A HERO'S DARK HORSE: DISCOVERY OF AN ULTRA-FAINT MILKY WAY SATELLITE IN PEGASUS

ABSTRACT We report the discovery of an ultra-faint Milky Way satellite galaxy in the constellation of Pegasus. The concentration of stars was detected by applying our overdensity detection algorithm to the SDSS-DR 10 and confirmed with deeper photometry from the Dark Energy Camera at the 4 m Blanco...

Full description

Saved in:
Bibliographic Details
Published in:Astrophysical journal. Letters 2015-05, Vol.804 (2), p.1-5
Main Authors: Kim, Dongwon, Jerjen, Helmut, Mackey, Dougal, Costa, Gary S. Da, Milone, Antonino P.
Format: Article
Language:English
Subjects:
Algorithms
Cameras
Dwarf galaxies
galaxies: dwarf
galaxies: individual (Pegasus III)
galaxies: stellar content
Galaxy: halo
Local Group
Luminosity
Milky Way Galaxy
Photometry
Satellites
Texts
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:ABSTRACT We report the discovery of an ultra-faint Milky Way satellite galaxy in the constellation of Pegasus. The concentration of stars was detected by applying our overdensity detection algorithm to the SDSS-DR 10 and confirmed with deeper photometry from the Dark Energy Camera at the 4 m Blanco telescope. Fitting model isochrones indicates that this object, Pegasus III, features an old and metal-poor stellar population ([Fe/H] ∼ -2.1) at a heliocentric distance of 205 20 kpc. The new stellar system has an estimated half-light radius of pc and a total luminosity of that places it into the domain of dwarf galaxies on the size-luminosity plane. Pegasus III is spatially close to the MW satellite Pisces II. It is possible that the two might be physically associated, similar to the Leo IV and Leo V pair. Pegasus III is also well aligned with the Vast Polar Structure, which suggests a possible physical association.
ISSN:2041-8205
2041-8213
2041-8213
DOI:10.1088/2041-8205/804/2/L44