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Title: Shadow of colossus: A z = 2.44 galaxy protocluster detected in 3D Ly α forest tomographic mapping of the cosmos field

Abstract

By using moderate-resolution optical spectra from 58 background Lyman-break galaxies and quasars at z ~ 2.3-3 within a 11'.5 × 13'.5 area of the COSMOS field (~1200 deg -2 projected area density or ~2.4 h -1 Mpc mean transverse separation), we reconstruct a 3D tomographic map of the foreground Lyα forest absorption at 2.2 < z < 2.5 with an effective smoothing scale of ϵ 3D ≈ 2.5 h -1 Mpc comoving. Comparing with 61 coeval galaxies with spectroscopic redshifts in the same volume, we find that the galaxy positions are clearly biased toward regions with enhanced intergalactic medium (IGM) absorption in the tomographic map. Here, we find an extended IGM overdensity with deep absorption troughs at z = 2.45 associated with a recently discovered galaxy protocluster at the same redshift. Based on simulations matched to our data, we estimate the enclosed dark matter mass within this IGM overdensity to be M dm (z= 2.45) = (1.1 ± 0.6) ×10 14 h -1 M ⊙ , and argue based on this mass and absorption strength that it will form at least one z ~ 0 galaxy cluster with M(z = 0) = (3 ± 1.5) ×10 14h -1 M more » , although its elongated nature suggests that it will likely collapse into two separate clusters. We also point out a compact overdensity of six MOSDEF galaxies at z = 2.30 within a r ~ 1 h -1 Mpc radius and Δz ~ 0.006, which does not appear to have a large associated IGM overdensity. Our results demonstrate the potential of Lyα forest tomography on larger volumes to study galaxy properties as a function of environment, as well as revealing the large-scale IGM overdensities associated with protoclusters or other features of large-scale structure.« less

Authors:
ORCiD logo [1];  [1]; ORCiD logo [2]; ORCiD logo [3];  [4];  [4];  [5];  [6]; ORCiD logo [2]; ORCiD logo [7];  [4]; ORCiD logo [8]; ORCiD logo [9]
  1. Max Planck Inst. for Astronomy, Heidelberg (Germany)
  2. Univ. of California, Berkeley, CA (United States). Dept. of Astronomy; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  3. Univ. of California, Santa Cruz, CA (United States). Dept. of Astronomy and Astrophysics; Univ. of California Observatories, Santa Cruz, CA (United States)
  4. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  5. Univ. of California, Los Angeles, CA (United States). Dept. of Physics and Astronomy
  6. Univ. of Tokyo (Japan). Kavli Inst. for the Physics and Mathematics of the Universe (IPMU)
  7. Aix-Marseille Univ., Marseille (France)
  8. Max Planck Inst. for Extraterrestrial Physics, Munich (Germany)
  9. National Inst. of Astrophysics (INAF), Bologna (Italy). Astronomical Observatory of Bologna
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR) (SC-21)
OSTI Identifier:
1379068
Grant/Contract Number:  
AC02-05CH11231
Resource Type:
Accepted Manuscript
Journal Name:
The Astrophysical Journal (Online)
Additional Journal Information:
Journal Name: The Astrophysical Journal (Online); Journal Volume: 817; Journal Issue: 2; Journal ID: ISSN 1538-4357
Publisher:
Institute of Physics (IOP)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; cosmology: observations; galaxies: high red-shift; intergalactic medium; quasars: absorption lines; galaxies: clusters: general; techniques: spectroscopic

Citation Formats

Lee, Khee-Gan, Hennawi, Joseph F., White, Martin, Prochaska, J. Xavier, Font-Ribera, Andreu, Schlegel, David J., Rich, R. Michael, Suzuki, Nao, Stark, Casey W., Fèvre, Olivier Le, Nugent, Peter E., Salvato, Mara, and Zamorani, Gianni. Shadow of colossus: A z = 2.44 galaxy protocluster detected in 3D Lyα forest tomographic mapping of the cosmos field. United States: N. p., 2016. Web. doi:10.3847/0004-637X/817/2/160.
Lee, Khee-Gan, Hennawi, Joseph F., White, Martin, Prochaska, J. Xavier, Font-Ribera, Andreu, Schlegel, David J., Rich, R. Michael, Suzuki, Nao, Stark, Casey W., Fèvre, Olivier Le, Nugent, Peter E., Salvato, Mara, & Zamorani, Gianni. Shadow of colossus: A z = 2.44 galaxy protocluster detected in 3D Lyα forest tomographic mapping of the cosmos field. United States. doi:10.3847/0004-637X/817/2/160.
Lee, Khee-Gan, Hennawi, Joseph F., White, Martin, Prochaska, J. Xavier, Font-Ribera, Andreu, Schlegel, David J., Rich, R. Michael, Suzuki, Nao, Stark, Casey W., Fèvre, Olivier Le, Nugent, Peter E., Salvato, Mara, and Zamorani, Gianni. Thu . "Shadow of colossus: A z = 2.44 galaxy protocluster detected in 3D Lyα forest tomographic mapping of the cosmos field". United States. doi:10.3847/0004-637X/817/2/160. https://www.osti.gov/servlets/purl/1379068.
@article{osti_1379068,
title = {Shadow of colossus: A z = 2.44 galaxy protocluster detected in 3D Lyα forest tomographic mapping of the cosmos field},
author = {Lee, Khee-Gan and Hennawi, Joseph F. and White, Martin and Prochaska, J. Xavier and Font-Ribera, Andreu and Schlegel, David J. and Rich, R. Michael and Suzuki, Nao and Stark, Casey W. and Fèvre, Olivier Le and Nugent, Peter E. and Salvato, Mara and Zamorani, Gianni},
abstractNote = {By using moderate-resolution optical spectra from 58 background Lyman-break galaxies and quasars at z ~ 2.3-3 within a 11'.5 × 13'.5 area of the COSMOS field (~1200 deg -2 projected area density or ~2.4 h -1 Mpc mean transverse separation), we reconstruct a 3D tomographic map of the foreground Lyα forest absorption at 2.2 < z < 2.5 with an effective smoothing scale of ϵ3D ≈ 2.5 h -1 Mpc comoving. Comparing with 61 coeval galaxies with spectroscopic redshifts in the same volume, we find that the galaxy positions are clearly biased toward regions with enhanced intergalactic medium (IGM) absorption in the tomographic map. Here, we find an extended IGM overdensity with deep absorption troughs at z = 2.45 associated with a recently discovered galaxy protocluster at the same redshift. Based on simulations matched to our data, we estimate the enclosed dark matter mass within this IGM overdensity to be Mdm (z= 2.45) = (1.1 ± 0.6) ×10 14 h -1 M ⊙ , and argue based on this mass and absorption strength that it will form at least one z ~ 0 galaxy cluster with M(z = 0) = (3 ± 1.5) ×10 14h-1 M⊙ , although its elongated nature suggests that it will likely collapse into two separate clusters. We also point out a compact overdensity of six MOSDEF galaxies at z = 2.30 within a r ~ 1 h -1 Mpc radius and Δz ~ 0.006, which does not appear to have a large associated IGM overdensity. Our results demonstrate the potential of Lyα forest tomography on larger volumes to study galaxy properties as a function of environment, as well as revealing the large-scale IGM overdensities associated with protoclusters or other features of large-scale structure.},
doi = {10.3847/0004-637X/817/2/160},
journal = {The Astrophysical Journal (Online)},
number = 2,
volume = 817,
place = {United States},
year = {2016},
month = {1}
}

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Works referenced in this record:

The Connection between Galaxies and Intergalactic Absorption Lines at Redshift 2 ≲  z  ≲ 3
journal, August 2005

  • Adelberger, Kurt L.; Shapley, Alice E.; Steidel, Charles C.
  • The Astrophysical Journal, Vol. 629, Issue 2
  • DOI: 10.1086/431753

A refined measurement of the mean transmitted flux in the Lyα forest over 2 < z < 5 using composite quasar spectra
journal, February 2013

  • Becker, George D.; Hewett, Paul C.; Worseck, Gábor
  • Monthly Notices of the Royal Astronomical Society, Vol. 430, Issue 3
  • DOI: 10.1093/mnras/stt031

STACKED REST-FRAME ULTRAVIOLET SPECTRA OF Lyα-EMITTING AND CONTINUUM-SELECTED GALAXIES AT 2 < z < 3.5
journal, March 2012


Possible evidence for an inverted temperature–density relation in the intergalactic medium from the flux distribution of the Lyα forest
journal, May 2008


3D-HST: A WIDE-FIELD GRISM SPECTROSCOPIC SURVEY WITH THE HUBBLE SPACE TELESCOPE
journal, May 2012

  • Brammer, Gabriel B.; van Dokkum, Pieter G.; Franx, Marijn
  • The Astrophysical Journal Supplement Series, Vol. 200, Issue 2
  • DOI: 10.1088/0067-0049/200/2/13

The First Release COSMOS Optical and Near‐IR Data and Catalog
journal, September 2007

  • Capak, P.; Aussel, H.; Ajiki, M.
  • The Astrophysical Journal Supplement Series, Vol. 172, Issue 1
  • DOI: 10.1086/519081

A MASSIVE, DISTANT PROTO-CLUSTER AT z = 2.47 CAUGHT IN A PHASE OF RAPID FORMATION?
journal, July 2015


CLUSTER CANDIDATES AROUND LOW-POWER RADIO GALAXIES AT z ∼ 1-2 IN COSMOS
journal, August 2014


Recovering the topology of the intergalactic medium at z∼ 2
journal, May 2008


Ancient Light from Young Cosmic Cities: Physical and Observational Signatures of Galaxy Proto-Clusters
journal, December 2013


DISCOVERY OF A LARGE NUMBER OF CANDIDATE PROTOCLUSTERS TRACED BY ∼15 Mpc-SCALE GALAXY OVERDENSITIES IN COSMOS
journal, January 2014


SURVEYING GALAXY PROTO-CLUSTERS IN EMISSION: A LARGE-SCALE STRUCTURE AT z = 2.44 AND THE OUTLOOK FOR HETDEX
journal, July 2015

  • Chiang, Yi-Kuan; Overzier, Roderik A.; Gebhardt, Karl
  • The Astrophysical Journal, Vol. 808, Issue 1
  • DOI: 10.1088/0004-637X/808/1/37

A z = 2.5 protocluster associated with the radio galaxy MRC 2104-242: star formation and differing mass functions in dense environments
journal, April 2014

  • Cooke, E. A.; Hatch, N. A.; Muldrew, S. I.
  • Monthly Notices of the Royal Astronomical Society, Vol. 440, Issue 4
  • DOI: 10.1093/mnras/stu522

The VLT LBG Redshift Survey★- II. Interactions between galaxies and the IGM at z∼ 3: VLT LBG Redshift Survey - II
journal, May 2011


Recovery of the Power Spectrum of Mass Fluctuations from Observations of the Lyα Forest
journal, March 1998

  • Croft, Rupert A. C.; Weinberg, David H.; Katz, Neal
  • The Astrophysical Journal, Vol. 495, Issue 1
  • DOI: 10.1086/305289

Discovery of a rich proto-cluster at z = 2.9 and associated diffuse cold gas in the VIMOS Ultra-Deep Survey (VUDS)
journal, October 2014


A PROTOCLUSTER AT z = 2.45
journal, March 2015


A Direct Precision Measurement of the Intergalactic Lyα Opacity at 2 ≤ z ≤ 4.2
journal, July 2008

  • Faucher‐Giguère, Claude‐André; Prochaska, Jason X.; Lidz, Adam
  • The Astrophysical Journal, Vol. 681, Issue 2
  • DOI: 10.1086/588648

A mature cluster with X-ray emission at z = 2.07
journal, January 2011


Quasar quartet embedded in giant nebula reveals rare massive structure in distant universe
journal, May 2015


Compact Groups of Galaxies
journal, September 1997


COSMOS PHOTOMETRIC REDSHIFTS WITH 30-BANDS FOR 2-deg 2
journal, December 2008


Multiscale inference of matter fields and baryon acoustic oscillations from the Lyα forest: Multiscale inference from the Lyα forest
journal, November 2011

  • Kitaura, Francisco-Shu; Gallerani, Simona; Ferrara, Andrea
  • Monthly Notices of the Royal Astronomical Society, Vol. 420, Issue 1
  • DOI: 10.1111/j.1365-2966.2011.19997.x

The COSMOS Survey: Hubble Space Telescope Advanced Camera for Surveys Observations and Data Processing
journal, September 2007

  • Koekemoer, A. M.; Aussel, H.; Calzetti, D.
  • The Astrophysical Journal Supplement Series, Vol. 172, Issue 1
  • DOI: 10.1086/520086

Galactic Wind Effects on the Lyα Absorption in the Vicinity of Galaxies
journal, February 2006

  • Kollmeier, Juna A.; Miralda‐Escude, Jordi; Cen, Renyue
  • The Astrophysical Journal, Vol. 638, Issue 1
  • DOI: 10.1086/498104

THE MOSFIRE DEEP EVOLUTION FIELD (MOSDEF) SURVEY: REST-FRAME OPTICAL SPECTROSCOPY FOR ∼1500 H -SELECTED GALAXIES AT $1.37\leqslant z\leqslant 3.8$
journal, May 2015

  • Kriek, Mariska; Shapley, Alice E.; Reddy, Naveen A.
  • The Astrophysical Journal Supplement Series, Vol. 218, Issue 2
  • DOI: 10.1088/0067-0049/218/2/15

The VIMOS Ultra-Deep Survey: ~10 000 galaxies with spectroscopic redshifts to study galaxy assembly at early epochs 2 < z ≃ 6
journal, April 2015


SYSTEMATIC CONTINUUM ERRORS IN THE Lyα FOREST AND THE MEASURED TEMPERATURE–DENSITY RELATION
journal, June 2012


THE BOSS Lyα FOREST SAMPLE FROM SDSS DATA RELEASE 9
journal, February 2013


IGM CONSTRAINTS FROM THE SDSS-III/BOSS DR9 Lyα FOREST TRANSMISSION PROBABILITY DISTRIBUTION FUNCTION
journal, January 2015


LYα FOREST TOMOGRAPHY FROM BACKGROUND GALAXIES: THE FIRST MEGAPARSEC-RESOLUTION LARGE-SCALE STRUCTURE MAP AT z > 2
journal, October 2014


OBSERVATIONAL REQUIREMENTS FOR Lyα FOREST TOMOGRAPHIC MAPPING OF LARGE-SCALE STRUCTURE AT z ∼ 2
journal, May 2014


MEAN-FLUX-REGULATED PRINCIPAL COMPONENT ANALYSIS CONTINUUM FITTING OF SLOAN DIGITAL SKY SURVEY Lyα FOREST SPECTRA
journal, January 2012


Probing High-Redshift Galaxy Formation at the Highest Luminosities: new Insights from Deimos Spectroscopy
journal, June 2013


DISCOVERY OF A VERY LARGE STRUCTURE AT Z = 3.78
journal, November 2014


zCOSMOS: A Large VLT/VIMOS Redshift Survey Covering 0 < z < 3 in the COSMOS Field
journal, September 2007

  • Lilly, S. J.; Fevre, O. Le; Renzini, A.
  • The Astrophysical Journal Supplement Series, Vol. 172, Issue 1
  • DOI: 10.1086/516589

A first step towards a direct inversion of the Lyman forest in QSO spectra
journal, February 1999


The Keck Low-Resolution Imaging Spectrometer
journal, April 1995

  • Oke, J. B.; Cohen, J. G.; Carr, M.
  • Publications of the Astronomical Society of the Pacific, Vol. 107
  • DOI: 10.1086/133562

A principal component analysis of quasar UV spectra at z  ~  3
journal, May 2011


Inversion of the Lyman α forest: three-dimensional investigation of the intergalactic medium
journal, September 2001


The SDSS Damped Lyα Survey: Data Release 3
journal, December 2005

  • Prochaska, Jason X.; Herbert‐Fort, Stephane; Wolfe, Arthur M.
  • The Astrophysical Journal, Vol. 635, Issue 1
  • DOI: 10.1086/497287

Calibrating galaxy redshifts using absorption by the surrounding intergalactic medium★: Calibrating galaxy redshifts using the IGM
journal, May 2011


A new Method to Directly Measure the Jeans Scale of the Intergalactic Medium Using Close Quasar Pairs
journal, September 2013


DISSECTING PHOTOMETRIC REDSHIFT FOR ACTIVE GALACTIC NUCLEUS USING XMM - AND CHANDRA -COSMOS SAMPLES
journal, November 2011


Stellar Masses from the Candels Survey: the Goods-South and uds Fields
journal, March 2015


The Cosmic Evolution Survey (COSMOS): Overview
journal, September 2007

  • Scoville, N.; Aussel, H.; Brusa, M.
  • The Astrophysical Journal Supplement Series, Vol. 172, Issue 1
  • DOI: 10.1086/516585

FIRST RESULTS FROM Z –FOURGE: DISCOVERY OF A CANDIDATE CLUSTER AT z = 2.2 IN COSMOS
journal, March 2012


Protocluster discovery in tomographic Ly α forest flux maps
journal, August 2015

  • Stark, Casey W.; White, Martin; Lee, Khee-Gan
  • Monthly Notices of the Royal Astronomical Society, Vol. 453, Issue 1
  • DOI: 10.1093/mnras/stv1620

Spectroscopic Identification of a Protocluster at z  = 2.300: Environmental Dependence of Galaxy Properties at High Redshift
journal, June 2005

  • Steidel, Charles C.; Adelberger, Kurt L.; Shapley, Alice E.
  • The Astrophysical Journal, Vol. 626, Issue 1
  • DOI: 10.1086/429989

THE STRUCTURE AND KINEMATICS OF THE CIRCUMGALACTIC MEDIUM FROM FAR-ULTRAVIOLET SPECTRA OF z ≃ 2-3 GALAXIES
journal, June 2010


A Survey of Star‐forming Galaxies in the 1.4 ≲  z  ≲  2.5 Redshift Desert: Overview
journal, April 2004

  • Steidel, Charles C.; Shapley, Alice E.; Pettini, Max
  • The Astrophysical Journal, Vol. 604, Issue 2
  • DOI: 10.1086/381960

The impact of feedback from galaxy formation on the Lyman α transmitted flux
journal, December 2012

  • Viel, Matteo; Schaye, Joop; Booth, C. M.
  • Monthly Notices of the Royal Astronomical Society, Vol. 429, Issue 2
  • DOI: 10.1093/mnras/sts465

The Mass Function
journal, December 2002

  • White, Martin
  • The Astrophysical Journal Supplement Series, Vol. 143, Issue 2
  • DOI: 10.1086/342752

PARTICLE MESH SIMULATIONS OF THE Lyα FOREST AND THE SIGNATURE OF BARYON ACOUSTIC OSCILLATIONS IN THE INTERGALACTIC MEDIUM
journal, March 2010


KECK/MOSFIRE SPECTROSCOPIC CONFIRMATION OF A VIRGO-LIKE CLUSTER ANCESTOR AT z = 2.095
journal, October 2014

  • Yuan, Tiantian; Nanayakkara, Themiya; Kacprzak, Glenn G.
  • The Astrophysical Journal, Vol. 795, Issue 1
  • DOI: 10.1088/2041-8205/795/1/L20