Keck spectroscopy of faint 3 < z < 7 Lyman break galaxies – I. New constraints on cosmic reionization from the luminosity and redshift-dependent fraction of Lyman α emission

We present the first results of a new Keck spectroscopic survey of UV faint Lyman break galaxies in the redshift range 3 1.9 with respect to the predicted z ≃ 7 value, a result which, if confirmed with future surveys, would suggest an increase in the neutral fraction by this epoch. Given the abundant supply of z and Y drops now available from deep Hubble WFC3/IR surveys, we show it will soon be possible to significantly improve estimates of the Lyα fraction using optical and near-infrared multi-object spectrographs, thereby extending the study conducted in this paper to 7 ≲ z ≲ 8.

[1]  M. Jarvis,et al.  Probing ∼L* Lyman‐break galaxies at z≈ 7 in GOODS‐South with WFC3 on Hubble Space Telescope , 2010 .

[2]  C. Steidel,et al.  THE STRUCTURE AND KINEMATICS OF THE CIRCUMGALACTIC MEDIUM FROM FAR-ULTRAVIOLET SPECTRA OF z ≃ 2–3 GALAXIES , 2010, 1003.0679.

[3]  S. Wilkins,et al.  New Star Forming Galaxies at z\approx 7 from WFC3 Imaging , 2010, 1002.4866.

[4]  C. Leitherer,et al.  Escape of about five per cent of Lyman-α photons from high-redshift star-forming galaxies , 2010, Nature.

[5]  Edward J. Wollack,et al.  SEVEN-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE (WMAP) OBSERVATIONS: POWER SPECTRA AND WMAP-DERIVED PARAMETERS , 2010, 1001.4635.

[6]  S. Okamura,et al.  Stellar populations of Lyα emitters at z= 3–4 based on deep large area surveys in the Subaru-SXDS/UKIDSS-UDS Field , 2009, 0911.2544.

[7]  C. Steidel,et al.  THE RELATIONSHIP BETWEEN STELLAR POPULATIONS AND Lyα EMISSION IN LYMAN BREAK GALAXIES , 2009, 0911.2000.

[8]  M. Franx,et al.  STAR FORMATION RATES AND STELLAR MASSES OF z = 7–8 GALAXIES FROM IRAC OBSERVATIONS OF THE WFC3/IR EARLY RELEASE SCIENCE AND THE HUDF FIELDS , 2009, 0911.1356.

[9]  D. Nidever,et al.  THE IMPORTANCE OF NEBULAR CONTINUUM AND LINE EMISSION IN OBSERVATIONS OF YOUNG MASSIVE STAR CLUSTERS , 2009, 0911.0447.

[10]  Institute for Advanced Study,et al.  RADIATIVE TRANSFER MODELING OF Lyα EMITTERS. I. STATISTICS OF SPECTRA AND LUMINOSITY , 2009, 0910.2712.

[11]  M. Jarvis,et al.  Probing $\sim L_{*}$ Lyman-break Galaxies at $z\approx 7$ in GOODS-South with WFC3 on HST , 2009, 0910.1098.

[12]  M. Franx,et al.  ULTRADEEP INFRARED ARRAY CAMERA OBSERVATIONS OF SUB-L* z ∼ 7 AND z ∼ 8 GALAXIES IN THE HUBBLE ULTRA DEEP FIELD: THE CONTRIBUTION OF LOW-LUMINOSITY GALAXIES TO THE STELLAR MASS DENSITY AND REIONIZATION , 2009, 0910.0838.

[13]  Astronomy,et al.  A study of interstellar gas and stars in the gravitationally lensed galaxy 'the Cosmic Eye' from rest-frame ultraviolet spectroscopy , 2009, 0910.0840.

[14]  M. Franx,et al.  VERY BLUE UV-CONTINUUM SLOPE β OF LOW LUMINOSITY z ∼ 7 GALAXIES FROM WFC3/IR: EVIDENCE FOR EXTREMELY LOW METALLICITIES? , 2009, 0910.0001.

[15]  M. Franx,et al.  UV CONTINUUM SLOPE AND DUST OBSCURATION FROM z ∼ 6 TO z ∼ 2: THE STAR FORMATION RATE DENSITY AT HIGH REDSHIFT , 2009, 0909.4074.

[16]  Marijn Franx,et al.  THE STELLAR MASS DENSITY AND SPECIFIC STAR FORMATION RATE OF THE UNIVERSE AT z ∼ 7 , 2009, 0909.3517.

[17]  J. Dunlop,et al.  Galaxies at z = 6 - 9 from the WFC3/IR imaging of the HUDF , 2009, 0909.2437.

[18]  Mark Lacy,et al.  The contribution of high-redshift galaxies to cosmic reionization: New results from deep WFC3 imaging of the Hubble Ultra Deep Field , 2009, 0909.2255.

[19]  R. Bouwens,et al.  z ∼ 7 GALAXIES IN THE HUDF: FIRST EPOCH WFC3/IR RESULTS , 2009, 0909.1806.

[20]  S. M. Fall,et al.  LARGE AREA SURVEY FOR z = 7 GALAXIES IN SDF AND GOODS-N: IMPLICATIONS FOR GALAXY FORMATION AND COSMIC REIONIZATION , 2009, 0908.3191.

[21]  Ucla,et al.  On the dependence between UV luminosity and Lyα equivalent width in high-redshift galaxies , 2009, 0907.3733.

[22]  Astronomy,et al.  Limits on the luminosity function of Ly alpha emitters at z=7.7 , 2009, 0907.3354.

[23]  M. Pettini,et al.  The ultraviolet spectrum of the gravitationally lensed galaxy ‘the Cosmic Horseshoe’: a close-up of a star-forming galaxy at z∼ 2 , 2009, 0906.2412.

[24]  D. Schaerer,et al.  The impact of nebular emission on the ages of z~6 galaxies , 2009, 0905.0866.

[25]  K. Bundy,et al.  THE EVOLUTIONARY HISTORY OF LYMAN BREAK GALAXIES BETWEEN REDSHIFT 4 AND 6: OBSERVING SUCCESSIVE GENERATIONS OF MASSIVE GALAXIES IN FORMATION , 2009, 0902.2907.

[26]  M. Nonino,et al.  SPECTROSCOPIC OBSERVATIONS OF LYMAN BREAK GALAXIES AT REDSHIFTS ∼4, 5, AND 6 IN THE GOODS-SOUTH FIELD , 2009, 0901.4364.

[27]  A. Fontana,et al.  The physical properties of Lyα emitting galaxies: not just primeval galaxies? , 2008, 0811.1861.

[28]  C. Steidel,et al.  A STEEP FAINT-END SLOPE OF THE UV LUMINOSITY FUNCTION AT z ∼ 2–3: IMPLICATIONS FOR THE GLOBAL STELLAR MASS DENSITY AND STAR FORMATION IN LOW-MASS HALOS , 2008, 0810.2788.

[29]  D. Schaerer,et al.  3D Lyα radiation transfer III. Constraints on gas and stellar properties of z ∼ 3 Lyman break galaxies (LBG) and implications for high-z LBGs and Lyα emitters , 2008, 0805.3601.

[30]  Observatoire de Geneve,et al.  On the Detectability of Lyman-alpha Emission in Star-forming Galaxies: The Role of Dust , 2008, 0805.3501.

[31]  J. Walsh,et al.  SPECTROSCOPIC CONFIRMATION OF FAINT LYMAN BREAK GALAXIES NEAR REDSHIFT FIVE IN THE HUBBLE ULTRA DEEP FIELD , 2008, 0805.1056.

[32]  R. Bouwens,et al.  z ∼ 7–10 GALAXIES BEHIND LENSING CLUSTERS: CONTRAST WITH FIELD SEARCH RESULTS , 2008, 0805.0593.

[33]  Richard S. Ellis,et al.  A Hubble and Spitzer Space Telescope Survey for Gravitationally Lensed Galaxies: Further Evidence for a Significant Population of Low-Luminosity Galaxies beyond z = 7 , 2008, 0803.4391.

[34]  M. Halpern,et al.  FIVE-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE OBSERVATIONS: LIKELIHOODS AND PARAMETERS FROM THE WMAP DATA , 2008, 0803.0586.

[35]  D. Schaerer,et al.  3D Lyα radiation transfer II. Fitting the Lyman break galaxy MS 1512-cB58 and implications for Lyα emission in high-z starbursts , 2008, 0801.1187.

[36]  M. Bremer,et al.  On contamination and completeness in z ≥ 5 Lyman-break galaxy surveys , 2007, 0712.2457.

[37]  Zurich,et al.  The effect of the intergalactic environment on the observability of Lyα emitters during reionization , 2007, 0711.2944.

[38]  R. Ellis,et al.  The Evolutionary History of Galactic Bulges: Photometric and Spectroscopic Studies of Distant Spheroids in the GOODS Fields , 2007, 0711.0238.

[39]  R. Dav'e.  The galaxy stellar mass-star formation rate relation: evidence for an evolving stellar initial mass function? , 2007, 0710.0381.

[40]  S. Finkelstein,et al.  Effects of Dust Geometry in Lyα Galaxies at z = 4.4 , 2007, 0708.4226.

[41]  S. Furlanetto,et al.  Lyα emitters during the early stages of reionization , 2007, 0708.0006.

[42]  S. Okamura,et al.  The Subaru/XMM-Newton Deep Survey (SXDS). IV. Evolution of Lyα Emitters from z = 3.1 to 5.7 in the 1 deg2 Field: Luminosity Functions and AGN , 2007, 0707.3161.

[43]  R. Bouwens,et al.  UV Luminosity Functions at z~4, 5, and 6 from the Hubble Ultra Deep Field and Other Deep Hubble Space Telescope ACS Fields: Evolution and Star Formation History , 2007, 0707.2080.

[44]  Takashi Hattori,et al.  Reionization and Galaxy Evolution Probed by z = 7 Lyα Emitters , 2007, 0707.1561.

[45]  Richard S. Ellis,et al.  A Keck Survey for Gravitationally Lensed Lyα Emitters in the Redshift Range 8.5 < z < 10.4: New Constraints on the Contribution of Low-Luminosity Sources to Cosmic Reionization , 2007 .

[46]  K. Aoki,et al.  LYMAN BREAK GALAXIES AT z ∼ 5: REST-FRAME UV SPECTRA. III. , 2007, 0705.1145.

[47]  M. Zaldarriaga,et al.  Studying reionization with Lyα emitters , 2007, 0704.2239.

[48]  M. Dijkstra,et al.  The impact of The IGM on high-redshift Lyα emission lines , 2007, astro-ph/0701667.

[49]  J. Rhoads,et al.  The GLARE Survey – II. Faint z≈ 6 Lyα line emitters in the HUDF , 2007, astro-ph/0701211.

[50]  R. Bouwens,et al.  Spectroscopy of z ~ 6 i-Dropout Galaxies: Frequency of Lyα Emission and the Sizes of Lyα-emitting Galaxies , 2006, astro-ph/0612454.

[51]  Z. Haiman,et al.  Luminosity functions of Lyα emitting galaxies and cosmic reionization of hydrogen , 2006, astro-ph/0611195.

[52]  T. Morokuma,et al.  A galaxy at a redshift z = 6.96 , 2006, Nature.

[53]  S. Okamura,et al.  Luminosity Functions of Lyman Break Galaxies at z ~ 4 and z ~ 5 in the Subaru Deep Field , 2006, astro-ph/0608512.

[54]  W. Sargent,et al.  The Evolution of Optical Depth in the Lyα Forest: Evidence Against Reionization at z~6 , 2006, astro-ph/0607633.

[55]  M. Lacy,et al.  The stellar mass density at z ~6 from Spitzer imaging of i'-drop galaxies , 2006, astro-ph/0607306.

[56]  Max Pettini,et al.  The Direct Detection of Lyman Continuum Emission from Star-forming Galaxies at z~3 , 2006, astro-ph/0606635.

[57]  K. Aoki,et al.  Deficiency of Large Equivalent Width Lyα Emission in Luminous Lyman Break Galaxies at z ~ 5-6? , 2006, astro-ph/0605289.

[58]  R. Bouwens,et al.  Galaxies in the Hubble Ultra Deep Field. I. Detection, Multiband Photometry, Photometric Redshifts, and Morphology , 2006, astro-ph/0605262.

[59]  H. Ferguson,et al.  The Stellar Masses and Star Formation Histories of Galaxies at z ≈ 6: Constraints from Spitzer Observations in the Great Observatories Origins Deep Survey , 2006, astro-ph/0604554.

[60]  M. Lacy,et al.  A New Measurement of the Stellar Mass Density at z ≈ 5: Implications for the Sources of Cosmic Reionization , 2006, astro-ph/0604250.

[61]  S. Okamura,et al.  The End of the Reionization Epoch Probed by Lyα Emitters at z = 6.5 in the Subaru Deep Field , 2006, astro-ph/0604149.

[62]  Mamoru Doi,et al.  Lyα Emitters at z = 5.7 in the Subaru Deep Field , 2006, astro-ph/0602614.

[63]  A. Meiksin.  Colour corrections for high-redshift objects due to intergalactic attenuation , 2005, astro-ph/0512435.

[64]  Robert H. Becker,et al.  Constraining the Evolution of the Ionizing Background and the Epoch of Reionization with z ∼ 6 Quasars. II. A Sample of 19 Quasars , 2005, astro-ph/0512082.

[65]  R. Bouwens,et al.  Galaxies at z ~ 6: The UV Luminosity Function and Luminosity Density from 506 HUDF, HUDF Parallel ACS Field, and GOODS i-Dropouts , 2005, astro-ph/0509641.

[66]  S. Oh,et al.  Lyman α radiative transfer in a multiphase medium , 2005, astro-ph/0507586.

[67]  M. Zaldarriaga,et al.  The effects of reionization on Lyα galaxy surveys , 2005, astro-ph/0507266.

[68]  M. Nonino,et al.  The Great Observatories Origins Deep Survey VLT/VIMOS Spectroscopy in the GOODS-South Field , 2005, 0802.2930.

[69]  Cambridge,et al.  Spitzer imaging of i′‐drop galaxies: old stars at z≈ 6 , 2005, astro-ph/0502385.

[70]  Patrick J. McCarthy,et al.  Hubble Space Telescope Imaging and Keck Spectroscopy of z ≈ 6 i-Band Dropout Galaxies in the Advanced Camera for Surveys GOODS Fields , 2004 .

[71]  R. McMahon,et al.  Near-infrared properties of i-drop galaxies in the Hubble Ultra Deep Field , 2004, astro-ph/0403585.

[72]  Cambridge,et al.  The star formation rate of the Universe at z~ 6 from the Hubble Ultra-Deep Field , 2004, astro-ph/0403223.

[73]  J. Kneib,et al.  A Probable z ~ 7 Galaxy Strongly Lensed by the Rich Cluster A2218: Exploring the Dark Ages , 2004, astro-ph/0402319.

[74]  S. Okamura,et al.  Subaru Deep Survey. VI. A Census of Lyman Break Galaxies at z ≃ 4 and 5 in the Subaru Deep Fields: Clustering Properties , 2003, astro-ph/0309657.

[75]  S. M. Fall,et al.  The Great Observatories Origins Deep Survey: Initial Results from Optical and Near-Infrared Imaging , 2003, astro-ph/0309105.

[76]  Michael R. Santos.  Probing reionization with Lyman α emission lines , 2003, astro-ph/0308196.

[77]  M. Giavalisco,et al.  Lyman Break Galaxies at Redshift z ~ 3: Survey Description and Full Data Set , 2003, astro-ph/0305378.

[78]  Alison L. Coil,et al.  The DEIMOS spectrograph for the Keck II Telescope: integration and testing , 2003, SPIE Astronomical Telescopes + Instrumentation.

[79]  Cambridge,et al.  Lyman break galaxies and the star formation rate of the Universe at z≈ 6 , 2003, astro-ph/0302212.

[80]  Puragra Guhathakurta,et al.  Discoveries and Research Prospects from 6- to 10-Meter-Class Telescopes II , 2003 .

[81]  M. Pettini,et al.  Rest-Frame Ultraviolet Spectra of z ∼ 3 Lyman Break Galaxies , 2003, astro-ph/0301230.

[82]  D. Schaerer.  The transition from Population III to normal galaxies: Lyα and He II emission and the ionising properties of high redshift starburst galaxies , 2002, astro-ph/0210462.

[83]  A. Fontana,et al.  A VLT/FORS2 spectroscopic survey in the HDF-S ? , 2002, astro-ph/0210146.

[84]  Marc Davis,et al.  Science Objectives and Early Results of the DEEP2 Redshift Survey , 2002, SPIE Astronomical Telescopes + Instrumentation.

[85]  M. Giavalisco,et al.  The Rest-Frame Optical Properties of z ≃ 3 Galaxies , 2001, astro-ph/0107324.

[86]  M. Giavalisco,et al.  Lyα Imaging of a Proto-Cluster Region at ⟨z⟩ = 3.09 , 1999, astro-ph/9910144.

[87]  Timothy M. Heckman,et al.  Dust Absorption and the Ultraviolet Luminosity Density at z ≈ 3 as Calibrated by Local Starburst Galaxies , 1999, astro-ph/9903054.

[88]  Denis Foo Kune,et al.  Starburst99: Synthesis Models for Galaxies with Active Star Formation , 1999, astro-ph/9902334.

[89]  Cambridge,et al.  ∼ 4 and the Evolution of the Uv Luminosity Density at High Redshift , 2022 .

[90]  N. Benı́tez.  Bayesian Photometric Redshift Estimation , 1998, astro-ph/9811189.

[91]  Z. Haiman,et al.  Models for Dusty Lyα Emitters at High Redshift , 1998, astro-ph/9809223.

[92]  James E. Larkin,et al.  Design and development of NIRSPEC: a near-infrared echelle spectrograph for the Keck II telescope , 1998, Astronomical Telescopes and Instrumentation.

[93]  E. Bertin,et al.  SExtractor: Software for source extraction , 1996 .

[94]  S. M. Fall,et al.  Lyman-Alpha Emission from Galaxies , 1993 .

[95]  D. Neufeld.  The Escape of Lyman-Alpha Radiation from a Multiphase Interstellar Medium , 1991 .

[96]  J. B. Oke,et al.  Secondary standard stars for absolute spectrophotometry , 1983 .

[97]  A. V. Filippenko,et al.  THE IMPORTANCE OF ATMOSPHERIC DIFFERENTIAL REFRACTION IN SPECTROPHOTOMETRY. , 1982 .

[98]  J. Rhoads,et al.  Optical-to-Mid-Infrared Observations of Lyα Galaxies at z ≈ 5 in the Hubble Ultra Deep Field: A Young and Low-Mass Population , 2007 .

[99]  R. Pelló,et al.  Accepted for Publication in Apj , 2007 .