INFERRED Hα FLUX AS A STAR FORMATION RATE INDICATOR AT z ∼ 4–5: IMPLICATIONS FOR DUST PROPERTIES, BURSTINESS, AND THE z = 4–8 STAR FORMATION RATE FUNCTIONS

2015/11/30 by Renske Smit, Rychard J. Bouwens, Ivo Labbé +3 · 103 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Burstiness #Flattening #Flux (metallurgy) #Galaxy #Population #Redshift #Star formation #Stellar population #Stellar, planetary, and galactic studies #astro-ph.CO #astro-ph.GA

paper · pdf · doi:10.3847/1538-4357/833/2/254

published in The Astrophysical Journal 833(2), 254 (IOP Publishing) · 22 pages, 13 figures, 9 tables, ApJ, in press

openalex created_date 2016/06/24 · arxiv created 2016/11/01 · openalex publication_date 2016/12/20 · arxiv updated 2016/12/28 · openalex updated_date 2026/08/05

Abstract

ABSTRACT We derive H α fluxes for a large spectroscopic and photometric-redshift-selected sample of sources over GOODS-North and South in the redshift range z = 3.8–5.0 with deep Hubble Space Telescope ( HST ), Spitzer /IRAC, and ground-based observations. The H α flux is inferred based on the offset between the IRAC 3.6 μ m flux and that predicted from the best-fit spectral energy distribution (SED). We demonstrate that the H α flux correlates well with dust-corrected UV star formation rate (SFR) and therefore can serve as an independent SFR indicator. However, we also find a systematic offset in the ratios for z ∼ 4–5 galaxies relative to local relations (assuming the same dust corrections for nebular regions and stellar light). We show that we can resolve the modest tension in the inferred SFRs by assuming bluer intrinsic UV slopes (increasing the dust correction), a rising star formation history, or assuming a low-metallicity stellar population with a hard ionizing spectrum (increasing the ratio). Using H α as an SFR indicator, we find a normalization of the star formation main sequence in good agreement with recent SED-based determinations and also derive the SFR functions at . In addition, we assess for the first time the burstiness of star formation in galaxies on <100 Myr timescales by comparing UV and H α -based sSFRs; their one-to-one relationship argues against significantly bursty star formation histories.

Citations

• INVESTIGATING Hα, UV, AND IR STAR-FORMATION RATE DIAGNOSTICS FOR A LARGE SAMPLE OFz∼ 2 GALAXIES
• THE SPECTRAL ENERGY DISTRIBUTIONS OF z ∼ 8 GALAXIES FROM THE IRAC ULTRA DEEP FIELDS: EMISSION LINES, STELLAR MASSES, AND SPECIFIC STAR FORMATION RATES AT 650 MYR
• Starburst99: Synthesis Models for Galaxies with Active Star Formation
• Dust Absorption and the Ultraviolet Luminosity Density atz ≈ 3 as Calibrated by Local Starburst Galaxies
• EAZY: A Fast, Public Photometric Redshift Code
• Secondary standard stars for absolute spectrophotometry
• UV CONTINUUM SLOPE AND DUST OBSCURATION FROMz∼ 6 TOz∼ 2: THE STAR FORMATION RATE DENSITY AT HIGH REDSHIFT
• STAR FORMATION IN GALAXIES ALONG THE HUBBLE SEQUENCE
• Multiwavelength Constraints on the Cosmic Star Formation History from Spectroscopy: The Rest‐Frame Ultraviolet, Hα, and Infrared Luminosity Functions at Redshifts 1.9 ≲z≲ 3.4
• The Great Observatories Origins Deep Survey
• Rotational mixing in massive binaries

Cited by

• Unveiling the nature of brightz ≃ 7galaxies with theHubble Space Telescope
• Spectral Signatures of Population III and Envelope-stripped Stars in Galaxies at the Epoch of Reionization
• High star cluster formation efficiency in the strongly lensed Sunburst Lyman-continuum galaxy at z=2.37