J/MNRAS/499/5022 MUSE Analysis of Gas around Galaxies II (Dutta+, 2020)
MUSE Analysis of Gas around Galaxies (MAGG).
II: metal-enriched halo gas around z ∼ 1 galaxies.
Dutta R., Fumagalli M., Fossati M., Lofthouse E.K., Prochaska J.X.,
Arrigoni Battaia F., Bielby R.M., Cantalupo S., Cooke R.J., Murphy M.T.,
O'Meara J.M.
<Mon. Not. R. Astron. Soc., 499, 5022-5046 (2020)>
=2020MNRAS.499.5022D 2020MNRAS.499.5022D (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Galaxies, group ; Redshifts ; Star Forming Region ;
Equivalent widths ; Spectra, optical
Keywords: galaxies: groups: general - galaxies: haloes -
quasars: absorption lines
Abstract:
We present a study of the metal-enriched cool halo gas traced by MgII
absorption around 228 galaxies at z∼0.8-1.5 within 28 quasar fields
from the MUSE Analysis of Gas around Galaxies survey. We observe no
significant evolution in the MgII equivalent width versus impact
parameter relation and in the MgII covering fraction compared to
surveys at z~<0.5. The stellar mass, along with distance from galaxy
centre, appears to be the dominant factor influencing the MgII
absorption around galaxies. With a sample that is 90 per cent complete
down to a star formation rate of ∼0.1M☉/yr and up to impact
parameters ∼250-350kpc from quasars, we find that the majority
(67+12-15 per cent or 14/21) of the MgII absorption systems are
associated with more than one galaxy. The complex distribution of
metals in these richer environments adds substantial scatter to
previously reported correlations. Multiple galaxy associations show on
average five times stronger absorption and three times higher covering
fraction within twice the virial radius than isolated galaxies. The
dependence of MgII absorption on galaxy properties disfavours the
scenario in which a widespread intragroup medium dominates the
observed absorption. This leaves instead gravitational interactions
among group members or hydrodynamic interactions of the galaxy haloes
with the intragroup medium as favoured mechanisms to explain the
observed enhancement in the MgII absorption strength and cross-section
in rich environments.
Description:
All the quasars in our sample have high-resolution spectra obtained
with the Ultraviolet and Visual Echelle Spectrograph (UVES; Dekker et
al. 2000SPIE.4008..534D 2000SPIE.4008..534D) at the VLT, the High Resolution Echelle
Spectrometer (HIRES; Vogt et al. 1994SPIE.2198..362V 1994SPIE.2198..362V) at Keck, or the
Magellan Inamori Kyocera Echelle (MIKE; Bernstein et al.
2003SPIE.4841.1694B 2003SPIE.4841.1694B) at the Magellan telescopes. These are often
supplemented with medium-resolution spectra from X-SHOOTER (Vernet et
al. 2011A&A...536A.105V 2011A&A...536A.105V) at the VLT and Echellette Spectrograph and
Imager (ESI; Sheinis et al. 2002PASP..114..851S 2002PASP..114..851S) at Keck. Details of
the reduction of these archival spectra and their properties are
summarized in section 3.1 and table 2 of Lofthouse et al.
(2020MNRAS.491.2057L 2020MNRAS.491.2057L, Cat. J/MNRAS/491/2057), respectively.
We searched for the doublet lines of MgIIλλ2796,2803 by
visually inspecting the quasar spectra, restricting to wavelengths
redward of the quasar Lyα forest for clarity of identification
(i.e. z≳0.8). We identified in total 114 MgII absorption line systems
over 0.8<z<3.8. For the purpose of this paper, we focus on the 27
systems present in the redshift range 0.8<z<1.5, where we are able to
search for the corresponding [OII] emission line in the MUSE spectra.
The properties of the MgII systems are summarized in Table S1.
In each of the MAGG fields we identify galaxies detected in continuum
in the MUSE white-light images as well as in line emission in the MUSE
3D cubes. For the purpose of this paper, we focus on the
continuum-detected galaxies within 0.8<z<1.5. We cross-match these
with the MgII absorbers. In addition, we specifically search for [OII]
line-emitting galaxies around the redshift of the MgII absorbers at
0.8<z<1.5, that are too faint to be detected in the continuum. A blind
search for line-emitting galaxies over the full MUSE wavelength range
will be presented in a future work.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tables1.dat 67 27 Properties of the MgII absorption lines detected
in the adopted quasar spectra
tables2.dat 91 228 Properties of the galaxies studied in this work
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See also:
J/MNRAS/491/2057 : MAGG I Near pristine gas cloud at z∼3.5
Byte-by-byte Description of file: tables1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- Quasar Quasar name (JHHMMSS.ss+DDMMSS.s)
21- 28 A8 --- Spectra Instrument name
(HIRES, MIKE, UVES or XSHOOTER)
30- 36 F7.5 --- zabs Redshift (1)
38- 42 F5.3 0.1nm EWMgII Rest-frame equivalent width
44- 48 F5.3 0.1nm e_EWMgII Error on EWMgII
50- 51 A2 --- l_logN [≥ ] Limit flag on logN
53- 57 F5.2 [cm-2] logN Logarithm of the MgII column density
59- 63 F5.2 [cm-2] e_logN ?=-1 Error on logN
65- 67 I3 km/s Dv90 Velocity width containing 90 per cent of
the total optical depth of the absorption
profile Δv90 (1)
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Note (1): The typical uncertainties in the redshifts and Δv90
measurements are ∼0.00003 (or ∼5km/s) and ∼7km/s, respectively
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Byte-by-byte Description of file: tables2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- Galaxy Galaxy name (JHHMMSS.ss+DDMMSS.s)
21- 27 F7.5 --- z Redshift (1)
29- 31 I3 kpc R Impact parameter from the quasar (2)
33- 39 F7.2 [Msun] logMass ?=-999 Logarithm of the stellar mass
41- 47 F7.2 [Msun] e_logMass ?=-999 Lower error on logMass
49- 55 F7.2 [Msun] E_logMass ?=-999 Upper error on logMass
57- 61 F5.2 Msun/yr SFR Star formation rate derived from [OII] (3)
63- 66 F4.2 Msun/yr e_SFR Lower error on SFR
68- 71 F4.2 Msun/yr E_SFR Upper error on SFR
73 A1 --- MethID Method of identification (4)
75 A1 --- Envflag Environment flag (5)
77- 78 A2 --- l_EWMgII [=< ] Limit flag on EWMgII
80- 84 F5.3 0.1nm EWMgII Rest-frame equivalent width (6)
86- 91 F6.3 0.1nm e_EWMgII ?=-1 Error on EWMgII
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Note (1): Typical uncertainty ∼0.0004 or ∼60km/s
Note (2): Typical uncertainty ∼8kpc
Note (3): SFR derived from [OII], corrected for dust-extinction using the
results from the SPS models, except in case of galaxies detected in
line emission
Note (4): Method of identification as follows:
C = continuum
L = line emission
Note (5): Environment flag as follows:
I = isolated
G = in group
Note (6): Rest-frame MgII equivalent width in case of detection of associated
MgII, 3σ upper limit otherwise
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History:
From electronic version of the journal
References:
Lofthouse et al., Paper I 2020MNRAS.491.2057L 2020MNRAS.491.2057L, Cat. J/MNRAS/491/2057
Fossati et al., Paper III 2021MNRAS.503.3044F 2021MNRAS.503.3044F
Lofthouse et al., Paper IV 2023MNRAS.518..305L 2023MNRAS.518..305L
Galbiati et al., Paper V 2023MNRAS.524.3474G 2023MNRAS.524.3474G
(End) Ana Fiallos [CDS] 08-Sep-2023