English
Related papers

Related papers: A stacking method to study the gamma-ray emission …

200 papers

In this letter, we introduce a new method of image stacking to directly study the undetected but possible gamma-ray point sources. Applying the method to the Australia Telescope 20 GHz Survey (AT20G) sources which have not been detected by…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Ming Zhou , Jiancheng Wang , Xiaoyan Gao

We propose a novel statistical method to extend Fermi-LAT catalogues of high-latitude $\gamma$-ray sources below their nominal threshold. To do so, we rely on a recent determination of the differential source-count distribution of…

High Energy Astrophysical Phenomena · Physics 2024-05-16 Aurelio Amerio , Francesca Calore , Pasquale Dario Serpico , Bryan Zaldivar

We studied the problematic of uncertainties in the diffuse gamma radiation apparent in stacking analysis of EGRET data at low Galactic latitudes. Subsequently, we co-added maps of counts, exposure and diffuse background, and residuals, in…

Astrophysics · Physics 2008-11-26 Analia N. Cillis , Olaf Reimer , Diego F. Torres

Searching for as yet undetected gamma-ray sources is a major target of the Fermi LAT Collaboration. We present an algorithm capable of identifying such type of sources by non-parametrically clustering the directions of arrival of the…

Instrumentation and Methods for Astrophysics · Physics 2023-01-30 Anna Montin , Alessandra R. Brazzale , Giovanna Menardi

We present evidence for $\gamma$-ray emission from a stacked population of 39 high-latitude globular clusters (GCs) not detected in the Fermi Point Source Catalog, likely attributable to populations of millisecond pulsars within them. In…

High Energy Astrophysical Phenomena · Physics 2024-10-17 Owen K. Henry , Timothy A. D. Paglione , Yuzhe Song , Joshua Tan , David Zurek , Vanessa Pinto

We report on a likelihood stacking search for gamma-ray pulsars at 362 high-latitude locations that coincide with known radio pulsar positions. We observe a stacked signal conservatively 2.5$\sigma$ over the background. Stacking their…

High Energy Astrophysical Phenomena · Physics 2023-08-04 Yuzhe Song , Timothy A. D. Paglione , Joshua Tan , Charles Lee-Georgescu , Danisbel Herrera

We employ an efficient method for identifying gamma-ray sources across the entire sky, leveraging advanced algorithms from Fermi p y, and cleverly utilizing the Galactic diffuse background emission model to partition the entire sky into 72…

High Energy Astrophysical Phenomena · Physics 2024-12-30 Y. C. Xiang , P. Feng , X. F. Lan

When it comes to identifying or to characterizing gamma-ray sources, X-ray observations are of paramount importance. Correlated X-and-gamma-ray flux variations are a powerful identification tool, if the gamma-ray source is unidentified, or…

High Energy Astrophysical Phenomena · Physics 2009-12-25 Patrizia A. Caraveo

Spatial extension is an important characteristic for correctly associating gamma-ray-emitting sources with their counterparts at other wavelengths and for obtaining an unbiased model of their spectra. We present a new method for quantifying…

Several classes of astrophysical sources contribute to the approximately isotropic gamma-ray background measured by the Fermi Gamma-Ray Space Telescope. In this paper, we use Fermi's catalog of gamma-ray sources (along with corresponding…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Ilias Cholis , Dan Hooper , Samuel D. McDermott

We present a new method to interpret the $\gamma$-ray data of our inner Galaxy as measured by the Fermi Large Area Telescope (Fermi LAT). We train and test convolutional neural networks with simulated Fermi-LAT images based on models tuned…

High Energy Astrophysical Phenomena · Physics 2018-05-29 Sascha Caron , Germán A. Gómez-Vargas , Luc Hendriks , Roberto Ruiz de Austri

The Density Based Spatial Clustering of Applications with Noise (DBSCAN) is a topometric algorithm used to cluster spatial data that are affected by background noise. For the first time, we propose the use of this method for the detection…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 A. Tramacere , C. Vecchio

Statistical properties of photon count maps have recently been proven as a new tool to study the composition of the gamma-ray sky with high precision. We employ the 1-point probability distribution function of 6 years of Fermi-LAT data to…

High Energy Astrophysical Phenomena · Physics 2016-08-01 Hannes-S. Zechlin , Alessandro Cuoco , Fiorenza Donato , Nicolao Fornengo , Marco Regis

Unassociated Fermi-LAT sources provide a population with discovery potential. We discuss efforts to find new source associations for this population, and summarize the successes to date. We discuss how the measured gamma-ray properties of…

High Energy Astrophysical Phenomena · Physics 2012-06-13 Elizabeth C. Ferrara , Roopesh Ojha , Maria Elena Monzani , Nicola Omodei

The sensitivity of the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope allows detection of thousands of new gamma-ray sources and detailed characterization of the spectra and variability of bright sources.…

Instrumentation and Methods for Astrophysics · Physics 2015-03-18 Matthew Kerr

Line-intensity mapping (LIM) is a growing technique that measures the integrated spectral-line emission from unresolved galaxies over a three-dimensional region of the Universe. Although LIM experiments ultimately aim to provide powerful…

The inner region of the Milky Way is one of the most interesting and complex regions of the gamma-ray sky. The intense interstellar emission and resolved point sources, as well as potential contributions by other sources such as unresolved…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Troy A. Porter , Simona Murgia

We present a new and efficient algorithm for finding point sources in the photon event data stream from the Fermi Gamma-Ray Space Telescope, FermiFAST. The key advantage of FermiFAST is that it constructs a catalogue of potential sources…

Instrumentation and Methods for Astrophysics · Physics 2017-01-25 Asha Asvathaman , Conor Omand , Alistair Barton , Jeremy S. Heyl

Stacks of digital astronomical images are combined in order to increase image depth. The variable seeing conditions, sky background and transparency of ground-based observations make the coaddition process non-trivial. We present image…

Instrumentation and Methods for Astrophysics · Physics 2018-03-28 Barak Zackay , Eran O. Ofek

During its first 2 years of mission the Fermi-LAT instrument discovered more than 1,800 gamma-ray sources in the 100 MeV to 100 GeV range. Despite the application of advanced techniques to identify and associate the Fermi-LAT sources with…

High Energy Astrophysical Phenomena · Physics 2016-03-02 David Salvetti
‹ Prev 1 2 3 10 Next ›