A Tale of Two Clusters: An Analysis of Gas-phase Metallicity and Nebular Gas Conditions in Proto-cluster Galaxies at z 2 Academic Article uri icon

abstract

  • Abstract The ZFIRE survey has spectroscopically confirmed two proto-clusters using the MOSFIRE instrument on Keck I: one at z=2.095 in COSMOS and another at z=1.62 in UKIRT Infrared Deep Sky Survey (UDS). Here, we use an updated ZFIRE data set to derive the properties of ionized gas regions of proto-cluster galaxies by extracting fluxes from emission lines H4861 , [O iii]5007 , H6563 , [N ii]6585 , and [S ii]6716,6731 . We measure gas-phase metallicity of members in both proto-clusters using two indicators, including a strong-line indicator relatively independent of the ionization parameter and electron density. Proto-cluster and field galaxies in both UDS and COSMOS lie on the same MassMetallicity Relation with both metallicity indicators. We compare our results to recent IllustrisTNG results, which report no significant gas-phase metallicity offset between proto-cluster and field galaxies until z=1.5. This is in agreement with our observed metallicities, where no offset is measured between proto-cluster and field populations. We measure tentative evidence from stacked spectra that indicate UDS high-mass proto-cluster and field galaxies have differing [O iii]/Hratios; however, these results are dependent on the sample size of the high-mass stacks.

published proceedings

  • ASTROPHYSICAL JOURNAL

altmetric score

  • 961.08

author list (cited authors)

  • Alcorn, L. Y., Gupta, A., Tran, K., Kacprzak, G. G., Yuan, T., Cohn, J., ... Straatman, C.

citation count

  • 7

complete list of authors

  • Alcorn, Leo Y||Gupta, Anshu||Tran, Kim-Vy||Kacprzak, Glenn G||Yuan, Tiantian||Cohn, Jonathan||Forrest, Ben||Glazebrook, Karl||Harshan, Anishya||Kewley, Lisa J||Labbe, Ivo||Nanayakkara, Themiya||Papovich, Casey||Spitler, Lee R||Straatman, Caroline MS

publication date

  • October 2019