Measuring the stellar masses of z ∼ 7 galaxies with the spitzer ultrafaint survey program (Surfs up)

R. E. Ryan, R. E. Ryan, A. H. Gonzalez, B. C. Lemaux, M. Bradač, S. Casertano, S. Allen, B. Cain, M. Gladders, N. Hall, H. Hildebradt, J. Hinz, K. H. Huang, L. Lubin, T. Schrabback, M. Stiavelli, T. Treu, A. Von Der Linden, Dennis F Zaritsky

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

We present Spitzer/IRAC observations of nine z′-band dropouts highly magnified (2 ≲ μ ≲ 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 Infrared Array Camera (IRAC) band. We detect (≳ 3σ) 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 ∼5 × 107 M·. The detected galaxy has an estimated magnification of μ = 12 ± 4, which implies this galaxy has an ultraviolet luminosity of-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 (SFR) of SFR ∼ 1.3 M· yr-1 and stellar mass of M ∼ 2.0 × 109 M·, which gives a specific star formation rate of sSFR ∼ 0.7 Gyr-1. If this galaxy had sustained this SFR 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 that the exponentially increasing model is unlikely. Finally, based on the intrinsic SFR, we estimate that this galaxy has a likely [C II] flux of 〈f [C II]〉 = 1.6 mJy.

Original languageEnglish (US)
Article numberL4
JournalAstrophysical Journal Letters
Volume786
Issue number1
DOIs
StatePublished - May 1 2014

Fingerprint

stellar mass
star formation rate
galaxies
cameras
luminosity
dropouts
estimates
rate
measuring
programme
magnification
photometry
star formation
histories
history
broadband
modeling

Keywords

  • galaxies: evolution
  • galaxies: formation
  • galaxies: high-redshift

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Measuring the stellar masses of z ∼ 7 galaxies with the spitzer ultrafaint survey program (Surfs up). / Ryan, R. E.; Ryan, R. E.; Gonzalez, A. H.; Lemaux, B. C.; Bradač, M.; Casertano, S.; Allen, S.; Cain, B.; Gladders, M.; Hall, N.; Hildebradt, H.; Hinz, J.; Huang, K. H.; Lubin, L.; Schrabback, T.; Stiavelli, M.; Treu, T.; Von Der Linden, A.; Zaritsky, Dennis F.

In: Astrophysical Journal Letters, Vol. 786, No. 1, L4, 01.05.2014.

Research output: Contribution to journalArticle

Ryan, RE, Ryan, RE, Gonzalez, AH, Lemaux, BC, Bradač, M, Casertano, S, Allen, S, Cain, B, Gladders, M, Hall, N, Hildebradt, H, Hinz, J, Huang, KH, Lubin, L, Schrabback, T, Stiavelli, M, Treu, T, Von Der Linden, A & Zaritsky, DF 2014, 'Measuring the stellar masses of z ∼ 7 galaxies with the spitzer ultrafaint survey program (Surfs up)', Astrophysical Journal Letters, vol. 786, no. 1, L4. https://doi.org/10.1088/2041-8205/786/1/L4
Ryan, R. E. ; Ryan, R. E. ; Gonzalez, A. H. ; Lemaux, B. C. ; Bradač, M. ; Casertano, S. ; Allen, S. ; Cain, B. ; Gladders, M. ; Hall, N. ; Hildebradt, H. ; Hinz, J. ; Huang, K. H. ; Lubin, L. ; Schrabback, T. ; Stiavelli, M. ; Treu, T. ; Von Der Linden, A. ; Zaritsky, Dennis F. / Measuring the stellar masses of z ∼ 7 galaxies with the spitzer ultrafaint survey program (Surfs up). In: Astrophysical Journal Letters. 2014 ; Vol. 786, No. 1.
@article{892c33b811ad4f9693f8923eccaeb843,
title = "Measuring the stellar masses of z ∼ 7 galaxies with the spitzer ultrafaint survey program (Surfs up)",
abstract = "We present Spitzer/IRAC observations of nine z′-band dropouts highly magnified (2 ≲ μ ≲ 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 Infrared Array Camera (IRAC) band. We detect (≳ 3σ) 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 ∼5 × 107 M·. The detected galaxy has an estimated magnification of μ = 12 ± 4, which implies this galaxy has an ultraviolet luminosity of-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 (SFR) of SFR ∼ 1.3 M· yr-1 and stellar mass of M ∼ 2.0 × 109 M·, which gives a specific star formation rate of sSFR ∼ 0.7 Gyr-1. If this galaxy had sustained this SFR 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 that the exponentially increasing model is unlikely. Finally, based on the intrinsic SFR, we estimate that this galaxy has a likely [C II] flux of 〈f [C II]〉 = 1.6 mJy.",
keywords = "galaxies: evolution, galaxies: formation, galaxies: high-redshift",
author = "Ryan, {R. E.} and Ryan, {R. E.} and Gonzalez, {A. H.} and Lemaux, {B. C.} and M. Bradač and S. Casertano and S. Allen and B. Cain and M. Gladders and N. Hall and H. Hildebradt and J. Hinz and Huang, {K. H.} and L. Lubin and T. Schrabback and M. Stiavelli and T. Treu and {Von Der Linden}, A. and Zaritsky, {Dennis F}",
year = "2014",
month = "5",
day = "1",
doi = "10.1088/2041-8205/786/1/L4",
language = "English (US)",
volume = "786",
journal = "Astrophysical Journal Letters",
issn = "2041-8205",
publisher = "IOP Publishing Ltd.",
number = "1",

}

TY - JOUR

T1 - Measuring the stellar masses of z ∼ 7 galaxies with the spitzer ultrafaint survey program (Surfs up)

AU - Ryan, R. E.

AU - Ryan, R. E.

AU - Gonzalez, A. H.

AU - Lemaux, B. C.

AU - Bradač, M.

AU - Casertano, S.

AU - Allen, S.

AU - Cain, B.

AU - Gladders, M.

AU - Hall, N.

AU - Hildebradt, H.

AU - Hinz, J.

AU - Huang, K. H.

AU - Lubin, L.

AU - Schrabback, T.

AU - Stiavelli, M.

AU - Treu, T.

AU - Von Der Linden, A.

AU - Zaritsky, Dennis F

PY - 2014/5/1

Y1 - 2014/5/1

N2 - We present Spitzer/IRAC observations of nine z′-band dropouts highly magnified (2 ≲ μ ≲ 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 Infrared Array Camera (IRAC) band. We detect (≳ 3σ) 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 ∼5 × 107 M·. The detected galaxy has an estimated magnification of μ = 12 ± 4, which implies this galaxy has an ultraviolet luminosity of-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 (SFR) of SFR ∼ 1.3 M· yr-1 and stellar mass of M ∼ 2.0 × 109 M·, which gives a specific star formation rate of sSFR ∼ 0.7 Gyr-1. If this galaxy had sustained this SFR 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 that the exponentially increasing model is unlikely. Finally, based on the intrinsic SFR, we estimate that this galaxy has a likely [C II] flux of 〈f [C II]〉 = 1.6 mJy.

AB - We present Spitzer/IRAC observations of nine z′-band dropouts highly magnified (2 ≲ μ ≲ 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 Infrared Array Camera (IRAC) band. We detect (≳ 3σ) 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 ∼5 × 107 M·. The detected galaxy has an estimated magnification of μ = 12 ± 4, which implies this galaxy has an ultraviolet luminosity of-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 (SFR) of SFR ∼ 1.3 M· yr-1 and stellar mass of M ∼ 2.0 × 109 M·, which gives a specific star formation rate of sSFR ∼ 0.7 Gyr-1. If this galaxy had sustained this SFR 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 that the exponentially increasing model is unlikely. Finally, based on the intrinsic SFR, we estimate that this galaxy has a likely [C II] flux of 〈f [C II]〉 = 1.6 mJy.

KW - galaxies: evolution

KW - galaxies: formation

KW - galaxies: high-redshift

UR - http://www.scopus.com/inward/record.url?scp=84899451606&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84899451606&partnerID=8YFLogxK

U2 - 10.1088/2041-8205/786/1/L4

DO - 10.1088/2041-8205/786/1/L4

M3 - Article

AN - SCOPUS:84899451606

VL - 786

JO - Astrophysical Journal Letters

JF - Astrophysical Journal Letters

SN - 2041-8205

IS - 1

M1 - L4

ER -