UVES spectra and Isis

[Jacques Montier]

Hello,

Is it possible to read UVES spectra directly from UVES web site with Isis ?
http://www.eso.org/sci/observing/tools/ ... rface.html
I downloaded tfits.gz files, and after uncompressing to tfits, i couldn't read them with Isis.
I tried to rename them to fits (or fit), but no success...

Thanks for your help

Regards,

[Martin Dubs]

Hello Jaques,

the short answer is no, but you can plot the spectrum and then save it as text file (plot as ASCII). This file then contains intensity and std vs. wavelength. You can delete the last column and the column header with a text editor or EXCEL and then save the spectrum as a *.dat file. Maybe not quite what you want, but at least it works. One problem with the fits file is that the wavelength interval changes for different orders, so other programs have problems with multiple orders.

Regards, Martin

[Robin Leadbeater]

VSpec will read the uves ASCII files direct if you change the file extension to uvs and you can then export this as a fits or dat file which ISIS etc will read but I too would like to find some windows tools to read some of the fits files that pros produce, particularly the IRAF multispec format commonly used for echelle spectra for example, even if they could just unpack and separately output the orders

Cheers
Robin

[Martin Dubs]

Hi Robin,

do you know fv: http://heasarc.gsfc.nasa.gov/ftools/fv
It is not very user friendly, but it can read any fits file, also multi table formats and you can plot the results easily. From astrometric calibrated images you can read coordinates with the mouse. Good, if you just want to see if the file is useful. Unfortunately the exported spectra e.g. from Elodie do not contain the wavelength, but have to be calculated from the fits header
But for UVES spectra *.tfits, you can export intensity vs. wavelength as *.dat file

regards, Martin

[Robin Leadbeater]

Hi Martin,

Yes I have in the past struggled through down the fv route, extracting individual orders from the multispec files and then applying the dispersion equation only to find that VSpec did not like the resultant unequal bin sizes, though I believe ISIS can at least cope with this. A lot of work though if you have many spectra. Mostly I have relied on various friendly professionals who have run them through an IRAF script and unpacked them for me. I have just upgraded my laptop and am considering rebuilding the old one as a linux machine and learning IRAF but to be honest I am not looking forward to it. I prefer doing astronomy to computing

I dont find extracting ELODIE spectra from the archive too bad as at least you can use the on line plotting tool to produce a linearly sampled 1D fits file of any region of interest

Cheers
Robin