NOAO >   Observing Info >   Approved Programs >   2018A-0144

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Program Information for 2018A-0144


PI: Marla Geha, Yale U., marla.geha@yale.edu
Address: Astronomy Department, New Haven, CT 06520 US

CoI: Risa Wechsler, Stanford U.
CoI: Yao-Yuan Mao, U. of Pittsburgh
CoI: Erik Tollerud, STScI
CoI: Benjamin Weiner, U. of Arizona

Title: The SAGA Project: An Optimized Search for Dwarf Galaxy Satellites Around Milky Way Analogs

Abstract: The SAGA project aims to measure the distribution of satellite galaxies around 100 systems analogous to the Milky Way down to the luminosity of the Leo,I dwarf galaxy ($M_r< -12$). We have published complete satellite galaxy luminosity functions for our first eight Milky Way-like systems. Surprisingly, the majority (26/27) of our satellites are star-forming, as compared to 2 of 5 star-forming Milky Way satellites in the same luminosity range. With 27 satellites across 8~hosts, we do not yet have statistics to determine whether our luminosity functions agree with galaxy formation models. However, our past work now provides a sufficient low redshift training sample to design a more efficient satellite selection method. Our method reduces the number of candidate satellites from 1000-1500 down to 150-200 per host, while maintaining high completeness for both star-forming and quenched satellites. To implement this selection, we request five AAT- 2dF nights to observe 30~Milky Way analogs, quadrupling the number of such systems with complete satellite luminosity functions down to $M_r<- 12$ ($r_o<20.75$) and bringing us closer to understanding the Milky Way satellite population in a cosmological context.

Program Type: Standard/Extragalactic

Scheduled Nights:
Run 1 (2018A):  AAT/AAOmega -- 5n on Jun 10 - Jun 15 2018


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2018A-0144

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