IGR J22517+2218=MG3 J225155+2217: A New Gamma-Ray Lighthouse in the Distant Universe

Igr J22517+2218=mg3 J225155+2217: a New Gamma-ray Lighthouse in the Distant Universe

We report on the identification of a new soft gamma ray source, namely IGR J22517+2218, detected with IBIS/INTEGRAL. The source, which has an observed 20-100 keV flux of ∼4 × 10 erg cm s, is spatially coincident with MG3 J225155+2217, a quasar at z=3.668. The Swift/XRT 0.5-10 keV continuum is flat (Γ=1.5) with evidence for a spectral curvature below 1-2 keV either due to intrinsic absorption (N...

Gamma Ray Bursts: new rulers to measure the Universe

The best measure of the Universe should be done using a standard “ruler” at any redshift. Type Ia Supernovae (SN Ia) probe the universe up to z∼1.5, while the Cosmic Microwave Background (CMB) primary anisotropies concern basically z ∼1000. Apparently, Gamma–Ray Bursts (GRBs) are all but standard candles. However, their emission is collimated and the collimation–corrected energy correlates tigh...

The Ptolemaic Gamma-ray Burst Universe

The Cosmic Gamma-Ray Halo – New Imperative for a Dialectical Perspective of the Universe

From the galaxies to man, natural science has so far sketched in the main outline an evolutionary picture of nature that is mediated by chance and necessity. Cosmic gamma-ray halo and the other observed cosmological phenomena must therefore, be viewed as the manifestation of the same evolutionary process of nature.

IGR J 16194 − 2810 : a new symbiotic X – ray binary ⋆

We here report on the multiwavelength study which led us to the identification of X–ray source IGR J16194−2810 as a new Symbiotic X–ray Binary (SyXB), that is, a rare type of Low Mass X–ray Binary (LMXB) composed of a M-type giant and a compact object. Using the accurate X–ray position allowed by Swift/XRT data, we pinpointed the optical counterpart, a M2 III star. Besides, the combined use of ...