相关论文: The 2175 A dust feature in a Gamma Ray Burst after…
We report the clear detection of the 2175A dust absorption feature in the optical afterglow spectrum of the gamma-ray burst (GRB) GRB070802 at a redshift of z=2.45. This is the highest redshift for a detected 2175A dust bump to date, and it…
The optical afterglow of long-duration GRB 071003 is among the brightest yet to be detected from any GRB, with R ~ 12 mag in KAIT observations starting 42 s after the GRB trigger, including filtered detections during prompt emission.…
We present observations and analysis of the broadband afterglow of Swift GRB 071025. Using optical and infrared (RIYJHK) photometry, we derive a photometric redshift of 4.4 < z < 5.2; at this redshift our simultaneous multicolour…
We present the discovery and high signal-to-noise spectroscopic observations of the optical afterglow of the long-duration gamma-ray burst GRB070125. Unlike all previously observed long-duration afterglows in the redshift range 0.5 < z <…
GRB 090417B was an unusually long burst with a T_90 duration of at least 2130 s and a multi-peaked light curve at energies of 15-150 keV. It was optically dark and has been associated with a bright star-forming galaxy at a redshift of 0.345…
Gamma-ray bursts (GRBs) and their afterglows have been proposed as an excellent probe to study the evolution of cosmic star formation, the reionization of the intergalactic medium, and the metal enrichment history of the universe, since the…
Gamma-ray bursts (GRBs) are the most luminous transients in the universe. The interaction of the relativistic jet with the circumburst medium produces an afterglow and generates multiwavelength emission. In this work, we present…
The UV extinction feature at 2175 \AA\ is ubiquitously observed in the Galaxy but is rarely detected at high redshifts. Here we report the spectroscopic detection of the 2175 \AA\ bump on the sightline to the \gamma-ray burst (GRB)…
We report on multi-wavelength observations, ranging from the X-ray to radio wave bands, of the IPN-localized gamma-ray burst GRB 070125. Spectroscopic observations reveal the presence of absorption lines due to O I, Si II, and C IV,…
We report near-infrared and optical follow-up observations of the afterglow of the Gamma-Ray Burst 000418 starting 2.5 days after the occurrence of the burst and extending over nearly seven weeks. GRB 000418 represents the second case for…
We present early-time optical through infrared photometry of the bright gamma-ray burst GRB 080607, starting only 6 s following the initial trigger in the rest frame. Complemented by our previously published spectroscopy, this high-quality…
We present multiwavelength observations of the afterglow of GRB 130427A, the brightest (in total fluence) gamma-ray burst of the past 29 years. Optical spectroscopy from Gemini-North reveals the redshift of the GRB to be z=0.340, indicating…
Gamma-ray bursts are powerful probes of the early universe, but locating and identifying very distant GRBs remains challenging. We report here the discovery of the K-band afterglow of Swift GRB 060923A, imaged within the first hour…
We explore the extinction properties of the dust in the distant universe through the afterglows of high-redshifted GRBs based on the "Drude" model which, unlike previous studies, does not require a prior assumption of template extinction…
We put stringent constraints for the first time on the dust properties in the circumburst medium of a gamma-ray burst (GRB) afterglow. This is based on the optical spectrum of GRB 020813 (z=1.255), obtained with Keck I LRIS 4.65 h after the…
In this paper we illustrate with the case of GRB 000926 how Gamma Ray Bursts (GRBs) can be used as cosmological lighthouses to identify and study star forming galaxies at high redshifts. The optical afterglow of the burst was located with…
The unequivocal, spectroscopic detection of the 2175 bump in extinction curves outside the Local Group is rare. To date, the properties of the bump have been examined in only two GRB afterglows (GRB 070802 and GRB 080607). In this work we…
We present our optical observations of {\em Swift} GRB 070518 afterglow obtained at the 0.8-m Tsinghua University-National Astronomical Observatory of China telescope (TNT) at Xinglong Observatory. Our follow-up observations were performed…
GRB 050730 is a long duration high-redshift burst (z=3.967) discovered by Swift. The afterglow shows variability and is well monitored over a wide wavelength range. We present comprehensive temporal and spectral analysis of the afterglow of…
GRB 970508 is the second gamma-ray burst (GRB) for which an optical afterglow has been detected. It is the first GRB for which a distance scale has been determined: absorption and emission features in spectra of the optical afterglow place…