Variations in Star Formation History and the Red Giant Branch Tip

Abstract

We examine the reliability of the tip of the red giant branch (TRGB) as a distance indicator for stellar populations with different star formation histories (SFHs) when photometric errors and completeness corrections at the TRGB are small. In general, the TRGB-distance method is insensitive to the shape of the SFH except when it produces a stellar population with a significant component undergoing the red giant branch phase transition. The I-band absolute magnitude of the TRGB for the middle and late stages of this transition (~1.3-1.7 Gyr) is several tenths of a magnitude fainter than the canonical value of M_I ~ -4.0. If more than 30% of all stars formed over the lifetime of the Universe are formed at these ages, then the distance could be overestimated by 10-25%. Similarly, the TRGB-distance method is insensitive to the metallicity distribution of stars formed except when the average metallicity is greater than <[Fe/H]> = -0.3. If more than ~70% of all stars formed have [Fe/H] > -0.3, the distance could be overestimated by ~10-45%. We find that two observable quantities, the height of the discontinuity in the luminosity function at the TRGB and the median (V-I)_0 at M_I = -3.5 can be used to test if the aforementioned age and metallicity conditions are met.

arXiv comment41 pages, 30 figures, uses emulateapj5.sty, accepted to ApJS, high resolution figures available at http://www.astro.ufl.edu/~mbarker/trgb_figs

References in corpus (18)

• Evolutionary tracks and isochrones for low- and intermediate-mass stars: from 0.15 to 7 M_sun, and from Z=0.0004 to 0.03
• Towards Better Age Estimates for Stellar Populations: The Y^2 Isochrones for Solar Mixture
• Numerical Methods of Star Formation History Measurement and Applications to Seven Dwarf Spheroidals
• Deviations from the Local Hubble Flow. I. The Tip of the Red Giant Branch as a Distance Indicator
• A step toward the calibration of the RGB Tip as a Standard Candle
• A Method for Determining the Star Formation History of a Mixed Stellar Population
• The Star Formation History and the spatial distribution of stellar populations in the Ursa Minor Dwarf Spheroidal Galaxy
• The very local Hubble flow
• WFPC2 Observations of Leo A: A Predominantly Young Galaxy within the Local Group
• Globular Clusters in the Magellanic Clouds.II: IR-Array Photometry for 12 Globulars and Contributions to the Integrated Cluster Light
• Cepheid and Tip of the Red Giant Branch Distances To the Dwarf Irregular Galaxy IC10
• Tip of the Red Giant Branch Distances to NGC 4214, UGC 685, and UGC 5456
• The Tip of the Red Giant Branch Distance to the Large Magellanic Cloud
• First detection of the RGB-bump in the Sagittarius dSph
• The Stellar Populations of the Cetus Dwarf Spheroidal Galaxy
• The Oldest Stars of the Extremely Metal-Poor Local Group Dwarf Irregular Galaxy Leo A
• Tip of the Red Giant Branch Distance for the Sculptor Group Dwarf ESO 540-032
• The Analysis of Isochrone Fitting Methods for Red Giant Branch Photometry, and Tip Red Giant Branch Distance Determination

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