New high energy γ-ray sources observed by COS B

LOCALISED γ-ray sources contribute to the overall galactic emission; some of these sources have been identified with known astronomical objects1,2, while several unidentified γ-ray sources have also been reported3,4. We describe here a search for γ-ray sources using data from the ESA γ-ray satellite COS B which revealed 10 new unidentified sources. These sources seem to be galactic with typical γ-ray luminosities above 100 MeV in excess of 1035 erg s−1.

INTEGRAL and RXTE observations of accreting millisecond pulsar IGR J00291+5934 in outburst

Simultaneous observations of the accretion-powered millisecond pulsar IGR J00291+5934 by International Gamma-Ray Astrophysics Laboratory and Rossi X-ray Timing Explorer during the 2004 December outburst are analysed. The average spectrum is well described by thermal Comptonization with an electron temperature of 50 keV and Thomson optical depth tau_T ~ 1 in a slab geometry. The spectral shape is almost constant during the outburst. We detect a spin-up of the pulsar with nudot=8.4x10E-13 Hz/s. The ISGRI data reveal the pulsation of X-rays at a period of 1.67 milliseconds up to ~150 keV. The pulsed fraction is shown to increase from 6 per cent at 6 keV to 12--20 per cent at 100 keV. This is n…

The Large Observatory for X-ray Timing (LOFT)

High-time-resolution X-ray observations of compact objects provide direct access to strong-field gravity, to the equation of state of ultra-dense matter and to black hole masses and spins. A 10 m^2-class instrument in combination with good spectral resolution is required to exploit the relevant diagnostics and answer two of the fundamental questions of the European Space Agency (ESA) Cosmic Vision Theme "Matter under extreme conditions", namely: does matter orbiting close to the event horizon follow the predictions of general relativity? What is the equation of state of matter in neutron stars? The Large Observatory For X-ray Timing (LOFT), selected by ESA as one of the four Cosmic Vision M…

COS B observation of high-energy γ radiation from 3C273

THE discovery of a high-energy γ-ray source at α(1950) = 12h 29 min±6 min, δ(1950)= +3°±1.5° is reported here. Arguments are given for the identification with 3C273. If this identification is correct, the γ-ray luminosity of 3C273 in the energy range 50–500 MeV is 2×1046 erg s−1 for H0 = 60 km s−1 Mpc−1.

The INTEGRAL view of the pulsating hard X-ray sky: from accreting and transitional millisecond pulsars to rotation-powered pulsars and magnetars

arXiv:2012.01346v1

COS-B OBSERVATION OF THE MILKY WAY IN HIGH-ENERGY GAMMA RAYS

The Large Observatory For x-ray Timing

The Large Observatory For x-ray Timing (LOFT) was studied within ESA M3 Cosmic Vision framework and participated in the final down-selection for a launch slot in 2022-2024. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument, LOFT will study the behaviour of matter under extreme conditions, such as the strong gravitational field in the innermost regions of accretion flows close to black holes and neutron stars, and the supra-nuclear densities in the interior of neutron stars. The science payload is based on a Large Area Detector (LAD, 10 m 2 effective area, 2-30 keV, 240 eV spectral resolution, 1 deg collimated field of view) and a WideFi…

ORIGIN: metal creation and evolution from the cosmic dawn

Herder, Jan-Willem den et al.

COS-B Observations of Long Term Variability and Absorption Phenomena in the X-ray Emission from Cen X-3

The COS-B satellite has observed the X-ray source Cen X-3 in the energy range 2 to 12 keV