J/MNRAS/442/946 z∼5.7 C IV absorption systems (Diaz+, 2014)
Large-scale environment of z∼5.7 C IV absorption systems.
I. Projected distribution of galaxies.
Diaz C.G., Koyama Y., Ryan-Weber E.V., Cooke J., Ouchi M., Shimasaku K.,
Nakata F.
<Mon. Not. R. Astron. Soc., 442, 946-978 (2014)>
=2014MNRAS.442..946D 2014MNRAS.442..946D
ADC_Keywords: Galaxies, photometry
Keywords: galaxies: distances and redshifts - galaxies: high-redshift -
intergalactic medium - early Universe
Abstract:
Metal absorption systems are products of star formation. They are
believed to be associated with massive star-forming galaxies, which
have significantly enriched their surroundings. To test this idea with
high column density CIV absorption systems at z∼5.7, we study the
projected distribution of galaxies and characterize the environment of
CIV systems in two independent quasar lines of sight:
J103027.01+052455.0 and J113717.73+354956.9. Using wide-field
photometry (∼80x60h-1 comoving Mpc), we select bright
(MUV(1350Å)≲-21.0mag) Lyman break galaxies (LBGs) at z∼5.7 in a
redshift slice Δz∼0.2 and we compare their projected
distribution with z∼5.7 narrow-band selected Lyman alpha emitters
(LAEs, Δz∼0.08). We find that the CIV systems are located more
than 10h-1 projected comoving Mpc from the main concentrations of
LBGs and no candidate is closer than ∼5h-1 projected comoving Mpc.
In contrast, an excess of LAEs - lower mass galaxies - is found on
scales of ∼10h-1 comoving Mpc, suggesting that LAEs are the primary
candidates for the source of the CIV systems. Furthermore, the closest
object to the system in the field J1030+0524 is a faint LAE at a
projected distance of 212h-1 physical kpc. However, this work cannot
rule out undiscovered lower mass galaxies as the origin of these
absorption systems. We conclude that, in contrast with lower redshift
examples (z≲3.5), strong CIV absorption systems at z∼5.7 trace
low-to-intermediate density environments dominated by low-mass
galaxies. Moreover, the excess of LAEs associated with high levels of
ionizing flux agrees with the idea that faint galaxies dominate the
ionizing photon budget at this redshift.
Description:
This work is based on broad-band and narrow-band photometry obtained
with Suprime-Cam on the Subaru Telescope. We use broad-band Rc, i'
and z' filters covering the wavelength range ∼5800-10000Å and a
custom-made NB filter to detect Lyα in emission at redshift
z=5.71±0.04 (NBC IV, λc=8162Å, FWHM=100Å).
Observations with the NBC IV, Rc and i' bands were acquired on the
nights of 2011 March 07-08 and images in the z' band were obtained on
2011 March 31 and April 01. We observed two fields centred on QSOs
SDSS J103027.01+052455.0 (zem=6.309, RA=10:30:27.01, DE=05:24:55.0),
SDSS J113717.73+354956.9 (zem=6.01, RA=11:37:17.73, DE=35:49:56.9)
(Fan et al., 2006AJ....132..117F 2006AJ....132..117F), hereafter J1030+0524 and
J1137+3549.
Objects:
------------------------------------------------------------------------
RA (ICRS) DE Designation(s)
------------------------------------------------------------------------
10 30 27.01 +05 24 55.0 SDSS J103027.01+052455.0 = QSO J1030+0524
11 37 17.73 +35 49 56.9 SDSS J113717.73+354956.9 = QSO J1137+3549
------------------------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablee1.dat 97 33 z∼5.7 Lyman break galaxies (LBGs) in J1030+0524 field
tablee2.dat 97 61 z∼5.7 Lyman break galaxies (LBGs) in J1137+3549 field
tablee3.dat 97 23 z∼6.0 i'-dropouts in J1030+0524 field
tablee4.dat 97 56 z∼6.0 i'-dropouts in J1137+3549 field
tablee5.dat 97 45 z∼5.7 Lyman alpha emitters (LAEs) in J1030+0524 field
tablee6.dat 97 15 z∼5.7 Lyman alpha emitters (LAEs) in J1137+3549 field
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See also:
J/PASJ/57/165 : Lyα emitters in SUBARU Deep Field (Taniguchi+, 2005)
J/ApJ/648/7 : Lyα emitters at z=6.5 in Subaru Deep Field
(Kashikawa+, 2006)
J/ApJ/693/507 : Stars of Lyman break galaxies at z∼5 (Yabe+, 2009)
J/ApJ/760/128 : Lyα emission from 4<z<6 sources in COSMOS
(Mallery+, 2012)
J/MNRAS/435/1198 : z∼6 QSOs CIV doublet absorption systems (D'Odorico+, 2013)
Byte-by-byte Description of file: tablee?.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Right ascension (J2000)
4- 5 I2 min RAm Right ascension (J2000)
7- 11 F5.2 s RAs Right ascension (J2000)
13 A1 --- DE- Declination sign (J2000)
14- 15 I2 deg DEd Declination (J2000)
17- 18 I2 arcmin DEm Declination (J2000)
20- 23 F4.1 arcsec DEs Declination (J2000)
25- 26 A2 --- l_Rcmag [~> ] Limit flag on Rcmag
27- 31 F5.2 mag Rcmag Cousins R magnitude in 2" or 2.4" aperture (1)
33- 36 F4.2 mag e_Rcmag ? rms uncertainty on Rcmag
38- 39 A2 --- l_i'mag [~> ] Limit flag on imag
40- 44 F5.2 mag i'mag i' magnitude (2"or 2.4" aperture radius) (1)
46- 49 F4.2 mag e_i'mag ? rms uncertainty on imag
51- 52 A2 --- l_z'mag [~> ] Limit flag on z'mag
53- 57 F5.2 mag z'mag z' magnitude (2"or 2.4" aperture radius) (1)
59- 62 F4.2 mag e_z'mag ? rms uncertainty on z'mag
64- 65 A2 --- l_NBCiv [~> ] Limit flag on NBCiv
66- 70 F5.2 mag NBCiv Magnitude in narrow-band NBCiv filter (8162Å) magnitude
(2" or 2.4" aperture radius) (1)
72- 75 F4.2 mag e_NBCiv ? rms uncertainty on NBCiv
77- 81 F5.2 mag z'maga z' magnitude (MAG_AUTO)
83- 86 F4.2 mag e_z'maga rms uncertainty on z'mag
88- 92 F5.3 pix rhl Half-light radius (1pix=0.2arcsec)
94- 97 F4.2 --- S/G [0/1] Stellarity index in z'-band
(0=galaxy, 1=star)
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Note (1):
aperture radius = 2" for J1030+0524 field (tablee1, tablee3 and tablee5)
aperture radius = 2.4" for J1137+3549 field (tablee2, tablee4 and tablee6)
NBCiv = custom-made narrow-band filter to detect Lyα in emission
at redshift z=5.71±0.04: λc=8162Å, FWHM=100Å
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 03-Mar-2015