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Calibration of X-ray absorption in our Galaxy
Prediction of the soft X-ray absorption along lines of sight through our Galaxy is crucial for understanding the spectra of extragalactic sources, but requires a good estimate of the foreground
Methods and results of an automatic analysis of a complete sample of Swift-XRT observations of GRBs
We present a homogeneous X-ray analysis of all 318 gamma-ray bursts detected by the X-ray telescope (XRT) on the Swift satellite up to 2008 July 23; this represents the largest sample of X-ray GRB
Distances and metallicities for 17 Local Group galaxies
We have obtained Johnson V and Gunn i photometry for a large number of Local Group galaxies using the Isaac Newton Telescope Wide Field Camera (INT WFC). The majority of these galaxies are members of
A photometric redshift of z ∼9.4 for GRB 090429B
Gamma-ray bursts (GRBs) serve as powerful probes of the early universe, with their luminous afterglows revealing the locations and physical properties of star-forming galaxies at the highest
Long γ-ray bursts and core-collapse supernovae have different environments
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
An Extremely Luminous Panchromatic Outburst from the Nucleus of a Distant Galaxy
Multiwavelength observations of a unique γ-ray–selected transient detected by the Swift satellite, accompanied by bright emission across the electromagnetic spectrum, and whose properties are unlike any previously observed source are presented.
An unusual supernova in the error box of the γ-ray burst of 25 April 1998
The discovery of afterglows associated with γ-ray bursts at X-ray, optical and radio wavelengths and the measurement of the redshifts of some of these events, has established that γ-ray bursts lie at
A Possible Relativistic Jetted Outburst from a Massive Black Hole Fed by a Tidally Disrupted Star
Observations suggest a sudden accretion event onto a central MBH of mass about 106 to 107 solar masses, which leads to a natural analogy of Sw 1644+57 to a temporary smaller-scale blazar.
A γ-ray burst at a redshift of z ≈ 8.2
Long-duration γ-ray bursts (GRBs) are thought to result from the explosions of certain massive stars, and some are bright enough that they should be observable out to redshifts of z > 20 using
A very energetic supernova associated with the γ-ray burst of 29 March 2003
Over the past five years evidence has mounted that long-duration (>2 s) γ-ray bursts (GRBs)—the most luminous of all astronomical explosions—signal the collapse of massive stars in our Universe. This