J/ApJ/861/60 z∼2.3 cosmic voids in the COSMOS field (Krolewski+, 2018)
Detection of z∼2.3 cosmic voids from 3D Lyα forest tomography in
the COSMOS field.
Krolewski A., Lee K.-G., White M., Hennawi J.F., Schlegel D.J., Nugent P.E.,
Lukic Z., Stark C.W., Koekemoer A.M., Le Fevre O., Lemaux B.C., Maier C.,
Rich R.M., Salvato M., Tasca L.
<Astrophys. J., 861, 60 (2018)>
=2018ApJ...861...60K 2018ApJ...861...60K
ADC_Keywords: Intergalactic medium; Spectroscopy; Redshifts; Optical
Keywords: cosmology: observations ; intergalactic medium ;
large-scale structure of universe ; quasars: absorption lines
Abstract:
We present the most distant detection of cosmic voids (z∼2.3) and the
first detection of three-dimensional voids in the Lyα forest. We
used a 3D tomographic map of the absorption with an effective comoving
spatial resolution of 2.5h-1Mpc and a volume of 3.15x105h-3Mpc3,
which was reconstructed from moderate-resolution Keck I/LRIS spectra
of 240 background Lyman-break galaxies and quasars in a 0.16deg2
footprint in the COSMOS field. Voids were detected using a spherical
overdensity finder calibrated from hydrodynamical simulations of the
intergalactic medium (IGM). This allows us to identify voids in the
IGM corresponding to voids in the underlying matter density field,
yielding a consistent volume fraction of voids in both data (19.5%)
and simulations (18.2%). We fit excursion set models to the void
radius function and compare the radially averaged stacked profiles of
large voids (r>5h-1Mpc) to stacked voids in mock observations and
the simulated density field. Comparing with 432 coeval galaxies with
spectroscopic redshifts in the same volume as the tomographic map, we
find that the tomography-identified voids are underdense in galaxies
by 5.95σ compared to random cells.
Description:
We identify voids in the reconstructed intergalactic medium (IGM)
tomographic map from the first data release of the COSMOS Lyα
Mapping and Tomography Observations (CLAMATO) survey. The observations
(pilot observations: 2014-2015 and 2016, 2017) are described in detail
by Lee+ (2017, arXiv:1710.02894).
The survey targeted 2.3<z<3 background Lyman-break galaxies and
quasars with the LRIS spectrograph on the Keck I telescope at
Maunakea, Hawaii.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 46 355 *Voids in CLAMATO 2017 map
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Note on table2.dat: the first data release of the COSMOS Lyα
Mapping and Tomography Observations (CLAMATO) survey is described in detail
by Lee+ (2017, arXiv:1710.02894).
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See also:
J/ApJS/172/70 : zCOSMOS-bright catalog (Lilly+, 2007)
J/ApJ/744/82 : Catalog of cosmic voids from the SDSS-DR7 (Varela+, 2012)
J/AJ/144/16 : Optical & HI properties of galaxies in voids (Kreckel+, 2012)
J/A+A/570/A106 : VIPERS. Searching for cosmic voids (Micheletti+, 2014)
J/ApJS/225/27 : 3D-HST Survey: grism spectra master catalog (Momcheva+, 2016)
J/ApJ/828/21 : ZFIRE v1.0 data release (Nanayakkara+, 2016)
J/MNRAS/464/666 : Void Galaxy Survey, photometry and structure (Beygu+, 2017)
J/ApJ/835/161 : A cosmic void catalog of SDSS DR12 BOSS galaxies (Mao+, 2017)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 F4.1 --- X [0/29.5] Tomographic X coordinate map position;
in units of h-1Mpc
6- 9 F4.1 --- Y [0/23.5] Tomographic Y coordinate map position
in units of h-1Mpc
11- 15 F5.1 --- Z [0/436] Tomographic Z coordinate map position
in units of h-1Mpc
17- 20 F4.2 --- Rad [2/9.4] Void radius in units of h-1Mpc
22- 30 F9.5 deg RAdeg [149.9/150.4] Right Ascension of void center (J2000)
32- 38 F7.5 deg DEdeg [2.1/2.5] Declination of void center (J2000)
40- 46 F7.5 --- zspec [2/2.6] Spectroscopic redshift
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 12-Jul-2019