Maqola

An Energetic Afterglow From A Distant Stellar Explosion

Frail, D ANational Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801Berger, EDivision of Physics, Mathematics, and Astronomy, MS 105-24, California Institute of Technology, Pasadena, CA 91125Cameron, P BDivision of Physics, Mathematics, and Astronomy, MS 105-24, California Institute of Technology, Pasadena, CA 91125Cenko, S BTheoretical Astrophysics, California Institute of Technology, MS 130-33, Pasadena, CA 91125Fox, D BInstitute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822Gal-Yam, AHubble FellowKasliwal, MDivision of Physics, Mathematics, and Astronomy, MS 105-24, California Institute of Technology, Pasadena, CA 91125Kulkarni, S RDivision of Physics, Mathematics, and Astronomy, MS 105-24, California Institute of Technology, Pasadena, CA 91125Nakar, EDepartment of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802Ofek, EDivision of Physics, Mathematics, and Astronomy, MS 105-24, California Institute of Technology, Pasadena, CA 91125Price, P AResearch School of Astronomy and Astrophysics, Australian National University, Mount Stromlo Observatory, via Cotter Road, Weston Creek, ACT 2611, AustraliaSchmidt, B PDivision of Physics, Mathematics, and Astronomy, MS 105-24, California Institute of Technology, Pasadena, CA 91125Soderberg, A MSpace Radiation Laboratory, MS 220-47, California Institute of Technology, Pasadena, CA 91125

2006en

ABI

Annotatsiya

We present the discovery of radio afterglow emission from the high redshift (z=6.295) burst GRB 050904. The peak flux density for this burst is similar to typical low-redshift gamma-ray bursts (GRB). We further show that beyond a redshift of order unity, the flux density of radio afterglows are largely insensitive to redshift, consistent with predictions. By combining the existing X-ray, near-infrared and radio measurements, we derive estimates for the kinetic energy and opening angle of the blast wave, and for the density of the circumburst medium into which it expands. Both the kinetic and radiated energy indicate that GRB 050904 was an unusally energetic burst (10**52 erg). More importantly, we are able to make an in situ measurement of the density structure of the circumburst medium. We conclude that GRB 050904 exploded into a constant density medium with n=680 cm**-3, which is two orders of magnitude above the nominal value for low-redshift GRBs. The next generation of centimeter (EVLA) and millimeter radio instuments (ALMA) will be able to routinely detect events like GRB 050904 and use them to study magnetic fields, and the atomic and molecular gas in the high redshift Universe.

Hali tarjima qilinmagan

Iqtiboslar va manbalar

2 ta iqtibos0 ta foydalanilgan manba

Koʻrsatkichlar — AkademScholar