%I IOP PUBLISHING LTD
%K galaxy: formation, galaxy: halo, galaxy: structure, local group, DIGITAL SKY SURVEY, EXPLORING HALO SUBSTRUCTURE, TRACING GALAXY FORMATION, HERCULES-AQUILA CLOUD, WAY GLOBULAR-CLUSTERS, MILKY-WAY, PISCES OVERDENSITY, DWARF GALAXY, TRIANGULUM-ANDROMEDA, SATELLITE GALAXIES
%J The Astrophysical Journal
%L discovery10055816
%X We report the discovery of an excess of main sequence turn-off stars in the direction of the constellations
of Eridanus and Phoenix from the first year data of the Dark Energy Survey (DES). The
Eridanus-Phoenix (EriPhe) overdensity is centered around l ∼ 285◦ and b ∼ −60◦ and spans at least
30â—¦
in longitude and 10â—¦
in latitude. The Poisson significance of the detection is at least 9σ. The
stellar population in the overdense region is similar in brightness and color to that of the nearby globular
cluster NGC 1261, indicating that the heliocentric distance of EriPhe is about d ∼ 16 kpc. The
extent of EriPhe in projection is therefore at least ∼ 4 kpc by ∼ 3 kpc. On the sky, this overdensity
is located between NGC 1261 and a new stellar stream discovered by DES at a similar heliocentric
distance, the so-called Phoenix Stream. Given their similar distance and proximity to each other, it is
possible that these three structures may be kinematically associated. Alternatively, the EriPhe overdensity
is morphologically similar to the Virgo overdensity and the Hercules-Aquila cloud, which also
lie at a similar Galactocentric distance. These three overdensities lie along a polar plane separated by
∼ 120◦ and may share a common origin. Spectroscopic follow-up observations of the stars in EriPhe
are required to fully understand the nature of this overdensity
%O This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions.
%T Discovery of a stellar overdensity in eridanus–phoenix in the dark energy survey
%A TS Li
%A E Balbinot
%A N Mondrik
%A JL Marshall
%A B Yanny
%A K Bechtol
%A A Drlica-Wagner
%A D Oscar
%A B Santiago
%A JD Simon
%A AK Vivas
%A AR Walker
%A MY Wang
%A TMC Abbott
%A FB Abdalla
%A A Benorr-Levy
%A GM Bernstein
%A E Bertin
%A D Brooks
%A DL Burke
%A A Carnero Rosell
%A MC Kind
%A J Carretero
%A LN da Costa
%A DL DePoy
%A S Desai
%A HT Diehl
%A P Doel
%A J Estrada
%A DA Finley
%A B Flaugher
%A J Frieman
%A D Gruen
%A RA Gruendl
%A G Gutierrez
%A K Honscheid
%A DJ James
%A K Kuehn
%A N Kuropatkin
%A O Lahav
%A MAG Maia
%A M March
%A P Martini
%A R Ogando
%A AA Plazas
%A K Reil
%A AK Romer
%A A Roodman
%A E Sanchez
%A V Scarpine
%A M Schubnell
%A I Sevilla-Noarbe
%A RC Smith
%A M Soares-Santos
%A F Sobreira
%A E Suchyta
%A MEC Swanson
%A G Tarle
%A D Tucker
%A Y Zhang
%V 817
%N 2
%D 2016