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Related papers: Variability-Selected Quasars in MACHO Project Mage…

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We present the discovery of nine quasars behind the Large Magellanic Cloud, with emission redshifts ranging from 0.07 to 2.0. Six of them were identified as part of the systematic variability-based search for QSOs in the objects from the…

Astrophysics · Physics 2008-11-07 A. Dobrzycki , L. Eyer , K. Z. Stanek , L. M. Macri

We present followup spectroscopic observations of quasar candidates in the Small Magellanic Cloud selected by Eyer from the OGLE database. Of twelve observed objects identified as "QSO Candidate", five are confirmed quasars, with the…

Astrophysics · Physics 2008-11-07 A. Dobrzycki , L. M. Macri , K. Z. Stanek , P. J. Groot

Quasi--stellar objects (quasars) located behind nearby galaxies provide an excellent absolute reference system for astrometric studies, but they are difficult to identify because of fore- and background contamination. Deep wide--field, high…

The Magellanic Quasars Survey (MQS) has now increased the number of quasars known behind the Magellanic Clouds by almost an order of magnitude. All survey fields in the Large Magellanic Cloud (LMC) and 70% of those in the Small Magellanic…

We report the spectroscopic confirmation of 29 new, 12 plausible, and 3 previously known quasars behind the central ~1.5 deg^2 region of the Small Magellanic Cloud. These were identified in a single 2df/AAOmega observation on the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Szymon Kozlowski , Christopher S. Kochanek , Andrzej Udalski

We report the identification of blazar candidates behind the Magellanic Clouds. The objects were selected from the Magellanic Quasars Survey (MQS), which targeted the entire Large Magellanic Cloud (LMC) and 70\% of the Small Magellanic…

We present the discovery of four X-ray quasars (z_em = 0.26, 0.53, 0.61, 1.63) located behind the Large Magellanic Cloud; three of them are located behind the bar of the LMC. The quasars were identified via spectroscopy of optical…

Astrophysics · Physics 2016-08-30 A. Dobrzycki , P. J. Groot , L. M. Macri , K. Z. Stanek

We present five X-ray quasars behind the Small Magellanic Cloud, increasing the number of known quasars behind the SMC by ca. 40%. They were identified via follow-up spectroscopy of serendipitous sources from the Chandra X-ray Observatory…

Astrophysics · Physics 2008-11-07 A. Dobrzycki , K. Z. Stanek , L. M. Macri , P. J. Groot

Quasi-stellar objects (QSOs) are a basis for an absolute reference system for astrometric studies. There is a need for creating such system behind nearby galaxies, to facilitate the measuring of the proper motions of these galaxies.…

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

We present an optical variability study of 44 newly identified blazar candidates behind the Magellanic Clouds, including 27 flat spectrum radio quasars (FSRQs) and 17 BL Lacertae objects (BL Lacs). All objects in the sample possess high…

Astrophysics of Galaxies · Physics 2020-01-29 Natalia Żywucka , Mariusz Tarnopolski , Markus Böttcher , Łukasz Stawarz , Volodymyr Marchenko

We quadruple the number of quasars known behind the Large Magellanic Cloud (LMC) from 55 (42 in the LMC fields of the third phase of the Optical Gravitational Lensing Experiment (OGLE)) to 200 by spectroscopically confirming 169 (144 new)…

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

The MACHO Project monitors millions of stars in the Large Magellanic Cloud, the Small Magellanic Cloud and the bulge of the Milky Way searching for the gravitational microlensing signature of baryonic dark matter. This Project has yielded…

We present results of a variability study in the optical band of 44 newly identified blazar candidates behind the Magellanic Clouds. Our sample contains 27 flat spectrum radio quasars (FSRQs) and 17 BL Lacertae objects (BL Lacs). However,…

High Energy Astrophysical Phenomena · Physics 2019-11-11 Natalia Żywucka , Mariusz Tarnopolski , Markus Böttcher , Łukasz Stawarz , Volodymyr Marchenko

We have used optical V and R band observations from the Massive Compact Halo Object (MACHO) project on a sample of 59 quasars behind the Magellanic clouds to study their long term optical flux and colour variations. These quasars lying in…

Astrophysics of Galaxies · Physics 2016-02-17 N. Sukanya , C. S. Stalin , S. Jeyakumar , D. Praveen , Arnab Dhani , R. Damle

Eclipsing binaries offer a unique opportunity to determine fundamental physical parameters of stars using the constraints on the geometry of the systems. Here we present a reanalysis of publicly available two-color observations of about…

Astrophysics · Physics 2009-03-09 A. Derekas , L. L. Kiss , T. R. Bedding

MAssive Compact Halo Objects such as brown dwarfs, Jupiters, and black holes are prime candidates to comprise the dark halo of our galaxy. Paczynski noted that objects (dubbed MACHOs) with masses in the range $10^{-6}M_\odot < M \simlt 100…

Astrophysics · Physics 2009-10-22 D. P. Bennett

I present a new analysis of the MACHO Project 5.7 year Large Magellanic Cloud (LMC) microlensing data set that incorporates the effects of contamination of the microlensing event sample by variable stars. Photometric monitoring of MACHO LMC…

Astrophysics · Physics 2009-11-10 David P. Bennett

The MACHO Project is searching for galactic dark matter in the form of massive compact halo objects (Machos). Millions of stars in the Large Magellanic Cloud (LMC), Small Magellanic Cloud (SMC), and Galactic bulge are photometrically…

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