J/ApJ/761/112 High-redshift MgII absorption QSOs with FIRE (Matejek+, 2012)
A survey of Mg II absorption at 2 < z < 6 with Magellan/FIRE.
I. Sample and evolution of the Mg II frequency.
Matejek M.S., Simcoe R.A.
<Astrophys. J., 761, 112 (2012)>
=2012ApJ...761..112M 2012ApJ...761..112M
ADC_Keywords: Equivalent widths ; Redshifts ; QSOs ; Spectra, infrared
Keywords: galaxies: evolution; galaxies: halos; galaxies: high-redshift;
infrared: general; intergalactic medium; quasars: absorption lines
Abstract:
We present initial results from the first systematic survey for Mg II
quasar absorption lines at z>2.5. Using infrared spectra of 46
high-redshift quasars, we discovered 111 Mg II systems over a path
covering 1.9<z<6.3. Five systems have z>5, with a maximum of z=5.33
--the most distant Mg II system now known. The comoving Mg II line
density for weaker systems (Wr<1.0Å) is statistically consistent
with no evolution from z=0.4 to 5.5, while that for stronger systems
increases three-fold until z∼3 before declining again toward higher
redshifts. The equivalent width distribution, which fits an
exponential, reflects this evolution by flattening as z-->3 before
steepening again. The rise and fall of the strong absorbers suggests a
connection to the star formation rate density, as though they trace
galactic outflows or other byproducts of star formation. The weaker
systems' lack of evolution does not fit within this interpretation,
but may be reproduced by extrapolating low redshift scaling relations
between host galaxy luminosity and absorbing halo radius to earlier
epochs. For the weak systems, luminosity-scaled models match the
evolution better than similar models based on Mg II occupation of
evolving cold dark matter halo masses, which greatly underpredict
dN/dz at early times unless the absorption efficiency of small halos
is significantly larger at early times. Taken together, these
observations suggest that the general structure of Mg II-bearing halos
was put into place early in the process of galaxy assembly. Except for
a transient appearance of stronger systems near the peak epoch of
cosmic star formation, the basic properties of Mg II absorbers have
evolved fairly little even as the (presumably) associated galaxy
population grew substantially in stellar mass and half-light radius.
Description:
Our sample consists of 46 quasar spectra taken with Magellan/FIRE,
between 2010 June and 2011 April. This instrument is a single object,
prism cross-dispersed infrared spectrometer with a spectral resolution
of R=6000, or approximately 50km/s, over the range of 0.8-2.5um.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 39 46 FIRE MgII survey sightlines
table2.dat 55 111 Summary of absorption properties for the
FIRE MgII sample
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See also:
V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)
VII/260 : The SDSS-DR7 quasar catalog (Schneider+, 2010)
J/PASJ/65/8 : Catalog of SDSS quasar absorption redshift (Qin+, 2013)
J/A+A/546/A67 : Catalog of strong MgII absorbers (Lawther+, 2012)
J/ApJ/754/38 : MgII absorption systems for FSRQs (Chand+, 2012)
J/ApJ/748/131 : MgII absorbers in SDSS-DR7 quasar catalog (Shen+, 2012)
J/ApJ/736/42 : HST QSO Catalog (Ribaudo+, 2011)
J/ApJ/727/47 : The MgII cross-section of red galaxies (Bowen+, 2011)
J/ApJ/724/L176 : MgII absorbing gas around galaxies (Chen+, 2010)
J/ApJ/718/392 : SDSS Lyman limit systems at z∼3.5 (Prochaska+, 2010)
J/ApJ/714/1521 : Spectroscopy of galaxies around distant QSOs (Chen+, 2010)
J/ApJ/698/819 : MgII and LRGs cross-correlation analysis (Lundgren+, 2009)
J/ApJ/662/72 : Lyman alpha forest of 55 QSOs (Becker+, 2007)
J/ApJ/639/766 : SDSS-DR3 strong MgII absorbers (Prochter+, 2006)
J/MNRAS/371/495 : Cat. of 1806 MgII absorbers from SDSS DR3 (Bouche+, 2006)
J/MNRAS/354/L25 : MgII absorbers in SDSS QSOs (Bouche+, 2004)
J/AJ/127/2002 : Star Formation Rate of NFGS galaxies (Kewley+, 2004)
J/A+A/421/41 : FORS Deep Field UV to blue photometry (Gabasch+, 2004)
J/A+A/410/33 : MgII/FeII absorbers in 2dF-quasar survey (Menard+, 2003)
J/AJ/106/848 : QSO MgII absorption line systems (Drinkwater+, 1993)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Object designation
15- 18 F4.2 --- zQSO [3.5/6.3] QSO redshift
20- 23 F4.2 --- lDz [1.9/2.2] Lower range of pathlength (Δz) (1)
25- 28 F4.2 --- uDz [3.5/6.3] Upper range of pathlength (Δz) (1)
30- 34 I5 s Exp [972/19275] Exposure time
36- 39 F4.1 --- S/N [4/47.2] Signal to noise ratio (2)
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Note (1): The pathlength is defined in equation A2. See section A.1.
Note (2): Median signal-to-noise ratio per pixel across MgII pathlength.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/111] Running sequence number
5 A1 --- f_Seq Flag on Seq (1)
7- 19 A13 --- Name Sightline designation
21- 25 F5.3 --- z [1.9/5.4] Redshift
27- 31 F5.3 0.1nm Wr2796 [0.08/5.6] Equivalent width of the MgII line
at 2796Å (in rest-frame)
33- 37 F5.3 0.1nm e_Wr2796 [0.01/0.2] Wr2796 uncertainty
39- 43 F5.3 0.1nm Wr2803 [0.08/5.1] Equivalent width of the MgII line
at 2803Å (in rest-frame)
45- 49 F5.3 0.1nm e_Wr2803 [0.008/0.2] Wr2803 uncertainty
51- 55 F5.1 km/s DVel [50.8/709.8] Velocity spread (ΔV) (2)
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Note (1): Flag as follows:
a = Poor telluric region.
b = Proximate system.
c = Missed by automated search algorithm.
Note (2): Equation (8): Δv=(125.7±6.0)(Wr/1Å)+(80.2±8.6)km/s
See section 4.1.
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History:
From electronic version of the journal
References:
Matejek et al. Paper II. 2013ApJ...764....9M 2013ApJ...764....9M Cat. J/ApJ/764/9
(End) Emmanuelle Perret [CDS] 08-Aug-2014