Thomas L. Cline

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The Swift mission, scheduled for launch in 2004, is a multiwavelength observatory for gamma-ray burst (GRB) astronomy. It is a first-of-its-kind autonomous rapid-slewing satellite for transient astronomy and pioneers the way for future rapid-reaction and multiwavelength missions. It will be far more powerful than any previous GRB mission, observing more(More)
We investigate spectral evolution in 37 bright, long gamma-ray bursts observed with the BATSE Spectroscopy Detectors. High resolution spectra are characterized by the energy of the peak of νFν and the evolution of this quantity is examined relative to the emission intensity. In most cases it is found that this peak energy either rises with or slightly(More)
Soft-gamma-ray repeaters (SGRs) are galactic X-ray stars that emit numerous short-duration (about 0.1 s) bursts of hard X-rays during sporadic active periods. They are thought to be magnetars: strongly magnetized neutron stars with emissions powered by the dissipation of magnetic energy. Here we report the detection of a long (380 s) giant flare from SGR(More)
We report the discovery of the gamma-ray burst GRB 000131 and its optical afterglow. The optical identification was made with the VLT 84 hours after the burst following a BATSE detection and an Inter Planetary Network localization. GRB 000131 was a bright, long-duration GRB, with an apparent precursor signal 62 s prior to trigger. The afterglow was detected(More)
The gamma–ray burst of 1997 February 28 was localized using the arrival– time analysis method with the Ulysses, BeppoSAX, and WIND spacecraft. The result is a ±31.5(3σ) wide annulus of possible arrival directions which intersects both the position of the burst determined independently by the SAX Wide Field Camera, and the position of a fading X-ray source(More)
We present a possible Cepheid-like luminosity estimator for long gamma-ray bursts based on the variability of their light curves. To construct the luminosity estimator, we use CGRO/BATSE data for 13 bursts, Wind/KONUS data for 5 bursts, Ulysses/GRB data for 1 burst, and NEAR/XGRS data for 1 burst. Spectroscopic redshifts, peak fluxes, and high resolution(More)
Results are presented of the observations of the soft gamma repeater SGR 1900+14 made on the Wind spacecraft during the source reactivation period from May 1998 to January 1999. Individual characteristics of recurrent bursts, such as their time histories, energy spectra, and maximum and integrated energy fluxes, are considered. Some statistical(More)
We report on two observations of a soft bursting source in 1997 June, whose time histories and energy spectra are consistent with those of the soft gamma repeaters. The source can only be localized to an ≈ 3.8 long error box in the direction of the Galactic center, whose area is ≈ 80 arcmin. The location of the source, while not consistent with that of any(More)
LOTIS (Llvermore OpticaJ Transient Imaging System) is a gammaray burst optical counterpart search experiment located near Lawrence Livermore National Laboratory in California. The system is linked to the GCN (GRB Coordinates Network) real-time coordinate distribution network and can respond to a burst trigger in 6-15 seconds. LOTIS has a total field-of-view(More)
The Gamma-Ray Optical Counterpart Search Experiment (GROCSE) presents new experimental upper limits on the optical flux from gamma-ray bursts (GRBs). Our experiment consisted of a fully-automated very wide-field opto-electronic detection system that imaged locations of GRBs within a few seconds of receiving trigger signals provided by BATSE’s real-time(More)