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arXiv · 1302.6999

CLUES to the past: Local Group progenitors amongst high-redshift Lyman Break Galaxies

Pratika Dayal·Noam I. Libeskind·James S. Dunlop
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Abstract

We use state-of-the-art numerical simulations to explore the observability and the expected physical properties of the progenitors of the local group galaxies at z=6-8, within 1 billion years of the big bang. We find that the most massive progenitors of the Milky Way (MW) and Andromeda (M31) at z=6 and 7 are predicted to have absolute UV continuum magnitudes between -17 and -18, suggesting that their analogues lie close to the detection limits of the deepest near-infrared surveys conducted to date (i.e. HST WFC3/IR UDF12). This in turn confirms that the majority of currently known z=6-8 galaxies are expected to be the seeds of present-day galaxies which are more massive than L* spirals. We also discuss the properties of the local-group progenitors at these early epochs, extending down to absolute magnitudes M_UV = -13. The most massive MW/M31 progenitors at z=7 have stellar masses of about 10^7.5-8 solar masses, stellar metallicities between 3 and 6% of the solar value, and predicted observed UV continuum slopes between -2.4 and -2.5.

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Pratika Dayal, Noam I. Libeskind, James S. Dunlop. 2013-03-11. CLUES to the past: Local Group progenitors amongst high-redshift Lyman Break Galaxies. https://doi.org/10.1093/mnras%2Fstt446

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