J/MNRAS/508/4573 Galaxy surveys in quasars fields (Dutta+, 2021)
Metal-enriched halo gas across galaxy overdensities over the last 10 billion
years.
Dutta R., Fumagalli M., Fossati M., Bielby R.M., Stott J.P.,
Lofthouse E.K., Cantalupo S., Cullen F., Crain R.A., Tripp T.M.,
Prochaska J.X., Arrigoni Battaia F., Burchett J.N., Fynbo J.P.U.,
Murphy M.T., Schaye J., Tejos N., Theuns T.
<Mon. Not. R. Astron. Soc. 508, 4573-4599>
=2021MNRAS.508.4573D 2021MNRAS.508.4573D (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Galaxies ; QSOs ; Redshifts ; Photometry ; Optical
Galaxies, group ; Spectroscopy ; Line Profiles ;
Equivalent widths
Keywords: galaxies: groups: general - galaxies: haloes -
quasars: absorption lines
Abstract:
We present a study of metal-enriched halo gas traced by Mg II and C IV
absorption at z < 2 in the MUSE Analysis of Gas around Galaxies survey
and the Quasar Sightline and Galaxy Evolution survey. Using these
large and complete galaxy surveys in quasar fields, we study the
dependence of the metal distribution on galaxy properties and
overdensities, out to physical projected separations of 750 kpc. We
find that the cool, low-ionization gas is significantly affected by
the environment across the full redshift range probed, with
≃ 2-3 times more prevalent and stronger Mg II absorption in higher
overdensity group environments and in regions with greater overall
stellar mass and star formation rates. Complementary to these results,
we have further investigated the more highly ionized gas as traced by
C IV absorption, and found that it is likely to be more extended than
the Mg II gas, with ≃ 2 times higher covering fraction at a given
distance. We find that the strength and covering fraction of C IV
absorption show less significant dependence on galaxy properties and
environment than the Mg II absorption, but more massive and star-forming
galaxies nevertheless also show ≃ 2 times higher incidence of
C IV absorption. The incidence of Mg II and C IV absorption within the
virial radius shows a tentative increase with redshift, being higher
by a factor of ≃ 1.5 and ≃4, respectively, at z > 1. It is clear
from our results that environmental processes have a significant
impact on the distribution of metals around galaxies and need to be
fully accounted for when analysing correlations between gaseous haloes
and galaxy properties.
Description:
In this work, we study gaseous haloes up to z ~=2 with a systematic
focus on the galaxy environment, taking advantage of the large and
complete galaxy surveys that are becoming available now in quasar
fields. In particular, we use data from two large, independent surveys
- the MUSE Analysis of Gas around Galaxies (MAGG; Dutta et al.
2020MNRAS.499.5022D 2020MNRAS.499.5022D, Cat. J/MNRAS/499/5022; Lofthouse et al.
2020MNRAS.491.2057L 2020MNRAS.491.2057L, Cat. J/MNRAS/491/2057; Fossati et al.
2021MNRAS.503.3044F 2021MNRAS.503.3044F) survey and the Quasar Sightline and Galaxy
Evolution (QSAGE; Bielby et al. 2019MNRAS.486...21B 2019MNRAS.486...21B, Cat.
J/MNRAS/486/21; Stott et al. 2020MNRAS.497.3083S 2020MNRAS.497.3083S) survey.
First, the QSAGE survey is based on 96 orbits of HST Wide-Field Camera
3 (WFC3) observations centred on 12 quasar fieldsThe WFC3 observations
consist of NIR imaging using the F140W and F160W filters and
spectroscopy using the G141 grism. The description of the WFC3 data
reduction is presented in Bielby et al. (2019MNRAS.486...21B 2019MNRAS.486...21B, Cat.
J/MNRAS/486/21). The F140W images of the 12 quasar fields are shown in
Stott et al. (2020MNRAS.497.3083S 2020MNRAS.497.3083S). All the fields have supporting
optical (g, r, i, z) imaging data from VLT FOcal Reducer/low
dispersion Spectrograph 2, William Herschel Telescope auxiliary-port
camera, Liverpool Telescope (LT) Infrared-Optical: Optical
instrument, and the Canada-France-Hawaii Telescope Legacy Survey
(CFHTLS) Wide survey. These imaging data are obtained from a
combination of our own and archival programmes, (all details on data
reduction and properties extraction are available in the section 2.1
and 2.2).
Secondly, the MAGG survey is primarily based on MUSE/VLT observations
of 28 fields, which are centred on quasars. A detailed description of
the reduction procedure of the MUSE data is presented in Lofthouse et
al. (2020MNRAS.491.2057L 2020MNRAS.491.2057L, Cat. J/MNRAS/491/2057) as well as examples
of the MUSE images and spectra. Line profile analysis giving us the
equivalent width for the observed absorption profile of the stronger
transition of the doublet Mg II λ2796, λ2803 lines and
the C IV λ1548, λ1550 lines and properties galaxy
properties extraction are well explained in the section 2.1, 2.2 and
2.3. These methods are similar to those used for the QSAGE survey. More,
as described in the section 2.4, we identify group of galaxy in the
QSAGE and MAGG galaxy samples with FoF algorithm. Our results sample
for all detected galaxies are presented and organized in the table.dat
and source.dat.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
source.dat 31 40 Observational fields centred on quasars
used in this study
table.dat 95 951 Galaxies properties and absorption lines of our
two fields
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See also:
J/MNRAS/486/21 : Quasar Sightline and Galaxy Evolution Survey I
(Bielby+, 2019)
J/MNRAS/491/2057 : MAGG I Near pristine gas cloud at z∼3.5 (Lofthouse+, 2020)
J/MNRAS/499/5022 : MUSE Analysis of Gas around Galaxies II (Dutta+, 2020)
J/MNRAS/490/1451 : MUDF properties of galaxy groups at 0.5<z<1.5
(Fossati+, 2019)
J/MNRAS/499/5022 : MUSE Analysis of Gas around Galaxies II (Dutta+, 2020)
J/ApJ/753/121 : zCOSMOS 20k sample group catalog to z≲1.2 (Knobel+, 2012)
Byte-by-byte Description of file: source.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Survey Survey name (Survey) (1)
7- 27 A21 --- Field Quasar sightline field name (Quasar)
29- 31 I3 --- NQuasar Number of detected quasars in this field
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Note (1): An overview of the QSAGE and MAGG survey data used in this work is
available in the section 2 Galaxy and absorption line data. For the
QSAGE (the Quasar Sightline and Galaxy Evolution) survey please see
Bielby et al. (2019MNRAS.486...21B 2019MNRAS.486...21B, Cat. J/MNRAS/486/21) and
Stott et al. (2020MNRAS.497.3083S 2020MNRAS.497.3083S). For the MAGG (the MUSE Analysis
of Gas around Galaxies) survey please see Lofthouse et al.
(2020MNRAS.491.2057L 2020MNRAS.491.2057L, Cat. J/MNRAS/491/2057) and Dutta et al.
(2020MNRAS.499.5022D 2020MNRAS.499.5022D, Cat. J/MNRAS/499/5022).
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Byte-by-byte Description of file: table.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Survey ?=[MAGG/QSAGE] Survey name (Survey) (1)
7- 27 A21 --- Field Quasar sightline field name (Quasar) (2)
29- 35 F7.5 --- z Galaxy spectroscopic redshift (Redshift) (3)
37- 42 F6.2 kpc R Impact parameter (R) (4)
44- 48 F5.2 [Msun] logM* Logarithm of the stellar mass from SPS
model fitting (logM) (5)
50- 55 F6.2 Msun/yr SFR Star formation rate from SPS
model fitting (SFR) (5)
57 I1 --- Groupflag Flag indicating whether galaxy belongs
to group 1 or not 0 (Flag) (6)
59- 65 F7.4 0.1nm EWMgII ?=-9.9999 Rest-frame equivalent width of
MgII in case of detection or 3-sigma upper
limit (WrMgII) (7)
67- 73 F7.4 0.1nm e_EWMgII ?=-9.9999 Error on rest-frame equivalent
width of MgII in case of detection
(e_WrMgII) (7)
75- 76 A2 --- f_EWMgII Flag on MgII absorption detection
(f_WrMgII) (8)
78- 84 F7.4 0.1nm EWCIV ?=-9.9999 Rest-frame equivalent width
of CIV in case of detection or 3-sigma
upper limit (WrCIV) (7)
86- 92 F7.4 0.1nm e_EWCIV ?=-9.9999 Error on rest-frame equivalent
width of CIV in case of detection
(e_WrCIV) (7)
94- 95 A2 --- f_EWCIV Flag on CIV absorption detection
(f_Wr^CIV) (8)
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Note (1): An overview of the QSAGE and MAGG survey data used in this work is
available in the section 2 Galaxy and absorption line data. For the
QSAGE (the Quasar Sightline and Galaxy Evolution) survey please see
Bielby et al. (2019MNRAS.486...21B 2019MNRAS.486...21B, Cat. J/MNRAS/486/21) and
Stott et al. (2020MNRAS.497.3083S 2020MNRAS.497.3083S). For the MAGG (the MUSE Analysis
of Gas around Galaxies) survey please see Lofthouse et al.
(2020MNRAS.491.2057L 2020MNRAS.491.2057L, Cat. J/MNRAS/491/2057) and Dutta et al.
(2020MNRAS.499.5022D 2020MNRAS.499.5022D, Cat. J/MNRAS/499/5022).
Note (2): The 12 quasar fields of QSAGE : 2MASSIJ0750546+425219,
2MASSIJ1124428-170517, HB890232-042, HE0515-4414,
LBQS-1435-0134, PG0117+213, QSO-B0810+2554,
QSO-B1521+1009, QSO-B1630+3744, QSO-B1634+7037,
QSO-J1019+2745, QSO-J1130-1449
The 28 quasar fields of MAGG :
J010619+004823, J012403+004432, J013340+040059, J013724-422417,
J015741-010629, J020944+051713, J024401-013403, J033413-161205,
J033900-013318, J094932+033531, J095852+120245, J102009+104002,
J111008+024458, J111113-080401, J120917+113830, J123055-113909,
J124957-015928, J133254+005250, J142438+225600, J162116-004251,
J193957-100241, J200324-325145, J205344-354652, J221527-161133,
J230301-093930, J231543+145606, J233446-090812, J234913-371259
Note (3): The redshifts of the sources identified in MUSE data were derived
based on the 1D spectra and spectral template fitting using marz
(Hinton et al. 2016A&C....15...61H 2016A&C....15...61H). The redshift identification of
all the WFC3 sources was carried out using a line fitting algorithm
and visual inspection as explained in Stott et al.
(2020MNRAS.497.3083S 2020MNRAS.497.3083S),
(More details in the section 2.1 QSAGE galaxy survey).
Note (4): The impact parameter of a quasar refers to the perpendicular distance
from the line of sight to a quasar to the center of a galaxy that it
might be interacting with or influencing.
Note (5): We derived the stellar mass and star formation rate (SFR) of the
sources using the Monte Carlo Spectro-Photometric Fitter (mc-spf;
Fossati et al. 2018A&A...614A..57F 2018A&A...614A..57F). We follow the procedure described
in Fossati et al. (2019MNRAS.490.1451F 2019MNRAS.490.1451F, Cat. J/MNRAS/490/1451) and
Dutta et al. (2020MNRAS.499.5022D 2020MNRAS.499.5022D, Cat. J/MNRAS/499/5022),
(i.e please refers to the section 2.1 QSAGE galaxy survey).
Note (6): Based on FoF group finding algorithm as explained in the section 2.4
Group identification, (Knobel et al. 2009ApJ...697.1842K 2009ApJ...697.1842K,
Cat. J/ApJ/697/1842, 2012ApJ...753..121K 2012ApJ...753..121K, Cat. J/ApJ/753/121;
Diener et al. 2013ApJ...765..109D 2013ApJ...765..109D).
Note that we use the term 'group' here to refer to an association of
two or more galaxies, without any specification on the group halo
mass, and these structures may not necessarily be virialized.
The FoF method links galaxies into structures by finding all the
galaxies that are connected within linking lengths in transverse
physical distance (Δr) and redshift space (Δv).
We use Δr = 500 kpc and Δv = 500 km/s to link the
galaxies together into groups.
Note (7): We measured the rest-frame equivalent width by integrating the spectra
over the observed absorption profile of the stronger transition of the
doublet Mg II λ2796, λ2803 lines and
the C IV λ1548, λ1550 lines. We determine the
sensitivity to detect absorption lines by estimating the 3σ
upper limits on the rest-frame equivalent widths over 100 km/s after
masking out strong contaminating absorption lines.
Based on the 90th percentile of this distribution we estimate
the WrMgII sensitivity as 0.03 Å over the full redshift range
probed. The overall WrCIV sensitivity is 0.1 Å , which is
dominated by measurements based on the UV spectra at z =< 1.
The WrCIV sensitivity is ~= 0.03 Å at z > 1, where the
measurements are based on the more sensitive optical spectra.
Note (8): Indicating whether MgII absorption is detected as follows:
1 = Detected within ±500 km/s of galaxy redshift
0 = Not detected
-1 = Not covered by the observations
As explained in the section 2.1 QSAGE galaxy survey, comparing the
redshifts obtained from WFC3 grism and MUSE spectra for the subset
of sources that have both, we find that in practice the velocity
uncertainty of the grism redshifts is closer to ~= 500 km/s at z = 1.
Hence, we adopt this as the uncertainty in the redshifts of the WFC3
sources.
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History:
From electronic version of the journal
(End) Luc Trabelsi [CDS] 02-Sep-2024