J/MNRAS/509/1536 Lyα absorbers redshifts (Maitra+, 2022)
Measurement of redshift-space two- and three-point correlation of Lyα
absorbers at 1.7 < z < 3.5: implications on evolution of the physical
properties of IGM.
Maitra S., Srianand R., Gaikwad P.
<Mon. Not. R. Astron. Soc. 509, 1536-1556>
=2022MNRAS.509.1536M 2022MNRAS.509.1536M (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Redshifts ; H I data
Keywords: intergalactic medium - quasars: absorption lines - diffuse radiation -
large-scale structure of Universe
Abstract:
We present redshift-space two-point (ξ), three-point ({dzeta}), and
reduced three- point (Q) correlation of Lyα absorbers (Voigt
profile components having HI column density, NHI>1013.5cm-2)
over three redshift bins spanning 1.7<z<3.5 using high-resolution
spectra of 292 quasars. We detect positive ξ up to 8h-1cMpc in
all three redshift bins. The strongest detection of
{dzeta}=1.81±0.59 (with Q=0.68±0.23) is in z=1.7-2.3 bin at
1-2h-1cMpc. The measured ξ and {dzeta} values show an increasing
trend with NHI, while Q remains relatively independent of NHI. We
find ξ and {dzeta} to evolve strongly with redshift. Using
simulations, we find that ξ and {dzeta} seen in real space may be
strongly amplified by peculiar velocities in redshift space.
Simulations suggest that while feedback, thermal and pressure
smoothing effects influence the clustering of Lyα absorbers at
small scales, i.e. <0.5h-1cMpc, the HI photoionization rate
({GAMMA}HI) has a strong influence at all scales. The strong
redshift evolution of ξ and {dzeta} (for a fixed NHI cut-off) is
driven by the redshift evolution of the relationship between HI and
baryon overdensity. Our simulation using best- fitting {GAMMA}HI(z)
measurements produces consistent clustering signals with observations
at z∼2 but underpredicts the clustering at higher redshifts. One
possible remedy is to have higher values of {GAMMA}HI at higher
redshifts. Alternatively the discrepancy could be related to
non-equilibrium and inhomogeneous conditions prevailing during He ii
reionization not captured by our simulations.
Description:
Redshifts of SQUAD (UVES Spectral Quasar Absorption Database, DR2,
Murphy et al., 2019MNRAS.482.3458M 2019MNRAS.482.3458M, Cat. J/MNRAS/482/3458) and KODIAQ
(KODIAQ-DR2 (O'Meara et al. 2017AJ....154..114O 2017AJ....154..114O, Cat. J/AJ/154/114,
https://www2.keck.hawaii.edu/koa/public/koa.php) QSO samples
considered in the study.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 47 77 SQUAD sample
table4.dat 47 214 KODIAQ sample
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Byte-by-byte Description of file: table3.dat table4.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- QSO QSO name (JHHMMSS+DDMMSS) (1)
17- 21 F5.3 --- zem Emission redshift
24- 30 F7.5 --- zmin Minimum value of redshift
33- 39 F7.5 --- zmax Maximum value of redshift
42- 47 F6.2 --- MedianSNR Median signal-to-noise ratio
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Note (1): SQUAD DR1 JHHMMSS+DDMMSS and KODIAQ JHHMMSS+DDMMSSA in Simbad,
respectively.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 14-Aug-2024