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Related papers: The VMC Survey : LI. Classifying extragalactic sou…

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The Magellanic clouds are uniquely placed to study the stellar contribution to dust emission. Individual stars can be resolved in these systems even in the mid-infrared, and they are close enough to allow detection of infrared excess caused…

The Large Area Telescope (LAT) on board the \emph{Fermi} Gamma-ray Space Telescope has been continuously providing good quality survey data of the entire sky in the high energy range from 30 MeV to 500 GeV and above since August 2008. A…

High Energy Astrophysical Phenomena · Physics 2025-10-13 A. Pathania , K. K. Singh , S. K. Singh , A. Tolamatti , B. B. Singh , K. K. Yadav

The study of the entire population of SNRs in a galaxy helps us to understand the underlying stellar populations, the environments, in which the SNRs are evolving, and the stellar feedback on the ISM. The all-sky survey carried out by the…

Using observations from the {\em Herschel} Inventory of The Agents of Galaxy Evolution (HERITAGE) survey of the Magellanic Clouds, we have found thirty five evolved stars and stellar end products that are bright in the far-infrared. These…

Solar and Stellar Astrophysics · Physics 2015-10-07 Olivia C. Jones , Margaret Meixner , Benjamin A. Sargent , Martha L. Boyer , Marta Sewilo , Sacha Hony , Julia Roman-Duval

The field of gamma ray astronomy relies heavily on the statistical analysis of data. Because of the paucity of data, and the often large errors associated with detecting gamma rays, analysis and interpretation of the data require…

Astrophysics · Physics 2007-05-23 W. F. Tompkins

A large number of unidentified sources found by astronomical surveys and other observations necessitate the use of an automated classification technique based on machine learning methods. The aim of this paper is to find a suitable…

High Energy Astrophysical Phenomena · Physics 2023-02-20 Shivam Kumaran , Samir Mandal , Sudip Bhattacharyya , Deepak Mishra

We collect data at all frequencies for the new sources classified as unknown active galactic nuclei (AGNs) in the latest Burst Alert Telescope (BAT) all-sky hard X-ray catalog. Focusing on the 36 sources with measured redshift, we compute…

High Energy Astrophysical Phenomena · Physics 2021-04-07 Luca Giuliani , Gabriele Ghisellini , Tullia Sbarrato

We conduct X-ray spectral fits on 184 likely counterparts to Fermi-LAT 3FGL unassociated sources. Characterization and classification of these sources allows for more complete population studies of the high-energy sky. Most of these X-ray…

High Energy Astrophysical Phenomena · Physics 2021-03-02 Stephen Kerby , Amanpreet Kaur , Abraham D. Falcone , Michael C. Stroh , Elizabeth C. Ferrara , Jamie A. Kennea , Joseph Colosimo

A complete demographic of active galactic nuclei (AGN) is essential to understand the evolution of the Universe. Optical surveys estimate the population of AGN in the local Universe to be of $\sim$ 4%. However, these results could be biased…

The Australia Telescope Large Area Survey (ATLAS) and the VLA survey in the XMM-LSS/VIDEO deep field provide deep ($\approx 15$ ${\mu}$Jybeam$^{-1}$) and high-resolution ($\approx$ 4.5--8 arcsec) radio coverage of the three XMM-SERVS fields…

Astrophysics of Galaxies · Physics 2023-05-03 Shifu Zhu , William N. Brandt , Fan Zou , Bin Luo , Qingling Ni , Yongquan Xue , Wei Yan

Data are given for 16 extragalactic objects (predominantly AGN) behind the Magellanic Clouds and for 146 quasar candidates behind the nearby galaxies NGC 45, 185, 253, 2366, 2403 and 6822, IC 1613, M31 and M33. The Magellanic Cloud objects…

Astrophysics · Physics 2009-10-30 David Crampton , G. Gussie , A. P. Cowley , P. C. Schmidtke

The Fermi Large Area Telescope First Source Catalog (1FGL) provided spatial, spectral, and temporal properties for a large number of gamma-ray sources using a uniform analysis method. After correlating with the most-complete catalogs of…

High Energy Astrophysical Phenomena · Physics 2015-05-30 LAT Collaboration

In deep X-ray surveys, active galactic nuclei (AGNs) with a broad range of luminosities have been identified. However, cosmologically distant low-luminosity AGN (LLAGN, $L_{\mathrm{X}} \lesssim 10^{42}$ erg s$^{-1}$) identification still…

Machine-learning (ML) algorithms will play a crucial role in studying the large datasets delivered by new facilities over the next decade and beyond. Here, we investigate the capabilities and limits of such methods in finding galaxies with…

Instrumentation and Methods for Astrophysics · Physics 2019-08-22 Andreas L. Faisst , Abhishek Prakash , Peter L. Capak , Bomee Lee

We present the results of our search for highly variable active galactic nuclei (AGNs) the X-ray flux from which changed by more than an order of magnitude during the SRG/eROSITA all-sky survey. Using the eROSITA data obtained in the period…

High Energy Astrophysical Phenomena · Physics 2023-09-21 Pavel Medvedev , Marat Gilfanov , Sergey Sazonov , Rashid Sunyaev , Georgii Khorunzhev

Optical variability has proven to be an effective way of detecting AGNs in imaging surveys, lasting from weeks to years. In the present work we test its use as a tool to identify AGNs in the VST multi-epoch survey of the COSMOS field,…

With growing data volumes from synoptic surveys, astronomers must become more abstracted from the discovery and introspection processes. Given the scarcity of follow-up resources, there is a particularly sharp onus on the frameworks that…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 Joseph W. Richards , Dan L. Starr , Adam A. Miller , Joshua S. Bloom , Nathaniel R. Butler , Henrik Brink , Arien Crellin-Quick

The survey of the COSMOS field by the VLT Survey Telescope is an appealing testing ground for variability studies of active galactic nuclei (AGN). With 54 r-band visits over 3.3 yr and a single-visit depth of 24.6 r-band mag, the dataset is…

Astrophysics of Galaxies · Physics 2021-01-27 D. De Cicco , F. E. Bauer , M. Paolillo , S. Cavuoti , P. Sánchez-Sáez , W. N. Brandt , G. Pignata , M. Vaccari , M. Radovich

Despite the plethora of deep (sub-mJy) radio surveys there remains considerable doubt as to the exact nature of the galaxies contributing to the source counts. Current evidence suggests that starformation in moderately luminous 'normal'…

Astrophysics · Physics 2009-11-11 Nick Seymour , Derek Moss , Ian McHardy , Katherine Gunn , Mat Page , Nic Loaring , Tom Dwelly