X-ray Characterization of Galaxy Groups and Hickson Groups in COSMOS-Web to z~3.8 I. X-ray Luminosity Function Evolution
Year: 2026
Type: preprint
Abstract: Galaxy groups are the dominant halo environment in the Universe and a sensitive laboratory for feedback and gas-cycling physics, yet a uniform, intermediate-redshift X-ray characterization of the group population has been limited by the availability of deep, wide-area imaging. We present a uniform X-ray characterization of the COSMOS-Web galaxy group population: 1,678 groups (CW-All) identified with the AMICO algorithm applied to the JWST-selected COSMOS-Web photometric catalog ($0.08 \lesssim z \lesssim 3.7$), and a parallel sample of 993 Hickson compact groups (CW-HCG; $0.08 \lesssim z \lesssim 3.82$) over $0.45~\mathrm{deg}^2$. We apply a uniform aperture-photometry X-ray pipeline to the combined Chandra and XMM-Newton COSMOS mosaic, measuring fluxes, luminosities, temperatures, and halo masses and radii for every group, together with detections, upper limits, and quality flags. We detect X-ray emission from 499 CW-All groups (29.7\%) and 332 CW-HCG groups (33.4\%) at SNR~$\geq 2.0$, and present the X-ray luminosity function in four redshift bins. The characteristic luminosity $L^\star$ rises monotonically by $\sim$1.9--2.1~dex from the lowest to highest redshift bin in both catalogs, a trend that persists under two independent cross-check binning schemes and is not explained by mass or richness selection of the detected population. A targeted search for diffuse X-ray emission from the AmicOne protocluster candidate at $2.50 \lesssim z < 3.09$ finds no statistically significant signal at the current depth. We publicly release the X-ray measurements and derived properties for both catalogs.
Source: arXiv (Cornell University)
Authors: Gozaliasl, Ghassem, Hasinger, Günther, Leroy, Gavin, Finoguenov, Alexis, Abedini, Fatemeh, Akins, Hollis B., Arango-Toro, Rafael C., Babul, Arif, Casey, Caitlin M., Drakos, Nicole E., Faisst, Andreas L., Flayhart, Carter, Franco, Maximilien, Ghaffari, Zohreh, Harish, Santosh, Hatamnia, Hossein, Ilbert, Olivier, Kartaltepe, Jeyhan S., Khostovan, Ali Ahmad, Korpi-Lagg, Maarit, Laishram, Ronaldo, Liu, Daizhong, Maturi, Matteo, McCracken, Henry Joy, McKinney, Jed, McMahon, Nicolas, Moscardini, Lauro, Mousavi-Sadr, Mahdiyar, Rhodes, Jason, Robertson, Brant E., Paquereau, Louise, Samir, Rasha M., Sargent, Mark, Scognamiglio, Diana, Shuntov, Marko, Toni, Greta, Ubertosi, Francesco, Vardoulaki, Eleni
Institutions: University of Helsinki, Aalto University, Deutsches Zentrum für Astrophysik, Technische Universität Dresden, Durham University, The University of Texas at Austin, Centre National de la Recherche Scientifique, Aix-Marseille Université, Laboratoire d’Astrophysique de Marseille, University of Victoria, Indian Institute of Science Bangalore, University of Hawaii at Hilo, California Institute of Technology, Infrared Processing and Analysis Center, Rochester Institute of Technology, Université Paris Cité, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Université Paris-Saclay, Astrophysique, Instrumentation et Modélisation, Trieste Astronomical Observatory, Institute for Fundamental Physics of the Universe, National Institute for Astrophysics, University of California, Riverside, University of Kentucky, National Astronomical Observatory of Japan, Chinese Academy of Sciences, Purple Mountain Observatory, Heidelberg University, Institut d'Astrophysique de Paris, Sorbonne Université, University of Copenhagen, Jet Propulsion Laboratory, University of California, Santa Cruz, National Research Institute of Astronomy and Geophysics, Institute for Research in Fundamental Sciences, Deutsches Elektronen-Synchrotron DESY, Osservatorio di Astrofisica e Scienza dello Spazio, University of Bologna
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7220440480