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ALFOSC spectroscopic flux-standard star monitoring

Setup:
- ALFOSC
- 10 arcsec slit (dont forget to update slitpos.def!   Xpos = 1050)
  (note that the automated pipe-line processing requires that you use this slit!)

Instructions:
- pick a low-airmass star from the catalogue SPnnnnSnnn (see table below)

- tcs.guide-object-with-parallactic   "SPnnnnSnnn"
- alfosc.acquisition   Slit_10.0   0.2

- resetxy
- xsize 400
- xbeg 851
- put in the Slit_10.0
- put in Grism nr. 3, 4, 5, 6, 7, or 8, 14, 16, 17, 18, 19, 20
- expose (see table below for approximate exposure times)
- check, using 'QuickSpec', that the peak counts are around 25000 - 60000 ADU or so

- no calibration frames are needed

name TCS catalog entryspectral typeexp time
HD 19445 SP0305+261 03:05:28.6 26:09:06 Mean 1950 -0.010 -0.830 8.0sdF (red) 5
He 3 SP0644+375 06:44:14.8 37:35:03 Mean 1950 -0.010 -0.910 12.1DA (blue) 150
HD 84937 SP0946+139 09:46:12.0 13:59:17 Mean 1950 +0.027 -0.790 8.3sdF (red) 6
Feige 34 SP1036+433 10:36:41.0 43:21:49 Mean 1950 +0.000 +0.000 11.3sdO (blue) 90
HD 93521 SP1045+378 10:48:23.5 37:34:13 Mean 2000 +0.000 +0.010 7.0O9Vp (blue) 2
BD+26 2606SP1446+259 14:46:50.2 25:54:53 Mean 1950 +0.000 -0.350 9.7sdF (red) 25
BD+33 2642SP1550+330 15:51:59.9 32:56:53 Mean 2000 10.7B2IVp (blue)60
Wolf 1346SP2032+248 20:32:14.0 24:53:57 Mean 1950 -0.030 -0.550 11.6DA (blue) 100
BD+17 4708SP2209+178 22:09:05.8 17:50:42 Mean 1950 +0.036 +0.050 9.4sdF (red) 15
Feige 110 SP2317-054 23:19:58.4 -05:09:57 Mean 2000 11.9DOp (blue) 150

Click on the objects, or check the ING pages for more information on these flux-standard stars, such as finding charts.


The visibility plot of today:

 

Data analysis

Please analyse the data using the automated interactive procedure on elena:
  • on tessa make sure the image is in /data/alfosc
  • ssh -X qc-user@elena alfosc/fluxstandard/doitall.script ALqb123456       or
  • ssh -X qc-user@elena alfosc/fluxstandard/doitall.script -noWWW ALqb123456

    Don't add the .fits suffix to the imagename. With the -noWWW option you postpone updating the WWW: if you are analysing several frames make sure to enable the WWW-updating for the last frame.

The script doitall.script calls an IRAF host script called doitall.ihs, which opens an Xgterm and interactively guides you through the reduction: read the instructions that it displays. For successful completion of the script only 6 keystrokes in 'splot' are necessary.

 

Results

Once you have analysed the data, hit 'reload' and have a look below.

Database ASCII table
PS file

Above: Grism photometry: the mean system efficiency in a wavelength interval of 500 Angstroms.
This interval is 490-540nm for grisms 3 (red), 4 (green), 6 (pink), 7 (cyan),
and is 600-650nm for grisms 5 (blue) and 8 (yellow) .

Below: All previous data in red, with the last spectrum in green.


Back to top Last modified: 09-May-2016