On the ages of the stellar populations of galaxies at $z=0.1$-7

Abstract

Recent studies have reported a non evolution of galaxy ages at redshifts higher than $z\sim$ 2.5, as well as galaxies older than the Universe. In this work, a sample of galaxies from JWST and HST was analysed via photometry to further understand this astronomical phenomenon. No prior cosmological parameters were assumed in the analysis, but the spectroscopic redshift. When compared to stellar population synthesis models, the results for mass-weighted galaxy ages indicate that the analysed objects seem to be divided into two subsets. The results for the subset with the majority of objects (60\% assuming a flat-$\Lambda$CDM cosmology) indicate an evolution of galaxy ages within the redshift range $z$=0.1-7.0, in the sense that higher redshift galaxies are younger than the Universe. Sources of systematic errors were discussed drawing into conclusion that degeneracies between reddening-age-metallicity, and/or AGN emission may explain the rest 40\% of the galaxies with ages older than expected from a flat-$\Lambda$CDM cosmology.

Accepted for publication in MNRAS

References in corpus (28)

• A simple model to interpret the ultraviolet, optical and infrared emission from galaxies
• The MUSE second-generation VLT instrument
• The Near-Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope I. Overview of the instrument and its capabilities
• A population of red candidate massive galaxies ~600 Myr after the Big Bang
• An ALMA survey of Sub-millimeter Galaxies in the Extended Chandra Deep Field South: Physical properties derived from ultraviolet-to-radio modelling
• The 1% Concordance Hubble Constant
• Evolution of asymptotic giant branch stars I. Updated synthetic TP-AGB models and their basic calibration
• Evidence for TP-AGB stars in high redshift galaxies, and their effect on deriving stellar population parameters
• NIRCam Performance on JWST In Flight
• JADES. The diverse population of infant Black Holes at 4<z<11: merging, tiny, poor, but mighty
• The Near-Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope II. Multi-object spectroscopy (MOS)
• A JWST/NIRCam Study of Key Contributors to Reionization: The Star-forming and Ionizing Properties of UV-faint $z\sim 7-8$ Galaxies
• UVUDF: Ultraviolet Through Near-infrared Catalog and Photometric Redshifts of Galaxies in the Hubble Ultra Deep Field
• The MUSE Hubble Ultra Deep Field Survey: II. Spectroscopic redshifts and comparisons to color selections of high-redshift galaxies
• RUBIES: Evolved Stellar Populations with Extended Formation Histories at $z\sim 7-8$ in Candidate Massive Galaxies Identified with JWST/NIRSpec
• Star formation histories of UV-luminous galaxies at $z\simeq 6.8$: implications for stellar mass assembly at early cosmic times
• Overview of the JWST Advanced Deep Extragalactic Survey (JADES)
• On the ages of bright galaxies $\sim 500$ Myr after the Big Bang: insights into star formation activity at $z\gtrsim 15$ with JWST
• Templates for Fitting Photometry of Ultra-High-Redshift Galaxies
• RUBIES: JWST/NIRSpec Confirmation of an Infrared-luminous, Broad-line Little Red Dot with an Ionized Outflow
• UNCOVER: 404 Error -- Models Not Found for the Triply Imaged Little Red Dot A2744-QSO1
• Implications of a Temperature Dependent IMF I: Photometric Template Fitting
• Improving $z\sim 7-11$ Galaxy Property Estimates with JWST/NIRCam Medium-Band Photometry
• Removing biases in resolved stellar mass-maps of galaxy disks through successive Bayesian marginalization
• Strong spectral features from asymptotic giant branch stars in distant quiescent galaxies
• BlackTHUNDER strikes twice: rest-frame Balmer-line absorption and high Eddington accretion rate in a Little Red Dot at $z=7.04$
• BlackTHUNDER -- A non-stellar Balmer break in a black hole-dominated little red dot at $z=7.04$
• On the Thermally Pulsing Asymptotic Giant Branch Contribution to the Light of Nearby Disk Galaxies