The Isaac Newton Telescope monitoring survey of Local Group dwarf galaxies--V. The star formation history of Sagittarius dwarf irregular galaxy derived from long period variable stars

Abstract

We conducted an optical monitoring survey of the Sagittarius dwarf irregular galaxy (SagDIG) during the period of June 2016 -- October 2017, using the 2.5-m Isaac Newton Telescope (INT) at La Palama. Our goal was to identify Long Period Variable stars (LPVs), namely asymptotic giant branch stars (AGBs) and red supergiant stars (RSGs), to obtain the Star Formation History (SFH) of isolated, metal-poor SagDIG. For our purpose, we used a method that relies on evaluating the relation between luminosity and the birth mass of these most evolved stars. We found $27$ LPV candidates within two half-light radii of SagDIG. $10$ LPV candidates were in common with previous studies, including one very dusty AGB (x-AGB). By adopting the metallicity $Z=0.0002$ for older population and $Z=0.0004$ for younger ages, we estimated that the star formation rate changes from $0.0005\pm 0.0002$ M${}_{\odot }$yr${}^{-1}$kpc${}^{-2}$ ($13$ Gyr ago) to $0.0021\pm 0.0010$ M${}_{\odot }$yr${}^{-1}$kpc${}^{-2}$ ($0.06$ Gyr ago). Like many dwarf irregular galaxies, SagDIG has had continuous star formation activity across its lifetime, though with different rates, and experiences an enhancement of star formation since $z\simeq 1$. We also evaluated the total stellar mass within two half-light radii of SagDIG for three choices of metallicities. For metallicity $Z=0.0002$ and $Z=0.0004$ we estimated the stellar mass M${}_{\ast }$ = ($5.4\pm 2.3$) $\times$ $10^6$ and ($3.0\pm 1.3$) $\times$ $10^6$ M${}_{\odot }$, respectively. Additionally, we determined a distance modulus $\mu$ = $25.27\pm 0.05$ mag, using the tip of the red giant branch (TRGB).

arXiv comment16 pages, Accepted for publication in ApJ

References in corpus (33)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• On the variation of the Initial Mass Function
• The observed properties of dwarf galaxies in and around the Local Group
• A new generation of PARSEC-COLIBRI stellar isochrones including the TP-AGB phase
• Star counts in the Galaxy. Simulating from very deep to very shallow photometric surveys with the TRILEGAL code
• The Faintest Dwarf Galaxies
• The Star Formation Histories of Local Group Dwarf Galaxies I. Hubble Space Telescope / Wide Field Planetary Camera 2 Observations
• Little Things
• GaBoDS: The Garching-Bonn Deep Survey; IV. Methods for the Image reduction of multi-chip Cameras
• An Infrared Census of DUST in Nearby Galaxies with Spitzer (DUSTiNGS), II. Discovery of Metal-poor Dusty AGB Stars
• Chemistry and Kinematics of the Late-Forming Dwarf Irregular Galaxies Leo A, Aquarius, and Sagittarius DIG
• An Infrared Census of DUST in Nearby Galaxies with Spitzer (DUSTiNGS), I. Overview
• The star formation history of the Magellanic Clouds derived from long-period variable star counts
• HST/ACS observations of the old and metal-poor Sagittarius dwarf irregular galaxy
• C star survey of the Local Group Galaxies. III The Sagittarius dwarf irregular and Leo I dwarf spheroidal galaxies
• The UK Infrared Telescope M33 monitoring project. II. The star formation history in the central square kiloparsec
• DUSTiNGS III: Distribution of Intermediate-Age and Old Stellar Populations in Disks and Outer Extremities of Dwarf Galaxies
• The UK Infrared Telescope M33 monitoring project. V. The star formation history across the galactic disc
• An Infrared Census of DUST in Nearby Galaxies with Spitzer (DUSTiNGS). IV. Discovery of High-Redshift AGB Analogs
• Long period variable stars in NGC 147 and NGC 185. I. Their star formation histories
• An Infrared Census Of Dust In Nearby Galaxies With Spitzer (DUSTiNGS): V. The Period-luminosity Relation For Dusty Metal-Poor AGB Stars
• The Sagittarius dwarf irregular galaxy: metallicity and stellar populations
• The UK Infrared Telescope M33 monitoring project. I. Variable red giant stars in the central square kiloparsec
• New abundance measurements in UKS 1927-177, a very metal-poor galaxy in the Local Group
• Solo Dwarfs I: Survey introduction and first results for the Sagittarius Dwarf Irregular Galaxy
• The Isaac Newton Telescope monitoring survey of Local Group dwarf galaxies. I. Survey overview and first results for Andromeda I
• Near-Infrared photometry of carbon stars in the Sagittarius dwarf irregular galaxy and DDO 210
• A Remarkable Oxygen-rich Asymptotic Giant Branch Variable in the Sagittarius Dwarf Irregular Galaxy
• The Isaac Newton Telescope monitoring survey of Local Group dwarf galaxies -- IV. The star formation history of Andromeda VII derived from long period variable stars
• The extended structure of the dwarf irregular galaxy Sagittarius
• The Isaac Newton Telescope monitoring survey of Local Group dwarf galaxies. II. The star formation history of Andromeda I derived from long period variables
• Monitoring survey of pulsating giant stars in the Local Group galaxies: survey description, science goals, target selection
• On the HI-Hole and AGB Stellar Population of the Sagittarius Dwarf Irregular Galaxy

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