ZFOURGE: Extreme 5007 Emission May Be a Common Early-lifetime Phase for Star-forming Galaxies at z > 2.5 Academic Article uri icon

abstract

  • Abstract Using the Prospector spectral energy distribution (SED) fitting code, we analyze the properties of 19 extreme emission-line galaxies (EELGs) identified in the bluest composite SED in the zfourge survey at 2.5z4. Prospector includes a physical model for nebular emission and returns probability distributions for stellar mass, stellar metallicity, dust attenuation, and nonparametric star formation history (SFH). The EELGs show evidence of a starburst in the most recent 50 Myr, with the median EELG having a specific star formation rate (sSFR) of 4.6 Gyr1 and forming 15% of its mass in this short time. For a sample of more typical star-forming galaxies (SFGs) at the same redshifts, the median SFG has an sSFR of 1.1 Gyr1 and forms only 4% of its mass in the last 50 Myr. We find that virtually all of our EELGs have rising SFHs, while most of our SFGs do not. From our analysis, we hypothesize that many, if not most, SFGs at z2.5 undergo an extreme H+[O iii] emission-line phase early in their lifetimes. In a companion paper, we obtain spectroscopic confirmation of the EELGs as part of our MOSEL survey. In the future, explorations of uncertainties in modeling the UV slope for galaxies at z>2 are needed to better constrain their properties, e.g., stellar metallicities.

published proceedings

  • ASTROPHYSICAL JOURNAL

altmetric score

  • 11.03

author list (cited authors)

  • Cohn, J. H., Leja, J., Tran, K., Forrest, B., Johnson, B. D., Tillman, M., ... Yuan, T.

citation count

  • 11

complete list of authors

  • Cohn, Jonathan H||Leja, Joel||Tran, Kim-Vy H||Forrest, Ben||Johnson, Benjamin D||Tillman, Megan||Alcorn, Leo||Conroy, Charlie||Glazebrook, Karl||Kacprzak, Glenn G||Kelson, Daniel D||Nanayakkara, Themiya||Papovich, Casey||van Dokkum, Pieter G||Yuan, Tiantian

publication date

  • December 2018