Cosmic gamma-ray burst spectroscopy

Mazets, E.; Golenetskii, S.; Ilyinskii, V. N.; Gur’yan, Yu. A.; Aptekar, R.; Панов, В. Н.; Соколов, И. А.; Sokolova, Z. Ya.; Харитонова, Т. В.

doi:10.1007/bf00651438

Cited by 59 publications

(30 citation statements)

References 21 publications

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“…In this paper, the authors affirmed that the doubts about the reality of the spectral details of GRBs in the hard x-ray region will remain until the causes for the differences between spectra of the same GRB observed by different detectors are understood. However, we note that the GRB 930916 spectra were obtained only within 20 s after the flare onset, and, according to [64], the strongest spectral details were observed at the GRB initial stage (see Fig. 34).…”

Section: Lines In the Hard X-ray Regionmentioning

confidence: 80%

Cosmic γ-ray bursts: Observations and modeling

Бисноватый-Коган

2006

Phys. Part. Nuclei

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It is now commonly accepted that cosmic γ -ray bursts (GRBs) are of cosmological origin. This conclusion is based on the statistical analysis of GRBs and the measurements of line redshifts in GRB optical afterglows, i.e., in the so-called long GRBs. In this review, the models of radiation and models of GRB sources are considered. In most of these models, if not in all of them, the isotropic radiation cannot provide the energy release necessary for the appearance of a cosmological GRB. No correlation is noted between the redshift, the GRB-spectrum shape, and the total detected energy. The comparison between data obtained in the Soviet experiment KONUS and the American experiment BATSE shows that they substantially differ in statistical properties and the detection of hard x-ray lines. The investigation of hard gamma (0.110 GeV) afterglows, the measurement of prompt optical spectra during the GRB detection, and the further investigation of hard x-ray lines is of obvious importance for gaining insight into the GRB origin. Observations of two bright optical GRB afterglows point to the fact that an initially bright optical flare is directly related to the GRB itself, and the subsequent weak and much more continuous optical radiation is of a different nature. The results of observations of optical GRB afterglows are discussed. They point to the fact that the GRBs originate in distant galaxies with a high matter density, where intense star formation takes place. The interaction of the cosmological GRB radiation with a dense surrounding molecular cloud results in the appearance of long-duration (up to 10 years) weak optical afterglows associated with the heating and reradiation of gas. Results of 2D numerical simulation of the heating and reradiation of gas in various variants of the relative disposition of GRB and molecular clouds are presented. In conclusion, the possible relation between

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Section: Lines In the Hard X-ray Regionmentioning

confidence: 80%

Cosmic γ-ray bursts: Observations and modeling

Бисноватый-Коган

2006

Phys. Part. Nuclei

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“…One of the strongest pieces of evidence in favor of the galactic point of view is the observation of statistically significant absorption-and emission-like features in the spectra of some bursts, and the interpretation of these features as cyclotron lines (Mazets et al 1981(Mazets et al , 1982Lamb 1982;Bussard & Lamb 1982;Mazets et al 1983;Hueter 1984;Hueter 1987;Murakami et al 1988;Fenimore et al 1988;Harding & Preece 1989;Wang et al 1989;Alexander & Mészáros 1989;Lamb et al 1989;Graziani et al 1992;Yoshida et al 1992;Nishimura & Ebisuzaki 1992;Barat 1993;Nishimura 1994;Mazets et al 1996;. Cyclotron lines are formed by the resonant scattering of photons by electrons in a magnetic field, B.…”

Section: Introductionmentioning

confidence: 99%

Cyclotron Line Formation in a Radiation‐driven Outflow

Isenberg¹,

Lamb²,

Wang³

1998

ApJ

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We calculate the properties of gamma-ray burst spectral lines formed by resonant cyclotron scattering in a radiation-driven outflow. Most previous models of line formation in gamma-ray bursts are appropriate at the polar cap of a neutron star located no further than several hundred parsecs away.However, the BATSE brightness and sky distributions indicate that, if bursters are galactic, they are located in a corona at distances greater than 100 kpc.At these distances the burst luminosity exceeds the Eddington luminosity and the plasma in a polar line-forming region is ejected along the field lines. The variation of the magnetic field strength and plasma velocity with altitude in such an outflow would seem to prevent the formation of narrow features like those observed by Ginga and other instruments. However, this is not the case because the majority of scatters occur close to the stellar surface, at altitudes below z ≈ r h , where r h ∼ 10 5 cm is the size of the photon source. Consequently, the interpretation of the observed features as cyclotron lines does not rule out burst sources in a galactic corona.The outflow model predicts both absorption-like and single-peaked emissionlike features. The latter do not occur in models with static line-forming regions, but have been observed in gamma-ray bursts by the Konus and BATSE instruments.

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“…Almost fifteen years ago Mazets et al (51,52) reported seeing single lines in the spectra of GRBs at low energies (E < ∼ 70 keV). Later Hueter (53) reported single lines at low energies in the spectra of two bursts seen by HEAO-1 A4.…”

Section: Cyclotron Linesmentioning

confidence: 99%