A5087334998- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Stellar, planetary, and galactic studies
- Pulsars and Gravitational Waves Research
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- High-pressure geophysics and materials
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Solar and Space Plasma Dynamics
- Mechanics and Biomechanics Studies
- Nuclear Physics and Applications
- Particle Accelerators and Free-Electron Lasers
- Advanced X-ray Imaging Techniques
- SAS software applications and methods
- Historical and Contemporary Political Dynamics
- CCD and CMOS Imaging Sensors
- Global Security and Public Health
- Advanced X-ray and CT Imaging
- Political and Social Issues
- Medical Imaging Techniques and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Multiculturalism, Politics, Migration, Gender
- Calibration and Measurement Techniques
Philipps University of Marburg
2021-2024
Lawrence Berkeley National Laboratory
2011
University of South Dakota
2011
Black Hills State University
2011
SRON Netherlands Institute for Space Research
1998-2007
Utrecht University
2002-2004
National Institute for Space Research
2003
University of Amsterdam
2000
Harvard University
1975
Royal Netherlands Academy of Arts and Sciences
1973
We present the main results of a study spectral and energetics properties twelve gamma-ray bursts (GRBs) with redshift estimates. All GRBs in our sample were detected by BeppoSAX broad energy range (2–700 ). From estimates good-quality time–integrated spectra we deduce their cosmological rest frames. are satisfactorily represented Band model, no significant soft X–ray excesses or absorptions. find positive correlation between estimated total (isotropic) energies 1–10 000 (Erad) redshifts z....
view Abstract Citations (287) References (14) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Discovery of intense X-ray bursts from the globular cluster NGC 6624. Grindlay, J. ; Gursky, H. Schnopper, Parsignault, D. R. Heise, Brinkman, A. C. Schrijver, A new type time variation cosmic sources has been found Astronomical Netherlands Satellite (ANS) observations source 3U 1820-30, associated with Two in 1-30 keV intensity this are reported. Each displayed a...
We report on the discovery of two emission features observed in x-ray spectrum afterglow gamma-ray burst (GRB) 16 December 1999 by Chandra X-ray Observatory. These are identified with Ly(alpha) line and narrow recombination continuum hydrogenic ions iron at a redshift z = 1.00 +/- 0.02, providing an unambiguous measurement distance GRB. Line width intensity imply that progenitor GRB was massive star system ejected, before event, quantity approximately 0.01 mass sun velocity 0.1 speed light,...
The two Wide Field Cameras (WFCs) currently flying on the Italian/Dutch X-ray satellite BeppoSAX, image sky in energy range of . field view is 20, angular resolution 5 arcmin and 20% at 6 , while source location accuracy will generally be better than one arcmin. All values are Full Width Half Maximum. design based coded mask principle where detector both have sizes about a Multi Wire Proportional Counter with position which 0.5 for energies below 10 pattern so called triadic residue set...
We report the possible detection (99.3% of statistical significance) redshifted Fe iron line emission in X-ray afterglow Gamma-ray burst GRB970508 observed by BeppoSAX. Its energy is consistent with redshift putative host galaxy determined from optical spectroscopy. The disappeared about 1 day after burst. have also analyzed spectral variability during outburst event that characterizes this GRB. spectrum gets harder flare, turning to steep when flux decreases. variability, intensity and...
We investigated the spectral evolution in 2-700 keV energy band of gamma-ray bursts (GRBs) detected by Gamma-Ray Burst Monitor (GRBM) and localized with Wide Field Cameras (WFCs) aboard BeppoSAX satellite before 1998 May. Most them have been followed up Narrow Instruments same satellite. In light these results we discuss open issues on GRB phenomenon. find that optically thin synchrotron shock model (SSM) provides an acceptable representation most time-resolved spectra extending down to 2...
We report the detection (3 sigma significance level) of a strong iron emission line in X-ray spectrum afterglow GRB 000214 (``Valentine's Day Burst'') observed by BeppoSAX. An feature was with centroid energy 4.7+/-0.2 keV which, if interpreted as K-alpha from hydrogen-like iron, corresponds to redshift z=0.47. The intensity (EW ~2 keV) and duration (tens hours) give information on distance, burst region, emitting material (R>3x10^15 cm) its mass (M>1.4 solar mass). These results are not...
We present BeppoSAX follow-up observations of GRB 980425 obtained with the Narrow Field Instruments (NFI) in 1998 April, May, and November. The first NFI observation has detected within 8' radius error box gamma-ray burst (GRB) an X-ray source positionally consistent supernova 1998bw, which exploded a day 980425, fainter source, not position supernova. former is following pointings exhibits decline factor 2 six months. If it associated SN this detection emission from Type I above keV. latter...
We present an overview of BeppoSAX Wide Field Cameras observations the nine most frequent type I X-ray bursters in Galactic center region. Six years (from 1996 to 2002) have amounted 7 Ms and detection 1823 bursts. The 3 are GX 354-0 (423 bursts), KS 1731-260 (339) GS 1826-24 (260). These numbers reflect unique dataset. show that all sources same global burst behavior as a function luminosity. At lowest luminosities () bursts occur quasi-periodically rate increases linearly with accretion...
view Abstract Citations (99) References (9) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Evidence for X-ray emission from flare stars observed by ANS. Heise, J. ; Brinkman, A. C. Schrijver, Mewe, R. Gronenschild, E. H. B. M. den Boggende, F. Grindlay, Observations that detected the first are described. An was YZ CMi at 0.28 keV and approximately 1-7 keV, although no optical or radio coverage available. During a very large UV Ceti, (only) detected. Upper...
view Abstract Citations (119) References (34) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Detection of X-ray emission from stellar coronae with ANS. Mewe, R. ; Heise, J. Gronenschild, E. H. B. M. Brinkman, A. C. Schrijver, den Boggende, F. The soft detector aboard the Astronomical Netherlands Satellite (ANS) has been used to search for in range 0.2 0.284 keV hot coronae. detected Capella (alpha Aur) and Sirius CMa). For 26 other stars (main sequence,...
We have discovered three certain (SAX J1324.5-6313, 2S 1711-339 and SAX J1828.5-1037) two likely J1818.7+1424 J2224.9+5421) new thermonuclear X-ray burst sources with the BeppoSAX Wide Field Cameras, observed a second ever from sixth one (2S 0918-549). Four of them (excluding 0918-549) are newly detected which we single bursts, but no persistent emission. observe first 11 bursts 1711-339; flux was during ten not around last burst. A recently 0918-549 by Jonker et al. (2001); showing radius...
We report on the results of optical follow-up observations counterpart gamma-ray burst GRB 970508, starting 7 hr after event. Multicolor U-, B-, V-, Rc-, and Ic-band were obtained during first three consecutive nights. The was monitored regularly in Rc until ~4 months burst. light curve maximum follows a decline that can be fitted with power law exponent α = -1.141 ± 0.014. Deviations from smooth power-law decay are moderate (rms 0.15 mag). find no flattening at late times. afterglow fluence...
Optical Transients from gamma-ray burst sources, in addition to offering a distance determination, convey important information about the physics of emission mechanism, and perhaps also underlying energy source. As phenomenon is extremely diverse, with timescales spanning several orders magnitude, some diversity optical counterpart signatures appears plausible.
Data of the 1996 outburst single-known accreting millisecond pulsar SAX J1808.4-3658, taken with Wide Field Cameras (WFCs) on BeppoSAX, are revisited more complete data coverage and comprehensive analysis techniques than in a previous report. An additional type-I X-ray burst was identified which occurred at time when persistent emission is below detection limit, roughly 30 days after maximum. This three times longer first two bursts, 50% brighter. It brightest within ~1700 bursts detected so...
We report on X-ray, optical and infrared follow-up observations of GRB 980703. detect a previously unknown X-ray source in the error box; assuming power law decline we find for its decay index alpha < -0.91 (3-sigma). invoke host galaxy extinction to match observed spectral slope with expected from `fireball' models. no evidence break range 1998 July 4.4, determine lower limit cooling frequency: nu_c > 1.3 x 10^{17} Hz. For this epoch obtain an A_V = 1.50 +/- 0.11. From data estimate be 20.2...