skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Digging deeper into the Southern skies: A compact Milky Way companion discovered in first-year Dark Energy Survey data

Abstract

Here, we use the first-year Dark Energy Survey (DES) data down to previously unprobed photometric depths to search for stellar systems in the Galactic halo, therefore complementing the previous analysis of the same data carried out by our group earlier this year. Our search is based on a matched filter algorithm that produces stellar density maps consistent with stellar population models of various ages, metallicities, and distances over the survey area. The most conspicuous density peaks in these maps have been identified automatically and ranked according to their significance and recurrence for different input models. We report the discovery of one additional stellar system besides those previously found by several authors using the same first-year DES data. The object is compact, and consistent with being dominated by an old and metal-poor population. DES 1 is found at high significance and appears in the DES images as a compact concentration of faint blue point sources. Assuming different spatial profile parameterizations, the best-fitting heliocentric distance and total absolute magnitude in the range of 77.6–87.1 kpc and -3.00 ≲ MV ≲ -2.21, respectively. The half-light radius of this object, rh ~ 10 pc and total luminosity are consistent with it being a low-massmore » halo cluster. It is also found to have a very elongated shape (ϵ ~ 0.57). In addition, our deeper probe of DES first-year data confirms the recently reported satellite galaxy candidate Horologium II as a significant stellar overdensity. We also infer its structural properties and compare them to those reported in the literature.« less

Authors:
 [1]
  1. Instituto de Fisica, Porto Alegre (Brazil); Lab. Interinstitucional de e-Astronomia - LIneA, Rio de Janeiro (Brazil). et al.
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP)
Contributing Org.:
DES Collaboration
OSTI Identifier:
1247534
Alternate Identifier(s):
OSTI ID: 1256636
Report Number(s):
arXiv:1508.02381; FERMILAB-PUB-15-455-AE; SLAC-PUB-16552
Journal ID: ISSN 0035-8711; 1388125
Grant/Contract Number:  
AC02-07CH11359; AC02-76SF00515
Resource Type:
Accepted Manuscript
Journal Name:
Monthly Notices of the Royal Astronomical Society
Additional Journal Information:
Journal Volume: 458; Journal Issue: 1; Journal ID: ISSN 0035-8711
Publisher:
Royal Astronomical Society
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; globular clusters: general; globular clusters: individual (DES 1); galaxies: dwarf; globular clusters; individual (DES 1)

Citation Formats

Luque, E. Digging deeper into the Southern skies: A compact Milky Way companion discovered in first-year Dark Energy Survey data. United States: N. p., 2016. Web. doi:10.1093/mnras/stw302.
Luque, E. Digging deeper into the Southern skies: A compact Milky Way companion discovered in first-year Dark Energy Survey data. United States. doi:10.1093/mnras/stw302.
Luque, E. Tue . "Digging deeper into the Southern skies: A compact Milky Way companion discovered in first-year Dark Energy Survey data". United States. doi:10.1093/mnras/stw302. https://www.osti.gov/servlets/purl/1247534.
@article{osti_1247534,
title = {Digging deeper into the Southern skies: A compact Milky Way companion discovered in first-year Dark Energy Survey data},
author = {Luque, E.},
abstractNote = {Here, we use the first-year Dark Energy Survey (DES) data down to previously unprobed photometric depths to search for stellar systems in the Galactic halo, therefore complementing the previous analysis of the same data carried out by our group earlier this year. Our search is based on a matched filter algorithm that produces stellar density maps consistent with stellar population models of various ages, metallicities, and distances over the survey area. The most conspicuous density peaks in these maps have been identified automatically and ranked according to their significance and recurrence for different input models. We report the discovery of one additional stellar system besides those previously found by several authors using the same first-year DES data. The object is compact, and consistent with being dominated by an old and metal-poor population. DES 1 is found at high significance and appears in the DES images as a compact concentration of faint blue point sources. Assuming different spatial profile parameterizations, the best-fitting heliocentric distance and total absolute magnitude in the range of 77.6–87.1 kpc and -3.00 ≲ MV ≲ -2.21, respectively. The half-light radius of this object, rh ~ 10 pc and total luminosity are consistent with it being a low-mass halo cluster. It is also found to have a very elongated shape (ϵ ~ 0.57). In addition, our deeper probe of DES first-year data confirms the recently reported satellite galaxy candidate Horologium II as a significant stellar overdensity. We also infer its structural properties and compare them to those reported in the literature.},
doi = {10.1093/mnras/stw302},
journal = {Monthly Notices of the Royal Astronomical Society},
number = 1,
volume = 458,
place = {United States},
year = {2016},
month = {2}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 12 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

The tidal tails of NGC 2298: The tidal tails of NGC 2298
journal, June 2011


A new Milky way halo star Cluster in the Southern Galactic sky
journal, April 2013


Eight new Milky way Companions Discovered in First-Year dark Energy Survey data
journal, June 2015


Big Fish, Little Fish: two new Ultra-Faint Satellites of the Milky way
journal, March 2010


SExtractor: Software for source extraction
journal, June 1996

  • Bertin, E.; Arnouts, S.
  • Astronomy and Astrophysics Supplement Series, Vol. 117, Issue 2
  • DOI: 10.1051/aas:1996164

parsec : stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
journal, October 2012


The Blanco Cosmology Survey: data Acquisition, Processing, Calibration, Quality Diagnostics, and data Release
journal, September 2012


Eight Ultra-Faint Galaxy Candidates Discovered in year two of the dark Energy Survey
journal, November 2015


SEGUE 3: AN OLD, EXTREMELY LOW LUMINOSITY STAR CLUSTER IN THE MILKY WAY's HALO
journal, August 2011


The dark Energy Camera
journal, October 2015


Too Many, too few, or just Right? the Predicted Number and Distribution of Milky way Dwarf Galaxies
journal, October 2014

  • Hargis, Jonathan R.; Willman, Beth; Peter, Annika H. G.
  • The Astrophysical Journal, Vol. 795, Issue 1
  • DOI: 10.1088/2041-8205/795/1/L13

The Sloan Digital Sky Survey View of the Palomar-Green Bright Quasar Survey
journal, September 2005

  • Jester, Sebastian; Schneider, Donald P.; Richards, Gordon T.
  • The Astronomical Journal, Vol. 130, Issue 3
  • DOI: 10.1086/432466

The Milky Way Tomography with SDSS. I. Stellar Number Density Distribution
journal, February 2008

  • Jurić, Mario; Ivezić, Željko; Brooks, Alyson
  • The Astrophysical Journal, Vol. 673, Issue 2
  • DOI: 10.1086/523619

A Hero'S Little Horse: Discovery of a Dissolving star Cluster in Pegasus
journal, January 2015


Horologium ii: a Second Ultra-Faint Milky way Satellite in the Horologium Constellation
journal, July 2015


Discovery of a Faint Outer halo Milky way star Cluster in the Southern sky
journal, April 2015


The structure of star clusters. I. an empirical density law
journal, October 1962


The Discovery of Two Extremely Low Luminosity Milky Way Globular Clusters
journal, November 2007

  • Koposov, S.; de Jong, J. T. A.; Belokurov, V.
  • The Astrophysical Journal, Vol. 669, Issue 1
  • DOI: 10.1086/521422

Beasts of the Southern Wild: Discovery of nine Ultra Faint Satellites in the Vicinity of the Magellanic Clouds
journal, May 2015

  • Koposov, Sergey E.; Belokurov, Vasily; Torrealba, Gabriel
  • The Astrophysical Journal, Vol. 805, Issue 2
  • DOI: 10.1088/0004-637X/805/2/130

On the variation of the initial mass function
journal, April 2001


A new Distant Milky way Globular Cluster in the Pan-Starrs1 3π Survey
journal, April 2014

  • Laevens, Benjamin P. M.; Martin, Nicolas F.; Sesar, Branimir
  • The Astrophysical Journal, Vol. 786, Issue 1
  • DOI: 10.1088/2041-8205/786/1/L3

A NEW FAINT MILKY WAY SATELLITE DISCOVERED IN THE PAN-STARRS1 3 π SURVEY
journal, March 2015

  • Laevens, Benjamin P. M.; Martin, Nicolas F.; Ibata, Rodrigo A.
  • The Astrophysical Journal, Vol. 802, Issue 2
  • DOI: 10.1088/2041-8205/802/2/L18

SAGITTARIUS II, DRACO II AND LAEVENS 3: THREE NEW MILKY WAY SATELLITES DISCOVERED IN THE PAN-STARRS 1 3 π SURVEY
journal, October 2015

  • Laevens, Benjamin P. M.; Martin, Nicolas F.; Bernard, Edouard J.
  • The Astrophysical Journal, Vol. 813, Issue 1
  • DOI: 10.1088/0004-637X/813/1/44

Assessing the Milky way Satellites Associated with the Sagittarius Dwarf Spheroidal Galaxy
journal, July 2010


The horizontal-branch stars in globular clusters. 2: The second parameter phenomenon
journal, March 1994

  • Lee, Young-Wook; Demarque, Pierre; Zinn, Robert
  • The Astrophysical Journal, Vol. 423
  • DOI: 10.1086/173803

The Observed Properties of Dwarf Galaxies in and Around the Local Group
journal, June 2012


The halo+cluster system of the Galactic globular cluster NGC 1851★
journal, June 2014

  • Marino, A. F.; Milone, A. P.; Yong, D.
  • Monthly Notices of the Royal Astronomical Society, Vol. 442, Issue 4
  • DOI: 10.1093/mnras/stu1099

Iron and s-elements abundance variations in NGC 5286: comparison with ‘anomalous' globular clusters and Milky Way satellites
journal, April 2015

  • Marino, A. F.; Milone, A. P.; Karakas, A. I.
  • Monthly Notices of the Royal Astronomical Society, Vol. 450, Issue 1
  • DOI: 10.1093/mnras/stv420

A Comprehensive Maximum Likelihood Analysis of the Structural Properties of Faint Milky Way Satellites
journal, September 2008

  • Martin, Nicolas F.; de Jong, Jelte T. A.; Rix, Hans‐Walter
  • The Astrophysical Journal, Vol. 684, Issue 2
  • DOI: 10.1086/590336

Hydra ii: a Faint and Compact Milky way Dwarf Galaxy Found in the Survey of the Magellanic Stellar History
journal, April 2015

  • Martin, Nicolas F.; Nidever, David L.; Besla, Gurtina
  • The Astrophysical Journal, Vol. 804, Issue 1
  • DOI: 10.1088/2041-8205/804/1/L5

Global and Nonglobal Parameters of Horizontal-Branch Morphology of Globular Clusters
journal, March 2014


The Discovery of an Ultra-Faint star Cluster in the Constellation of ursa Minor
journal, June 2012


The VPOS: a vast polar structure of satellite galaxies, globular clusters and streams around the Milky Way: The VPOS: a vast polar structure around the MW
journal, May 2012


The new Milky Way satellites: alignment with the VPOS and predictions for proper motions and velocity dispersions
journal, August 2015

  • Pawlowski, Marcel S.; McGaugh, Stacy S.; Jerjen, Helmut
  • Monthly Notices of the Royal Astronomical Society, Vol. 453, Issue 1
  • DOI: 10.1093/mnras/stv1588

A Matched-Filter Analysis of the Tidal Tails of the Globular Cluster Palomar 5
journal, July 2002

  • Rockosi, Constance M.; Odenkirchen, Michael; Grebel, Eva K.
  • The Astronomical Journal, Vol. 124, Issue 1
  • DOI: 10.1086/340957

Measuring Reddening with Sloan Digital sky Survey Stellar Spectra and Recalibrating sfd
journal, August 2011


Maps of Dust Infrared Emission for Use in Estimation of Reddening and Cosmic Microwave Background Radiation Foregrounds
journal, June 1998

  • Schlegel, David J.; Finkbeiner, Douglas P.; Davis, Marc
  • The Astrophysical Journal, Vol. 500, Issue 2
  • DOI: 10.1086/305772

The Kinematics of the Ultra‐faint Milky Way Satellites: Solving the Missing Satellite Problem
journal, November 2007

  • Simon, Joshua D.; Geha, Marla
  • The Astrophysical Journal, Vol. 670, Issue 1
  • DOI: 10.1086/521816

An Optical Catalog of Galaxy Clusters Obtained from an Adaptive Matched Filter Finder Applied to Sloan Digital sky Survey data Release 6
journal, June 2011


Hundreds of Milky Way Satellites? Luminosity Bias in the Satellite Luminosity Function
journal, November 2008

  • Tollerud, Erik J.; Bullock, James S.; Strigari, Louis E.
  • The Astrophysical Journal, Vol. 688, Issue 1
  • DOI: 10.1086/592102

The globular cluster system of the galaxy. IV - The halo and disk subsystems
journal, June 1985


    Works referencing / citing this record:

    Constraining self-interacting dark matter with scaling laws of observed halo surface densities
    journal, April 2018

    • Bondarenko, Kyrylo; Boyarsky, Alexey; Bringmann, Torsten
    • Journal of Cosmology and Astroparticle Physics, Vol. 2018, Issue 04
    • DOI: 10.1088/1475-7516/2018/04/049

    Constraining self-interacting dark matter with scaling laws of observed halo surface densities
    journal, April 2018

    • Bondarenko, Kyrylo; Boyarsky, Alexey; Bringmann, Torsten
    • Journal of Cosmology and Astroparticle Physics, Vol. 2018, Issue 04
    • DOI: 10.1088/1475-7516/2018/04/049

    The contribution of dissolving star clusters to the population of ultra faint objects in the outer halo of the Milky Way
    journal, December 2016

    • Contenta, Filippo; Gieles, Mark; Balbinot, Eduardo
    • Monthly Notices of the Royal Astronomical Society, Vol. 466, Issue 2
    • DOI: 10.1093/mnras/stw3178

    Pristine dwarf galaxy survey – I. A detailed photometric and spectroscopic study of the very metal-poor Draco II satellite
    journal, July 2018

    • Longeard, Nicolas; Martin, Nicolas; Starkenburg, Else
    • Monthly Notices of the Royal Astronomical Society, Vol. 480, Issue 2
    • DOI: 10.1093/mnras/sty1986

    A Gaia DR2 search for dwarf galaxies towards Fermi-LAT sources: implications for annihilating dark matter
    journal, July 2018

    • Ciucă, Ioana; Kawata, Daisuke; Ando, Shin’ichiro
    • Monthly Notices of the Royal Astronomical Society, Vol. 480, Issue 2
    • DOI: 10.1093/mnras/sty1994

    The multiplicity and anisotropy of galactic satellite accretion
    journal, February 2018

    • Shao, Shi; Cautun, Marius; Frenk, Carlos S.
    • Monthly Notices of the Royal Astronomical Society, Vol. 476, Issue 2
    • DOI: 10.1093/mnras/sty343

    Nine tiny star clusters in Gaia DR1, PS1, and DES
    journal, January 2019

    • Torrealba, G.; Belokurov, V.; Koposov, S. E.
    • Monthly Notices of the Royal Astronomical Society, Vol. 484, Issue 2
    • DOI: 10.1093/mnras/stz071

    Robust velocity dispersion and binary population modelling of the ultrafaint dwarf galaxy Reticulum II
    journal, June 2019

    • Minor, Quinn E.; Pace, Andrew B.; Marshall, Jennifer L.
    • Monthly Notices of the Royal Astronomical Society, Vol. 487, Issue 2
    • DOI: 10.1093/mnras/stz1468

    The hidden giant: discovery of an enormous Galactic dwarf satellite in Gaia DR2
    journal, June 2019

    • Torrealba, G.; Belokurov, V.; Koposov, S. E.
    • Monthly Notices of the Royal Astronomical Society, Vol. 488, Issue 2
    • DOI: 10.1093/mnras/stz1624

    SEARCHING FOR DARK MATTER ANNIHILATION IN RECENTLY DISCOVERED MILKY WAY SATELLITES WITH FERMI -LAT
    journal, January 2017


    On the Nature of Ultra-faint Dwarf Galaxy Candidates. I. DES1, Eridanus III, and Tucana V
    journal, January 2018

    • Conn, Blair C.; Jerjen, Helmut; Kim, Dongwon
    • The Astrophysical Journal, Vol. 852, Issue 2
    • DOI: 10.3847/1538-4357/aa9eda

    Chemical Abundance Analysis of Three α -poor, Metal-poor Stars in the Ultrafaint Dwarf Galaxy Horologium I
    journal, January 2018

    • Nagasawa, D. Q.; Marshall, J. L.; Li, T. S.
    • The Astrophysical Journal, Vol. 852, Issue 2
    • DOI: 10.3847/1538-4357/aaa01d

    On the Nature of Ultra-faint Dwarf Galaxy Candidates. II. The Case of Cetus II
    journal, April 2018

    • Conn, Blair C.; Jerjen, Helmut; Kim, Dongwon
    • The Astrophysical Journal, Vol. 857, Issue 1
    • DOI: 10.3847/1538-4357/aab61c

    Stellar Streams Discovered in the Dark Energy Survey
    journal, July 2018


    Proper Motions of Milky Way Ultra-faint Satellites with Gaia DR2 × DES DR1
    journal, April 2019


    A Faint Halo Star Cluster Discovered in the Blanco Imaging of the Southern Sky Survey
    journal, April 2019


    Chemical Abundance Analysis of Tucana III, the Second r -process Enhanced Ultra-faint Dwarf Galaxy
    journal, September 2019