CLEAR: The Ionization and Chemical-enrichment Properties of Galaxies at 1.1 < z < 2.3 Academic Article uri icon


  • Abstract We use deep spectroscopy from the Hubble Space Telescope Wide-Field-Camera 3 IR grisms combined with broadband photometry to study the stellar populations, gas ionization and chemical abundances in star-forming galaxies at z 1.12.3. The data stem from the CANDELS Ly Emission At Reionization (CLEAR) survey. At these redshifts, the grism spectroscopy measure the [O II] 3727, 3729, [O III] 4959, 5008, and H strong emission features, which constrain the ionization parameter and oxygen abundance of the nebular gas. We compare the line-flux measurements to predictions from updated photoionization models (MAPPINGS V; Kewley et al.), which include an updated treatment of nebular gas pressure, log P / k = n e T e . Compared to low-redshift samples (z 0.2) at fixed stellar mass, log M * / M = 9.49.8, the CLEAR galaxies at z = 1.35 (1.90) have lower gas-phase metallicity, m{Delta }}(mathrm{log}Z)$?> ( log Z ) = 0.25 (0.35) dex, and higher ionization parameters, m{Delta }}(mathrm{log}q)$?> ( log q ) = 0.25 (0.35) dex, where U q/c. We provide updated analytic calibrations between the [O III], [O II], and H emission-line ratios, metallicity, and ionization parameter. The CLEAR galaxies show that at fixed stellar mass, the gas ionization parameter is correlated with the galaxy specific star formation rates, where m{Delta }}mathrm{log}qsimeq 0.4 imes {
    m{Delta }}(

published proceedings

  • The Astrophysical Journal

author list (cited authors)

  • Papovich, C., Simons, R. C., Estrada-Carpenter, V., Matharu, J., Momcheva, I., Trump, J. R., ... Weiner, B.

complete list of authors

  • Papovich, Casey||Simons, Raymond C||Estrada-Carpenter, Vicente||Matharu, Jasleen||Momcheva, Ivelina||Trump, Jonathan R||Backhaus, Bren E||Brammer, Gabriel||Cleri, Nikko J||Finkelstein, Steven L||Giavalisco, Mauro||Ji, Zhiyuan||Jung, Intae||Kewley, Lisa J||Nicholls, David C||Pirzkal, Norbert||Rafelski, Marc||Weiner, Benjamin

publication date

  • September 2022