rspectext on FUSE data

Guest wrote on Jul 01, 2008

Hello,

I converted FUSE data to a table of type .dat. It consists of 4 columns: wavelength, flux, error and quality.

1. My problem is to convert it to IRAF spectra. First I typed

on> rspectext star1.dat spec1
lo> splot spec1.fits

I get a linear graph with slope = -1, trailed by a horizontal line. rspectext is supposed to take only two columns wavelaength and flux. Could this be the reason?

2. I also want to conserve the wavelength, so what shall I put for the parameter 'dtype'? Do I have to change the default values of 'crval1' and 'cdelt1'?

Please help me. Thanks.

Siti :cry:

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Francisco Valdes wrote on Jul 01, 2008

The third and fourth columns should not be a problem. To help I would need to see the parameters you used for rspectext (lpar rspectext) and at least part of the data file, particularly the beginning and end.

Yours,
Frank Valdes

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Guest wrote on Jul 01, 2008

Dear Frank,

Thanks very much for responding to my question.

1. I will send a sample .dat file to your e-mail. It was produced when I attended a course on UV astronomy and applied the CALFUSE pipeline and IDL to reduce FUSE data. Now back at my institution, I only have access to IRAF to continue with my analysis.

2. Here are the parameters for rspectext that I used:

input = star1.dat
output = spec1
(title = "")
(flux = no)
(dtype = "non-linear") If I set to "none", "linear" or "log" I get nothing with splot, but if I set to "interp", I get almost linear plot, but no spectra.
(crval = 1.)
(cdelt1 = 1)
(fd1 = "")
(fd2 = "")
(mode = "q1")

I have experimented wspectext on .ms.fits spectra, then do a rspectext to see if rspectext works. It does.

I intend to use FUSE data as part of my thesis. Does IRAF have special packages for FUSE data? Thanks in advance.

Siti :D

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Guest wrote on Jul 01, 2008

Hi Frank.,

1. I solved the problem of converting the .dat files to .fit files by removing the number 1 in the first line of the first column of those .dat files. When I apply rspectext, I set the parameter dtype = interp. I get the .fits files and was able to do the usual stuff like SPLOT etc.

2. However, I still have no idea what to do with raw FUSE data. I am not an expert IRAF user. Perhaps someone can help me? Thanks.

Cheers,

Siti :)

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Francisco Valdes wrote on Jul 01, 2008

This is a log of an email exchange to complete this topic.

From: sitij109
To: valdes
Posted: Thu Jul 10, 2008 9:39 am
Subject: FUSE data

Hi Frank,

I already solved the problem of displaying the .dat file. We just have to remove the number 1 in the first column and everything works.

I also saw from the archive e-mail that you had a discussion with Phil Massey about combining FUSE spectra. Do you have experience with raw FUSE spectra? If so, can you assist me? I downloaded some spectra to check it out. I know how to reduce spectrum from ground telescopes using APALL, DISPCOR etc but no idea of what to do with FUSE data. Thanks for you assistance.

From: Frank Valdes
Date: July 15, 2008 9:21:42 AM MST
To: sitij109
Subject: Re: FUSE data

Hello Siti,

I'm glad you solved your problem. I was away on holiday. I really don't have any special knowledge about FUSE data. I suggest you contact someone with the FUSE project and ask about reducing the data with IRAF. If you don't have a direct contact with the FUSE project probably you can find them by an internet search.

This email comes from my work address in response to your question about sending me small attachments.

Yours,
Frank

From: siti109
Date: July 15, 2008 10:04:24 AM MST
To: Frank Valdes
Subject: Re: FUSE data

Hi frank,

I will try to contact someone with the FUSE project.

Cheers,

Siti

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Last post on Jul 01, 2008