If you're starting IRAF for the first time or need to restart it, go here.
Start up:
Sometime in the afternoon, fill the CCD dewar. (The hold time on the dewar is about 8-10 hours, it takes about 2-3 hours to cool down from ambient temperature, but never let it warm up higher than ~ -70°C during a run. For observing the temperature should be -99 to -103°C). You can get a longer hold time ont the PFC dewar if the stinger from the 50l LN2 hose is not left in the dewar.
Check filter status:
Use a flashlight to check the current filter position (the U filter appears almost opaque, the B filter is blue, the V filter is green, the R filter is orange, and the I filter is a very deep red). With the cursor in the ICEX window type 'instrp'. Tell ICEX the current filter position by entering 'h[n]' on the parameter line 'instrfi=', where n=1,2,3,4,5 (e.g. 'h4 tells ICE that the current filter position is the R filter). Type CTRL-d to exit the parameter page and type 'instru' to make the changes effective.
To move the filter wheel type 'instrp' and enter '@[n]' where n=1,2,3,4,5 or n=U,B,V,R,I in the 'instrfi=' parameter line. Type CTRL-d to exit the parameter page and type: 'instru' to make the changes take effect.
For more on the IRAF/ICE parameters, see Phillip MacQueen's notes here.
Calibration frames:
Make sure you are in your data directory. Saving data in your home directory can cause IRAF (and sometimes even the Sun) to crash if you fill up the filesystem. Type 'obsp' (or 'epar obspars') to edit the observation parameters (e.g. observer designation and file designation sequence number and root if necessary). Type CTRL-d to exit and save the observation parameters. Check the CCD size by typing 'detp' (or 'epar detpars');. You should see
(firstco= 1) First column of data (device coordinates)
(lastcol= 2048) Last column of data (device coordinates)
(firstro= 1) First row of data (device coordinates)
(lastrow= 2048) Last row of data (device coordinates)
(colbin = 1) Column binning factor
(rowbin = 1) Row binning factor
If the values differ, enter the correct values and exit by typing CTRL-d.
Put the 'Calibration process in progress'; sign onto the outside of the dome door, so no one walks in while the flats are being exposed. To take the zero frames, type 'zeros' and enter the parameter values or a carriage return for each parameter inquiry.
To take the flats set the telescope position to 0h 0m, -20o (stow position). Turn on the calibration lamp following the instructions posted on the side of the lamp stand. The lamp current level for R is 3.55A, the exposure time is 10 sec. (For B the values are 5A/50sec and for V 4.3A/15sec). Make sure the filter is in the correct position.
Type 'flats' and enter the parameter values or a carriage return for each parameter inquiry. We normally take 5-10 flats for each filter are typica. Some observers do more, some less depending on their program.
At dusk:
- Open the dome.
- Refill/top off the CCD dewar.
- Point the telescope out the slit.
- Turn the tube fans switch to the 'manual' position.
- Turn off the air conditioner in the dome.
After the temperature in the dome has equilibrated (usually within a couple of hours of opening), the tube fans switch should be moved back to the 'auto' position.
Pointing alignment and focus procedure:
With the cursor in the ICEX window type 'detp' and enter '850' in the 'firstro=' parameter line and '1150' in the 'lastrow=' parameter line. Save the detector parameters. Type 'obsp'; to make sure that the line labelled 'command'; is blank. Turn on the track box, and set the trackrate to 14.952.
For pointing alignment, set on a bright star and take a test image. Enter 'object'; when asked about the image type. Display the image by typing 'display test 1' in the IRAF window. Move the telescope with the guide paddle between exposures, until the bright star is near the coordinates (960,150) when using the 850:1150 subset of rows. This will put the target between the two column defects near the center of the chip and on about the middle row. Once the star is in the right spot set the dials by using the hex key.
To start the focus procedure, type 'instrp' and enter 'h' in the 'instrfo=' parameter line to home (zero) the focus offset and start the focus servo system. Save the parameters with Ctrl-d, then type 'instru'. Type 'test' and select the focus option. A 10 sec integration is usually sufficient for focusing.
When the exposure has been read out type 'display test 1' in the IRAF window on titan. The focus routine generates seven separate images for each star. The last star image is separated from the rest of the sequence; the corresponding focus position is 3 x fdelta, fdelta usually set to 200 in obsp. Now type 'imexa' in the IRAF window to bring up image examine routine. There will now be a circular cursor in the ximtool window. Place that cursor on each star of a series and type 'a' each time to get the FWHM of the image in pixels. For each 'a'; typed you will get a line with images statistics, seven lines for each series. Typing '?' with the cursor in the 'ximtool' window will produce a menu of the other imexa functions. Several of the functions (e.g. contour plot (e) or radial plot (r)) will bring up the 'IRAF(Tek)' window, which can then be iconized. With the cursor still in the 'ximtool' window type 'q' to quit.
When the telescope is in focus, the FWHM is at its minimum. We need to find this location. Look for this trend in the FWHM. With the cursor in the ICEX window edit 'instrp' and enter your estimate of the new focus position by typing '@[n]' on the 'instrfo=' parameter line (e.g. @-100). Save the instrument parameters with Ctrl-d. Type 'instru' for it to take effect, then edit 'instrp' again, enter 'h' in the 'instrfo=' parameter line. Exit and activate autofocusing with 'instru'. Type 'test' to take another focus frame, and repeat until you are satisfied with the focus. (The best attainable focus with the PFC is about 1.5 pixels.)
When finished with the calibration, focus and pointing exposures edit the obspar file.
Observing
Make sure you are in the directory where you wish your data to be stored, typically /data1/titan/yourname (if you don't have a directory there, make one). /data2/titan/yourname could also be used.
Image display and manipulation
For further help on this, see the user manual for SAOimage DS9. Ximtool has its own online manual. DS9 has some nifty features, but it can be very much slower than ximtool. Both can be started from the command line prompt--"ximtool" or "ds9" or "saoimage" for the old version of saoimage--or you may start them by choosing from the Sun menu by holding down the right mouse button (ds9 is not on the Sun menu).Warning! Do not run ximtool and SAOimage at the same time! Make certain that your image display program is running before you take your first integration. Iraf will need to be restarted if you don't.You may use Ximtool or SAOimage DS9 for the graphic interface. DS9 has pull-down menus and two rows of 'buttons'; just above the image, and you can also use the mouse buttons.
Just as for Ximtool you can use the left button to move around the image, the right button the adjust brighness and contrast at the same time. When you want to center the image on a particular object, put the cursor over it, and press both buttons at the same time (this combination is the same as the middle button on a three-button mouse). To zoom in and out you need to click once with the left button on 'Zoom'; in the top row above the image, and choose your option from the buttons below.
The easiest way(in DS9) to move between frames is to tear off the 'Frame' menu. With the left button click once on 'Frame'. The menu will appear with a dashed line just under Frame, click again once, and in a few seconds it will appear as a separate window, which you can pull onto the desktop. Clicking on 'Reset' will center the frame and set the zoom to 1. To start and stop blinking you need to click on 'Blink frames', to stop, click on 'Single frame'. You cannot specify the blinking order, it is always in increasing sequence. By default DS9 wants to blink all the frames, you need to hide the ones you do not need. Click on 'Show/Hide frames' and in the side menu click on the buffer you want to hide or raise. The active buffers are highlighted in red. To change frames just click on the appropriate frame button.
The easiest way to reset the contrast and brightness is to click on 'Color' on the pull-down menu and click on 'BB', even if it is highlighted in red.
Shut Down
At the end of the night:
- Fill out the night report even if you did not open. Use 'xreport'; in the luna console window. xreport will not work on titan. Be sure to save and close the xreport before you leave.
- Fill the CCD dewar and stow the telescope at H.A.=0, Dec.=-20.
- Turn on the air conditioner in the control room and the dome.
- Turn on the ventilation fan in the control room.
- You need not log out of titan until ready to leave the mountain, but turn off any password screen locks. Staff must have daytime access to the consoles.
Useful iraf commands and other tidbits
- To edit parameters of a built in ICEX task it is enough to type its name e.g. 'obsp' will open the parameter files for obsp
- To edit an IRAF or user defined task you need to type 'epar task';
- To exit the parameter editor without change use 'Ctrl-c' to save the changes use 'Ctrl-d'.
- To make a list of images do: files *.fits > list
- To display the contents of the header file for a frame use
imhead s11001 l+ | more
- To correct erroneous header information use epar hedit.
- To change fitting box value while measuring a target close to brighter sources type ':' in the DS9 (ximtool) window, then move the cursor to the IRAF window and type cbox [n], n= box size in pixels.