HOW LYMAN ALPHA EMISSION DEPENDS ON GALAXY STELLAR MASS

• Published in: Astrophysical journal. Letters Vol. 821; no. 1; p. L14
• Main Authors: Oyarzún, Grecco A., Blanc, Guillermo A., González, Valentino, Mateo, Mario, III, John I. Bailey, Finkelstein, Steven L., Lira, Paulina, Crane, Jeffrey D., Olszewski, Edward W.
• Format: Journal Article
• Language: English
• Published: The American Astronomical Society 10.04.2016
• Subjects: Bins; Design engineering; Emission; Equivalence; Fluxes; Galaxies; galaxies: evolution; galaxies: high-redshift; galaxies: statistics; Galaxy distribution; Stellar mass
• ISSN: 2041-8205; 2041-8213
• DOI: 10.3847/2041-8205/821/1/L14

ABSTRACT In this work, we show how the stellar mass (M*) of galaxies affects the 3 < z < 4.6 Ly equivalent width (EW) distribution. To this end, we design a sample of 629 galaxies in the M* range from the 3D-HST/CANDELS survey. We perform spectroscopic observations of this sample using the Michigan/Magellan Fiber System, allowing us to measure Ly fluxes and use 3D-HST/CANDELS ancillary data. In order to study the Ly 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 . Through a Bayesian analysis, we confirm that lower M* galaxies have higher Ly 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 and . These results are crucial for proper interpretation of Ly emission trends reported in the literature that may be affected by strong M* selection biases.