The AGB population in IC 1613 using JHK photometry

Abstract

A member of the Local Group, IC 1613 is a gas rich irregular dwarf galaxy that appears to have formed stars continuously over the last 10 Gyr and is relatively independent of external influences from other galaxies. This paper aims to study the spatial distribution of the asymptotic giant branch (AGB) population in IC 1613 and its metallicity. Using WFCAM on UKIRT, high quality JHK photometry of an area of 0.8 deg^2 centered on IC 1613 was obtained. The data have been used to isolate the C- and M-type components of the AGB population and using their number ratio, C/M, a global mean metallicity has been derived. The metallicity and the TRGB magnitude have been studied as a function of distance from the galactic centre and as a function of azimuthal angle. The tip of the RGB (TRGB) has been found at K_0 = 18.25 +/- 0.15 mag. The colour separation between the C- and M-type components of the AGB population has been located at (J-K) = 1.15 +/- 0.05 mag, giving a global C/M ratio of 0.52 +/- 0.04 and from this an iron abundance of [Fe/H] = -1.26 +/- 0.07 dex has been calculated. The AGB population has been detected out to a radial distance of 4.5 kpc in the de-projected plane of the galaxy. The measured TRGB is consistent with previous measurements and no significant variation is detected in the TRGB or in metallicity either with galactocentric distance or azimuthal angle.

References in corpus (12)

• The UKIRT Wide Field Camera ZYJHK Photometric System: Calibration from 2MASS
• The ACS Nearby Galaxy Survey Treasury IX. Constraining asymptotic giant branch evolution with old metal-poor galaxies
• Near-Infrared Photometry of Carbon Stars
• AGB stars in the Magellanic Clouds. II. The rate of star formation across the LMC
• A Spitzer mid-infrared spectral survey of mass-losing carbon stars in the Large Magellanic Cloud
• The ACS LCID project. X. The Star Formation History of IC 1613: Revisiting the Over-Cooling Problem
• Stellar Content and Recent Star Formation History of the Local Group Dwarf Irregular Galaxy IC1613
• The evolved stars of Leo II dSph galaxy from near-infrared UKIRT/WFCAM observations
• A Spitzer/IRAC Census of the Asymptotic Giant Branch Populations in Local Group Dwarfs. I. WLM
• A Spitzer IRAC Census of the Asymptotic Giant Branch Populations in Local Group Dwarfs. II. IC 1613
• C stars in the outer spheroid of NGC 6822
• The assessment of the near infrared identification of Carbon stars. I. The Local Group galaxies WLM, IC 10 and NGC 6822

Cited by in corpus (6)

• DUSTiNGS III: Distribution of Intermediate-Age and Old Stellar Populations in Disks and Outer Extremities of Dwarf Galaxies
• Astrophysical Distance Scale II. Application of the JAGB Method: A Nearby Galaxy Sample
• Carbon stars as standard candles: II. The median J magnitude as a distance indicator
• Carbon stars as standard candles -- III. Un-binned maximum likelihood fitting and comparison with TRGB estimations
• Physical parameters of red supergiants in dwarf irregular galaxies in the Local Group
• Red supergiant stars in IC 1613 and metallicity-dependent mixing length in the evolutionary model