The Burst and Transient Source Experiment (BATSE) Earth Occultation Catalog of Low‐Energy Gamma‐Ray Sources

Harmon, B. A.; Wilson, C. A.; Fishman, G. J.; Connaughton, V.; Henze, W.; Pačiesas, W. S.; Finger, Mark H.; McCollough, M. L.; Sahi, M.; Peterson, B. A.; Shrader, C. R.; Grindlay, Jonathan E.; Barret, D.

doi:10.1086/421940

Cited by 57 publications

(57 citation statements)

References 118 publications

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“…Durant et al (2011) discovered a large-scale extended component in X-rays up to 1 from LS 5039. The system has also been detected by INTEGRAL up to 200 keV (Goldoni et al 2007;Hoffmann et al 2009), and with BATSE up to 1 MeV (Harmon et al 2004). LS 5039 was first associated with an EGRET source in Paredes et al (2000), and variability was detected by Fermi between 100 and 300 GeV with a 3.9-d period (Abdo et al 2009).…”

Section: The Gamma-ray Binary Ls 5039mentioning

confidence: 99%

On the origin of LS 5039 and PSR J1825−1446

Moldón

Ribó

Paredes

et al. 2012

A&A

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Context. The gamma-ray binary LS 5039 and the isolated pulsar PSR J1825−1446 were proposed to have been formed in the supernova remnant (SNR) G016.8−01.1. Aims. We aim to obtain the Galactic trajectory of LS 5039 and PSR J1825−1446 to find their origin in the Galaxy, and in particular to check their association with SNR G016.8−01.1 to restrict their age. Methods. By means of radio and optical observations we obtained the proper motion and the space velocity of the sources. Results. The proper motion of PSR J1825−1446 corresponds to a transverse space velocity of 690 km s −1 at a distance of 5 kpc. Its Galactic velocity at different distances is not compatible with the expected Galactic rotation. The velocity and characteristic age of PSR J1825−1446 make it incompatible with SNR G016.8−01.1. There are no clear OB associations or SNRs crossing the past trajectory of PSR J1825−1446. We estimate the age of the pulsar to be 80-245 kyr, which is compatible with its characteristic age. The proper motion of LS 5039 is μ α cos δ = 7.09 and μ δ = −8.82 mas yr −1 . The association of LS 5039 with SNR G016.8−01.1 is unlikely, although we cannot discard it. The system would have had to be formed in the association Ser OB2 (at 2.0 kpc) if the age of the system is 1.0-1.2 Myr, or in the association Sct OB3 (distance 1.5-2 kpc) for an age of 0.1-0.2 Myr. If the system were not formed close to Ser OB2, the pseudo-synchronization of the orbit would be unlikely. Conclusions. PSR J1825−1446 is a high-velocity isolated pulsar ejected from the Galaxy. The distance to LS 5039, which needs to be constrained by future astrometric missions such as Gaia, is a key parameter for restricting its origin and age.

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Section: The Gamma-ray Binary Ls 5039mentioning

confidence: 99%

On the origin of LS 5039 and PSR J1825−1446

Moldón

Ribó

Paredes

et al. 2012

A&A

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“…We investigated the CGRO/BATSE occultation measurements (see, e.g., Harmon et al 2004) in the period April 1991 and November 2000; they show 10-day average 20−100 keV fluxes from non-detections (with typical 10-day 3σ upper limits between about 50−70 mCrab) up to about 150 mCrab. During the period of the EURECA/WATCH observations when 4U 0614+091 was in the field of view, the 20−100 keV flux was on average 57 ± 6 mCrab; close to the time of the bursts seen by EURECA/WATCH it was around 100 mCrab.…”

Section: Asm Long-term Persistent Flux and Burst Recurrence Timesmentioning

confidence: 99%

What ignites on the neutron star of 4U 0614+091?

Kuulkers¹,

Zand

Atteia

et al. 2010

A&A

103

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The low-mass X-ray binary 4U 0614+091 is a source of sporadic thermonuclear (type I) X-ray bursts. We find bursts with a wide variety of characteristics in serendipitous wide-field X-ray observations by the WATCH on EURECA, the ASM on RXTE, the WFCs on BeppoSAX, the FREGATE on HETE-2, the IBIS/ISGRI on INTEGRAL, and the BAT on Swift, as well as pointed observations with the PCA and HEXTE on RXTE. Most of the bursts are bright, i.e., they reach a peak flux of about 15 Crab, but a few are weak and only reach a peak flux below a Crab. One of the bursts shows a very strong photospheric radius-expansion phase. This allows us to evaluate the distance to the source, which we estimate to be 3.2 kpc. The burst durations vary generally from about 10 s to 5 min. However, after one of the intermediate-duration bursts, a faint tail is seen to at least about 2.4 h after the start of the burst. One very long burst was observed, which lasted for several hours. This superburst candidate was followed by a normal type-I burst only 19 days later. This is, to our knowledge, the shortest burst-quench time among the superbursters. The observation of a superburst in this system is difficult to reconcile if the system is accreting at about 1% of the Eddington limit. We describe the burst properties in relation to the persistent emission. No strong correlations are apparent, except that the intermediate-duration bursts occurred when 4U 0614+091's persistent emission was lowest and calm, and when bursts were infrequent (on average roughly one every month to 3 months). The average burst rate increased significantly after this period. The maximum average burst recurrence rate is about once every week to 2 weeks. The burst behaviour may be partly understood if there is at least an appreciable amount of helium present in the accreted material from the donor star. If the system is an ultra-compact X-ray binary with a CO white-dwarf donor, as has been suggested, this is unexpected. If the bursts are powered by helium, we find that the energy production per accumulated mass is about 2.5 times less than expected for pure helium matter.

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“…However, with the only exception being the CGRO/BATSE instrument, detecting only a handful of AGN (Harmon et al 2004), long-term hard X-ray monitoring has not been possible until recent years, because of the observing strategy of the hard X-ray satellites and the limited size of the field of view of their instruments. Furthermore, latest generation and future hard-X-ray telescopes such as NuSTAR will have small fields of view and relatively inflexible scheduling capabilities, so future studies may tend to be limited to either short time scales or in the number of observed objects.…”

Section: Introductionmentioning

confidence: 99%

Long-term variability of AGN at hard X-rays

Soldi¹,

Beckmann²,

Baumgartner³

et al. 2014

A&A

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Aims. Variability at all observed wavelengths is a distinctive property of active galactic nuclei (AGN). Hard X-rays provide us with a view of the innermost regions of AGN, mostly unbiased by absorption along the line of sight. Characterizing the intrinsic hard X-ray variability of a large AGN sample and comparing it to the results obtained at lower X-ray energies can significantly contribute to our understanding of the mechanisms underlying the high-energy radiation. Methods. Swift/BAT provides us with the unique opportunity to follow, on time scales of days to years and with regular sampling, the 14-195 keV emission of the largest AGN sample available up to date for this kind of investigation. As a continuation of an early work using the first 9 months of BAT data, we study the amplitude of the variations and their dependence on subclass and on energy, for a sample of 110 radio quiet and radio loud AGN selected from the BAT 58-month survey. Results. About 80% of the AGN in the sample are found to exhibit significant variability on month-to-year time scales. In particular, radio loud sources are the most variable, and Seyfert 1.5−2 galaxies are slightly more variable than Seyfert 1, while absorbed and unabsorbed objects show similar timing properties. The amplitude of the variations and their energy dependence are incompatible with variability being driven at hard X-rays by changes in the absorption column density. In general, the variations in the 14-24 and 35-100 keV bands are correlated well, suggesting a common origin to the variability across the BAT energy band. However, radio quiet AGN display on average 10% larger variations at 14-24 keV than at 35-100 keV, and a softer-when-brighter behavior for most of the Seyfert galaxies with detectable spectral variability on a time scale of a month. In addition, sources with harder spectra are found to be more variable than softer ones, unlike what it is observed below 10 keV. These properties are generally consistent with a variable, in flux and shape, power law continuum, pivoting at energies > ∼ 50 keV, to which a constant reflection component is superposed. When the same time scales are considered, the timing properties of AGN at hard X-rays are comparable to those at lower energies, with at least some of the differences possibly ascribable to components contributing differently in the two energy domains (e.g., reflection, absorption).

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The Burst and Transient Source Experiment (BATSE) Earth Occultation Catalog of Low‐Energy Gamma‐Ray Sources

Cited by 57 publications

References 118 publications

On the origin of LS 5039 and PSR J1825−1446

On the origin of LS 5039 and PSR J1825−1446

What ignites on the neutron star of 4U 0614+091?

Long-term variability of AGN at hard X-rays

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