#  ITC Seminar: Ivanna Escala (Caltech) 

 



####  calendar\_today Date and Time 

 **October 8, 2019** 

 12:00PM - 01:00PM EDT 

####  pin\_drop Location 

 **Phillips**  



 

 



 

First Alpha and Iron Element Abundances in the Outer Disk, Giant Stellar Stream, and Inner Halo of Andromeda  
 Measurements of chemical abundances (\[Fe/H\] and \[alpha/Fe\]) in individual stars can probe the formation history of a galaxy. In contrast to the Milky Way, relatively little is known about \[alpha/Fe\] of individual red giant branch stars in Andromeda (M31). To make progress with existing telescopes, we have measured abundances from deep, low- and medium-resolution DEIMOS spectroscopy of individual M31 RGB stars using spectral synthesis. I will present measurements of \[alpha/Fe\] and \[Fe/H\] for 91 M31 RGB stars across 5 fields spanning the inner halo, Giant Stellar Stream, and outer disk. Prior to this work, only 4 M31 halo stars had such measurements. I will discuss what the abundance distributions reveal about the progenitor(s) of M31’s halo, including the Giant Stellar Stream progenitor, and the formation of M31’s disk.

 

 



 

 See also:- [ 2019 - 20 ](/academic-year/2019-20)
- [ Seminars ](/event-type/seminars)
 
 

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