ARC 3.5m | GFP

Please find additional information for taking and reducing data here.

Goddard Fabry Perot Observing Manual: Instructions for a Typical Observing Run

Computers you will need to access:





(Contact APO for current passwords)

1. Start aiscam from finesse account by typing from /home/visitor1 on

finesse{visitor1}18: aiscamremote

2. Install Appropriate Filters and Edit filters.txt file

Edit filters.txt file on aiscam@finesse in /home/aiscam/config

The file typically looks like this:


FILTER1 4050/160



FILTER2 empty



Type the following to load the filter information on VNC

aiscam: filter -ini ; initializes filter information

aiscam: filter -r ; lists filters installed

aiscam: filter 4 ; moves filter wheel

3. Take Wavelength Calibration Images for each Filter Used

Adjust course z-setting on the CS-100 controller.

Edit gfp.cfg file on aiscam@finesse in /home/aiscam/config

Input all the relevant CS-100 setting information

When only changing course z, these three need to be edited

GFPCALD blue.cald-4



If course z has been changed, quit aiscam on VNC interface. Restart aiscam from VNC interface by typing:

finesse{visitor1}25: aiscam -tcc -camera -gfp

This initializes control of the fabry-perot instrument as well as the telescope and CCD camera. It also loads the filter info and the gfp.cfg settings including the calibration file for the appropriate course z-setting

aiscam: etalon in ;load etalon into optical path

aiscam: filter 1 ;move filter wheel

aiscam: fptrackT off ;turn off temp tracking, moves z position

aiscam: calsetup ar 2 ;put in mirror, turn on lamp, ept=2.0 sec

aiscam: wtoz 4044.4 ;find calibration line, get z setting

aiscam: fpscan -1595 5 18 ;scan z (central z interval num steps)

aiscam: fpline -cur ;plot of intensity vs z, use cursor

aiscam: fpzero -w 4044.4 -1591.47 ;set fpzero with wavelength and central z

aiscam: fpw 4002.2 ;set vnc to appropriate z for observations

aiscam: fptrackT on ;turn on temperature tracking

aiscam: wtoz -o 5650 ;give all possible z values for a given wavelength

aiscam: fporder 46 ;select order to observe in, this does nothing to the instrument, it is a software aid

aiscam: wtoz 5650 ;will now look for z value on order 46 or warn if out

of range for etalon

Now you may calibrate fpzero for the new order and course z-setting

aiscam: fpzero -126.5 ;forces fpzero to the given z-setting

Note that the fpzero changes automatically with temperature, given calibration images dz/dT is calculated and tracked automaticall. If we want to calibrate for 600 km/sec fwhm in a given filter, adjust course z, choose appropriate order, determine fwhm in z, convert to Angstroms using dw/dz and then calculate:

fwhm (km/sec) = ( fwhm (A)/wavelength of cal line ) * c(300,000 km/sec)

Use fpline for a claibration image of a lamp

4. Procedure for taking skyflats

aiscam: path /export/data32/visitor1/apo2001d/n1

aiscam: fpw 4002 ;set z-setting to appropriate wavelength

aiscam: file sflat

aiscam: tcc hi

aiscam: filter 3

aiscam: fpw 4319

aiscam: time 40

aiscam: flat

aiscam: offset 30 0

aiscam: time 80

aiscam: flat

aiscam: etalon out

aiscam: filter 5

aiscam: time 15

aiscam: offset 30 0

aiscam: flat

5. Procedure for taking Images

First, focus the telescope on a standard star approx 8.0 magnitude

aiscam: obssetup 5 ;set up for 5 second focus image

aiscam: file focus

aiscam: obj

aiscam: dofocus -150 50 7 ;find best focal position

aiscam: focus 0 ;set focus of telescope

You must look at the focus images to determine minimum fwhm. Use (a)perture photometry on iraf and rimexam (r)adial profiles

First take a broad band image to identify star field appropriately

aiscam: etalon out

aiscam: filter 5

aiscam: slew 02 18 57.3 +08 17 28 -rot 0 2000 ;move telescope to position

aiscam: obssetup 60

aiscam: file obj

aiscam: name Q0216+080

aiscam: comment Q0216+080 60s B

aiscam: obj

Now, prepare for narrow band fabry-perot imaging

aiscam: etalon in

aiscam: input /home/aiscam/macros/pentagram ;load macro for pentagram dither

aiscam: obssetup 2400 ;turn lamp off, remove mirror

aiscam: name Q0216+080 ;name of object in header

aiscam: file obj ;name of file obj0083.fits

aiscam: num 83 ;number of file

aiscam: ext fits ;extension of filename

aiscam: pentagram 437 319 431 267 1 ; ( Xobj Yobj Xccd Yccd Pos)

Need center of object, center of CCD, position of pentagram (1-5)

aiscam: comment Q0216+080 2400s 4002.2 pentagram pos 1

aiscam: time 2400 ;set exposure time

aiscam: obj ;take object image (open shutter, etc)

aiscam: read ;read image before finishing (clouds)

6. Procedure for taking darks and biases

aiscam: file dark ;set filename for dark exposures

aiscam: time 2400

aiscam: dark 6 ;take 6 darks, time =2400 seconds

aiscam: file bias ;set filename for biases, no time needed

aiscam: bias 30 ;take thirty biases

aiscam: quit ;quit aiscam, vnc remains open