J/A+A/678/A174 4 MUSE LAE (Goovaerts+, 2023)
Evolution of the Lyman-alpha-emitting fraction and UV properties of
lensed star-forming galaxies in the range 2.9 < z < 6.7.
Goovaerts I., Pello R., Thai T.T., Tuan-Anh P., Richard J., Claeyssens A.,
Carinos E., de La Vieuville G., Matthee J.
<Astron. Astrophys. 678, A174 (2023)>
=2023A&A...678A.174G 2023A&A...678A.174G (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Redshifts
Keywords: gravitational lensing: strong - galaxies: high redshift -
dark ages, reionisation, first stars
Abstract:
Faint galaxies are theorised to have played a major role, perhaps the
dominant role, in reionising the Universe. Their
properties, as well as the Lyman-α emitter (LAE) fraction, XLAE,
could provide useful insights into this epoch.
We used four clusters of galaxies from the Lensed Lyman-alpha MUSE
Arcs Sample (LLAMAS) that also have deep HST photometry to select a
population of intrinsically faint Lyman break galaxies (LBGs) and
LAEs. We study the interrelation between these two populations, their
properties, and the fraction of LBGs that display Lyman-α
emission.
The use of lensing clusters allows us to access an intrinsically faint
population of galaxies, the largest such sample collected for this
purpose: 263 LAEs and 972 LBGs with redshifts between 2.9 and 6.7,
Lyman-α luminosities in the range
39.5≲log(LLyα)(erg/s)≲42, and absolute UV magnitudes in the
range -22≲M1500≲-12. In addition to matching LAEs and LBGs, we
define an LAE+continuum sample for the LAEs that match with a
continuum object that is not selected as an LBG. Additionally, with
the use of MUSE integral field spectroscopy, we detect a population of
LAEs completely undetected in the continuum.
We find a redshift evolution of XLAE in line with literature results,
with diminished values above z=6. In line with past studies, we take
this as signifying an increasingly neutral intervening intergalactic
medium. When inspecting this redshift evolution with different limits
on EWLyα and M1500, we find that the XLAE for the UV-brighter
half of our sample is higher than the XLAE for the UV-fainter half, a
difference that increases at higher redshifts. This is a surprising
result and can be interpreted as the presence of a population of low
Lyman-α equivalent width (EWLyα), UV-bright galaxies
situated in reionised bubbles and overdensities. This result is
especially interesting in the context of similar, UV-bright, low
EWLyα objects recently detected during and around the epoch of
reionisation. For intrinsically fainter objects, we confirm the
previously observed trend of LAEs among LBGs as galaxies with high
star formation rates and low dust content, as well as the trend of the
strongest LAEs having, in general, fainter M1500 and steeper UV
slopes.
Description:
Tables of data relating to four clusters of galaxies, MUSE
observations of these clusters and galaxies detected behind them in
one table and HST (HFF-Deepspace) (Shipley+, 2018ApJS..235...14S 2018ApJS..235...14S)
limiting magnitudes in all filters in another table.
Redshift catalog, spectral line catalogs and models are available at
https://cral-perso.univ-lyon1.fr/labo/perso/johan.richard/MUSE_data_release
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 122 5 Details of each lensing cluster used in this study
table2.dat 26 19 5σ limiting magnitudes of each filter
for the four clusters
redshift/* . 5 Redshift catalogs
spectral-lines/* . 5 Spectral lines catalogs
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- Cluster Name of cluster
8- 9 I2 h RAh Right Ascension (J2000)
11- 12 I2 min RAm Right Ascension (J2000)
14- 19 F6.3 s RAs Right Ascension (J2000)
21 A1 --- DE- Declination sign (J2000)
22- 23 I2 deg DEd Declination (J2000)
25- 26 I2 arcmin DEm Declination (J2000)
28- 32 F5.2 arcsec DEs Declination (J2000)
34- 38 F5.3 --- z Redshift
40- 46 A7 h Texp MUSE Exposure Time (Hrs) (1)
48- 52 I5 Mpc+3 Co-V Co-volume (Mpc^3)
54- 55 I2 --- LAE Number of LAE only
57- 59 I3 --- LBG Number of LBG only
61- 62 I2 --- LAE+LBG Number of LAE + LBG
64- 65 I2 --- LAE+cont Number of LAE + continuum
67- 86 A20 --- RedCat Name of the fits redshift catalog,
in subdirectory redshift
88-113 A26 --- LineCat Name of the fits spectral lines catalog,
in subdirectory spectral-lines
115-122 A8 ---- MassMod Name of the Mass model repertory (2)
--------------------------------------------------------------------------------
Note (1): The different exposure times for three of the clusters come from the
range of exposure times for different MUSE pointings for these clusters.
Note (2): at https://cral-perso.univ-lyon1.fr/labo/perso/johan.richard/MUSEdatarelease/models/
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- Filter Filter
8- 11 F4.1 mag A2744 ?=- 5σ limiting magnitude in filter
for A2744 (AB)
13- 16 F4.1 mag A370 ?=- 5σ limiting magnitude in filter
for A370 (AB)
18- 21 F4.1 mag AS1063 5σ limiting magnitude in filter
for AS1063 (AB)
23- 26 F4.1 mag M0416 5σ limiting magnitude in filter
for M0416 (AB)
--------------------------------------------------------------------------------
Acknowledgements:
Ilias Goovaerts, ilias.goovaerts(at)lam.fr
(End) Patricia Vannier [CDS] 07-Oct-2023