma cutoff
B: 1.6-sigma cutoff
NGC 733212931350.24B: 0.0-5.0°
AB: 0.0-3.6°
1.00
1.00
20.8
20.8
B: 11.7/?/?used B-0.0°
NGC 7457773750.54B: 6.0°
AB: 0.0-6.0°
0.91
1.00
8.4
9.3
B: 3.0/10.6/?used B-6.0°

Spirals
NGC 7013779900.44B: 6.0°
AB: 0.0-6.0°
0.88
1.00
10.0
11.4
B: 11.1/26.6/?used B-6.0°
NGC 26834271430.93AB: 0.0-6.0°1.005.4 ?
NGC 5907667?2.04B: 6.0°
AB: 0.0-6.0?°
0.65?
1.00?
1.6?
2.5?
?
NGC 73391337????B: 0.0-5.4?°
AB: 0.0-4.0?°
1.00?
1.00?
~15?
~15?
?used B-0.0°
NGC 3031-341613.30A: 0.0-2.4°???multiple pointings
M514631002.08AB: 0.0-6.0°1.002.4?multiple pointings
M101240965.74A: ?
AB: 6.0°
1.000.9?multiple pointings
M943081461.3A: ?
AB: 6.0°
0.883.4?
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