CaltechAUTHORS
Published September 2015 | Version Published + Submitted
Journal Article Open

What powers Lyα blobs?

Creators

  • 1. ROR icon National Astronomical Observatory of Japan
  • 2. ROR icon Purple Mountain Observatory
  • 3. ROR icon Institut d'Astrophysique Spatiale
  • 4. ROR icon King Abdulaziz University
  • 5. ROR icon Princeton University
  • 6. ROR icon European Southern Observatory
  • 7. ROR icon Australian National University
  • 8. ROR icon California Institute of Technology
  • 9. ROR icon Aix-Marseille University
  • 10. ROR icon Institut d'Astrophysique de Paris
  • 11. ROR icon University of Tasmania
  • 12. ROR icon Australia Telescope National Facility
  • 13. ROR icon University of Utah

Abstract

Lyα blobs (LABs) are spatially extended Lyα  nebulae seen at high redshift. The origin of Lyα emission in the LABs is still unclear and under debate. To study their heating mechanism(s), we present Australia Telescope Compact Array (ATCA) observations of the 20 cm radio emission and Herschel PACS and SPIRE measurements of the far-infrared (FIR) emission toward the four LABs in the protocluster J2143-4423 at z = 2.38. Among the four LABs, B6 and B7 are detected in the radio with fluxes of 67±17 μJy and 77±16 μJy, respectively, and B5  is marginally detected at 3σ (51±16 μJy). For all detected sources, their radio positions are consistent with the central positions of the LABs. Among them, B6 and B7 are obviously also detected in the FIR. By fitting the data with different templates, we obtained redshifts of 2.20^(+0.30)_(-0.35) for B6 and 2.20^(+0.45)_(-0.30) for B7, which are consistent with the redshift of the Lyα emission within uncertainties, indicating that both FIR sources are likely associated with the LABs. The associated FIR emission in B6 and B7 and high star formation rates strongly favor star formation in galaxies as an important powering source for the Lyα emission in both LABs. However, the other two, B1 and B5, are predominantly driven by the active galactic nuclei or other sources of energy still to be specified, but not mainly by star formation. In general, the LABs are powered by quite diverse sources of energy.

Additional Information

© 2015 ESO. Received 9 May 2014. Accepted 20 July 2015. Published online 22 September 2015. We thank the anonymous referee for valuable comments that improved this manuscript. Y.A. acknowledges partial support by NSFC grant 11373007 and Youth Innovation Promotion Association CAS. R.C. is supported in part by NASA grant NNX11AI23G. Y.M. acknowledges support from JSPS KAKENHI Grant Number 20647268. Z.Z. was partially supported by NSF grant AST-1208891 and NASA grant NNX14AC89G. This research has made use of NASA's Astrophysical Data System (ADS). PACS has been developed by a consortium of institutes led by MPE (Germany) and including UVIE (Austria); KU Leuven, CSL, IMEC (Belgium); CEA, LAM (France); MPIA (Germany); INAF-IFSI/OAA/OAP/OAT, LENS, SISSA (Italy); IAC (Spain). This development has been supported by the funding agencies BMVIT (Austria), ESA-PRODEX (Belgium), CEA/CNES (France), DLR (Germany), ASI/INAF (Italy), and CICYT/MCYT (Spain). SPIRE has been developed by a consortium of institutes led by Cardiff University (UK) and including Univ. Lethbridge (Canada); NAOC (China); CEA, LAM (France); IFSI, Univ. Padua (Italy); IAC (Spain); Stockholm Observatory (Sweden); Imperial College London, RAL, UCL-MSSL, UKATC, Univ. Sussex (UK); and Caltech, JPL, NHSC, Univ. Colorado (USA). This development has been supported by national funding agencies: CSA (Canada); NAOC (China); CEA, CNES, CNRS (France); ASI (Italy); MCINN (Spain); SNSB (Sweden); STFC, UKSA (UK); and NASA (USA).

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Additional details

Identifiers

Eprint ID
61738
Resolver ID
CaltechAUTHORS:20151030-095317976

Related works

Describes
http://arxiv.org/abs/1507.07627 (URL)

Funding

National Natural Science Foundation of China
11373007
Chinese Academy of Sciences
NASA
NNX11AI23G
Japan Society for the Promotion of Science (JSPS)
20647268
NSF
AST-1208891
NASA
NNX14AC89G
Bundesministerium für Verkehr, Innovation und Technologie (BMVIT)
ESA-PRODEX (Belgium)
Commissariat à l'Energie Atomique (CEA)
Deutsches Zentrum für Luft- und Raumfahrt (DLR)
Agenzia Spaziale Italiana (ASI)
Comisión Interministerial de Ciencia y Tecnología (CICYT)
Canadian Space Agency (CSA)
National Astronomical Observatories, Chinese Academy of Sciences (NAOC)
Centre National d'Études Spatiales (CNES)
Ministerio de Economía y Competitividad (MCINN)
Swedish National Space Board (SNSB)
Science and Technology Facilities Council (STFC)
Centre National de la Recherche Scientifique (CNRS)
United Kingdom Space Agency (UKSA)
Istituto Nazionale di Astrofisica (INAF)

Dates

Created
2015-11-03
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Updated
2021-11-10
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