A5051449587- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Mechanics and Biomechanics Studies
- High-pressure geophysics and materials
- Geophysics and Gravity Measurements
- Galaxies: Formation, Evolution, Phenomena
- Solar and Space Plasma Dynamics
- Adaptive optics and wavefront sensing
- Nuclear Physics and Applications
- Statistical and numerical algorithms
- Ionosphere and magnetosphere dynamics
- SAS software applications and methods
- Astro and Planetary Science
- Advanced X-ray and CT Imaging
- Superconducting Materials and Applications
- Distributed and Parallel Computing Systems
- Earthquake Detection and Analysis
- Astrophysics and Star Formation Studies
- Scientific Measurement and Uncertainty Evaluation
- Particle Detector Development and Performance
European Space Astronomy Centre
2014-2024
European Space Agency
2009-2020
University of Geneva
2020
Centro de Astrobiología
2017
Universitat de València
2017
Foundation for Research and Technology Hellas
2017
University of Turku
2017
University of Cape Town
2017
Parc Científic de la Universitat de València
2017
European Space Research and Technology Centre
2017
We report on INTEGRAL observations of the soft $\gamma$-ray repeater SGR 1935+2154 performed between 2020 April 28 and May 3. Several short bursts with fluence $\sim10^{-7}-10^{-6}$ erg cm$^{-2}$ were detected by IBIS instrument in 20-200 keV range. The burst hardest spectrum, discovered localized real time Burst Alert System, was spatially temporally coincident a very bright radio CHIME STARE2 telescopes at 400-800 MHz 1.4 GHz, respectively. Its lightcurve shows three narrow peaks separated...
We observed the Galactic black hole candidate XTE J1650-500 early in its fall of 2001 outburst with XMM-Newton European Photon Imaging pn Camera (EPIC-pn). The spectrum is consistent source having been "very high" state. find a broad, skewed Fe Kα emission line that suggests primary this system may be Kerr and indicates steep disk emissivity profile hard to explain terms standard accretion model. These results are quantitatively qualitatively similar those from an observation Seyfert galaxy...
Abstract The launch of the Imaging X-ray Polarimetry Explorer (IXPE) on 2021 December 9 has opened a new window in astronomy. We report here results first IXPE observation weakly magnetized neutron star, GS 1826−238, performed 2022 March 29–31 when source was high soft state. An upper limit (99.73% confidence level) 1.3% for linear polarization degree is obtained over 2–8 keV energy range. Coordinated INTEGRAL and NICER observations were carried out simultaneously with IXPE. spectral...
The black hole (BH) binary V404 Cyg entered the outburst phase in 2015 June after 26 yr of X-ray quiescence, and with its behaviour broke evolution pattern typical most BH binaries. We observed entire Swift satellite performed time-resolved spectroscopy active phase, obtaining over a thousand spectra exposures from tens to hundreds seconds. All can be fitted an absorbed power-law model, which time required presence partial covering. A blueshifted iron-Kα line appears 10 per cent together...
Typical black hole binaries in outburst show spectral states and transitions, characterized by a clear connection between the inflow onto outflow from its vicinity. The transient stellar mass binary V404 Cyg apparently does not fit this picture. Its outbursts are intense flares intermittent low-flux states, with dynamical range of several orders magnitude on timescales hours. During 2015 June-July X-ray joint Swift INTEGRAL observing campaign captured one these states. simultaneous Swift/XRT...
Aims.The Galactic bulge region is a rich host of variable high-energy point sources. Since 2005, February 17 we are monitoring the source activity in regularly and frequently, i.e., about every three days, with instruments onboard INTEGRAL. Thanks to large field view, imaging capabilities sensitivity at hard X-rays, able present for first time detailed homogeneous (hard) X-ray view sample 76 sources region.
The European Space Agency's INTErnational Gamma-Ray Astrophysics Laboratory (ESA/INTEGRAL) was launched aboard a Proton-DM2 rocket on 17 October 2002 at 06:41 CEST, from Baikonur in Kazakhstan. Since then, INTEGRAL has been providing long, uninterrupted observations (up to about 47 h, or 170 ksec, per satellite orbit of 2.7 days) with large field-of-view (FOV, fully coded: 100 deg2), millisecond time resolution, keV energy polarization measurements, as well additional wavelength coverage...
Type-I X-ray bursts are thermonuclear explosions caused by the unstable burning of accreted material on surface neutron stars. We report detection seven type-I from ultracompact binary M15 X-2 observed Neutron Star Interior Composition Explorer (NICER) during its 2022 outburst. found all occurred in soft state and exhibited similar light curve profiles, with no cases photospheric radius expansion. Time-resolved spectroscopy showed clear deviations blackbody model first ten seconds bursts....
We present optical photometry and spectroscopy of the X-ray transient XTE J1859+226, obtained during outburst its subsequent decay to quiescence. Both properties are very similar those well-studied black hole soft transients. have detected three mini-outbursts, when J1859+226 was approaching quiescence, as has been previously in transients GRO J0422+32 GRS 1009–45. By 2000 August 24 system had reached quiescence with R= 22.48 ± 0.07. The estimated distance source is ∼11 kpc. Photometry taken...
Aims. INTEGRAL has been monitoring the Galactic center region for more than a decade. Over this time detected hundreds of type-I X-ray bursts from neutron star low-mass binary 4U 1728-34, a.k.a. "the slow burster". Our aim is to study connection between persistent spectra and burst in broad spectral range. Methods. We performed modeling emission 1728-34 using data JEM-X IBIS/ISGRI instruments. Results. constructed hardness intensity diagram track state variations. In soft energy are...
We present the largest sample of type-I (thermonuclear) X-ray bursts yet assembled, comprising 7083 from 85 bursting sources. The is drawn observations with Xenon-filled proportional counters on long-duration satellites RXTE, BeppoSAX and INTEGRAL, between 1996 February 8, 2012 May 3. burst sources were a comprehensive catalog 115 sources, assembled earlier catalogs literature. carried out consistent analysis for each lightcurve (normalised to relative instrumental effective area), provide...
We analyzed two 1996 observations of the Galactic Microquasar GRS 1915+105 taken with Proportional Counter Array on board Rossi X-ray Timing Explorer. focus properties high-frequency QPO as a function "dip"oscillations, factor 1000 slower. In one observation, May 5th, we find that energy spectrum at ~65 Hz changes drastically between high-intervals and dips, hardening during dips to point peak is no longer detected low energies. second 14th, although it has similar overall characteristics,...
We report near-infrared and optical follow-up observations of the afterglow GRB 000418 starting 2.5 days after occurrence burst extending over nearly 7 weeks. represents second case for which was initially identified by in near-infrared. During first 10 its R-band well characterized a single power-law decay with slope 0.86. However, at later times temporal evolution flattens respect to simple decay. Attributing this an underlying host galaxy, we find magnitude be R = 23.9 intrinsic 1.22. The...
Observations of the core massive cluster Cl 0024+1654, at a redshift z=0.39, were obtained with Infrared Space Observatory using ISOCAM 6.7 mum and 14.3 (hereafter 15 mum). Thirty five sources detected thirteen them are spectroscopically identified galaxies. The remaining consist four stars, one quasar, foreground galaxy, three background galaxies unknown redshift. have best-fit SEDs typical spiral or starburst models observed 1 Gyr after main event. median infrared luminosity twelve is...
Abstract The microquasar MAXI J1820+070 went into outburst from 2018 mid-March until mid-July, with several faint rebrightenings afterward. With a peak flux of approximately 4 Crab in the 20–50 keV energy range, source was monitored across electromagnetic spectrum detections radio to hard X-ray frequencies. Using these multiwavelength observations, we analyzed quasi-simultaneous observations April 12, near (∼March 23). Analysis found it indicative an accreting black hole binary state,...
Aims. Hard X-ray spectra of black hole binaries (BHB) are produced by Comptonization soft seed photons hot electrons near the hole. The slope resulting energy is governed two main parameters: electron temperature (Te) and optical depth (τ) emitting plasma. Given extreme brightness V404 Cyg during 2015 outburst, we aim to constrain source spectral properties using an unprecedented time resolution in hard X-rays, monitor evolution Te τ over outburst.
ABSTRACT In 2015 June, the black hole X-ray binary (BHXRB) V404 Cygni went into outburst for first time since 1989. Here, we present a comprehensive search quasi-periodic oscillations (QPOs) of during its recent outburst, utilizing data from six instruments on board five different missions: Swift /XRT, Fermi /GBM, Chandra /ACIS, INTEGRAL ’s IBIS/ISGRI and JEM-X, NuSTAR . We report detection QPO at 18 mHz simultaneously with both /GBM another example rare but slowly growing new class mHz-QPOs...
We present the results from a multiwavelength campaign of GRS 1915+105 performed 2000 April 16 to 25. This is one largest coordinated set observations ever for this source, covering wide energy band in radio (13.3-0.3 cm), near-infrared (J-H-K), X-rays and Gamma-rays (from 1 keV 10 MeV). During was predominantly "plateau" (or low/hard) state but sometimes showed soft X-ray oscillations: before 20.3, rapid, quasi-periodic (~= 45 min) flare-dip cycles were observed. The flares observed on 17...
When the upper layer of an accreting neutron star experiences a thermonuclear runaway helium and hydrogen, it exhibits X-ray burst few keV with cool-down phase typically 1~minute. there is surplus hydrogen fusion expected to simmer during that same minute due rp process, which consists rapid proton captures slow beta-decays proton-rich isotopes. We have analyzed high-quality light curves 1254 bursts, obtained Proportional Counter Array on Rossi Timing Explorer between 1996 2012,...
The Be X-ray binary EXO 2030+375 was in an extended low luminosity state during most of 2016. We observed this with NuSTAR and Swift, supported by INTEGRAL observations as well optical spectroscopy the NOT. present a comprehensive spectral timing analysis these data here to study accretion geometry investigate possible onset propeller effect. H-alpha show that circumstellar disk Be-star is still present. measure equivalent widths similar values found more active phases past, indicating...