NEW OBSERVATIONS OF z ~ 7 GALAXIES: EVIDENCE FOR A PATCHY REIONIZATION

L. Pentericci; E. Vanzella; A. Fontana; M. Castellano; T. Treu; A. Mesinger; M. Dijkstra; A. Grazian; M. Bradac; C. Conselice; S. Cristiani; J. Dunlop; A. Galametz; M. Giavalisco; E. Giallongo; A. Koekemoer; R. McLure; R. Maiolino; D. Paris; P. Santini

doi:10.1088/0004-637X/793/2/113

NEW OBSERVATIONS OF z ~ 7 GALAXIES: EVIDENCE FOR A PATCHY REIONIZATION

L. Pentericci^*, E. Vanzella, A. Fontana, M. Castellano, T. Treu, A. Mesinger, M. Dijkstra, A. Grazian, M. Bradac, C. Conselice, S. Cristiani, J. Dunlop, A. Galametz, M. Giavalisco, E. Giallongo, A. Koekemoer, R. McLure, R. Maiolino, D. Paris, P. Santini

^*Corresponding author for this work

School of Physics and Astronomy

Research output: Contribution to journal › Article › peer-review

Abstract / Description of output

We present new results from our search for z similar to 7 galaxies from deep spectroscopic observations of candidate z dropouts in the CANDELS fields. Despite the extremely low flux limits achieved by our sensitive observations, only two galaxies have robust redshift identifications, one from its Ly alpha emission line at z = 6.65, the other from its Lyman break, i.e., the continuum discontinuity at the Ly alpha wavelength consistent with a redshift of 6.42 but with no emission line. In addition, for 23 galaxies we present deep limits in the Ly alpha equivalent width derived from the nondetections in ultradeep observations. Using this new data as well as previous samples, we assemble a total of 68 candidate z similar to 7 galaxies with deep spectroscopic observations, of which 12 have a line detection. With this much enlarged sample we can place solid constraints on the declining fraction of Ly alpha emission in z similar to 7 Lyman-break galaxies compared to z similar to 6, both for bright and faint galaxies. Applying a simple analytical model, we show that the present data favor a patchy reionization process rather than a smooth one.

Original language	English
Article number	113
Number of pages	10
Journal	Astrophysical Journal
Volume	793
Issue number	2
DOIs	https://doi.org/10.1088/0004-637X/793/2/113
Publication status	Published - 1 Oct 2014

Keywords / Materials (for Non-textual outputs)

galaxies: distances and redshifts
galaxies: formation
galaxies: high-redshift
LYMAN-BREAK GALAXIES
LY-ALPHA-EMITTERS
STAR-FORMING GALAXIES
COSMIC REIONIZATION
SPECTROSCOPIC CONFIRMATION
LUMINOSITY FUNCTION
KECK SPECTROSCOPY
PROBING REIONIZATION
IONIZING EMISSIVITY
EARLIEST GALAXIES

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Pentericci, L., Vanzella, E., Fontana, A., Castellano, M., Treu, T., Mesinger, A., Dijkstra, M., Grazian, A., Bradac, M., Conselice, C., Cristiani, S., Dunlop, J., Galametz, A., Giavalisco, M., Giallongo, E., Koekemoer, A., McLure, R., Maiolino, R., Paris, D., & Santini, P. (2014). NEW OBSERVATIONS OF z ~ 7 GALAXIES: EVIDENCE FOR A PATCHY REIONIZATION. Astrophysical Journal, 793(2), Article 113. https://doi.org/10.1088/0004-637X/793/2/113

@article{22829d0bc5744217a45f0f4575586403,

title = "NEW OBSERVATIONS OF z ~ 7 GALAXIES: EVIDENCE FOR A PATCHY REIONIZATION",

abstract = "We present new results from our search for z similar to 7 galaxies from deep spectroscopic observations of candidate z dropouts in the CANDELS fields. Despite the extremely low flux limits achieved by our sensitive observations, only two galaxies have robust redshift identifications, one from its Ly alpha emission line at z = 6.65, the other from its Lyman break, i.e., the continuum discontinuity at the Ly alpha wavelength consistent with a redshift of 6.42 but with no emission line. In addition, for 23 galaxies we present deep limits in the Ly alpha equivalent width derived from the nondetections in ultradeep observations. Using this new data as well as previous samples, we assemble a total of 68 candidate z similar to 7 galaxies with deep spectroscopic observations, of which 12 have a line detection. With this much enlarged sample we can place solid constraints on the declining fraction of Ly alpha emission in z similar to 7 Lyman-break galaxies compared to z similar to 6, both for bright and faint galaxies. Applying a simple analytical model, we show that the present data favor a patchy reionization process rather than a smooth one.",

keywords = "galaxies: distances and redshifts, galaxies: formation, galaxies: high-redshift, LYMAN-BREAK GALAXIES, LY-ALPHA-EMITTERS, STAR-FORMING GALAXIES, COSMIC REIONIZATION, SPECTROSCOPIC CONFIRMATION, LUMINOSITY FUNCTION, KECK SPECTROSCOPY, PROBING REIONIZATION, IONIZING EMISSIVITY, EARLIEST GALAXIES",

author = "L. Pentericci and E. Vanzella and A. Fontana and M. Castellano and T. Treu and A. Mesinger and M. Dijkstra and A. Grazian and M. Bradac and C. Conselice and S. Cristiani and J. Dunlop and A. Galametz and M. Giavalisco and E. Giallongo and A. Koekemoer and R. McLure and R. Maiolino and D. Paris and P. Santini",

year = "2014",

month = oct,

day = "1",

doi = "10.1088/0004-637X/793/2/113",

language = "English",

volume = "793",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "IOP Publishing Ltd.",

number = "2",

}

Pentericci, L, Vanzella, E, Fontana, A, Castellano, M, Treu, T, Mesinger, A, Dijkstra, M, Grazian, A, Bradac, M, Conselice, C, Cristiani, S, Dunlop, J, Galametz, A, Giavalisco, M, Giallongo, E, Koekemoer, A, McLure, R, Maiolino, R, Paris, D & Santini, P 2014, 'NEW OBSERVATIONS OF z ~ 7 GALAXIES: EVIDENCE FOR A PATCHY REIONIZATION', Astrophysical Journal, vol. 793, no. 2, 113. https://doi.org/10.1088/0004-637X/793/2/113

TY - JOUR

T1 - NEW OBSERVATIONS OF z ~ 7 GALAXIES

T2 - EVIDENCE FOR A PATCHY REIONIZATION

AU - Pentericci, L.

AU - Vanzella, E.

AU - Fontana, A.

AU - Castellano, M.

AU - Treu, T.

AU - Mesinger, A.

AU - Dijkstra, M.

AU - Grazian, A.

AU - Bradac, M.

AU - Conselice, C.

AU - Cristiani, S.

AU - Dunlop, J.

AU - Galametz, A.

AU - Giavalisco, M.

AU - Giallongo, E.

AU - Koekemoer, A.

AU - McLure, R.

AU - Maiolino, R.

AU - Paris, D.

AU - Santini, P.

PY - 2014/10/1

Y1 - 2014/10/1

N2 - We present new results from our search for z similar to 7 galaxies from deep spectroscopic observations of candidate z dropouts in the CANDELS fields. Despite the extremely low flux limits achieved by our sensitive observations, only two galaxies have robust redshift identifications, one from its Ly alpha emission line at z = 6.65, the other from its Lyman break, i.e., the continuum discontinuity at the Ly alpha wavelength consistent with a redshift of 6.42 but with no emission line. In addition, for 23 galaxies we present deep limits in the Ly alpha equivalent width derived from the nondetections in ultradeep observations. Using this new data as well as previous samples, we assemble a total of 68 candidate z similar to 7 galaxies with deep spectroscopic observations, of which 12 have a line detection. With this much enlarged sample we can place solid constraints on the declining fraction of Ly alpha emission in z similar to 7 Lyman-break galaxies compared to z similar to 6, both for bright and faint galaxies. Applying a simple analytical model, we show that the present data favor a patchy reionization process rather than a smooth one.

AB - We present new results from our search for z similar to 7 galaxies from deep spectroscopic observations of candidate z dropouts in the CANDELS fields. Despite the extremely low flux limits achieved by our sensitive observations, only two galaxies have robust redshift identifications, one from its Ly alpha emission line at z = 6.65, the other from its Lyman break, i.e., the continuum discontinuity at the Ly alpha wavelength consistent with a redshift of 6.42 but with no emission line. In addition, for 23 galaxies we present deep limits in the Ly alpha equivalent width derived from the nondetections in ultradeep observations. Using this new data as well as previous samples, we assemble a total of 68 candidate z similar to 7 galaxies with deep spectroscopic observations, of which 12 have a line detection. With this much enlarged sample we can place solid constraints on the declining fraction of Ly alpha emission in z similar to 7 Lyman-break galaxies compared to z similar to 6, both for bright and faint galaxies. Applying a simple analytical model, we show that the present data favor a patchy reionization process rather than a smooth one.

KW - galaxies: distances and redshifts

KW - galaxies: formation

KW - galaxies: high-redshift

KW - LYMAN-BREAK GALAXIES

KW - LY-ALPHA-EMITTERS

KW - STAR-FORMING GALAXIES

KW - COSMIC REIONIZATION

KW - SPECTROSCOPIC CONFIRMATION

KW - LUMINOSITY FUNCTION

KW - KECK SPECTROSCOPY

KW - PROBING REIONIZATION

KW - IONIZING EMISSIVITY

KW - EARLIEST GALAXIES

U2 - 10.1088/0004-637X/793/2/113

DO - 10.1088/0004-637X/793/2/113

M3 - Article

SN - 0004-637X

VL - 793

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2

M1 - 113

ER -

NEW OBSERVATIONS OF z ~ 7 GALAXIES: EVIDENCE FOR A PATCHY REIONIZATION

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Keywords / Materials (for Non-textual outputs)

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