Discovery of Lyman break galaxies at z ∼ 7 from the zFourGE survey

V. Tilvi, C. Papovich, K. V.H. Tran, I. Labbé, L. R. Spitler, C. M.S. Straatman, S. E. Persson, A. Monson, K. Glazebrook, R. F. Quadri, P. Van Dokkum, M. L.N. Ashby, S. M. Faber, G. G. Fazio, S. L. Finkelstein, H. C. Ferguson, N. A. Grogin, G. G. Kacprzak, D. D. Kelson, A. M. KoekemoerD. Murphy, P. J. McCarthy, J. A. Newman, B. Salmon, S. P. Willner

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

Star-forming galaxies at redshifts z > 6 are likely responsible for the reionization of the universe, and it is important to study the nature of these galaxies. We present three candidates for z ∼ 7 Lyman break galaxies (LBGs) from a 155 arcmin2 area in the CANDELS/COSMOS field imaged by the deep FourStar Galaxy Evolution (zFourGE) survey. The FourStar medium-band filters provide the equivalent of R ∼ 10 spectroscopy, which cleanly distinguishes between z ∼ 7 LBGs and brown dwarf stars. The distinction between stars and galaxies based on an object's angular size can become unreliable even when using Hubble Space Telescope imaging; there exists at least one very compact z ∼ 7 candidate (FWHM ∼ 0.5-1 kpc) that is indistinguishable from a point source. The medium-band filters provide narrower redshift distributions compared with broadband-derived redshifts. The UV luminosity function derived using the three z ∼ 7 candidates is consistent with previous studies, suggesting an evolution at the bright end (M UV ∼ -21.6 mag) from z ∼ 7 to z ∼ 5. Fitting the galaxies' spectral energy distributions, we predict Lyα equivalent widths for the two brightest LBGs, and find that the presence of a Lyα line affects the medium-band flux thereby changing the constraints on stellar masses and UV spectral slopes. This illustrates the limitations of deriving LBG properties using only broadband photometry. The derived specific star-formation rates for the bright LBGs are ∼13 Gyr-1, slightly higher than the lower-luminosity LBGs, implying that the star-formation rate increases with stellar mass for these galaxies.

Original languageEnglish (US)
Article number56
JournalAstrophysical Journal
Volume768
Issue number1
DOIs
StatePublished - May 1 2013

Fingerprint

galaxies
filter
point source
spectroscopy
energy
star formation rate
stellar mass
luminosity
distribution
rate
brown dwarf stars
broadband
filters
stars
spectral energy distribution
Hubble Space Telescope
point sources
photometry
COSMOS
universe

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Tilvi, V., Papovich, C., Tran, K. V. H., Labbé, I., Spitler, L. R., Straatman, C. M. S., ... Willner, S. P. (2013). Discovery of Lyman break galaxies at z ∼ 7 from the zFourGE survey. Astrophysical Journal, 768(1), [56]. https://doi.org/10.1088/0004-637X/768/1/56
Tilvi, V. ; Papovich, C. ; Tran, K. V.H. ; Labbé, I. ; Spitler, L. R. ; Straatman, C. M.S. ; Persson, S. E. ; Monson, A. ; Glazebrook, K. ; Quadri, R. F. ; Van Dokkum, P. ; Ashby, M. L.N. ; Faber, S. M. ; Fazio, G. G. ; Finkelstein, S. L. ; Ferguson, H. C. ; Grogin, N. A. ; Kacprzak, G. G. ; Kelson, D. D. ; Koekemoer, A. M. ; Murphy, D. ; McCarthy, P. J. ; Newman, J. A. ; Salmon, B. ; Willner, S. P. / Discovery of Lyman break galaxies at z ∼ 7 from the zFourGE survey. In: Astrophysical Journal. 2013 ; Vol. 768, No. 1.
@article{f0137573175c4cd584a7169d13657b64,
title = "Discovery of Lyman break galaxies at z ∼ 7 from the zFourGE survey",
abstract = "Star-forming galaxies at redshifts z > 6 are likely responsible for the reionization of the universe, and it is important to study the nature of these galaxies. We present three candidates for z ∼ 7 Lyman break galaxies (LBGs) from a 155 arcmin2 area in the CANDELS/COSMOS field imaged by the deep FourStar Galaxy Evolution (zFourGE) survey. The FourStar medium-band filters provide the equivalent of R ∼ 10 spectroscopy, which cleanly distinguishes between z ∼ 7 LBGs and brown dwarf stars. The distinction between stars and galaxies based on an object's angular size can become unreliable even when using Hubble Space Telescope imaging; there exists at least one very compact z ∼ 7 candidate (FWHM ∼ 0.5-1 kpc) that is indistinguishable from a point source. The medium-band filters provide narrower redshift distributions compared with broadband-derived redshifts. The UV luminosity function derived using the three z ∼ 7 candidates is consistent with previous studies, suggesting an evolution at the bright end (M UV ∼ -21.6 mag) from z ∼ 7 to z ∼ 5. Fitting the galaxies' spectral energy distributions, we predict Lyα equivalent widths for the two brightest LBGs, and find that the presence of a Lyα line affects the medium-band flux thereby changing the constraints on stellar masses and UV spectral slopes. This illustrates the limitations of deriving LBG properties using only broadband photometry. The derived specific star-formation rates for the bright LBGs are ∼13 Gyr-1, slightly higher than the lower-luminosity LBGs, implying that the star-formation rate increases with stellar mass for these galaxies.",
author = "V. Tilvi and C. Papovich and Tran, {K. V.H.} and I. Labb{\'e} and Spitler, {L. R.} and Straatman, {C. M.S.} and Persson, {S. E.} and A. Monson and K. Glazebrook and Quadri, {R. F.} and {Van Dokkum}, P. and Ashby, {M. L.N.} and Faber, {S. M.} and Fazio, {G. G.} and Finkelstein, {S. L.} and Ferguson, {H. C.} and Grogin, {N. A.} and Kacprzak, {G. G.} and Kelson, {D. D.} and Koekemoer, {A. M.} and D. Murphy and McCarthy, {P. J.} and Newman, {J. A.} and B. Salmon and Willner, {S. P.}",
year = "2013",
month = "5",
day = "1",
doi = "10.1088/0004-637X/768/1/56",
language = "English (US)",
volume = "768",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1",

}

Tilvi, V, Papovich, C, Tran, KVH, Labbé, I, Spitler, LR, Straatman, CMS, Persson, SE, Monson, A, Glazebrook, K, Quadri, RF, Van Dokkum, P, Ashby, MLN, Faber, SM, Fazio, GG, Finkelstein, SL, Ferguson, HC, Grogin, NA, Kacprzak, GG, Kelson, DD, Koekemoer, AM, Murphy, D, McCarthy, PJ, Newman, JA, Salmon, B & Willner, SP 2013, 'Discovery of Lyman break galaxies at z ∼ 7 from the zFourGE survey', Astrophysical Journal, vol. 768, no. 1, 56. https://doi.org/10.1088/0004-637X/768/1/56

Discovery of Lyman break galaxies at z ∼ 7 from the zFourGE survey. / Tilvi, V.; Papovich, C.; Tran, K. V.H.; Labbé, I.; Spitler, L. R.; Straatman, C. M.S.; Persson, S. E.; Monson, A.; Glazebrook, K.; Quadri, R. F.; Van Dokkum, P.; Ashby, M. L.N.; Faber, S. M.; Fazio, G. G.; Finkelstein, S. L.; Ferguson, H. C.; Grogin, N. A.; Kacprzak, G. G.; Kelson, D. D.; Koekemoer, A. M.; Murphy, D.; McCarthy, P. J.; Newman, J. A.; Salmon, B.; Willner, S. P.

In: Astrophysical Journal, Vol. 768, No. 1, 56, 01.05.2013.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Discovery of Lyman break galaxies at z ∼ 7 from the zFourGE survey

AU - Tilvi, V.

AU - Papovich, C.

AU - Tran, K. V.H.

AU - Labbé, I.

AU - Spitler, L. R.

AU - Straatman, C. M.S.

AU - Persson, S. E.

AU - Monson, A.

AU - Glazebrook, K.

AU - Quadri, R. F.

AU - Van Dokkum, P.

AU - Ashby, M. L.N.

AU - Faber, S. M.

AU - Fazio, G. G.

AU - Finkelstein, S. L.

AU - Ferguson, H. C.

AU - Grogin, N. A.

AU - Kacprzak, G. G.

AU - Kelson, D. D.

AU - Koekemoer, A. M.

AU - Murphy, D.

AU - McCarthy, P. J.

AU - Newman, J. A.

AU - Salmon, B.

AU - Willner, S. P.

PY - 2013/5/1

Y1 - 2013/5/1

N2 - Star-forming galaxies at redshifts z > 6 are likely responsible for the reionization of the universe, and it is important to study the nature of these galaxies. We present three candidates for z ∼ 7 Lyman break galaxies (LBGs) from a 155 arcmin2 area in the CANDELS/COSMOS field imaged by the deep FourStar Galaxy Evolution (zFourGE) survey. The FourStar medium-band filters provide the equivalent of R ∼ 10 spectroscopy, which cleanly distinguishes between z ∼ 7 LBGs and brown dwarf stars. The distinction between stars and galaxies based on an object's angular size can become unreliable even when using Hubble Space Telescope imaging; there exists at least one very compact z ∼ 7 candidate (FWHM ∼ 0.5-1 kpc) that is indistinguishable from a point source. The medium-band filters provide narrower redshift distributions compared with broadband-derived redshifts. The UV luminosity function derived using the three z ∼ 7 candidates is consistent with previous studies, suggesting an evolution at the bright end (M UV ∼ -21.6 mag) from z ∼ 7 to z ∼ 5. Fitting the galaxies' spectral energy distributions, we predict Lyα equivalent widths for the two brightest LBGs, and find that the presence of a Lyα line affects the medium-band flux thereby changing the constraints on stellar masses and UV spectral slopes. This illustrates the limitations of deriving LBG properties using only broadband photometry. The derived specific star-formation rates for the bright LBGs are ∼13 Gyr-1, slightly higher than the lower-luminosity LBGs, implying that the star-formation rate increases with stellar mass for these galaxies.

AB - Star-forming galaxies at redshifts z > 6 are likely responsible for the reionization of the universe, and it is important to study the nature of these galaxies. We present three candidates for z ∼ 7 Lyman break galaxies (LBGs) from a 155 arcmin2 area in the CANDELS/COSMOS field imaged by the deep FourStar Galaxy Evolution (zFourGE) survey. The FourStar medium-band filters provide the equivalent of R ∼ 10 spectroscopy, which cleanly distinguishes between z ∼ 7 LBGs and brown dwarf stars. The distinction between stars and galaxies based on an object's angular size can become unreliable even when using Hubble Space Telescope imaging; there exists at least one very compact z ∼ 7 candidate (FWHM ∼ 0.5-1 kpc) that is indistinguishable from a point source. The medium-band filters provide narrower redshift distributions compared with broadband-derived redshifts. The UV luminosity function derived using the three z ∼ 7 candidates is consistent with previous studies, suggesting an evolution at the bright end (M UV ∼ -21.6 mag) from z ∼ 7 to z ∼ 5. Fitting the galaxies' spectral energy distributions, we predict Lyα equivalent widths for the two brightest LBGs, and find that the presence of a Lyα line affects the medium-band flux thereby changing the constraints on stellar masses and UV spectral slopes. This illustrates the limitations of deriving LBG properties using only broadband photometry. The derived specific star-formation rates for the bright LBGs are ∼13 Gyr-1, slightly higher than the lower-luminosity LBGs, implying that the star-formation rate increases with stellar mass for these galaxies.

UR - http://www.scopus.com/inward/record.url?scp=84876808881&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84876808881&partnerID=8YFLogxK

U2 - 10.1088/0004-637X/768/1/56

DO - 10.1088/0004-637X/768/1/56

M3 - Article

AN - SCOPUS:84876808881

VL - 768

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

M1 - 56

ER -

Tilvi V, Papovich C, Tran KVH, Labbé I, Spitler LR, Straatman CMS et al. Discovery of Lyman break galaxies at z ∼ 7 from the zFourGE survey. Astrophysical Journal. 2013 May 1;768(1). 56. https://doi.org/10.1088/0004-637X/768/1/56