FLAMINGOS at the KPNO 2.1-m An Observer's Guide Dick Joyce, Nick Raines, Richard Elston Version 2.39, 2011 May 13 (2.1-m Figure © NOAO/AURA/NSF) FLAMINGOS@2.1-m, Ver. 2.
Contents I. FLAMINGOS + KPNO 2.1-m Overview II. Starting FLAMINGOS III.Nightly Startup Tasks A. FLAMINGOS Setup B. Startup on the Sky IV.Imaging with FLAMINGOS A. Overview B. Wheel Setup for Imaging C. Configuring an Exposure D. Taking an Image at a Single Pointing E. Taking Dithered Images F. Offsetting the Telescope from Flamingos1a G. Taking Darks H. Dome Flats I. Custom Scripts V. Taking Spectra with FLAMINGOS A. Overview B. Preliminary Setup C. Long Slit Alignment D.
I. FLAMINGOS + KPNO 2.1-m Overview FLAMINGOS is the FLoridA Multi-object Imaging Near-ir Grism Observational Spectrometer. This manual provides the user with a good portion of the tools needed to successfully take data with FLAMINGOS at the KPNO 2.1-m telescope. The 2.1-m is a completely hands-on facility. The observer runs both the instrument and telescope (there is no telescope operator).
Filters: J, H, K, Ks, JH (0.9 μm – 1.8 μm), and HK (1.25 μm – 2.5 μm) bandpass filters. Grisms: Two grisms are available, covering the JH (0.9 μm – 1.8 μm) and HK (1.25 μm – 2.5 μm) bandpasses. The HK grism may be used with the HK filter to obtain H- and K-band spectra in first order, or it may be used with the JH filter to obtain H-band in first order, and J-band in second order. For spectra in the K band only, the K or Ks filter may be used to reduce the background.
Data Acquisition & Storage: While you are taking data, all data will be located on flamingos1a in /data/2mguest//. If you type df -h, you can see how much of the 68 GB disk space is available; similarly if you type du -h, you can see how much disk space is used in the present directory (the -h option is for human readable format, and it prints values out with KB, MB, and GB suffixes as appropriate).
Figure 1: FLAMINGOS Functional Diagram. The relative layout and connections between the various parts of FLAMINGOS are shown schematically. The MOS and Camera dewars are shown in the middle of the figure, including the relative layout of the 5 internal mechanisms above the detector array, and the elements of the two electronics racks are shown on either side of the dewars, much as they are in actuality.
Imaging Sensitivity FWHM = 2 pixels (1.2 arcsec) Aperture 2.8 arcsec diameter Band e/s for mag=15 sky J 1050 15.1 H 1320 K Ks 10 σ limiting magnitude mag-arcsec-2 e-sec-1-pixel-1 60 seconds 600 seconds 3600 seconds 335 17.6 18.8 19.8 13.1 2815 16.7 17.9 18.9 1300 12.7 4028 16.5 17.7 18.7 1140 12.9 3925 16.3 17.6 18.6 These data are from the KPNO FLAMINGOS web site, http://www.kpno.noao.edu/manuals/flmn.
II.Starting FLAMINGOS When you arrive at the 2.1-m telescope, you may have to bring up the FLAMINGOS windows and initialize the system (this should have been done during the checkout night). The initial steps of this procedure will hopefully only need to be done once at the beginning of your run; however, you may need to repeat this process during the course of your observing time if you get logged out, or if the system crashes. The observer interface at the 2.1-m has been significantly upgraded.
5. Open an xterm, and initialize FLAMINGOS. 2mguest@flmn-2m-1a{4} xterm -T FLAMINGOS -n FLAMINGOS & Type all following FLAMINGOS commands within this xterm (appropriately titled FLAMINGOS). We recommend that you move this window to the lower left of the screen, since the daemon windows will automatically appear in the upper left corner. 6. You are now ready to initialize FLAMINGOS! This is done by running the command ♫ initflam.
Array Temperature Quick Look Plot Tool – This GUI will appear, along with an xterm messaging window. Please do not close this window or the associated xterm to which messages are printed; you can minimize the xterm or move it and the plot window to another space on the monitor. After about 30 minutes there will be ~3 points in the Record Temperatures log file, and you can hit the Update button to plot the present temperature.
III.Nightly Startup Tasks A. FLAMINGOS Setup We recommend that you carry out the following procedures prior to each night's observing. 1. Restart all daemons, temperature logging and temperature plotting windows. Please see the notes at the end of the previous section. The daemons should all be Quit (not Closed, as this just minimizes them), and initflam.pl immediately re-run, in order to restart the daemons. 2. Fill Both Dewars. Observing with FLAMINGOS at the 2.1-m is very much a do-it-yourself operation.
about face-level in height. Do not stand close enough to the vent such that liquid nitrogen can splash you in the face! • Close the valve on the storage dewar, and remove the line from the inlet port of the LN 2 manifold, then close the silver valve and loosely screw the brass cap back in place. CAUTION: Do not simultaneously close both manifold valves and the storage dewar valve. This traps liquid nitrogen within the fill line, with potentially nasty consequences. 3. Remove the MOS dewar window cover.
In this example the data disk on flamingos1a, /data, is 44% full, and has 38 GB of available space. For imaging you should ensure that there is at least 10 GB of space available; for spectroscopy you should have ~5 GB of space. However, note that the image acquisition scripts will complain on each and every image if the flamingos1a disk space is ≥ 93% full, and will refuse to take any more data if the disk is ≥ 97% full. 5. Open the shortcuts menu.
6. Set up header information, data location, file names. Several parameters need to be set before taking an exposure. The script config.exposure.pl [Configure Exposure] will print out a list of exposure parameters, and query if you wish to change any of them. If you do, you can step through each of the modifiable parameters; enter the new value or hit return to keep the old value.
MacMini for analysis or archiving on storage media such as a USB drive. From a terminal on second-1 or 2, run % ~/bin/mirror flamingos1a /data/2mguest/
where is the data subdirectory in /data/2mguest on flamingos1a. It is probably safest to use the full path name. The command will create the subdirectory on the MacMini, in whichever directory you ran the mirror command and will use rsync to update the files every 30 seconds.Note: δRA and δDec must be in arcseconds (see the previous step). Look at the compass arrows in ds9 to determine which of (x, y) corresponds to (RA, Dec); you may have to darken the display to create enough contrast to see the arrows clearly. With FLAMINGOS mounted onto the 2.1-m in the usual way, moving an object from its present location by (+dx, +dy) in detector space corresponds to (-δRA, +δDec). • Take another image, and iterate with rulers and relative.offset.kpno.pl until the star is centered.
root = First = Last = (telesco= (mode = • ugc3371.j 21 25 KPNO2.1m) q) Root infile name? First image in set? Last image in set? Telescope(MMT, Mayall, KPNO2.1m)? fwscan takes a range of images as inputs, in the form fwscan It computes running difference images from which it computes the FWHM. You can use this to monitor the seeing during a sequence of observations. To use this for focus runs, e.g., • • • 2mguest@flmn-2m-1a{17} singleimage.
7. Variation of focus with temperature and airmass. The telescope changes focus due to temperature variations; the focus value will increase with decreasing temperature. Similarly, the focus value will decrease as the airmass increases: • Temperature Variation: ∆T(+1 C) = -75 focus units • Airmass Variation: ∆X = -130 focus units It's advisable to watch the temperature every 30 – 60 minutes, and if necessary adjust the focus. 8. Check the display orientation.
IV.Imaging with FLAMINGOS A. Overview FLAMINGOS may be used for imaging through J-, H-, K-, and Ks-band filters. Sky emission in these bands is variable and may be bright3. Exposure times are kept reasonably short as a result and guiding is not required. The general observing procedure is to point the telescope in a dither pattern about the source, taking one or more images at each location. FLAMINGOS has a dither script with several different dither patterns available.
On the FLAMINGOS command line: config.dither.kpno.pl config.exposure.pl config.filter.grism.decker.wheels.pl config.rel.mv.filter.grism.decker. wheels.pl config.rel.mv.mos.wheel.pl dither.source.kpno.pl fast.singleimage.pl more.singleimages.pl offset.kpno.pl relative.offset.kpno.pl set.bias.pl set.exposuretime.pl set.filename.pl singleimage.pl Set up a sequence of images dithered about a common pointing center.
printed to the screen. It is unnecessary to hit the Update All Items button on the UFSTATUS GUI during execution of either of these scripts. It is, however, a good idea to update the GUI after the script has successfully completed. NOTE: It is not possible to move more than one wheel at a time. The only useful dark position is on the Grism wheel; there is a dark position on the Decker wheel, but it does not provide a truly dark condition, since it is not directly in front of the detector.
pattern and take images. Immediately after hitting return this script print out information about the requested dither pattern, and it will ask you to type either HOME or CLEAR before beginning the dither pattern. If you have any offsets showing on the TCS, typing HOME will cause the script to dither about the pointing center where the offsets are (0,0), while typing CLEAR will absorb any offsets present into the current pointing coordinates, and dither about that new position (i.e.
If you need to take many darks at several different exposure times, consider writing a cshell (csh) script which consecutively calls config.exposure.pl and more.singleimages.pl multiple times, each time passing the proper keystrokes into each script. An example, based on a script written by Anthony Gonzalez (UF), appears in ~2mguest/bin/Example.many.scripted.darks.csh Note that the blank lines are very important! Also, be very certain to check later that the script completed successfully; cf. § VIII.
V.Taking Spectra with FLAMINGOS A. Overview FLAMINGOS may be used for obtaining long slit spectra at the 2.1-m; please see § I. FLAMINGOS + KPNO 2.1-m Overview for resolving powers within selected passbands. Multiobject spectroscopy is currently supported only at the 4-m telescope. As with imaging, the sky emission is variable and bright, and there is additional background in the HK mode from the camera dewar window. It is necessary to subtract this contribution from the target spectrum.
Figure 4: Schematic of the UF 3pix long slit (left) and NOAO slit (right). The acquisition box for the NOAO slit is 20 arcsec square at the 2.1-m. The two slits are each 120 arcsec long, centered 120 arcsec on either side of the center of the mask. The general outline for spectral observations is: 1. Verify telescope pointing on a SAO or Fixed Bright star close to target position. 2. Acquire target close to the long slit center or alignment aperture in slit MOS plate. 3. Check focus. 4.
The following commands are used for long slit and MOS plate spectroscopy: On the Flamingos command line: config.exposure.pl config.filter.grism.decker.wheels.pl config.rel.mv.filter.grism.decker. wheels.pl config.rel.mv.mos.wheel.pl config.mos.dither.kp2m.pl dither.mos.nonudge.kp2m.pl guide.define.abba.manual.beams.kp2m.pl guide.define.slit.center.manual.kp2m.pl guide.mos.offset.kp2m.pl set.bias.pl tweak.decker.pl tweak.mos.
C. Long Slit Alignment 1. Verify telescope pointing. • Acquisition can be done with the Decker wheel in mos, MOS wheel in imaging, Filter wheel in H, and Grism wheel in open1. • Take a quick image (2-5 seconds) of an SAO or Fixed Bright Star near the target field, and make certain the SAO star is well centered at the position of the slit or acquisition aperture for the slit mask to be used. If is not, center the star with relative.offset.kpno.pl, then take another image.
Walking up the slit: • • • Move the star up the slit in steps of 10" for a total of 5-7 positions. The MOS mask slits are 120" long, so one can easily stay within the slit. Use singleimage.pl to take an image at every location. Use guide.mos.offset.kpno.pl to move the star up and down the slit (while continuing to guide). Setup to execute a dithered ABBA script: 1. Set up lock position definition for the current guide position.
Answer "y" to this last query; it will then print some numbers and other information to the screen. It will conclude with: The MOS dither script requires the slit center have zero offsets. Clear the present offsets (i.e. set to zero)? (y/n) y Answer "y" to this query. It will set the offsets (see cyan's telescope status screen) to zero, but it will not move the telescope. The following output will be printed, and the script will be finished.
Are you ready? (y/n) This script will prompt you through the above 5 steps. Do them quickly, as guiding will be off during them, and it needs to be restarted as soon as the last beam is defined. Answering "y" will generate the following output: <><><><><><><><><><><><><><><><><><><><> Step 1) Clear offsets. If the telescope offsets are not zero, then they need to be zeroed. Clear the offsets? (y/n)y EXECUTING CLEAR OFFSET COMMAND: /usr/local/uf2001May17/sbin/tcs2m "tele offset = zero" Step 2: Guiding off.
It should print out some statements such as Moving guide box to lock position 2. Executing /home/raines/gdrrpc/gdrrpc guide pos2 gdrrpc reply = Executing /home/raines/gdrrpc/gdrrpc guide on At this point three guide lock positions have been defined, and the telescope is locked and guiding in beam A, which is 4" away (South, I think) from the initial alignment position for the long slit. 4. 5. 6. 7. 8. Insert filter and grism combination with config.rel.mv.filter.grism.decker.wheels.pl [Move Wheels].
1. Carry out the following steps at the telescope: • Stop guiding (cf. Figure 8 of Guider GUI's). • Turn down the guide camera gain (cf. Figure 3, ibid). • Turn on the dome flatfield lamps (cf. Figure 11, ibid).
VI.Shutting Down at the End of the Night At the end of a long and (we hope!) productive night of observing, there are a few things that need to be done. In order, they are: 1. Move the wheels to their default positions. Using the scripts config.rel.mv.mos.wheel.pl [Move MOS Wheel] and config.rel.mv.filter.grism.decker.wheels.pl [Move Wheels] send the MOS wheel to imaging, the Decker wheel to imaging, the Filter wheel to J, and the Grism wheel to true_dark. 2. Take any necessary dark frames.
VIII.Troubleshooting 1) Problem: The image looks funny. You can see all 32 amplifiers, and the signal level is ~58,000 ADU; the preceding or following image(s) has 0 counts. Solution: This is a hardware problem related to electrical noise causing an early readout of the detector. In imaging mode, MCE4 reads the array once, and then lets it integrate before reading it again (cf. Appendix 2: Readout Schematic). The final image written to disk is the difference of these two images.
casts a large amount of thermal radiation on the lower right hand corner of the array. c) Check that the MOS dewar temperature is lower than 200 K. If the temperature is not between 80 – 95 K, and is rising monotonically with time, the MOS dewar may have run out of LN 2. Verify that the camera dewar is cold by checking the detector temperature, which should be near 77 K. 4) Various Problems related to image readout, wheel motion and Perle communication. The three daemons started by initflam.
RPC-3 Telnet Host Revision F 4.20a, (C) 1999 Bay Technical Associates Unit ID: flmn-4m-1b Enter username>mce4pow Enter password>____________[regular flamingos1a password] Option(s) installed: True RMS Current Internal Temperature True RMS current: 1.6 Amps Maximum Detected: 1.7 Amps Internal Temperature: 18.
testing that the fiber is working. Figure 6: Fiber optic converter boxes below MCE4 (left panel) and below perle (right panel) c) Problem: The image acquisition counts past the exposure time without reading out an image. Solution: This problem rarely happens anymore. With the previous slower version of flamingos1a, it would sometimes take an extra 5 to 10 seconds to finish reordering the pixels; i.e., applying the look up table, or LUT, before writing the image to disk.
Wheel]. The script ends by saying that the time for the wheel's motion to complete has expired. The Initialize Wheels button will execute the script engineering.config.filter.grism.decker.wheels.pl, which will rotate the wheels until the home position switch is activated, tell the controller to zero the position, and then move to the commanded position. We refer to this as a home-type of limit, or limit switch operation.
IX.Contacts & Further Information 1. Dick Joyce, Ron Probst, and/or Nick Raines will help new observers during their first night of observing with FLAMINGOS at the 2.1-m. If simple questions arise during the run, please address them first to Dick or Ron, and then to Nick. Their contact information is listed below. Nick Raines, University of Florida, FLAMINGOS support scientist office 352-392-2052, ext. 244 home: 352-870-0004 raines@astro.ufl.
Appendix 1: FLAMINGOS Command Listing and Partial Description of Function A. Basic Instrument Configuration Commands config.exposure.pl config.filter.grism.decker.wheels.pl config.rel.mv.filter.grism.decker. wheels.pl config.rel.mv.mos.wheel.pl initflam.pl set.bias.pl set.exposuretime.pl set.filename.pl Set object, filebase, data directory, exposure time. Set up and move Filter and Decker wheels. Execute relative motion of Filter, Grism, or Decker wheel Move the MOS wheel in relative motion mode.
F. Resetting the MCE4 Array Controller, the Motor Controller, and the Perle From flamingos1a: 1. telnet baytech userid: mce4pow, motorpow, or perlepow password: __________[regular flamingos1a password] (For telnet from a Kitt Peak machine, the baytech's name is flmn-2m-p). 2. reboot 1 3. logout 4. If you rebooted the perle close all daemons (the TEMPS, MOTOR, and MCE4 xterm windows), otherwise leave them open. 5. initflam.pl G.
H. Instrument Engineering Commands center.of.rotation.pl config.location.pl Determine the center of rotation from 3 points. Copy the correct Flamingos FITS header for a telescope. engineering.config.home.type.wheels.pl engineering.config.rel.mv.filter.grism. decker.wheels.pl engineering.config.mst.pl engineering.config.output.pl engineering.ct10.singleimage.pl engineering.ct12.singleimage.pl engineering.ct17.pl engineering.ct40.takecnt.pl engineering.more.ct10.pl engineering.more.ct17.pl engineering.set.
Appendix 2: Readout Schematic Figure 7: Array Readout Timing. All 4 quadrants of the array are readout simultaneously; within one quadrant all 8 amplifiers are readout, with pairs of amplifiers multiplexed down into one A/D input. Thus in a frame time of 1.33 seconds 1024 × 256 pixels are readout. The image delivered by MCE4 for a CDS frame is the difference image from two nondestructive reads of the array; the timing for a CDS frame with integration time of 6 seconds is shown.
Appendix 3: XBOX Default Parameter List for Instrument at PA = 0 degrees PACKAGE = ucsclris TASK = xbox image input (stars (nxbox (nybox (xsz (ysz (fwhm tel (rotdir rot_2m xrot_2m yrot_2m invert2m rot_4m xrot_4m yrot_4m invert4m MMT_rot MMT_xrot MMT_yrot MMT_inve GemS_rot GemS_xro GemS_yro GemS_inv (xoff (yoff (def_ref (def_err (niter (box_siz new_x_fw new_y_fw vmag wt (coord (mode = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = target.
Appendix 4: Additional Notes on MOS Plates An example MOS plate for use at the 4-m is shown adjacent, in Figure 8, at approximately full size (~105 mm in length). The sizes of the slits and alignment boxes are the same size in pixels for both telescopes. The slitlets are 3 pixels (1.8" at the 2.1-m) wide, with a minimum length of approximately 30 to 40 pixels (18" to 24" at the 2.1-m). The alignment boxes are 25 to 30 pixels (15" to 18" at the 2.1-m) on a side.
Appendix 4: Additional Notes on MOS Plates: A Figure of the MOS Wheel, Useful When Loading Plates MOS Position PA B ______ D ______ F ______ H ______ K ______ L ______ Name ____________________ ____________________ ____________________ ____________________ ____________________ ____________________ MOS Position PA M ______ N ______ O ______ P ______ Q ______ Name ________________ ________________ ________________ ________________ ________________ Telescope: ___________________________________ Date Loade
