Measuring the Stellar Masses of z~7 Galaxies with Spitzer Ultrafaint Survey Program (SURFS UP)

Abstract

We present Spitzer/IRAC observations of nine $z^{\prime }$-band dropouts highly magnified (2<mu<12) by the Bullet Cluster. We combine archival imaging with our Exploratory program (SURFS UP), which results in a total integration time of ~30 hr per IRAC band. We detect (>3sigma) in both IRAC bands the brightest of these high-redshift galaxies, with [3.6]=23.80+-0.28 mag, [4.5]=23.78+-0.25 mag, and (H-[3.6])=1.17+-0.32 mag. The remaining eight galaxies are undetected to [3.6]~26.4 mag and [4.5]~26.0 mag with stellar masses of ~5x10^7 M_sol. The detected galaxy has an estimated magnification of mu=12+-4, which implies this galaxy has an ultraviolet luminosity of L_1500~0.3 L*_{z=7} --- the lowest luminosity individual source detected in IRAC at z>7. By modeling the broadband photometry, we estimate the galaxy has an intrinsic star-formation rate of SFR~1.3 M_sol/yr and stellar mass of M~2x10^9 M_sol, which gives a specific star-formation rate of sSFR~0.7 Gyr^-1. If this galaxy had sustained this star-formation rate since z~20, it could have formed the observed stellar mass (to within a factor of ~2), we also discuss alternate star-formation histories and argue the exponentially-increasing model is unlikely. Finally, based on the intrinsic star-formation rate, we estimate this galaxy has a likely [C II] flux of <f_[C II]> = 10^{-17} erg/s/cm2.

arXiv commentAccepted to ApJL. 6 pages, 3 figures, 2 tables

References in corpus (46)

• Stellar population synthesis at the resolution of 2003
• Galactic Stellar and Substellar Initial Mass Function
• Star Formation in Galaxies Along the Hubble Sequence
• The Dust Content and Opacity of Actively Star-Forming Galaxies
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results
• Detailed Structural Decomposition of Galaxy Images
• The Average Star Formation Histories of Galaxies in Dark Matter Halos from z=0-8
• Star Formation in AEGIS Field Galaxies since z=1.1 : The Dominance of Gradually Declining Star Formation, and the Main Sequence of Star-Forming Galaxies
• Accurate photometric redshifts for the CFHT Legacy Survey calibrated using the VIMOS VLT Deep Survey
• COSMOS Photometric Redshifts with 30-bands for 2-deg2
• Evidence for Reionization at z ~ 6: Detection of a Gunn-Peterson Trough in a z=6.28 Quasar
• Cluster Lensing And Supernova survey with Hubble (CLASH): An Overview
• UV Luminosity Functions at z~4, 5, and 6 from the HUDF and other Deep HST ACS Fields: Evolution and Star Formation History
• UV Luminosity Functions from 132 z~7 and z~8 Lyman-Break Galaxies in the ultra-deep HUDF09 and wide-area ERS WFC3/IR Observations
• Mergers and Bulge Formation in Lambda-CDM: Which Mergers Matter?
• Galaxies at z~6: The UV Luminosity Function and Luminosity Density from 506 UDF, UDF-Ps, and GOODS i-dropouts
• Demographics and Physical Properties of Gas Out/Inflows at 0.4 < z < 1.4
• A highly magnified candidate for a young galaxy seen when the Universe was 500 Myrs old
• The Direct Detection of Lyman-Continuum Emission from Star-forming Galaxies at z~3
• Star formation rates and masses of z ~ 2 galaxies from multicolour photometry
• 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
• Stellar sources of dust in the high redshift Universe
• Very blue UV-continuum slopes of low luminosity z~7 galaxies from WFC3/IR: Evidence for extremely low metallicities?
• On the Stellar Populations and Evolution of Star-Forming Galaxies at 6.3 < z < 8.6
• Star formation rates and stellar masses of z=7-8 galaxies from IRAC observations of the WFC3/IR ERS and the HUDF field
• The Direct Detection of Cool, Metal-Enriched Gas Accretion onto Galaxies at z ~ 0.5
• The reliability of [CII] as a star formation rate indicator
• Improving the Estimation of Star formation Rates and Stellar Population Ages of High-redshift Galaxies from Broadband Photometry
• The Stellar Mass Density at z~6 from Spitzer Imaging of i-drop Galaxies
• [CII] line emission in massive star-forming galaxies at z=4.7
• On the relative Contribution of high-redshift Galaxies and Active Galactic Nuclei to Reionization
• Discovery of a possibly old galaxy at $z=6.027$, multiply imaged by the massive cluster Abell 383
• The rise and fall of the star formation histories of blue galaxies at redshifts 0.2<z<1.4
• The Major Sources of the Cosmic Reionizing Background at z ~ 6
• The Rest Frame UV to Optical Colors and SEDs of z~4-7 Galaxies
• Keck Deep Fields. III. Luminosity-dependent Evolution of the Ultraviolet Luminosity and Star Formation Rate Densities at z~4, 3, and 2
• The impact of nebular emission on the broadband fluxes of high-redshift galaxies
• Evolution of the observed Ly-alpha luminosity function from z = 6.5 to z = 7.7: evidence for the epoch of reionization ?
• Serendipitous Discovery of an Overdensity of Lyman-Alpha Emitters at z~4.8 in the Cl1604 Supercluster Field
• CLASH: Discovery of a Bright z~6.2 Dwarf Galaxy Quadruply Lensed by MACS J0329.6-0211
• Luminous and High Stellar Mass Candidate Galaxies at z ~ 8 Discovered in CANDELS
• On Measuring the Infrared Luminosity of Distant Galaxies with the Space Infrared Telescope Facility
• Stellar Populations of Lyman Break Galaxies at z=1-3 in the HST/WFC3 Early Release Science Observations
• Spectroscopic Confirmation of a z=6.740 Galaxy behind the Bullet Cluster
• Using the Bullet Cluster as a Gravitational Telescope to Study z~7 Lyman Break Galaxies
• PyGFit: A Tool for Extracting PSF Matched Photometry

Cited by in corpus (19)

• RELICS: Reionization Lensing Cluster Survey
• Constraining the neutral fraction of hydrogen in the IGM at redshift 7.5
• VIMOS Ultra-Deep Survey (VUDS): Witnessing the Assembly of a Massive Cluster at z~3.3
• The VIMOS Ultra Deep Survey: The reversal of the star-formation rate $-$ density relation at $2<z<5$
• ALMA Lensing Cluster Survey: $HST$ and $Spitzer$ Photometry of 33 Lensed Fields Built with CHArGE
• Persistence of the Color-Density Relation and Efficient Environmental Quenching to $z\sim 1.4$
• The Grism Lens-Amplified Survey from Space (GLASS). IV. Mass reconstruction of the lensing cluster Abell 2744 from frontier field imaging and GLASS spectroscopy
• Chronos and Kairos: Mosfire Observations of Post-Starburst Galaxies in z~1 Clusters and Groups
• Spitzer UltRa Faint SUrvey Program (SURFS UP). II. IRAC-Detected Lyman-Break Galaxies at 6 < z < 10 Behind Strong-Lensing Clusters
• Stellar Properties of z ~ 8 Galaxies in the Reionization Lensing Cluster Survey
• The Gentle Growth of Galaxies at High Redshifts in Overdense Environments
• Hubble Frontier Field Photometric Catalogues of Abell 370 and RXC J2248.7-4431: Multiwavelength photometry, photometric redshifts, and stellar properties
• RELICS: Properties of z>5.5 Galaxies Inferred from Spitzer and Hubble Imaging Including A Candidate z~6.8 Strong [OIII] Emitter
• The Size and Pervasiveness of Ly$\alpha$-UV Spatial Offsets in Star-Forming Galaxies at $z\sim 6$
• Mass Modeling of Frontier Fields Cluster MACS J1149.5+2223 Using Strong and Weak Lensing
• De-Confusing blended field images using graphs and bayesian priors
• RCS2 J232727.6-020437: An Efficient Cosmic Telescope at $z=0.6986$
• The Baryon Cycle at High Redshifts: Effects of Galactic Winds on Galaxy Evolution in Overdense and Average Regions
• The KMOS Lens-Amplified Spectroscopic Survey (KLASS): Kinematics and clumpiness of low-mass galaxies at cosmic noon