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Measure radial velocity of nearby galaxies

Posted: Tue Aug 13, 2013 9:55 pm
by Christian Buil
During the OHP 2013 course, a quick expriment about the measure of nearby galaxies radial velocity (M31, M33, NGC 7331à) with Alpy and a 200-mm telescope
(a possible student project). See details here:

http://www.astrosurf.com/buil/redshift/demo.htm

Example, the central part of Messier 31 galaxy (Alpy guiding Atik314L camera):

Image

and the corresponding 2D spectrum:

Image

Another example for M33. The target is here a extragalactic nebula (NGC604):

Image

The nebula spectrum for evaluate radial veolocity;

Image

Christian

Re: Measure radial velocity of nearby galaxies

Posted: Wed Aug 14, 2013 11:13 am
by Robin Leadbeater
Hello Christian,

I found this reference for NGC 604
http://cdsads.u-strasbg.fr/cgi-bin/nph- ... .130...29R
which gives the mean RV of NGC 604 as -240km/s, compared with the published figure of -182km/s for M33. This makes your measurement slightly closer and still within the +-50km/s uncertainty.

Cheers
Robin

Re: Measure radial velocity of nearby galaxies

Posted: Wed Aug 14, 2013 4:00 pm
by Christian Buil
Hello Robin

Thanks for this important info about NGC 604 RV (different from M33 mean velocity). I have added a line of these reference in my page.

Christian