Advanced search
1 file | 1.59 MB Add to list

Massive stars formed in atomic hydrogen reservoirs : H i observations of gamma-ray burst host galaxies

Author
Organization
Abstract
Long gamma-ray bursts (GRBs), among the most energetic events in the Universe, are explosions of massive and short-lived stars, so they pinpoint locations of recent star formation. However, several GRB host galaxies have recently been found to be deficient in molecular gas (H-2), believed to be the fuel of star formation. Moreover, optical spectroscopy of GRB afterglows implies that the molecular phase constitutes only a small fraction of the gas along the GRB line of sight. Here we report the first ever 21 cm line observations of GRB host galaxies, using the Australia Telescope Compact Array, implying high levels of atomic hydrogen (HI), which suggests that the connection between atomic gas and star formation is stronger than previously thought. In this case, it is possible that star formation is directly fuelled by atomic gas (or that the HI- to- H-2 conversion is very efficient, which rapidly exhaust molecular gas), as has been theoretically shown to be possible. This can happen in low-metallicity gas near the onset of star formation because cooling of gas (necessary for star formation) is faster than the HI- to- H-2 conversion. Indeed, large atomic gas reservoirs, together with low molecular gas masses, stellar, and dust masses are consistent with GRB hosts being preferentially galaxies which have very recently started a star formation episode after accreting metal-poor gas from the intergalactic medium. This provides a natural route for forming GRBs in low-metallicity environments. The gas inflow scenario is also consistent with the existence of the companion HI object with no optical counterpart similar to 19 kpc from the GRB 060505 host, and with the fact that the HI centroids of the GRB 980425 and 060505 hosts do not coincide with optical centres of these galaxies, but are located close to the GRB positions.
Keywords
gamma, galaxies: star formation, extinction, galaxies: ISM, ray burst: general, radio continuum: galaxies, radio lines: galaxies, HERSCHEL REFERENCE SURVEY, GIANT MOLECULAR CLOUDS, LARGE-MAGELLANIC-CLOUD, GRB 980425/SN 1998BW, SPECTRAL ENERGY-DISTRIBUTIONS, VLT/X-SHOOTER SPECTROSCOPY, NOBEYAMA MILLIMETER ARRAY, COSMIC CHEMICAL EVOLUTION, FORMING DWARF GALAXIES, HIGH-METALLICITY HOST, dust

Downloads

  • Michalowski et al. 2015.pdf
    • full text
    • |
    • open access
    • |
    • PDF
    • |
    • 1.59 MB

Citation

Please use this url to cite or link to this publication:

MLA
Michalowski, MJ et al. “Massive Stars Formed in Atomic Hydrogen Reservoirs : H i Observations of Gamma-ray Burst Host Galaxies.” ASTRONOMY & ASTROPHYSICS 582 (2015): n. pag. Print.
APA
Michalowski, M., Gentile, G., Hjorth, J., Krumholz, M., Tanvir, N., Kamphuis, P., Burlon, D., et al. (2015). Massive stars formed in atomic hydrogen reservoirs : H i observations of gamma-ray burst host galaxies. ASTRONOMY & ASTROPHYSICS, 582.
Chicago author-date
Michalowski, MJ, Gianfranco Gentile, J Hjorth, MR Krumholz, NR Tanvir, P Kamphuis, D Burlon, et al. 2015. “Massive Stars Formed in Atomic Hydrogen Reservoirs : H i Observations of Gamma-ray Burst Host Galaxies.” Astronomy & Astrophysics 582.
Chicago author-date (all authors)
Michalowski, MJ, Gianfranco Gentile, J Hjorth, MR Krumholz, NR Tanvir, P Kamphuis, D Burlon, Maarten Baes, S Basa, S Berta, JMC Ceron, D Crosby, V D’Elia, J Elliott, J Greiner, LK Hunt, S Klose, MP Koprowski, E Le Floc’h, D Malesani, T Murphy, AN Guelbenzu, E Palazzi, J Rasmussen, A Rossi, S Savaglio, P Schady, J Sollerman, AD Postigo, D Watson, P van der Werf, SD Vergani, and D Xu. 2015. “Massive Stars Formed in Atomic Hydrogen Reservoirs : H i Observations of Gamma-ray Burst Host Galaxies.” Astronomy & Astrophysics 582.
Vancouver
1.
Michalowski M, Gentile G, Hjorth J, Krumholz M, Tanvir N, Kamphuis P, et al. Massive stars formed in atomic hydrogen reservoirs : H i observations of gamma-ray burst host galaxies. ASTRONOMY & ASTROPHYSICS. 2015;582.
IEEE
[1]
M. Michalowski et al., “Massive stars formed in atomic hydrogen reservoirs : H i observations of gamma-ray burst host galaxies,” ASTRONOMY & ASTROPHYSICS, vol. 582, 2015.
@article{7059520,
  abstract     = {Long gamma-ray bursts (GRBs), among the most energetic events in the Universe, are explosions of massive and short-lived stars, so they pinpoint locations of recent star formation. However, several GRB host galaxies have recently been found to be deficient in molecular gas (H-2), believed to be the fuel of star formation. Moreover, optical spectroscopy of GRB afterglows implies that the molecular phase constitutes only a small fraction of the gas along the GRB line of sight. Here we report the first ever 21 cm line observations of GRB host galaxies, using the Australia Telescope Compact Array, implying high levels of atomic hydrogen (HI), which suggests that the connection between atomic gas and star formation is stronger than previously thought. In this case, it is possible that star formation is directly fuelled by atomic gas (or that the HI- to- H-2 conversion is very efficient, which rapidly exhaust molecular gas), as has been theoretically shown to be possible. This can happen in low-metallicity gas near the onset of star formation because cooling of gas (necessary for star formation) is faster than the HI- to- H-2 conversion. Indeed, large atomic gas reservoirs, together with low molecular gas masses, stellar, and dust masses are consistent with GRB hosts being preferentially galaxies which have very recently started a star formation episode after accreting metal-poor gas from the intergalactic medium. This provides a natural route for forming GRBs in low-metallicity environments. The gas inflow scenario is also consistent with the existence of the companion HI object with no optical counterpart similar to 19 kpc from the GRB 060505 host, and with the fact that the HI centroids of the GRB 980425 and 060505 hosts do not coincide with optical centres of these galaxies, but are located close to the GRB positions.},
  articleno    = {A78},
  author       = {Michalowski, MJ and Gentile, Gianfranco and Hjorth, J and Krumholz, MR and Tanvir, NR and Kamphuis, P and Burlon, D and Baes, Maarten and Basa, S and Berta, S and Ceron, JMC and Crosby, D and D'Elia, V and Elliott, J and Greiner, J and Hunt, LK and Klose, S and Koprowski, MP and Le Floc'h, E and Malesani, D and Murphy, T and Guelbenzu, AN and Palazzi, E and Rasmussen, J and Rossi, A and Savaglio, S and Schady, P and Sollerman, J and Postigo, AD and Watson, D and van der Werf, P and Vergani, SD and Xu, D},
  issn         = {1432-0746},
  journal      = {ASTRONOMY & ASTROPHYSICS},
  keywords     = {gamma,galaxies: star formation,extinction,galaxies: ISM,ray burst: general,radio continuum: galaxies,radio lines: galaxies,HERSCHEL REFERENCE SURVEY,GIANT MOLECULAR CLOUDS,LARGE-MAGELLANIC-CLOUD,GRB 980425/SN 1998BW,SPECTRAL ENERGY-DISTRIBUTIONS,VLT/X-SHOOTER SPECTROSCOPY,NOBEYAMA MILLIMETER ARRAY,COSMIC CHEMICAL EVOLUTION,FORMING DWARF GALAXIES,HIGH-METALLICITY HOST,dust},
  language     = {eng},
  pages        = {14},
  title        = {Massive stars formed in atomic hydrogen reservoirs : H i observations of gamma-ray burst host galaxies},
  url          = {http://dx.doi.org/10.1051/0004-6361/201526542},
  volume       = {582},
  year         = {2015},
}

Altmetric
View in Altmetric
Web of Science
Times cited: