Статья

A New Population of High‐Redshift Short‐Duration Gamma‐Ray Bursts

E. BergerHubble FellowD. B. FoxDepartment of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802P. A. PriceInstitute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822E. NakarDivision of Physics, Mathematics and Astronomy, 105-24, California Institute of Technology, Pasadena, CA 91125A. Gal‐YamDivision of Physics, Mathematics and Astronomy, 105-24, California Institute of Technology, Pasadena, CA 91125D. E. HolzKavli Institute for Cosmological Physics and Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637B. P. SchmidtResearch School of Astronomy and Astrophysics, Australian National University, Mount Stromlo Observatory, via Cotter Road, Weston Creek, ACT 2611, AustraliaA. CucchiaraDepartment of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802S. B. CenkoSpace Radiation Laboratory, California Institute of Technology, Mail Stop 220-47, Pasadena, CA 91125S. R. KulkarniDivision of Physics, Mathematics and Astronomy, 105-24, California Institute of Technology, Pasadena, CA 91125A. M. SoderbergDivision of Physics, Mathematics and Astronomy, 105-24, California Institute of Technology, Pasadena, CA 91125D. A. FrailNational Radio Astronomy Observatory, Socorro, NM 87801B. E. PenprasePomona College Department of Physics and Astronomy, 610 North College Avenue, Claremont, CA 91711A. RauDivision of Physics, Mathematics and Astronomy, 105-24, California Institute of Technology, Pasadena, CA 91125E. OfekDivision of Physics, Mathematics and Astronomy, 105-24, California Institute of Technology, Pasadena, CA 91125S. J. Bell BurnellDepartment of Astrophysics, University of Oxford, Oxford OX1 3RH, UKP. B. CameronDivision of Physics, Mathematics and Astronomy, 105-24, California Institute of Technology, Pasadena, CA 91125L. L. CowieInstitute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822M. A. DopitaResearch School of Astronomy and Astrophysics, Australian National University, Mount Stromlo Observatory, via Cotter Road, Weston Creek, ACT 2611, AustraliaI. HookDepartment of Astrophysics, University of Oxford, Oxford OX1 3RH, UKB. A. PetersonResearch School of Astronomy and Astrophysics, Australian National University, Mount Stromlo Observatory, via Cotter Road, Weston Creek, ACT 2611, AustraliaP. PodsiadlowskiDepartment of Astrophysics, University of Oxford, Oxford OX1 3RH, UKK. C. RothGemini Observatory, 670 North Aohoku Place, Hilo, HI 96720R. E. RutledgeDepartment of Physics, Rutherford Physics Building, McGill University, 3600 University Street, Montreal, QC H3A 2T8, CanadaS. S. SheppardDepartment of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road NW, Washington, DC 20015A. SongailaInstitute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822

2007en

ABI

Аннотация

The redshift distribution of the short-duration gamma-ray bursts (GRBs) is a crucial, but currently fragmentary, clue to the nature of their progenitors. Here we present optical observations of nine short GRBs obtained with Gemini, Magellan, and the Hubble Space Telescope. We detect the afterglows and host galaxies of two short bursts, and host galaxies for two additional bursts with known optical afterglow positions, and five with X-ray positions (≲6" radius). In eight of the nine cases we find that the most probable host galaxies are faint, R ≈ 23-26.5 mag, and are therefore starkly different from the first few short GRB hosts with R ≈ 17-22 mag and z ≲ 0.5. Indeed, we measure spectroscopic redshifts of z ≈ 0.4-1.1 for the four brightest hosts. A comparison to large field galaxy samples, as well as the hosts of long GRBs and previous short GRBs, indicates that the fainter hosts likely reside at z ≳ 1. Our most conservative limit is that at least half of the five hosts without a known redshift reside at z > 0.7 (97% confidence level), suggesting that about 1/3 to 2/3 of all short GRBs originate at higher redshifts than previously determined. This has two important implications: (1) we constrain the acceptable age distributions to a wide lognormal (σ ≳ 1) with τ* ~ 4-8 Gyr, or to a power law, P(τ)α τ^n, with -1 ≲ n ≲ 0; and (2) the inferred isotropic energies, E_γ,iso ~ 10^50-10^52 ergs, are significantly larger than ~10^48-10^49 ergs for the low-redshift, short GRBs, indicating a large spread in energy release or jet opening angles. Finally, we reiterate the importance of short GRBs as potential gravitational-wave sources and find a conservative detection rate with the advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) of ~2-6 yr^-1.

Перевод пока недоступен

Идентификаторы

DOI: 10.1086/518762

Цитирования и источники

Цитирований: 4Использованных источников: 0

Показатели — AkademScholar