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Title: Neutral hydrogen gas, past and future star formation in galaxies in and around the ‘Sausage’ merging galaxy cluster

CIZA J2242.8+5301 (z = 0.188, nicknamed ‘Sausage’) is an extremely massive (M 200 ~2.0 × 10 15 M ), merging cluster with shock waves towards its outskirts, which was found to host numerous emission line galaxies. We performed extremely deep Westerbork Synthesis Radio Telescope H i observations of the ‘Sausage’ cluster to investigate the effect of the merger and the shocks on the gas reservoirs fuelling present and future star formation (SF) in cluster members. By using spectral stacking, we find that the emission line galaxies in the ‘Sausage’ cluster have, on average, as much H i gas as field galaxies (when accounting for the fact cluster galaxies are more massive than the field galaxies), contrary to previous studies. Since the cluster galaxies are more massive than the field spirals, they may have been able to retain their gas during the cluster merger. The large H i reservoirs are expected to be consumed within ~0.75–1.0 Gyr by the vigorous SF and active galactic nuclei activity and/or driven out by the outflows we observe. We find that the star formation rate (SFR) in a large fraction of H α emission line cluster galaxies correlates well with the radio broad-band emission, tracingmore » supernova remnant emission. This suggests that the cluster galaxies, all located in post-shock regions, may have been undergoing sustained SFR for at least 100 Myr. In conclusion, this fully supports the interpretation proposed by Stroe et al. and Sobral et al. that gas-rich cluster galaxies have been triggered to form stars by the passage of the shock.« less
 [1] ;  [2] ;  [1] ;  [3] ;  [4] ;  [5]
  1. Leiden Univ. (Netherlands). Leiden Observatory
  2. ASTRON, Dwingeloo (The Netherlands); Kapteyn Astronomical Inst., Groningen (The Netherlands)
  3. Leiden Univ. (Netherlands). Leiden Observatory; Univ. de Lisboa, Lisbon (Portugal). Inst. de Astroisica e Ciencias do Espaco, Observatorio Astronomico de Lisboa, and Dept. de Fisica
  4. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
  5. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0035-8711
Grant/Contract Number:
AC52-07NA27344; IF/01154/2012/CP0189/CT0010; PF2-130104; PEst-OE/FIS/UI2751/2014
Accepted Manuscript
Journal Name:
Monthly Notices of the Royal Astronomical Society
Additional Journal Information:
Journal Volume: 452; Journal Issue: 3; Journal ID: ISSN 0035-8711
Royal Astronomical Society
Research Org:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org:
USDOE; National Aeronautic and Space Administration (NASA)
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; shock waves, galaxies: active, galaxies: clusters: individual: CIZA J2242.8+5301, radio continuum: galaxies, radio lines: galaxies
OSTI Identifier: