排序方式: 共有5条查询结果,搜索用时 125 毫秒
1
1.
Haislip JB Nysewander MC Reichart DE Levan A Tanvir N Cenko SB Fox DB Price PA Castro-Tirado AJ Gorosabel J Evans CR Figueredo E MacLeod CL Kirschbrown JR Jelinek M Guziy S de Ugarte Postigo A Cypriano ES LaCluyze A Graham J Priddey R Chapman R Rhoads J Fruchter AS Lamb DQ Kouveliotou C Wijers RA Bayliss MB Schmidt BP Soderberg AM Kulkarni SR Harrison FA Moon DS Gal-Yam A Kasliwal MM Hudec R Vitek S Kubanek P Crain JA Foster AC Clemens JC Bartelme JW Canterna R Hartmann DH Henden AA Klose S 《Nature》2006,440(7081):181-183
Gamma-ray bursts (GRBs) and their afterglows are the most brilliant transient events in the Universe. Both the bursts themselves and their afterglows have been predicted to be visible out to redshifts of z approximately 20, and therefore to be powerful probes of the early Universe. The burst GRB 000131, at z = 4.50, was hitherto the most distant such event identified. Here we report the discovery of the bright near-infrared afterglow of GRB 050904 (ref. 4). From our measurements of the near-infrared afterglow, and our failure to detect the optical afterglow, we determine the photometric redshift of the burst to be z = 6.39 - 0.12 + 0.11 (refs 5-7). Subsequently, it was measured spectroscopically to be z = 6.29 +/- 0.01, in agreement with our photometric estimate. These results demonstrate that GRBs can be used to trace the star formation, metallicity, and reionization histories of the early Universe. 相似文献
2.
Fynbo JP Watson D Thöne CC Sollerman J Bloom JS Davis TM Hjorth J Jakobsson P Jørgensen UG Graham JF Fruchter AS Bersier D Kewley L Cassan A Cerón JM Foley S Gorosabel J Hinse TC Horne KD Jensen BL Klose S Kocevski D Marquette JB Perley D Ramirez-Ruiz E Stritzinger MD Vreeswijk PM Wijers RA Woller KG Xu D Zub M 《Nature》2006,444(7122):1047-1049
It is now accepted that long-duration gamma-ray bursts (GRBs) are produced during the collapse of a massive star. The standard 'collapsar' model predicts that a broad-lined and luminous type Ic core-collapse supernova accompanies every long-duration GRB. This association has been confirmed in observations of several nearby GRBs. Here we report that GRB 060505 (ref. 10) and GRB 060614 (ref. 11) were not accompanied by supernova emission down to limits hundreds of times fainter than the archetypal supernova SN 1998bw that accompanied GRB 980425, and fainter than any type Ic supernova ever observed. Multi-band observations of the early afterglows, as well as spectroscopy of the host galaxies, exclude the possibility of significant dust obscuration and show that the bursts originated in actively star-forming regions. The absence of a supernova to such deep limits is qualitatively different from all previous nearby long-duration GRBs and suggests a new phenomenological type of massive stellar death. 相似文献
3.
4.
Nugent PE Sullivan M Cenko SB Thomas RC Kasen D Howell DA Bersier D Bloom JS Kulkarni SR Kandrashoff MT Filippenko AV Silverman JM Marcy GW Howard AW Isaacson HT Maguire K Suzuki N Tarlton JE Pan YC Bildsten L Fulton BJ Parrent JT Sand D Podsiadlowski P Bianco FB Dilday B Graham ML Lyman J James P Kasliwal MM Law NM Quimby RM Hook IM Walker ES Mazzali P Pian E Ofek EO Gal-Yam A Poznanski D 《Nature》2011,480(7377):344-347
Type Ia supernovae have been used empirically as 'standard candles' to demonstrate the acceleration of the expansion of the Universe even though fundamental details, such as the nature of their progenitor systems and how the stars explode, remain a mystery. There is consensus that a white dwarf star explodes after accreting matter in a binary system, but the secondary body could be anything from a main-sequence star to a red giant, or even another white dwarf. This uncertainty stems from the fact that no recent type Ia supernova has been discovered close enough to Earth to detect the stars before explosion. Here we report early observations of supernova SN 2011fe in the galaxy M101 at a distance from Earth of 6.4 megaparsecs. We find that the exploding star was probably a carbon-oxygen white dwarf, and from the lack of an early shock we conclude that the companion was probably a main-sequence star. Early spectroscopy shows high-velocity oxygen that slows rapidly, on a timescale of hours, and extensive mixing of newly synthesized intermediate-mass elements in the outermost layers of the supernova. A companion paper uses pre-explosion images to rule out luminous red giants and most helium stars as companions to the progenitor. 相似文献
5.
Fruchter AS Levan AJ Strolger L Vreeswijk PM Thorsett SE Bersier D Burud I Castro Cerón JM Castro-Tirado AJ Conselice C Dahlen T Ferguson HC Fynbo JP Garnavich PM Gibbons RA Gorosabel J Gull TR Hjorth J Holland ST Kouveliotou C Levay Z Livio M Metzger MR Nugent PE Petro L Pian E Rhoads JE Riess AG Sahu KC Smette A Tanvir NR Wijers RA Woosley SE 《Nature》2006,441(7092):463-468
When massive stars exhaust their fuel, they collapse and often produce the extraordinarily bright explosions known as core-collapse supernovae. On occasion, this stellar collapse also powers an even more brilliant relativistic explosion known as a long-duration gamma-ray burst. One would then expect that these long gamma-ray bursts and core-collapse supernovae should be found in similar galactic environments. Here we show that this expectation is wrong. We find that the gamma-ray bursts are far more concentrated in the very brightest regions of their host galaxies than are the core-collapse supernovae. Furthermore, the host galaxies of the long gamma-ray bursts are significantly fainter and more irregular than the hosts of the core-collapse supernovae. Together these results suggest that long-duration gamma-ray bursts are associated with the most extremely massive stars and may be restricted to galaxies of limited chemical evolution. Our results directly imply that long gamma-ray bursts are relatively rare in galaxies such as our own Milky Way. 相似文献
1