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

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We investigate the physical nature of active galactic nuclei (AGNs) using machine learning (ML) tools. We show that the redshift, $z$, bolometric luminosity, $L_{\rm Bol}$, central mass of the supermassive black hole (SMBH), $M_{\rm BH}$,…

Astrophysics of Galaxies · Physics 2024-05-17 Sarah Mechbal , Markus Ackermann , Marek Kowalski

Aims. We analyze the properties of the sources in the NGC253 to define an up to date catalog of GC candidates in the galaxy. Methods. Our analysis is based on the science verification data of two ESO survey telescopes, VST and VISTA. Using…

We investigate the optical morphologies of candidate active galaxies identified at radio, X-ray, and mid-infrared wavelengths. We use the Advanced Camera for Surveys General Catalog (ACS-GC) to identify 372, 1360, and 1238 AGN host galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-19 Roger L. Griffith , Daniel Stern

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

We present a first catalog of sources detected by the Mikhail Pavlinsky ART-XC telescope on board the SRG observatory in the 4-12 keV energy band during its ongoing all-sky survey. The catalog comprises 867 sources detected on the combined…

In this study, we conduct a pilot program aimed at the red supergiant population of the Magellanic Clouds. We intend to extend the current known sample to the unexplored low end of the brightness distribution of these stars, building a more…

Solar and Stellar Astrophysics · Physics 2015-05-27 Carlos González-Fernández , Ricardo Dorda , Ignacio Negueruela , Amparo Marco

We present an analysis of the X-ray bright point source population in 43 massive clusters of galaxies observed with the Chandra X-ray Observatory. We have constructed a catalog of 4210 rigorously selected X-ray point sources in these…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 S. Ehlert , S. W. Allen , W. N. Brandt , Y. Q. Xue , B. Luo , A. von der Linden , A. Mantz , R. G. Morris

Bent radio active galactic nuclei (RAGNs) -- wide-angle tails (WATs) and narrow-angle tails (NATs) -- trace dense environments in galaxy groups and clusters, yet no multiclass classifier simultaneously separates them from straight…

Instrumentation and Methods for Astrophysics · Physics 2026-05-28 M. S. Hossain , M. S. H. Shahal , K. M. B. Asad , P. Saikia , A. Khan , F. Akter , A. Ali , M. A. Amin , D. P. Guha , M. O. B. Jihad , A. Momen , S. Sen , A. K. M. M. Rahman

Within the framework of our program (running since 2004) of identification of hard X-ray INTEGRAL sources through optical spectroscopy, we present the results concerning the nature of 33 high-energy objects. The data were acquired with the…

We have extended our PNe survey to the outer ~64deg^2 of the LMC using maps from the Magellanic Cloud Emission Line Survey (MCELS) and the UK Schmidt Telescope (UKST) H-alpha survey. Although the MCELS survey has poorer ~5 arcsecond…

Astrophysics of Galaxies · Physics 2015-06-17 Warren A. Reid , Quentin A. Parker

In an analysis of XMM-Newton archival observations of the bright Local Group spiral galaxy M 31 we study the population of X-ray sources (X-ray binaries, supernova remnants) down to a 0.2-4.5 keV luminosity of 4.4E34 erg/s. EPIC hardness…

Astrophysics · Physics 2009-11-10 W. Pietsch , M. Freyberg , F. Haberl

The number and spatial distribution of confirmed quasi-stellar objects (QSOs) behind the Magellanic system is limited. This undermines their use as astrometric reference objects for different types of studies. We have searched for criteria…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 M. -R. L. Cioni , D. Kamath , S. Rubele , J. Th. van Loon , P. R. Wood , J. P. Emerson , B. K. Gibson , M. A. T. Groenewegen , V. D. Ivanov , B. Miszalski , V. Ripepi

Using archival X-ray data from the second XMM-Newton serendipitous source catalogue, we present comparative analysis of the overall population of X-ray sources in the Large and Small Magellanic Clouds. We see a difference between the…

Astrophysics · Physics 2008-09-16 Andrew J. Gosling , Sean A. Farrell , Natalie A. Webb , Jari J. E. Kajava

A VLA Sky Survey of the extragalactic sky at S band (2-4 GHz) with polarization information can uniquely probe the magneto-ionic medium in a wide range of astrophysical environments over cosmic time. For a shallow all-sky survey, we expect…

A survey of extended objects in the Large Magellanic Cloud was carried out on the ESO/SERC R and J Sky Survey Atlases, checking entries in previous catalogs and searching for new objects. The census provided 6659 objects including star…

Astrophysics · Physics 2008-11-26 Eduardo L. D. Bica , Henrique R. Schmitt , Carlos , M. Dutra , Humberto L. Oliveira

In this work we analyse Colour-Magnitude Diagrams (CMDs) of catalogued star clusters located in the Large Magellanic Cloud (LMC), from a YJKs photometric data set obtained by the Visible and Infrared Survey Telescope for Astronomy (VISTA)…

As a pilot study for the first all-sky radio survey at short wavelengths, we have observed 1216 sq. deg. of the southern sky at 18GHz (16mm) using a novel wide-band (3.4GHz bandwidth) analogue correlator on one baseline of the Australia…

We use machine learning techniques to investigate their performance in classifying active galactic nuclei (AGNs), including X-ray selected AGNs (XAGNs), infrared selected AGNs (IRAGNs), and radio selected AGNs (RAGNs). Using known physical…

Astrophysics of Galaxies · Physics 2021-10-26 Yu-Yen Chang , Bau-Ching Hsieh , Wei-Hao Wang , Yen-Ting Lin , Chen-Fatt Lim , Yoshiki Toba , Yuxing Zhong , Siou-Yu Chang

In order to find more examples of the elusive high-redshift molecular absorbers, we have embarked on a systematic discovery program for highly obscured, radio-loud "invisible AGN" using the VLA Faint Images of the Radio Sky at Twenty…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 T. Yan , J. T. Stocke , J. Darling , F. Hearty

Extragalactic globular clusters (GCs) are important tracers of galaxy formation and evolution. Obtaining GC catalogues from photometric data involves several steps which will likely become too time-consuming to perform on the large data…

Astrophysics of Galaxies · Physics 2022-07-20 Dominik Dold , Katja Fahrion