Search Publications
The synthesis of the cosmic X-ray background in the Chandra and XMM-Newton era
Gilli, R.; Comastri, A.; Hasinger, G.
We present a detailed and self-consistent modeling of the cosmic X-ray background (XRB) based on the most up-to-date X-ray luminosity functions (XLF) and evolution of Active Galactic Nuclei (AGN). The large body of observational results collected by soft (0.5-2 keV) and hard (2-10 keV) X-ray surveys are used to constrain at best the properties of …
The Hubble Diagram to Redshift >6 from 69 Gamma-Ray Bursts
Schaefer, Bradley E.
One of the few ways to measure the properties of dark energy is to extend the Hubble diagram (HD) to higher redshifts with gamma-ray bursts (GRBs). GRBs have at least five properties (their spectral lag, variability, spectral peak photon energy, time of the jet break, and the minimum rise time) that have correlations to the luminosity of varying q…
Exciting dark matter and the INTEGRAL/SPI 511keV signal
Finkbeiner, Douglas P.; Weiner, Neal
We propose a dark matter candidate with an “excited state” 1 2 MeV above the ground state, which may be collisionally excited and deexcites by e+e- pair emission. By converting its kinetic energy into pairs, such a particle could produce a substantial fraction of the 511 keV line observed by the International Gamma-Ray Astrop…
The Third IBIS/ISGRI Soft Gamma-Ray Survey Catalog
Götz, D.; Hill, A. B.; Walter, R. +20 more
In this paper we report on the third soft gamma-ray source catalog obtained with the IBIS/ISGRI gamma-ray imager on board the INTEGRAL satellite. The scientific data set is based on more than 40 Ms of high-quality observations performed during the first 3.5 yr of Core Program and public IBIS/ISGRI observations. Compared to previous IBIS/ISGRI surv…
Modeling the emission processes in blazars
Böttcher, Markus
Blazars are the most violent steady/recurrent sources of high-energy gamma-ray emission in the known Universe. They are prominent emitters of electromagnetic radiation throughout the entire electromagnetic spectrum. The observable radiation most likely originates in a relativistic jet oriented at a small angle with respect to the line of sight. Th…
INTEGRAL observations of the cosmic X-ray background in the 5-100 keV range via occultation by the Earth
Sunyaev, R.; Revnivtsev, M.; Sazonov, S. +32 more
Aims: We study the spectrum of the cosmic X-ray background (CXB) in energy range ~5-100 keV.
Methods: Early in 2006 the INTEGRAL observatory performed a series of four 30 ks observations with the Earth disk crossing the field of view of the instruments. The modulation of the aperture flux due to occultation of extragalactic objects by the Eart…
INTEGRAL/IBIS all-sky survey in hard X-rays
Sunyaev, R.; Krivonos, R.; Revnivtsev, M. +3 more
We present results of an all-sky hard X-ray survey based on almost four years of observations with the IBIS telescope onboard the INTEGRAL observatory. The dead time-corrected exposure of the survey is ~33 Ms. Approximately 12% and 80% of the sky has been covered to limiting fluxes lower than 1 and 5 mCrab, respectively. Our catalog of detected so…
Probing clumpy stellar winds with a neutron star
Walter, R.; Zurita Heras, J.
Context: INTEGRAL, the European Space Agency's γ-ray observatory, tripled the number of super-giant high-mass X-ray binaries (sgHMXB) known in the Galaxy by revealing absorbed and fast transient (SFXT) systems.
Aims: In these sources, quantitative constraints on the wind clumping of the massive stars could be obtained from the study of the har…
Six new candidate ultracompact X-ray binaries
in't Zand, J. J. M.; Jonker, P. G.; Markwardt, C. B.
Ultracompact X-ray binaries (UCXBs) appear able to sustain accretion onto the compact accretor at rates lower than in wider X-ray binaries. This may be understood by the smaller accretion disks in UCXBs: a lower X-ray luminosity suffices to keep a disk completely ionized through irradiation and, thus, keep the viscosity at a sufficiently high leve…
Polarisation studies of the prompt gamma-ray emission from GRB 041219a using the spectrometer aboard INTEGRAL
McGlynn, S.; McBreen, S.; Foley, S. +6 more
Context: Linear polarisation in gamma-ray burst prompt emission is an important diagnostic with the potential to significantly constrain models. The spectrometer aboard INTEGRAL, SPI, has the capability to detect the signature of polarised emission from a bright γ-ray source. GRB 041219a is the most intense burst localised by INTEGRAL with a fluen…