A new type of repetitive behavior in a high-energy transient

Laros, J. G.; Fenimore, E. E.; Klebesadel, R. W.; Atteia, J. L.; Boër, M.; Hurley, K.; Niel, M.; Védrenne, G.; Kane, S. R.; Kouveliotou, C.

doi:10.1086/184985

Cited by 93 publications

(75 citation statements)

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“…In particular, SGR 1806-20 was discovered and localized on January 7, 1979 during a single <0.25 s long burst in soft gamma rays (Mazets & Golenetskii 1981b;Laros et al 1986). Numerous bursts have been detected from this source since then (Atteia et al 1987;Kouveliotou et al 1987;Kuznetsov et al 1987;Laros et al 1987) and intermittent bursting activity has continued up to the present day.…”

Section: Introductionmentioning

confidence: 94%

The broad-band spectrum of the persistent emission from SGR 1806-20

Molkov

Hurley

Sunyaev

et al. 2005

A&A

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Abstract. We present the results of an analysis of the quiescent X-ray emission from the Soft Gamma-Ray Repeater SGR 1806-20, taken during an INTEGRAL ultra-deep survey of the Galactic center region in Aug.−Sep. 2003. The total effective exposure time spent on the source by the IBIS telescope during these observations was 1.6 million seconds. Combining the INTEGRAL results with results from the XMM-Newton observatory, we present the broad band (1−200 keV) spectrum of the quiescent emission from this source. This is the first spectrum of the persistent emission from an SGR in the broad energy range up to 200 keV. The spectrum of the source is very hard and has a power law shape (Γ = 1.6 ± 0.1) without any trace of a high energy cutoff up to ∼160 keV. No strong cyclotron line was detected in the persistent spectrum. The luminosity of SGR 1806-20 in this range (1−200 keV) was ∼3.6 × 10 36 erg s −1 for an assumed distance of 15 kpc. We show that weak undetected bursts should not contribute significantly to the quiescent emission. During our next observations in August 2004 the source went into an active phase and its average flux between powerful bursts was 2−3 times higher than in 2003. During Aug.−Sep. 2003, two other SGR candidates, SGR 1801-23 and SGR 1808-20, were in the field of view. Neither persistent hard X-ray emission nor bursts were detected from them. The upper limit on the persistent flux from each of them in the energy band 18−100 keV is about 4 × 10 −11 erg s −1 cm −2 .

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Section: Introductionmentioning

confidence: 94%

The broad-band spectrum of the persistent emission from SGR 1806-20

Molkov

Hurley

Sunyaev

et al. 2005

A&A

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“…SGR 1806−20 has been observed to exhibit sporadic bursting behavior since 1983 (Laros et al 1987). The Burst and Transient Source Experiment (BATSE) onboard the Compton Gamma-Ray Observatory launched in (April 1991) detected more sporadic bursting behavior.…”

Section: Targets and Observationsmentioning

confidence: 99%

“…Differential and cumulative event fluence distributions are presented for each source. These were fitted with single power laws as reported by past authors (Laros et al 1987;Woods et al 1999;Goǧus et al 1999), but we also fitted single and broken power laws with exponential cutoffs and were able to improve upon the quality of fit for each source. We also use the large number of bursts observed to define periods of high and low burst activity.…”

Section: Introductionmentioning

confidence: 99%

BURST FLUENCE DISTRIBUTIONS OF SOFT GAMMA REPEATERS 1806–20 AND 1900+14 IN THEROSSI X-RAY TIMING EXPLORERPCA ERA

Prieskorn

Kaaret

2012

ApJ

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We study the fluence distributions of over 3040 bursts from SGR 1806−20 and over 1963 bursts from SGR 1900+14 using the complete set of observations available from the Rossi X-Ray Timing Explorer/Proportional Counter Array through 2011 March. Cumulative event distributions are presented for both sources and are fitted with single and broken power laws as well as an exponential cutoff. The distributions are best fitted by a broken power law with exponential cutoff; however the statistical significance of the cutoff is not high and the upper portion of the broken power law can be explained as the expected number of false bursts due to random noise fluctuations. Event distributions are also examined in high and low burst rate regimes and power-law indices are found to be consistent, independent of the burst rate. The contribution function of the event fluence is calculated. This distribution shows that the energy released in the soft gamma repeater (SGR) bursts is dominated by the most powerful events for both sources. The power-law nature of these distributions combined with the dominant energy dissipation of the system occurring in the large, less frequent bursts is indicative of a self-organized critical system, as suggested by Goǧus et al. in 1999.

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“…Complicating things further was early evidence for a bimodal GRB duration distribution (13). John Laros, using a solar x-ray detector on ISEE-3, found a third soft repeater (14) in 1985. I then published the 3-SGR source map (15) as evidence for a galactic plane / LMC pattern (Fig.…”

Section: Pos(grb 2012)115mentioning

confidence: 99%

The Initial Gamma Ray Transient Studies

Cline¹

2012

Proceedings of Gamma-Ray Bursts 2012 Conference — PoS(GRB 2012)

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A new type of repetitive behavior in a high-energy transient

Cited by 93 publications

References 0 publications

The broad-band spectrum of the persistent emission from SGR 1806-20

The broad-band spectrum of the persistent emission from SGR 1806-20

BURST FLUENCE DISTRIBUTIONS OF SOFT GAMMA REPEATERS 1806–20 AND 1900+14 IN THEROSSI X-RAY TIMING EXPLORERPCA ERA

The Initial Gamma Ray Transient Studies

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