Skip to main content
OSTI.GOVU.S. Department of Energy Office of Scientific and Technical Information
U.S. Department of Energy
Office of Scientific and Technical Information
 

Variable Stars in the Giant Satellite Galaxy Antlia 2

Journal Article · · The Astrophysical Journal
 [1];  [2];  [1];  [3];  [4];  [5]
  1. Cerro Tololo Inter-American Observatory, La Serena (Chile)
  2. Cerro Tololo Inter-American Observatory, La Serena (Chile); Gemini Observatory, Hilo, HI (United States)
  3. University of Cambridge (United Kingdom)
  4. University of Toronto, ON (Canada)
  5. University of Surrey, Guildford (United Kingdom)
+ Show Author Affiliations
We report 350 pulsating variable stars found in four DECam fields (~12 deg2) covering the Antlia 2 satellite galaxy. The sample of variables includes 318 RR Lyrae stars and eight anomalous Cepheids in the galaxy. Reclassification of several objects designated previously to be RR Lyrae as anomalous Cepheids get rid of the satellite's stars intervening along the line of sight. This in turn removes the need for prolific tidal disruption of the dwarf, in agreement with the recently updated proper motion and pericenter measurements based on Gaia EDR3. There are also several bright foreground RR Lyrae stars in the field, and two distant background variables located ~45 kpc behind Antlia 2. We found RR Lyrae stars over the full search area, suggesting that the galaxy is very large and likely extends beyond our observed area. The mean period of the RRab in Antlia 2 is 0.599 days, while the RRc have a mean period of 0.368 days, indicating the galaxy is an Oosterhoff-intermediate system. The distance to Antlia 2 based on the RR Lyrae stars is 124.1 kpc (μ0 = 20.47) with a dispersion of 5.4 kpc. We measured a clear distance gradient along the semimajor axis of the galaxy, with the southeast side of Antlia 2 being ~13 kpc farther away from the northwest side. This elongation along the line of sight is likely due to the ongoing tidal disruption of Ant 2.
Research Organization:
Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN (United States)
Sponsoring Organization:
Council of the United Kingdom; Ministry of Science and Education of Spain; National Science Foundation; USDOE Office of Science (SC)
Contributing Organization:
DES Collaboration
Grant/Contract Number:
SC0014664
OSTI ID:
1983219
Journal Information:
The Astrophysical Journal, Journal Name: The Astrophysical Journal Journal Issue: 1 Vol. 926; ISSN 0004-637X
Publisher:
IOP PublishingCopyright Statement
Country of Publication:
United States
Language:
English

References (49)

Horizontal branch stars: the interplay between observations and theory, and insights into the formation of the Galaxy journal February 2009
Galactic Archaeology: The dwarfs that survived and perished journal September 2013
An eclipsing-binary distance to the Large Magellanic Cloud accurate to two per cent journal March 2013
Anomalous Cepheids in the Large Magellanic Cloud: Insight into their origin and connection with the star formation history⋆ journal April 2012
Gaia Data Release 2 : Specific characterisation and validation of all-sky Cepheids and RR Lyrae stars★ journal January 2019
The age of the Milky Way inner stellar spheroid from RR Lyrae population synthesis journal September 2020
Gaia Early Data Release 3: Summary of the contents and survey properties journal April 2021
Variable Stars in the Sextans Dwarf Spheroidal Galaxy journal November 1995
DAOPHOT - A computer program for crowded-field stellar photometry journal March 1987
The center of the core-cusp globular cluster M15: CFHT and HST Observations, ALLFRAME reductions journal March 1994
Maps of Dust Infrared Emission for Use in Estimation of Reddening and Cosmic Microwave Background Radiation Foregrounds journal June 1998
New Understanding of Large Magellanic Cloud Structure, Dynamics, and Orbit from Carbon Star Kinematics journal November 2002
Are the Magellanic Clouds on Their First Passage about the Milky Way? journal October 2007
The Period‐Luminosity Relation of RR Lyrae Stars in the SDSS Photometric System journal November 2008
The Variable Stars of the Draco Dwarf Spheroidal Galaxy: Revisited journal October 2008
Low-Amplitude Variables: Distinguishing rr Lyrae Stars from Eclipsing Binaries journal April 2010
The Observed Properties of Dwarf Galaxies in and Around the Local Group journal June 2012
A Comprehensive, Wide-Field Study of Pulsating Stars in the Carina Dwarf Spheroidal Galaxy journal October 2013
The dark Energy Camera journal October 2015
Light Curve Templates and Galactic Distribution of rr Lyrae Stars from Sloan Digital sky Survey Stripe 82 journal December 2009
Measuring Reddening with Sloan Digital sky Survey Stellar Spectra and Recalibrating sfd journal August 2011
Variability and star Formation in leo t, the Lowest Luminosity Star-Forming Galaxy Known Today journal August 2012
THIRD-EPOCH MAGELLANIC CLOUD PROPER MOTIONS. I. HUBBLE SPACE TELESCOPE /WFC3 DATA AND ORBIT IMPLICATIONS journal February 2013
The Carina Project. ix. on Hydrogen and Helium Burning Variables journal November 2015
The Catalina Surveys Periodic Variable star Catalog journal June 2014
‘Skinny Milky Way please’, says Sagittarius journal October 2014
Variable stars in Local Group Galaxies – II. Sculptor dSph journal August 2016
The mass distribution and gravitational potential of the Milky Way journal October 2016
The feeble giant. Discovery of a large and diffuse Milky Way dwarf galaxy in the constellation of Crater journal April 2016
On binary channels to anomalous Cepheids journal April 2017
The total mass of the Large Magellanic Cloud from its perturbation on the Orphan stream journal May 2019
The hidden giant: discovery of an enormous Galactic dwarf satellite in Gaia DR2 journal June 2019
A DECam view of the diffuse dwarf galaxy Crater II – Variable stars journal December 2019
Mass models of the Milky Way journal March 1998
The Faintest Dwarf Galaxies journal August 2019
In Pursuit of the Least Luminous Galaxies journal January 2010
dustmaps: A Python interface for maps of interstellar dust journal June 2018
Variable Stars in the Field of the Hydra ii Ultra-Faint Dwarf Galaxy journal April 2016
SMASH: Survey of the MAgellanic Stellar History journal October 2017
The Population of Pulsating Variable Stars in the Sextans Dwarf Spheroidal Galaxy journal January 2019
THE PAndAS VIEW OF THE ANDROMEDA SATELLITE SYSTEM. II. DETAILED PROPERTIES OF 23 M31 DWARF SPHEROIDAL GALAXIES journal December 2016
The ISLAnds Project. III. Variable Stars in Six Andromeda Dwarf Spheroidal Galaxies journal November 2017
Discovery of Distant RR Lyrae Stars in the Milky Way Using DECam journal March 2018
Stellar Streams Discovered in the Dark Energy Survey journal July 2018
On the Use of Field RR Lyrae as Galactic Probes. I. The Oosterhoff Dichotomy Based on Fundamental Variables journal September 2019
Milky Way Satellite Census. I. The Observational Selection Function for Milky Way Satellites in DES Y3 and Pan-STARRS DR1 journal April 2020
Broken into Pieces: ATLAS and Aliqa Uma as One Single Stream journal April 2021
Kinematics of Antlia 2 and Crater 2 from the Southern Stellar Stream Spectroscopic Survey (S 5 ) journal October 2021
Measuring the Mass of the Large Magellanic Cloud with Stellar Streams Observed by S 5 journal December 2021

Similar Records

VARIABLE STARS IN LARGE MAGELLANIC CLOUD GLOBULAR CLUSTERS. II. NGC 1786
Journal Article · Fri Nov 30 23:00:00 EST 2012 · Astronomical Journal (New York, N.Y. Online) · OSTI ID:22089767
VARIABLE STARS IN LARGE MAGELLANIC CLOUD GLOBULAR CLUSTERS. I. NGC 1466
Journal Article · Sat Oct 15 00:00:00 EDT 2011 · Astronomical Journal (New York, N.Y. Online) · OSTI ID:21582844
THE ACS LCID PROJECT. I. SHORT-PERIOD VARIABLES IN THE ISOLATED DWARF SPHEROIDAL GALAXIES CETUS AND TUCANA
Journal Article · Fri Jul 10 00:00:00 EDT 2009 · Astrophysical Journal · OSTI ID:21333709

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
RR Lyrae variable stars
anomalous Cephid variable stars
dwarf galaxies
local group