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Getting flux from spectra

PostPosted: Sat Aug 30, 2014 2:20 am
by srgold
Hello all,

I am also a neophyte in the radio astronomy world and I'm trying to figure out which task to use (mbspect, imspec, or imspect) to create some spectra. I'd like to create spectra centered around a star, at multiple frequencies and create output ascii files. I would also like to get spectra with the beam corrected flux on the y axis.

I've played with all three options and the best seems to be imspec, but the region seems to need to be in odd numbers of pixels. Using

plot=flux
options=list, noheader

I can get a spectrum with beam-correct flux in ascii form but not with the ideal region and not completely centered on the target. Is there a way to overcome this?


Thanks for the help,
Steve

Re: Getting flux from spectra

PostPosted: Mon Sep 01, 2014 10:22 am
by Mark.Wieringa
Hi Steve,

I'm not an expert in spectral line analysis, but another option to look at for point sources is uvspec - you can specify the exact offset of the source. If there are other sources in the field you may need to subtract those off first (with uvmodel).
You can also shift the image during imaging to make the source of interest fall exactly on a pixel, using the offset parameter in invert.

Cheers,

Mark

Re: Getting flux from spectra

PostPosted: Wed Sep 24, 2014 3:05 am
by srgold
Thanks for the advice mark, i'll give it a shot!

Kind regards,
Steve