* Astronomy

Members Login
Username 
 
Password 
    Remember Me  
Post Info TOPIC: Andromeda XXIX


L

Posts: 131433
Date:
RE: Andromeda XXIX
Permalink  
 


Newly found dwarf galaxies could help reveal the nature of dark matter

In work that could help advance astronomers' understanding of dark matter, University of Michigan researchers have discovered two additional dwarf galaxies that appear to be satellites of Andromeda, the closest spiral galaxy to Earth.
Eric Bell and Colin Slater found Andromeda XXVIII and XXIX. They did it by using a tested star-counting technique on the newest data from the Sloan Digital Sky Survey, which has mapped more than a third of the night sky. They also used follow-up data from the Gemini North Telescope in Hawaii.

Read more



__________________


L

Posts: 131433
Date:
Permalink  
 

Title: Andromeda XXIX: A New Dwarf Spheroidal Galaxy 200kpc from Andromeda
Authors: Eric F. Bell, Colin T. Slater (University of Michigan), Nicolas F. Martin (MPIA Heidelberg)

We report the discovery of a new dwarf galaxy, Andromeda XXIX, using data from the recently-released Sloan Digital Sky Survey DR8, and confirmed by Gemini North telescope Multi-Object Spectrograph imaging data. And XXIX appears to be a dwarf spheroidal galaxy, separated on the sky by a little more than 15 degrees from M31, with a distance inferred from the tip of the red giant branch of 730kpc75kpc, corresponding to a three dimensional separation from M31 of between 205kpc and 227kpc (close to M31's virial radius). Its absolute magnitude, as determined by comparison to the red giant branch luminosity function of the Draco dwarf spheroidal, is M_V = -8.30.4. And XXIX's stellar populations appear very similar to Draco's; consequently, we estimate a metallicity for And XXIX of [Fe/H] ~-1.8. The half-light radius of And XXIX is 360pc60pc and its ellipticity is 0.350.06, typical of dwarf satellites of the Milky Way and M31 at this absolute magnitude range.

Read more (195kb, PDF)



__________________
Page 1 of 1  sorted by
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard