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In an attempt to increase the number of known microquasars, Paredes et al. (2002) have presented a long-term project focused on the search for new objects of this type. They performed a cross-identification between X-ray and radio catalogs…

Astrophysics · Physics 2007-05-23 M. Ribo , E. Ros , J. M. Paredes , M. Massi , J. Marti

Based on data from the ongoing OGLE Galaxy Variability Survey (OGLE GVS) we have verified observed properties of stars detected by the near-infrared VVV survey in a direction near the Galactic plane at longitude l~-27 deg and recently…

Studies of young stellar objects (YSOs) in the Galaxy have found that a significant fraction exhibit photometric variability. However, no systematic investigation has been conducted on the variability of extragalactic YSOs. Here we present…

We present variability and multi-wavelength photometric information for the 933 known quasars in the QUEST Variability Survey. These quasars are grouped into variable and non-variable populations based on measured variability confidence…

Astrophysics · Physics 2008-11-26 Adam W. Rengstorf , Robert J. Brunner , Brian C. Wilhite

The "VISTA Variables in the Via Lactea eXtended (VVVX)" ESO Public Survey is a near-infrared photometric sky survey that covers nearly 1700 sq. deg towards the Galactic disk and bulge. It is well-suited to search for new open clusters,…

We use a sample of 3791 quasars from the Sloan Digital Sky Survey (SDSS) Early Data Release (EDR), and compare their photometry to historic plate material for the same set of quasars in order to study their variability properties. The time…

Astrophysics · Physics 2009-11-07 Wim de Vries , Bob Becker , Rick White

This paper presents preliminary lists of potentially interesting point-like sources extracted from multicolor data obtained for a 1.7 square degree region near the South Galactic Pole. The region has been covered by the ESO Imaging Survey…

The Quintuplet cluster is one of the most massive star clusters in the Milky Way, situated very close to the Galactic center. We present a new search for variable stars in the vicinity of the cluster, using the five-year database of the…

Solar and Stellar Astrophysics · Physics 2016-07-26 C. Navarro Molina , J. Borissova , M. Catelan , J. Alonso-García , E. Kerins , R. Kurtev , P. W. Lucas , N. Medina , D. Minniti , I. Dékány

Photometric observations of 235 extragalactic objects that are potential targets for the Space Interferometry Mission (SIM) are presented. Mean B, V, R, I magnitudes at the 5% level are obtained at 1 - 4 epochs between 2005 and 2007 using…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Roopesh Ojha , Norbert Zacharias , Gregory S. Hennessey , Ralph A. Gaume , Kenneth J. Johnston

Context. The Vista Variables in the Via Lactea (VVV) near-infrared variability survey explores some of the most complex regions of the Milky Way bulge and disk in terms of high extinction and high crowding. Aims. We add a new wavelength…

Quasars behind the Galactic plane (GPQs) are important astrometric references and valuable probes of Galactic gas, yet the search for GPQs is difficult due to severe extinction and source crowding in the Galactic plane. In this paper, we…

The study of absorptions along the lines of sight to bright high-$z$ QSOs is an invaluable cosmological tool that provides a wealth of information on the inter-/circum-galactic medium, Dark Matter, primordial elements, reionization,…

Instrumentation and Methods for Astrophysics · Physics 2020-01-08 Calderone G. , Boutsia K. , Cristiani S. , Grazian A. , Amorin R. , D'Odorico V. , Cupani G. , Fontanot F. , Salvato M

We present the initial results of a 40 night contiguous ground-based campaign of time series photometric observations of a 1.39 sq. deg field located within the NASA Kepler mission field of view. The goal of this pre-launch survey was to…

We present a sample of 209 variable objects - very likely optical counterparts to the X-ray sources detected in the direction of the Galactic center by the Galactic Bulge Survey (GBS) carried out with the Chandra satellite. The variable…

From our position embedded within the Milky Way's interstellar medium (ISM), we have limited ability to detect gas at low relative velocities in the extended Galactic halo because those spectral lines are blended with much stronger signals…

Astrophysics of Galaxies · Physics 2021-05-21 Hannah V. Bish , Jessica K. Werk , Joshua Peek , Yong Zheng , Mary Putman

This paper presents 19 additional candidate clusters detected using the galaxy catalog extracted from the I-band images taken for the ESO Imaging Survey (EIS). The candidates are found over a region of 1.1 square degrees, located near the…

We search for extragalactic sources in the VISTA Variables in the V\'ia L\'actea survey that are hidden by the Galaxy. Herein, we describe our photometric procedure to find and characterize extragalactic objects using a combination of…

Astrophysics of Galaxies · Physics 2018-01-10 Laura D. Baravalle , M. Victoria Alonso , José L. Nilo Castellón , Juan C. Beamín , Dante Minniti

We have conducted a large-scale survey of the northern plane using Kiso Wide Field Camera attached to Schmidt telescope at Kiso observatory. The KISOGP (KWFC Intensive Survey of the Galactic Plane) project have made 40-70 epoch observations…

Solar and Stellar Astrophysics · Physics 2017-09-13 Noriyuki Matsunaga

The variability of quasars across multiple wavelengths is a useful probe of physical conditions in active galactic nuclei. In particular, variable accretion rates, instabilities, and reverberation effects in the accretion disk of a…

Astrophysics of Galaxies · Physics 2020-05-13 Chengcheng Xin , Maria Charisi , Zoltán Haiman , David Schiminovich

We report the first results of a study of variable point sources identified using multi-color time-series photometry from Sloan Digital Sky Survey (SDSS) Stripe 82 over a span of nearly 10 years (1998-2007). We construct a light-curve…

Solar and Stellar Astrophysics · Physics 2014-11-20 Waqas A. Bhatti , Michael W. Richmond , Holland C. Ford , Larry D. Petro