J/A+A/702/A146 Multiple star-forming episodes of galaxies (Munoz Lopez+, 2025)
Multiple star-forming episodes of intermediate-redshift galaxies.
Munoz Lopez C., Krajnovic D., Epinat B., Urrutia T., Pessa I., Contini T.,
Nanayakkara T., Pharo J., Goncalves T.S., Thi Thai T., Bouche N.F.
<Astron. Astrophys. 702, A146 (2025)>
=2025A&A...702A.146M 2025A&A...702A.146M (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies ; Redshifts ; Morphology
Keywords: galaxies: evolution - galaxies: formation - galaxies: star formation -
galaxies: stellar content - galaxies: structure
Abstract:
In this work, we derive and analyse the star formation histories of 393
intermediate-redshift (0.1≤z≤0.9) galaxies with stellar masses between
∼108-1012M☉. We focus on galaxies located in the
CANDELS/GOOD-S and CANDELS/COSMOS fields that have been observed with
different surveys using MUSE. We probe a cosmic time of approximately
6 billion years (Gyr) and a range of environments, from field
(low-density systems) to rich groups (high-density systems). We find
that the galaxies' stellar mean ages, metallicities, and star
formation rates (SFRs) follow similar trends to galaxies as those
characterising the nearby Universe. We modelled the derived SFRs,
quantifying and characterising the number of star-forming episodes
(SFEs). We found that more than 85% of the galaxies have more than one
event of star formation, typically described with an exponentially
decaying SFR and subsequent Gaussian-like episode(s) of star
formation. We also observe that massive galaxies have fewer SFEs than
low-mass systems and that they form their stellar mass and reach
quiescence faster than lower mass galaxies. Moreover, the history of
mass assembly for the most massive galaxies in the sample can be
described with only one episode of star formation in the early
Universe, which we detected as an exponential decrease that was longer
in duration than subsequent SF events. This early event has typically
been completed by z∼3 and it accounts for a high fraction of the total
stellar mass, from ∼40% for low-mass galaxies to more than 50% for
higher-mass galaxies. We also analysed the dependence of stellar
population parameters with the various environments probed by the
sample, finding no significant correlations between different group
environments; however, our field galaxies are generally distinct from
group galaxies in terms of the mass, metallicity, stellar ages, and
formation timescales. We discuss possible biases in the sample
selection and examine how representative our galaxies are of the
overall galaxy population at the targeted redshifts.
Description:
We measured the stellar population parameters and derived the SFH of a
sample of 393 galaxies in various MUSE surveys. The sample contains
galaxies in the redshift range of 0.1≤z≤0.9, stellar masses from
∼108M[sun to 1012M☉, and SFRs derived from SED fitting
from Log10(SFR/[M☉/yr])~-3 to ∼2. The stellar population
parameters were computed within an aperture of 1Re for each galaxy.
Stellar population parameters of 393 galaxies.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 217 393 Galaxy sample properties
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See also:
J/A+A/624/A141 : MUSE-Wide Survey DR1 catalog (Urrutia+, 2019)
J/AJ/132/1729 : Hubble Ultra Deep Field BVI-dropout sources (Beckwith+, 2006)
J/A+A/670/A4 : MUSE Hubble Ultra Deep Field surveys. DR2 (Bacon+, 2023)
J/A+A/683/A205 : MAGIC group and galaxy catalogs (Epinat+, 2024)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- N [1/393] Galaxy index
5- 14 F10.6 deg RAdeg Right ascension (J2000.0)
16- 26 F11.7 deg DEdeg Declination (J2000.0)
28- 37 F10.8 --- z MUSE spectroscopic redshift
39- 48 F10.7 --- S/N MUSE S/N ratio measured within
effective radius
50- 60 F11.8 kpc Remaj Size parameter, Rmaj
62- 71 F10.7 [Msun] logMasssed Galaxy stellar mass from SED fitting
73- 82 F10.6 [1/Gyr] logSFRsed ?=- Galaxy SFR from SED fitting
84- 93 F10.7 [Msun] logMasspPXF Galaxy stellar mass from
spectral pPXF fitting
95-105 F11.9 [Msun] e_logMasspPXF Galaxy stellar mass error,
spectral fitting
107-116 F10.7 [yr] logAge Galaxy stellar ages from
spectral pPXF fitting
118-129 F12.10 [yr] e_logAge Galaxy stellar ages error rate from
fitting
131-143 F13.10 --- Metal Galaxy stellar metallicity,
spectral fitting
145-155 F11.9 --- e_Metal Galaxy stellar metallicity error
157-167 F11.8 [1/Gyr] logSFROII ?=- Galaxy SFR from [OII] doublet emission
169-180 F12.9 [yr] logt50 ?=- Time taken to assemble 50% of
the stellar mass
182-193 F12.9 [yr] logt90 ?=- Time taken to assemble 90% of
the stellar mass
195-206 E12.10 --- eta ?=-99.9 Environmental global density
parameter
208-210 F3.1 --- NSFE Number of tar-forming episodes
212-217 A6 --- TSFE Types of tar-forming episodes (1)
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Note (1): Type indicate the shape of the SFR:
exp = exponential
g1 = one Gaussian
g5 = five Gaussian
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Acknowledgements:
Constanza Munoz Lopez, cmunoz(at)aip.de
(End) Constanza Munoz Lopez [AIP], Patricia Vannier [CDS] 07-Oct-2025