Search
Text Size:
Smaller Text Normal Text Larger Text

Facebook

Follow us on Twitter

Astro-support issues and how to observe standard stars
FIES astro support: what to do?
FIES tech/service-night afternoon checks: what to do?
Checking the fiber positions on StanCam

How to observe standard stars for Quality Control
Flux-standard stars
Radial-velocity standard stars

Calibration procedures, Quality Control, monitoring
Calibration procedures
Instrument/detector quality control
Stability monitoring
ThAr-lamp QC and the dying ThAr-lamp phenomenon
FIES change log

Data reduction
Some hints for FIEStool usage
HowTo: Re-run FIEStool when it has failed

Data archive
A list with all FIES data from the FITSheader archive (up to FIyk290133.fits)

Known problems
New top unit very unstable slide (arm) and mask
How to change a lamp
Recovering from CryoTiger Failure
More trouble shooting
How to remotely power cycle the FIES CCD controller
Alternative; How power cycle the FIES CCD controller locally  If remote power cycle doesn't work!

Documentation
Pumping the FIES Dewar
How to observe with FIES, non-sequencer engineering mode
Skew readout mode   Old stuff for CCD#13
The FIES solar experiment   Old stuff
Using the FIES fibre shaker   Old stuff
Fibguider instructions
Fiber-bundle constraints and requirements, development of bundle D
FIES acquisition with ALFOSC instead of STANCAM



FIES astro support: what to do?
FIES tech/service night: what to do?

The below lists the setup and checks that need to be done when FIES is to be introduced to a visiting astronomer,
or when using FIES on a tech/service night.


Before a visiting observers' run:

If required, explain the choices (these should really already be known to us at NIRF stage):

  • Resolution low, med, high.
    Low-res has bigger sky-aperture (2.5 arcsec) and can be binned 2x2 without losing resolution. High-res has lowest throughput.

  • SimulThAr mode or sandwiched ThAr spectra.
    If a rad-vel precision of better than 150 m/s is necesary, then use either SimulThAr mode or sandwiched ThAr spectra. In practice, the same rad-vel accuracy can be reached with simulthar as with sandwiched ThAr spectra. But with simulthar the arc lines scatter into the target spectrum of faint targets. Simulthar mode can only be done with med- and high-res fibers.

    Note that the SimulThAr mode is rarely used, and in practise requires a dedicated reduction procedure. FIEStool has not been actively maintained to support the SimulThAr mode.

    If a rad-vel precision of worse than 150 m/s is OK, then ThAr frames in evening, midnight and morning, are sufficient.

  • Binning 1x1 (default) or 2x2 for low-res. Other binning mode to be considered: 2x1 . For simulthar: 1x1 .
    It is necesary to know the binning mode for the setup of FIEStool.


This should all be done in the morning/afternoon before the first night of the run, or before your tech/service night.

  1. Check the fiber positions on StanCam

  2. For all the fibers that will be used (including fiber #5 when simulthar is to be used), check that the lamps are working properly.
    If a lamp shows signs of deterioration, then the lamp has to be changed: change the lamp .
    Call for help when you need it:
        either to change the lamp,
        or to judge whether a lamp needs to be changed.
    Afterwards, write a fault report to indicate a lamp had to be changed.

    An easy way to find out a suitable exposure time for a FIES calibration-lamp setup is the following:

    • for a ThAr exposure
      setup-fibN-thar
      easythar

    • for a halogen (flatfield) exposure
      setup-fibN-halo
      easyhalo
    The scripts easyflat-fies and easythar-fies will take a fast windowed test exposure to determine the countrate, and will set the CCD back to the original window/binning to obtain a halogen or ThAr image with sufficient counts for FIEStool.
    The flats will have approximately 350000 ADU peak counts. For the ThAr frames the 4764.9 line, one of the brightest lines in the center of the image, will have approximately 80000 ADU peak counts.
    For a log of the test-image counts in the 4764.9 line:

  3. Make sure to switch off all the lamps.

  4. If it does not exist, create the Sequencer script directory for the observer, e.g.
          mkdir ~/scripts/64-210
    If new scripts are to be made 'by hand', copy in some example scripts from the directory ~/scripts/staff/FIEStemplates/ .

  5. Explain the following to the visiting astronomer:
    • Software startup
    • FIESTA mimic, and calibration arm !!
    • How to start and abort exposures
    • How to start and abort scripts
    • setup-fibN-star, setup-fibN-thar, setup-fibN-halo
    • fies-calibs
    • simulthar and extra calibrations for simulthar-mode (arcs and flats for fib #5)
    • lamp 1,4,6,7 on/off command
    • Telescope
    • camera probe !!
    • setup-tel-fies
    • exposure meter
    • Target acquisition
    • How to use FIEStool
    • That there may be ALFOSC overrides....
    • What more??

  6. Help the visiting astronomer make some SEQUENCER scripts,
    using the templates in directory ~/scripts/staff/FIEStemplates/ .

  7. The visiting astronomers should be advised to obtain a full set of calibrations every afternoon, and possibly additionally every morning.

  8. At night, during the first acquistions, see if there is a large offset when stancam.fiboff (or stancam.acquisition) tries to bring the star close to the fiber. If the offset is more than a few pixels, then consider running stancam.fibposcalib in order to make the offset more accurate.


Checking the fiber positions on StanCam (in the afternoon)

At the start of each run check the fiber positions for all fibers, using the StanCam filter that will be used. Note that for different StanCam filters the fiber positions are slightly different. The filters B, V, R, SDSS g', and Clear#126 can be used for FIES; typically the g' filter is used.

In the afternoon, please follow the software-startup section of the general observing instructions.

In the afternoon, check the fiber positions in fiber-viewing mode (camera-probe-fies).
The instructions below are for fiber #4 with the g' StanCam filter.

  • Sequencer window: camera-probe-fies
  • Sequencer window: ccd-filter 6 (g' = default)
  • TCS: o-m-c y
  • switch on some dome lamps

    1. Sequencer window: setup-fib4-star
    2. Sequencer window: fib4window
    3. StanCam Sequencer: exp 1 (check required expo time!)

      • ds9: zscale
      • ds9: zoom to fit

      • StanCam Sequencer: fibmark no
      • StanCam Sequencer: fibmark yes

      • Use
            fibpos-man 4
        to redetermine the green-cross position.

      • StanCam Sequencer: fibmark no
      • StanCam Sequencer: fibmark yes

      • Iterate step 3 until the mark is centered on the hole

    4. Repeat the above (step 1-3) for the other fibers.

  • Switch off the lamp!
  • TCS: close-mirror-cover
To check the fiber positions in direct StanCam mode:
At night, once a star has been well centered onto a fiber, flip the camera probe back to the StanCam position (cam-probe-ccd). Then take a full-frame unbinned StanCam image and use stancam.fibpos-man to record the X,Y positions of the star=fiber. Or use the command stancam.fibposcalib to do all that from within a script.
Note that there is a flip in Y when moving the camera probe from StanCam direct imaging to the FIES fiber viewing position.


Quality Control: How to observe flux standard stars for FIES

In the afternoon, please follow the software-startup section of the general observing instructions. At night, secure a spectrum of one of the following stars on fibers #1, #3 and #4 (low-res, med-res, high-res). No other calibration images/spectra are necessary.

From the (!!) STANCAM (!!) sequencer window you can execute the following:
    fies.fies-FS
or
    fies.fies-FS -tutorial
This script sets up and slews the telescope, will lead you through the process of target acquisition, and will do the actual FIES exposure. The script will allow you to put the same star subsequently on different fibers. When an exposure is finished the script will initiate reduction of the obtained spectrum (as postprocess@virt-elena), and a few minutes later the results will be available in an ASCII database. The results contain the average system efficiency [in %] in the BVR bands.
In case you want to manually start the reduction, open a terminal and type
    ssh postprocess@virt-elena "cd fies/fluxstandard; ./fluxstandard.py FIqb230123.fits"
with the filename of your choice.


Detailed instructions on how to observe the standard stars without the use of the script are listed below.

name TCS catalog entryspectral typeexp time
G191-B2B SP0501+527 05:05:30.6 52:49:56 Mean 2000 +0.030 -0.090 11.9DA0 (blue) 300  
HD 93521 SP1045+378 10:48:23.5 37:34:13 Mean 2000 +0.000 +0.010 7.0O9Vp (blue) 60  
BD+33 2642 SP1550+330 15:51:59.9 32:56:53 Mean 2000 10.7B2IVp (blue)300  
BD+28 4211 SP2148+286 21:51:11.1 28:51:53 Mean 2000 10.7sdOp (blue) 300  
Feige 110 SP2317-054 23:19:58.4 -05:09:57 Mean 2000 11.9DOp (blue) 300  

NB the above exposure times are for FIES, for target acquisition with StanCam use someting on the order of 0.1 to 5 seconds. Click on the objects, or see the ING standard-star page for finding charts and more info on these stars.
The visibility plot of today!


Observing steps (the general observing instructions explain how to do these steps in detail).
First fiber #1:

  • start the software in the afternoon as indicated in the general observing instructions

  • To load the flux-standard catalog into the TCS type:
        read /catalogue/JHTFS.cat

  • sequencer: type mask 1 to open Hole #1, arm 17 to move the calibration arm away from Hole #1. Switch all FIES lamps off (lampsoff).

  • StanCam Sequencer: put the star close to Hole #1 , and check the telescope focus for CAM-probe-SPLIT (default focus 27500, with foc-del 0)

  • StanCam Sequencer: accurately center the star on Hole #1. See 'acquisition hints' in the general observing instructions

  • sequencer: type fies.expose nnn to expose (see table for expo time)
Now fiber #3:
  • Sequencer: type mask 3 to open Hole #3
  • StanCam Sequencer: accurately center the star on Hole #3. To do this, leave the cam-probe at c-p-split, and do fiberoffset fib=3. Then fib3window and continue like normal with the acquisition onto the fiber.
  • sequencer: type fies.expose nnn to expose (see table for expo time)
Now fiber #4:
  • sequencer: type mask 4 to open Hole #4
  • StanCam Sequencer: accurately center the star on Hole #4. To do this, leave the cam-probe at c-p-split, and do fiberoffset fib=4. Then fib4window and continue like normal with the acquisition onto the fiber.
  • sequencer: type fies.expose nnn to expose (see table for expo time)


Quality Control: How to observe radial-velocity standard stars for FIES

For RV zero-point monitoring the sky should be clear, and the seeing better than 1.3 arcsec.

In the afternoon, please follow the software-startup section of the general observing instructions.
Execute fies-calibs -fib N for all fibers you want to get RV data for. For monitoring these are fibers 3 and 4 (med-res, high-res).

At night, use script fies.fies-RV, to secure a spectrum of one of the following stars.
!! The highest-priority target is HD182488 !!

name TCS catalog entryspectral typeradial velocityexp time
HD182488 19:23:34.0 33:13:19 Mean 2000.0 0.0 0.0 6.4 G8V -21.55 120

HD3765 00:40:49.3 40:11:14 Mean 2000.0 0.0 0.0 7.4 K2V -63.30 300
HD38230 05:46:01.9 37:17:05 Mean 2000.0 0.0 0.0 7.4 K0V -29.25 300
HD79210 09:14:22.8 52:41:12 Mean 2000.0 0.0 0.0 7.6 M0V 10.65 300
HD115404 13:16:51.1 17:01:02 Mean 2000.0 0.0 0.0 6.6 K2V 7.60 120
HD151541 16:42:38.6 68:06:08 Mean 2000.0 0.0 0.0 7.6 K1V 9.40 300
HD197076 20:40:45.1 19:56:08 Mean 2000.0 0.0 0.0 6.5 G5V -35.40 120

NB the above exposure times are for FIES; for target acquisitioning with StanCam use someting on the order of 0.5 seconds.
RV standards visibility plot of today.

Please use fies.fies-RV to do the whole observation. The script will let you cycle through all desired fibers, i.e. fibers 3 and 4 for monitoring.


FIES calibration procedures and instrument/detector quality control

These calibrations have to be initiated and executed by staff or observers.
  • Calibrations for data reduction
    For the data-reduction tool FIEStool, a full set of calibrations should be taken at the start of each run. Use the script fies-calibs.
    The visiting astronomers should be advised to obtain a full set of calibrations every afternoon.

  • System-throughput monitoring
    At least once every other month standard-star observations should be obtained on technical and/or Nordic-service nights.

  • Radial-velocity stability monitoring
    See the description above.

  • Light-pollution testing
    It has repeatedly happened that LEDs and/or the CCD-controller display inside the white box were not taped off; this gives rise to low-level (about 10 ADU in 300 sec) diffuse scattered light on the red side of the CCD, when exposed with the shutter open.

    To test for light pollution make a 300 sec exposure with the dome- and calibration-lights switched off. Do this every time after electronics components have been changed (controllers, pressure sensor, etc.), or in general when the CCD controller has been touched.


The calibrations described below are done automatically and do not require any assistance from staff, unless an error or anomaly is reported through email warnings.

  • Monitoring of gain, RON and bias levels, for all amplifier modes. This has been discontinued since the installation of CCD15.
    This is being done automatically every Sunday afternoon 13:30, through a cronjob by obs@verushka:
    > crontab -l
      30 13 * * Sun /usr/local/bin/Xvfb-run /home/softremote/obs/fiesmonitoring/fiesGR.main >> /home/softremote/obs/fiesmonitoring/crontab.log 2>&1

    The job starts the complete FIES data acquisition set of programs, but only if no other FIES observing system is running. Then it takes the required data, which is saved in /data/fies/FIESgainron/ , and fires off in parallel the Pyraf reduction script fiesgainron.py as qc-user@elena.

    The results are kept in an ASCII database elena:~qc-user/fies/gainron/fiesgainron.database , and are graphically visualised on the Detector Quality Control pages.

  • FIES stability monitoring. This has been discontinued.
    This to be able to monitor echellogram shifts as a function of atmospheric parameters, or before/after changes of the instrumentation or staff activities.
    Images using the top calib unit (halogen, ThAr) are taken automatically, once every other hour, through a cronjob by obs@verushka:
    > crontab -l
      20 1,3,5,7,9,11,13,15,17,19,21,23 * * * /usr/local/bin/Xvfb-run /home/softremote/inst-scripts/FIES/monitoring/fiesmon.main >> /home/softremote/inst-scripts/FIES/monitoring/crontab.log 2>&1
    The job starts the complete FIES data acquisition set of programs, but only if no other FIES observing system is running.
    Then it takes the required data, which is saved in /data/fies/FIESstability/ .

    ToDO: automated analysis and reporting is pending.

  • CCD temperature monitoring.
    This is now part of the general TMS. See graphs .
    The sensors are sampled with 1-minute interval.

  • ThAr-lamp monitoring; the dying ThAr lamp phenomenon
    From experience we know that on a time-scale of days a well-functioning ThAr lamp can go into a state in which the excitation balance is gradually changing, and subsequently the strength of lines will change accordingly.
    For Hereus lamps: over the course of several days-weeks, the lamp will gradually die.
    For PHOTRON lamps: these dont seem to terminate, but the differing excitation balance makes a change of the lamp necessary.
    Lamp life time for the top-calib unit is typically between 0.5 and 1 year.

    The phenomeneon may picked up by the QC routine triggered by fies-calibs. The QC routine logs the number of ThAr lines found by FIEStool in the ThAr frames that are exposure-level scaled to have 80000ADU in a particular blue line (4765 Angstrom, see above).
    If an anomalous number of lines is found (50-90% of nominal), then a warning is sent to the talker, and an email to 'duty'. If less than 50% of the lines are found, then ERROR-level warnings are sent.

    If the warnings persist, or an ERROR is given, then it is likely that the lamp needs to be changed. Some more info, in particular on how to diagnose the phenomenon, is given in the trouble shooting page.

    Apart from this, the fies-calibs/easythar test-ThAr-image image counts in the 4765 line, are saved in a log by postproces@virt-elena. The line strength depends on the state of the lamp, but also of the alignment of calibration arm wrt the main fibers, under the telescope. This alignment, and of other fiber couplings, can change gradually over time.

    A new ThAr-lamp QC routine has been setup, that is based on FIEStool-reduced ThAr spectra of fiber 4 (high-res). As this routine relies on FIEStool, it also provides QC of the FIEStool itself. For each ThAr spectrum, gaussian profiles are fitted to 20 Argon I, 20 Argon II, 20 Thorium I and 20 Thorium II lines. This analysis is done by obs@postproc:/home/postprocess/fies/lampQC/analyse-lines.py, and is triggered daily by a CRON job by admin@scheduler. The aim is to be able to see (gradual) changes of the excitation balance, that is expected for aging lamps.

    This plot

    shows the evolution of the strength of the arc line, the wavelength offset of the arc line with respect to the wavelength solution of the individual spectra, and the FWHM of the arc-line which is a good measure of spectrograph focus.

    As the ThAr exposures triggered by fies-calibs are exposure-time scaled to give a constant arc-line strength of the 4765 Ar II line, the green points labelled 'fies-calibs' in the top-right panel for other arc-line species can be used to witness any changes of the excitation balance of the lamp.



Back to top Last modified: 11-May-2022