English

Post-starburst galaxies in the centers of intermediate redshift clusters

Astrophysics of Galaxies 2022-05-18 v1

Abstract

We present results from MUSE spatially-resolved spectroscopy of 21 post-starburst galaxies in the centers of 8 clusters from z0.3z\sim0.3 to z0.4z\sim0.4. We measure spatially resolved star-formation histories (SFHs), the time since quenching (tQt_Q) and the fraction of stellar mass assembled in the past 1.5 Gyr (μ1.5\mu_{1.5}). The SFHs display a clear enhancement of star-formation prior to quenching for 16 out of 21 objects, with at least 10% (and up to >50>50%) of the stellar mass being assembled in the past 1.5 Gyr and tQt_Q ranging from less than 100 Myrs to 800\sim800 Myrs. By mapping tQt_Q and μ1.5\mu_{1.5}, we analyze the quenching patterns of the galaxies. Most galaxies in our sample have quenched their star-formation from the outside-in or show a side-to-side/irregular pattern, both consistent with quenching by ram-pressure stripping. Only three objects show an inside-out quenching pattern, all of which are at the high-mass end of our sample. At least two of them currently host an active galactic nucleus. In two post-starbursts, we identify tails of ionized gas indicating that these objects had their gas stripped by ram pressure very recently. Post-starburst features are also found in the stripped regions of galaxies undergoing ram-pressure stripping in the same clusters, confirming the link between these classes of objects. Our results point to ram-pressure stripping as the main driver of fast quenching in these environments, with active galactic nuclei playing a role at high stellar masses.

Keywords

Cite

@article{arxiv.2203.08862,
  title  = {Post-starburst galaxies in the centers of intermediate redshift clusters},
  author = {Ariel Werle and Bianca Poggianti and Alessia Moretti and Callum Bellhouse and Benedetta Vulcani and Marco Gullieuszik and Mario Radovich and Jacopo Fritz and Alessandro Ignesti and Johan Richard and Geneviève Soucail and Gustavo Bruzual and Stephane Charlot and Matilde Mingozzi and Cecilia Bacchini and Neven Tomicic and Rory Smith and Andrea Kulier and Giorgia Peluso and Andrea Franchetto},
  journal= {arXiv preprint arXiv:2203.08862},
  year   = {2022}
}

Comments

Accepted for publication in ApJ