The Hα Luminosity Function of Galaxies at z {\sim} 4.5

Abstract

We present the Hα luminosity function (LF) derived from a large sample of Lyman break galaxies at z {\sim} 4.5 over the GOODS-South and North fields. This study makes use of the new, full-depth Spitzer/IRAC [3.6] and [4.5] imaging from the GOODS Re-ionization Era wide-Area Treasury from the Spitzer program. The Hα flux is derived from the offset between the continuum flux estimated from the best-fit spectral energy distribution, and the observed photometry in IRAC [3.6]. From these measurements, we build the Hα LF and study its evolution providing the best constraints of this property at high redshift, where spectroscopy of Hα is not yet available. Schechter parameterizations of the Hα LF show a decreasing evolution of {Φ^\star} with redshift, increasing evolution in L{^\star}, and no significant evolution in the faint-end slope at high z. We find that star formation rates (SFRs) derived from Hα are higher than those derived from the rest-frame UV for low SFR galaxies but the opposite happens for the highest SFRs. This can be explained by lower mass galaxies (also lower SFR) having, on average, rising star formation histories (SFHs), while at the highest masses the SFHs may be declining. The SFR function is steeper, and because of the excess SFR(Hα) compared to SFR(UV) at low SFRs, the SFR density estimated from Hα is higher than the previous estimates based on UV luminosities.

Astrophysical Journal, Accepted, 17 pages, 16 figures

References in corpus (21)

• Cosmic Star Formation History
• UV Luminosity Functions at redshifts z~4 to z~10: 10000 Galaxies from HST Legacy Fields
• 3D-HST WFC3-selected Photometric Catalogs in the Five CANDELS/3D-HST Fields: Photometry, Photometric Redshifts and Stellar Masses
• The Hubble Ultra Deep Field
• The MOSFIRE Deep Evolution Field (MOSDEF) Survey: Rest-Frame Optical Spectroscopy for ~1500 H-Selected Galaxies at 1.37 < z < 3.8
• H-alpha Observations of a Large Sample of Galaxies at z~2: Implications for Star Formation in High Redshift Galaxies
• A Spectroscopic Redshift Measurement for a Luminous Lyman Break Galaxy at z=7.730 using Keck/MOSFIRE
• HiZELS: a high redshift survey of H-alpha emitters. I: the cosmic star-formation rate and clustering at z=2.23
• The evolution of the specific star formation rate of massive galaxies to z ~ 1.8 in the E-CDFS
• The GREATS H$\beta$+[OIII] Luminosity Function and Galaxy Properties at $\mathbf{z}\sim 8$: Walking the Way of JWST
• The MOSDEF Survey: the Variation of the Dust Attenuation Curve with Metallicity
• The H-alpha Luminosity Function and Star Formation Rate Volume Density at z=0.8 from the NEWFIRM H-alpha Survey
• Lyman-break galaxies at z~5 -I. First significant stellar mass assembly in galaxies that are not simply z~3 LBGs at higher redshift
• Are high redshift Galaxies hot? - Temperature of z > 5 Galaxies and Implications on their Dust Properties
• Evidence for GN-z11 as a luminous galaxy at redshift 10.957
• The Star Formation Burstiness and Ionizing Efficiency of Low-mass Galaxies
• The evolution of the star formation rate function in the EAGLE simulations: A comparison with UV, IR and H$\alpha$ observations from z ~ 8 to z ~ 0
• A Comprehensive Study of Ly$\alpha$ Emission in the High-redshift Galaxy Population
• Investigating H$\alpha$, UV, and IR star-formation rate diagnostics for a large sample of z ~ 2 galaxies
• A large H$\alpha$ survey of star formation in relaxed and merging galaxy cluster environments at $z\sim 0.15-0.3$
• The evolution of the star formation rate function and cosmic star formation rate density of galaxies at $z\sim 1-4$

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• An Hα view of galaxy build-up in the first 2 Gyr: luminosity functions at z~4-6.5 from NIRCam/grism spectroscopy
• A systematic search for dormant galaxies at z~5-7 from the JWST NIRSpec archive
• The slope and scatter of the star forming main sequence at z~5 : reconciling observations with simulations