A JWST survey of eight gravitationally lensed galaxies at z=2-4 resolves 10-200 pc star-forming clumps and finds early evidence of recently quenched, post-starburst clumps.
Differential Galaxy Evolution in Cluster and Field Galaxies at z=0.3
8 Pith papers cite this work. Polarity classification is still indexing.
abstract
(abridged) We measure spectral indices for 1823 galaxies in the CNOC1 sample of fifteen X-ray luminous clusters at 0.18<z<0.55, to investigate the mechanisms responsible for differential evolution between the galaxy cluster and field environments. The radial trends of D4000, Hdelta and [OII] are all consistent with an age sequence, in the sense that the last episode of star formation occurred more recently in galaxies farthest from the cluster center. Throughout the cluster environment, galaxies show evidence for older mean stellar populations than field galaxies. From the subsample of galaxies more luminous than M_r=-18.8 + 5log h, we identify a sample of K+A galaxies, which may result from recently terminated star formation. Corrected for a systematic effect which results from the large uncertainties on individual spectral index measurements, we estimate that K+A galaxies make up only 1.5 +/- 0.8 % of the cluster sample, and 1.2 +/- 0.8 % of the field. We compare our data with spectrophotometric models and conclude that up to 1.9 +/- 0.8 % of the cluster population may have had its star formation recently truncated without a starburst. However, this is still not significantly greater than the fraction of such galaxies in the field, 3.1 +/- 1.0 %. Furthermore, we do not detect an excess of cluster galaxies that have unambiguously undergone a starburst within the last 1 Gyr. Our results imply that these cluster environments are not responsible for inducing starbursts; thus, the increase in cluster blue galaxy fraction with redshift may not be a strictly cluster--specific phenomenon. We suggest that the truncation of star formation in clusters may largely be a gradual process, perhaps due to the exhaustion of gas in the galactic disk over fairly long timescales.
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unclear 2representative citing papers
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Massive post-starburst galaxies at 1<z<2 show no mid-IR excess, limiting any dust-obscured AGN to Eddington ratios below 1%, while low-mass PSBs retain residual star formation.
Galaxy size-mass relations exhibit double power-law breaks at different pivot masses for quiescent versus bulge-dominated samples, coinciding with AGN activity scales.
In TNG50, compact dwarf satellites (log M_star 8.4-9.2) form via DM-rich gas inflows in low-merger environments, tidal stripping for DM-poor cases, and ram-pressure starbursts for some metal-rich ones.
Einstein-Cartan model with torsion and H = -α φ assumption fitted via MCMC to CC data produces H0 values of 66-69 km/s/Mpc favoring the CMB side of the Hubble tension.
SKA-mid AA4 will enable deep, spatially resolved HI imaging over hundreds of square degrees at column densities down to 10^18 cm^{-2} to study environmental gas processes from isolated galaxies to clusters.
Optical spectroscopy is required to unlock the full potential of SKAO extragalactic surveys through precise redshifts, activity diagnostics, HI stacking, and large-scale structure mapping.
citing papers explorer
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LEGGOS I: The JWST LEGGOS Survey -- LEnsing and Galaxy Growth: Observing Substructures -- Unpacks the Nature of Clumpy Star Formation and Quenching in Gravitationally Lensed Galaxies beyond Cosmic Noon
A JWST survey of eight gravitationally lensed galaxies at z=2-4 resolves 10-200 pc star-forming clumps and finds early evidence of recently quenched, post-starburst clumps.
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pop-cosmos: Disentangling galaxy properties from observables using data-driven approaches
Rest-frame optical galaxy SEDs from a 16-parameter SPS model are captured by five disentangled VAE latents (mass, young stars, dust, soft/hard ionization); metallicity and age are not independent drivers.
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No hidden monsters: Probing recently-quenched galaxies for obscured AGN with JWST-PRIMER MIRI and NIRCam
Massive post-starburst galaxies at 1<z<2 show no mid-IR excess, limiting any dust-obscured AGN to Eddington ratios below 1%, while low-mass PSBs retain residual star formation.
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pop-cosmos: Galaxy size evolution across structural and star-formation classifications in COSMOS-Web
Galaxy size-mass relations exhibit double power-law breaks at different pivot masses for quiescent versus bulge-dominated samples, coinciding with AGN activity scales.
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Satellite compaction pathways: environmental drivers shaping dwarf galaxy corpulence in the TNG50 simulation
In TNG50, compact dwarf satellites (log M_star 8.4-9.2) form via DM-rich gas inflows in low-merger environments, tidal stripping for DM-poor cases, and ram-pressure starbursts for some metal-rich ones.
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Cosmic Dynamics in Einstein-Cartan Theory: Analysing Hubble Tension through Curvature and Torsion field
Einstein-Cartan model with torsion and H = -α φ assumption fitted via MCMC to CC data produces H0 values of 66-69 km/s/Mpc favoring the CMB side of the Hubble tension.
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Resolved HI and Environmental Dynamics
SKA-mid AA4 will enable deep, spatially resolved HI imaging over hundreds of square degrees at column densities down to 10^18 cm^{-2} to study environmental gas processes from isolated galaxies to clusters.
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Unlocking the Full Potential of SKAO Extra-galactic Science with High-multiplex Optical Spectroscopy
Optical spectroscopy is required to unlock the full potential of SKAO extragalactic surveys through precise redshifts, activity diagnostics, HI stacking, and large-scale structure mapping.