Potential of LOFT telescope for the search of dark matter

Large Observatory For X-ray Timing (LOFT) is a next generation X-ray telescope selected by European Space Agency as one of the space mission concepts within the ``Cosmic Vision'' programme. The Large Area Detector on board of LOFT will be a collimator-type telescope with an unprecedentedly large collecting area of about 10 square meters in the energy band between 2 and 100 keV. We demonstrate that LOFT will be a powerful dark matter detector, suitable for the search of the X-ray line emission expected from decays of light dark matter particles in galactic halos. We show that LOFT will have sensitivity for dark matter line search more than an order of magnitude higher than that of all existing X-ray telescopes. In this way, LOFT will be able to provide a new insight into the fundamental problem of the nature of dark matter.Comment: 9 pages, 8 figure

Predicted gamma-ray image of SN 1006 due to inverse Compton emission

We propose a method to synthesize the inverse Compton (IC) γ-ray image of a supernova remnant starting from the radio (or hard X-ray) map and using results of the spatially resolved X-ray spectral analysis. The method is successfully applied to SN 1006. We found that synthesized IC γ-ray images of SN 1006 show morphology in nice agreement with that reported by the High Energy Stereoscopic System (HESS) collaboration. The good correlation found between the observed very high energy γ-ray and X-ray/radio appearance can be considered as evidence of the fact that the γ-ray emission of SN 1006 observed by HESS is leptonic in origin, although a hadronic origin may not be excluded.Fil: Petruk, O.. Institute for Applied Problems in Mechanics and Mathematics; UcraniaFil: Bocchino, F.. Istituto Nazionale Di Astrofísica. Osservatorio Astronómico Di Palermo; ItaliaFil: Miceli, M.. Istituto Nazionale Di Astrofísica. Osservatorio Astronómico Di Palermo; ItaliaFil: Dubner, Gloria Mabel. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Castelletti, Gabriela Marta. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Orlando, S.. Istituto Nazionale Di Astrofísica. Osservatorio Astronómico Di Palermo; ItaliaFil: Iakubovskyi, D.. Bogolyubov Institute for Theoretical Physics; UcraniaFil: Telezhinsky, I.. Kiev National Taras Shevchenko University; Ucrani

Constraining Properties of Dark Matter particles Using Astrophysical Data

A microscopic origin of dark matter phenomenon is the most plausible hypothesis to explain the mystery of dark matter. The dark matter particle hypothesis necessarily implies an extension of the Standard Model. In this thesis, we undertook a systematic model-independent program of studying the properties of decaying dark matter. By analyzing the experimental data for dwarf spheroidal galaxies it was shown that the X-ray energy range is a preferred region when searching for radiatively decaying dark matter. By analyzing dark matter distributions in different types of galaxies and in galaxy clusters we show that the expected dark matter signal increases slowly with the mass of the object. Therefore, dwarf and spiral galaxies are the observational targets with the optimal signal-to-noise ratio. To probe the theoretically interesting regions of particle physics models we performed a combined analysis of a very large dataset of archival XMM-Newton observations of galaxies. Finally, we discussed an ultimate way to probe the whole parameter space of minimal models of decaying dark matter. We argue that a new X-ray telescope with the narrow energy resolution (comparable to internal width of the line) and large field-of-view is required.Theoretical Physic

On the validity of the 5-dimensional Birkhoff theorem: The tale of an exceptional case

The 5-dimensional (5d) Birkhoff theorem gives the class of 5d vacuum space-times containing spatial hypersurfaces with cosmological symmetries. This theorem is violated by the 5d vacuum Gergely-Maartens (GM) space-time, which is not a representant of the above class, but contains the static Einstein brane as embedded hypersurface. We prove that the 5d Birkhoff theorem is still satisfied in a weaker sense: the GM space-time is related to the degenerated horizon metric of certain black-hole space-times of the allowed class. This result resembles the connection between the Bertotti-Robinson space-time and the horizon region of the extremal Reissner-Nordstrom space-time in general relativity.Comment: 13 pages; v2: title amended, to be published in Classical and Quantum Gravit

RADIAL PROFILE OF THE 3.5 keV LINE OUT TO R 200 IN THE PERSEUS CLUSTER

The recent discovery of the unidentified emission line at 3.5 keV in galaxies and clusters has attracted great interest from the community. As the origin of the line remains uncertain, we study the surface brightness distribution of the line in the Perseus cluster since that information can be used to identify its origin. We examine the flux distribution of the 3.5 keV line in the deep Suzaku observations of the Perseus cluster in detail. The 3.5 keV line is observed in three concentric annuli in the central observations, although the observations of the outskirts of the cluster did not reveal such a signal. We establish that these detections and the upper limits from the non-detections are consistent with a dark matter decay origin. However, absence of positive detection in the outskirts is also consistent with some unknown astrophysical origin of the line in the dense gas of the Perseus core, as well as with a dark matter origin with a steeper dependence on mass than the dark matter decay. We also comment on several recently published analyses of the 3.5 keV line.United States. National Aeronautics and Space Administration (Contracts NNX14AF78G and NNX123AE77G

Potential of the Large Observatory for X-ray Timing telescope for the search for dark matter

Theoretical Physic

Checking the dark matter origin of a 3.53 keV line with the Milky Way center

Theoretical Physic