J/MNRAS/490/1451 MUDF properties of galaxy groups at 0.5<z<1.5 (Fossati+, 2019)
The MUSE Ultra Deep Field (MUDF). II.
Survey design and the gaseous properties of galaxy groups at 0.5<z<1.5.
Fossati M., Fumagalli M., Lofthouse E.K., D'Odorico V., Lusso E.,
Cantalupo S., Cooke R.J., Cristiani S., Haardt F., Morris S.L., Peroux C.,
Prichard L.J., Rafelski M., Smail I., Theuns T.
<Mon. Not. R. Astron. Soc., 490, 1451-1469 (2019)>
=2019MNRAS.490.1451F 2019MNRAS.490.1451F (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, optical ; Redshifts
Keywords: galaxies: evolution - galaxies: groups: general -
galaxies: high-redshift - galaxies: haloes -
quasars: absorption lines
Abstract:
We present the goals, design, and first results of the MUSE Ultra Deep
Field (MUDF) survey, a large programme using the Multi Unit
Spectroscopic Explorer (MUSE) instrument at the ESO Very Large
Telescope. The MUDF survey is collecting ∼150h on-source of integral
field optical spectroscopy in a 1.5x1.2arcmin2 region which hosts
several astrophysical structures along the line of sight, including
two bright z∼3.2 quasars with close separation (∼500kpc). Following
the description of the data reduction procedures, we present the
analysis of the galaxy environment and gaseous properties of seven
groups detected at redshifts 0.5<z<1.5, spanning a large dynamic range
in halo mass, log(Mh/M☉)∼11-13.5. For four of the groups, we
find associated MgII absorbers tracing cool gas in high-resolution
spectroscopy of the two quasars, including one case of correlated
absorption in both sightlines at distance ∼480kpc. The absorption
strength associated with the groups is higher than what has been
reported for more isolated galaxies of comparable mass and impact
parameters. We do not find evidence for widespread cool gas giving
rise to strong absorption within these groups. Combining these results
with the distribution of neutral and ionized gas seen in emission in
lower redshift groups, we conclude that gravitational interactions in
the group environment strip gas from the galaxy haloes into the
intragroup medium, boosting the cross-section of cool gas and leading
to the high fraction of strong MgII absorbers that we detect.
Description:
The science goals of the MUDF programme include the study of the
galaxy population around and along the line of sight to the quasar
pair, a deep search for Ly α emission from the putative
filaments which are expected to connect the two quasars at z∼3.22.
Because the projected distance of these quasars is ∼62arcsec on the
sky, a single Wide Field MUSE pointing of 60arcsec on a side would not
allow a full mapping of the area of interest. For these reasons, we
designed an observational strategy that includes two heavily
overlapping pointings: North-West and South-East. Throughout the
entire survey, we plan to collect ∼200 frames dithered around each of
these centres. The nominal exposure time of each frame is 1450s and
different frames include small on-sky dithers (∼3-4arcsec), as well as
10deg rotations of the instrument to reduce systematic errors arising
from the different response of the 24 spectrographs and detectors of
MUSE.
We identify continuum sources using the SExtractor (Bertin & Arnouts
1996A&AS..117..393B 1996A&AS..117..393B) software on the white light image reconstructed
from the MUSE datacubes. We input a variance image and we use a
conservative threshold of 3σ above the local noise, and a
minimum area of 10 pixels for detection. This procedure identified 250
sources. For each of them, we extract the magnitude in the detection
image and we measure redshifts using the MARZ software (Hinton et al.
2016A&C....15...61H 2016A&C....15...61H). Typical redshift uncertainties are
{delt}z∼0.0002(1+z), corresponding to δv∼60km/s.
The final redshift classification is presented in Table 1.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 71 250 The properties of the continuum sources in the
MUDF extracted by SEXTRACTOR with S/N>3
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [1/250] Internal source identifier
5- 27 A23 --- Name Source name (MUDFJHHMMSS.ss-DDMMSS.s)
29- 37 F9.5 deg RAdeg Right ascension (J2000)
39- 47 F9.5 deg DEdeg Declination (J2000)
49- 52 F4.1 mag MUSEmag MUSE white-light magnitude of the source
54- 56 F3.1 mag e_MUSEmag Error on MUSEmag
58- 63 F6.4 --- z ? Redshift obtained using MARZ
65 I1 --- Confidence [1/6] Redshift confidence class (1)
67- 71 F5.2 [Msun] logM* ? Logarithm of the stellar mass
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Note (1): Confidence flag as follows:
1 = Unknown redshift (106/250)
2 = Possible redshift, based on a single feature (16/250)
3 = Good redshift with single but unambiguous feature (31/250)
4 = Secure redshift with multiple absorption or emission features (86/250)
6 = Other (11/250)
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History:
From electronic version of the journal
References:
Lusso et al., Paper I 2019MNRAS.485L..62L 2019MNRAS.485L..62L
(End) Ana Fiallos [CDS] 26-Jan-2023