A fast usage of tablist, fitscopy and fitshead

By Yücel Kılıç · · , , · Leave a comment

In this post, i wanted to take some notes about a few useful CFITSIO tools’ commands for myself.

First of all you need to install cfitsio library into your OS.

  • For OS X;

$ brew install cfitsio
  • For Debian Based GNU/Linux distributions;

$ sudo apt-get update
$ sudo apt-get install libcfitsio-dev
  • For RPM-based GNU/Linux distributions;

$ sudo dnf install cfitsio-devel

I often have to deal with public astronomical catalogues and I have to fetch a certain part of the sky. In particular, I would prefer the FITS tables not images :). For this reason, I need a quick manipulation tool: CFITSIO – A FITS File Subroutine Library. Especially; tablist, fitscopy, listhead…

listhead:
It is very simple. List FITS file’s header&keywords…

  • For whole header information: 
    $ listhead 'file_name.fits[0]'
  • For a specific keyword: 
    $ listhead 'file_name.fits[0]'| grep -i "keyword"
  • Example:
$ listhead 'astronomia_0012_R.fits[0]'| grep -i "OBJCTRA"
OBJCTRA = '10:36:41.8' /        Nominal Right Ascension of center of image
  • Bring the catalogue’s column names:
$ listhead 'tyc2_sample.fits[0]'
Header listing for HDU #1:
SIMPLE  =                    T / Standard FITS Format
BITPIX  =                    8 / Character data
NAXIS   =                    0 / No Image --- just extension(s)
EXTEND  =                    T / There are standard extensions
ORIGIN  = 'xml2fits_v1.95'     / Converted from XML-Astrores to FITS
...
         **********************************************************
             EXCERPT from catalogues stored in VizieR (CDS)
                        with the following conditions:
         **********************************************************

         VizieR Astronomical Server vizier.u-strasbg.fr
         Date: 2017-02-04T08:24:44 [V1.99+ (14-Oct-2013)]
         In case of problem, please report to: cds-question@unistra.fr
...
         -out=TYC1
         -out=TYC2
         -out=TYC3
         -out=pmRA
         -out=pmDE
         -out=BTmag
         -out=VTmag
         -out=HIP
         -out=RA(ICRS)
         -out=DE(ICRS)
         #
INFO    = '-c=150.418448+17.409087,rd=2.'
END

tablist:

Please note that, in the last example “-out=” indicates column names. We can just extract the column(s) we’re interested in with;

  • Usage:

    tablist 'intab.fit[1][RA;DEC; X; Y][PHA > 24]'  - print rows with PHA < 24
  • Example:
$ tablist "tyc2_sample.fits[1][col TYC1;RA_ICRS_;DE_ICRS_;pmRA;pmDE;][pmRA<=1 && pmDE<=1]"

    TYC1    pmRA    pmDE     RA_ICRS_     DE_ICRS_
   1 1411   -42.4   -18.6 148.84569528  17.33590806
   2 1411   -20.2    -8.0 149.18173167  17.25955361
   3 1411    -9.6    -3.3 148.34490528  17.40581389
   4 1411    -4.7   -53.4 148.87273306  17.48238361
   5 1411   -12.7   -12.9 148.99339639  16.43346194
   6 1411   -17.2   -14.4 148.85315028  17.16688167
   7 1411                 148.82302972  16.59136000
   8 1411   -17.6    -8.3 148.49574417  17.10538167
   9 1411    -1.9    -7.3 148.60960694  16.49546000
  10 1411   -96.7   -38.5 148.82500167  16.42460056
  11 1411     0.7   -35.9 148.94166750  16.46986167

fitscopy:

Sometimes I have to deal with very large catalog files. I’m reducing their size (by extracting only selected columns) for the rapid reduction process. This process is very similar to the tablist.

  • Usage:

    $ fitscopy 'in.fit[2][bin X,Y]' out.fit
  • Example:
$ fitscopy tyc2_sample.fits"[1][col TYC1;RA_ICRS_;DE_ICRS_;pmRA;pmDE;][pmRA<=1 && pmDE<=1]" out_cat.fits

I wrote a script file that can do this very easily. You may wish to take a look at them from here.

Reference:

  1. https://heasarc.gsfc.nasa.gov/docs/software/fitsio/cexamples.html