English
Related papers

Related papers: Bayesian evidence for flux scale errors in Galacti…

200 papers

We present a comprehensive temporal and spectral analysis of a few blazars using multi-wavelength observations. Rapid flux variations are quantified via the doubling/halving timescale method, revealing the shortest variability timescales of…

High Energy Astrophysical Phenomena · Physics 2025-06-17 Ajay Sharma , Aishwarya Sarath , Sakshi Chaudhary , Debanjan Bose

The Fermi-LAT data appear to have an excess of gamma rays from the inner 150 pc of the Galactic Center. The main explanations proposed for this are: an unresolved population of millisecond pulsars (MSPs), dark matter (DM) annihilation, and…

High Energy Astrophysical Phenomena · Physics 2014-03-19 Oscar Macias , Chris Gordon

Based on general relativity, it can be argued that deviations from a uniform Hubble flow should be thought of as variations in the Universe's expansion velocity field, rather than being thought of as peculiar velocities with respect to a…

Astrophysics · Physics 2008-11-26 M. L. McClure , C. C. Dyer

We use Bayesian methods to study anisotropic models for the distribution of gamma ray burst intensities and directions reported in the Third BATSE Catalog (3B catalog) of gamma ray bursts. We analyze data obtained using both the 64 ms and…

Astrophysics · Physics 2009-10-30 Thomas J. Loredo , Ira M. Wasserman

The SIS100 synchrotron as a part of the new FAIR accelerator facility at GSI should be operated at the "space charge limit" for light and heavy ion beams. Beam losses due to space charge induced resonance crossing should not exceed a few…

Galactic all-sky maps at very disparate frequencies, like in the radio and $\gamma$-ray regime, show similar morphological structures. This mutual information reflects the imprint of the various physical components of the interstellar…

We present an in-depth and systematic variability study of a sample of 20 powerful blazars, including 12 BL Lacs and 8 flat spectrum radio quasars, applying various analysis tools such as flux distribution, symmetry analysis, and time…

High Energy Astrophysical Phenomena · Physics 2020-03-18 Gopal Bhatta , Niraj Dhital

Recently a symmetry-based method to test for statistical isotropy of the cosmic microwave background was developed. We apply the method to template-cleaned 3-year and 5-year WMAP-$DA$ maps. We examine a wide range of angular multipoles from…

Astrophysics · Physics 2010-11-02 Pramoda Kumar Samal , Rajib Saha , Pankaj Jain , John P. Ralston

A detailed study of the spectrum and variability of the source HESS J1745-290 in the Galactic Center (GC) region using new data from the H.E.S.S. array of Cherenkov telescopes is presented. Flaring activity and Quasi Periodic Oscillations…

Astrophysics of Galaxies · Physics 2012-08-27 H. E. S. S. collaboration , : , F. Aharonian

The observed distribution of galaxies has local transverse isotropy around the line-of- sight (LOS) with respect to the observer. The difference in the statistical clustering signal along and across the line-of-sight encodes important…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-13 Lado Samushia , Enzo Branchini , Will Percival

Complementary views of galaxy clusters in the radio synchrotron, hard X-ray inverse Compton, and high-energy gamma-ray regimes are critical in calibrating them as high-precision cosmological probes. We present predictions for scaling…

Astrophysics · Physics 2009-11-13 Christoph Pfrommer

We used the data from the Fermi Gamma-ray Space Telescope to characterise the {\gamma}-ray flux variability of blazars on month-like time scales. Our sample consists of 1120 blazars of which 481 are flat spectrum radio quasars (FSRQs) and…

High Energy Astrophysical Phenomena · Physics 2020-02-12 Bhoomika Rajput , C. S. Stalin , Suvendu Rakshit

The High Latitude Spectroscopic Survey (HLSS) is the reference baseline spectroscopic survey for NASA's Nancy Grace Roman space telescope, measuring redshifts of $\sim 10$M H$\alpha$ emission line galaxies over a $2000$ deg$^2$ footprint at…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-31 Kevin S. McCarthy , Zhongxu Zhai , Yun Wang

Blazars with redshifts z<0.1 are likely candidates for detection at energies in the range 300 GeV - 50 TeV with Cerenkov telescopes and scintillator arrays. We present gamma-ray flux predictions for a sample of 15 nearby flat-spectrum radio…

Astrophysics · Physics 2011-05-23 K. Mannheim , S. Westerhoff , H. Meyer , H. -H. Fink

We extend previous work modeling the Galactic magnetic field in the plane using synchrotron emission in total and polarised intensity. In this work, we include a more realistic treatment of the cosmic-ray electrons using the GALPROP…

Astrophysics of Galaxies · Physics 2018-02-14 T. R. Jaffe , A. J. Banday , J. P. Leahy , S. Leach , A. W. Strong

Anomalous microwave emission at 20-40 GHz has been detected across our Galactic sky. It is highly correlated with thermal dust emission and hence it is thought to be due to spinning dust grains. Alternatively, this emission could be due to…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-09 M. W. Peel , C. Dickinson , R. D. Davies , A. J. Banday , T. R. Jaffe , J. L. Jonas

We present an attempt to measure the large angular scale fluctuations in the X-Ray Background (XRB) from the HEAO1-A2 data, expressed in terms of spherical harmonics. We model the harmonic coefficients assuming a power spectrum and an…

Astrophysics · Physics 2009-10-30 Marie Treyer , Caleb Scharf , Ofer Lahav , Keith Jahoda , Elihu Boldt , Tsvi Piran

We use Bayesian methods to analyze the distribution of gamma ray burst intensities reported in the Third BATSE Catalog (3B catalog) of gamma ray bursts, presuming the distribution of burst sources (``bursters'') is isotropic. We study both…

Astrophysics · Physics 2009-10-30 Thomas J. Loredo , Ira M. Wasserman

We use the COBE Differential Microwave Radiometers (DMR) 4-year sky maps to model Galactic microwave emission at high latitudes (|b| > 20 deg). Cross-correlation of the DMR maps with Galactic template maps detects fluctuations in the…

Astrophysics · Physics 2009-10-28 A. Kogut , G. Hinshaw , A. J. Banday , C. L. Bennett , K. Gorski , G. F. Smoot , E. L. Wright
‹ Prev 1 3 4 5 6 7 10 Next ›