HOW LYMAN ALPHA EMISSION DEPENDS ON GALAXY STELLAR MASS

Grecco A. Oyarzún, Guillermo A. Blanc, Valentino González, Mario Mateo, John I. Bailey, Steven L. Finkelstein, Paulina Lira, Jeffrey D. Crane, Edward W Olszewski

Research output: Contribution to journalArticle

16 Scopus citations

Abstract

In this work, we show how the stellar mass (M∗) of galaxies affects the 3 <z <4.6 Lyα equivalent width (EW) distribution. To this end, we design a sample of 629 galaxies in the M∗ range 7.6 <log M∗/M <10.6 from the 3D-HST/CANDELS survey. We perform spectroscopic observations of this sample using the Michigan/Magellan Fiber System, allowing us to measure Lyα fluxes and use 3D-HST/CANDELS ancillary data. In order to study the Lyα EW distribution dependence on M∗, we split the whole sample in three stellar mass bins. We find that, in all bins, the distribution is best represented by an exponential profile of the form dN (M∗)/dEW = W0(M∗)-1A(M∗)e-EW/W0(M∗). Through a Bayesian analysis, we confirm that lower M∗ galaxies have higher Lyα EWs. We also find that the fraction A of galaxies featuring emission and the e-folding scale W0 of the distribution anti-correlate with M∗, recovering expressions of the forms A(M∗) = -0.26(.13)log M∗/M + 3.01(1.2) and W0(M∗) = - 15.6(3.5)log M∗/M + 166(34). These results are crucial for proper interpretation of Lyα emission trends reported in the literature that may be affected by strong M∗ selection biases.

Original languageEnglish (US)
Article numberL14
JournalAstrophysical Journal Letters
Volume821
Issue number1
DOIs
StatePublished - Apr 10 2016

Keywords

  • galaxies: evolution
  • galaxies: high-redshift
  • galaxies: statistics

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

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    Oyarzún, G. A., Blanc, G. A., González, V., Mateo, M., Bailey, J. I., Finkelstein, S. L., Lira, P., Crane, J. D., & Olszewski, E. W. (2016). HOW LYMAN ALPHA EMISSION DEPENDS ON GALAXY STELLAR MASS. Astrophysical Journal Letters, 821(1), [L14]. https://doi.org/10.3847/2041-8205/821/1/L14