Related papers: Mapping optically variable quasars towards the gal…

A survey of CO and its isotope lines for possible cloud-cloud collision candidates

In the 12CO (J=1-0) survey for the 1331 cold IRAS sources 214 sources show profiles with multiple-peak profiles and are selected as cloud-cloud collision candidates. In January 2005, 201 sources are detected with 12CO(1-0), 13CO(1-0), and…

Solar and Stellar Astrophysics · Physics 2015-06-12 Nan Li , Jun-Jie Wang

Milky Way demographics with the VVV survey. IV. PSF photometry from almost one billion stars in the Galactic bulge and adjacent southern disk

The inner regions of the Galaxy are severely affected by extinction, which limits our capability to study the stellar populations present there. The Vista Variables in the Via Lactea (VVV) ESO Public Survey has observed this zone at…

Astrophysics of Galaxies · Physics 2018-10-31 Javier Alonso-García , Roberto K. Saito , Maren Hempel , Dante Minniti , Joyce Pullen , Márcio Catelan , Rodrigo Contreras Ramos , Nicholas J. G. Cross , Oscar A. Gonzalez , Philip W. Lucas , Tali Palma , Elena Valenti , Manuela Zoccali

Extreme variability quasars from the Sloan Digital Sky Survey and the Dark Energy Survey

We perform a systematic search for long-term extreme variability quasars (EVQs) in the overlapping Sloan Digital Sky Survey (SDSS) and 3-Year Dark Energy Survey (DES) imaging, which provide light curves spanning more than 15 years. We…

Astrophysics of Galaxies · Physics 2018-02-28 Nick Rumbaugh , Yue Shen , Eric Morganson , Xin Liu , Manda Banerji , Richard G. McMahon , Filipe Abdalla , Aurelien Benoit-Levy , Emmanuel Bertin , David Brooks , Elizabeth Buckley-Geer , Diego Capozzi , Aurelio Carnero Rosell , M. Carrasco Kind , Jorge Carretero , Carlos Cunha , Chris D'Andrea , Luiz da Costa , Darren DePoy , Shantanu Desai , Peter Doel , Joshua Frieman , Juan Garcia-Bellido , Daniel Gruen , Robert Gruendl , Julia Gschwend , Gaston Gutierrez , Klaus Honscheid , David James , Kyler Kuehn , Steve Kuhlmann , Nikolay Kuropatkin , Marcos Lima , Marcio Maia , Jennifer Marshall , Paul Martini , Felipe Menanteau , Andres Plazas Malagon , Kevin Reil , Aaron Roodman , Eusebio Sanchez , Vic Scarpine , Rafe Schindler , Michael Schubnell , Erin Sheldon , Mathew Smith , Marcelle Soares-Santos , Flavia Sobreira , Eric Suchyta , Molly Swanson , Alistair Walker , William Wester

VVV-WIT-04: an extragalactic variable source caught by the VVV Survey

We report the discovery of VVV-WIT-04, a near-infrared variable source towards the Galactic disk located ~0.2 arcsec apart from the position of the radio source PMN J1515-5559. The object was found serendipitously in the near-IR data of the…

Astrophysics of Galaxies · Physics 2019-10-02 Roberto K. Saito , Dante Minniti , Valentin D. Ivanov , Nicola Masetti , Maria Gabriela Navarro , Roberto Cid Fernandes , Daniel Ruschel-Dutra , Leigh C. Smith , Philip W. Lucas , Carlos Gonzalez-Fernandez , Rodrigo Contreras Ramos

Variability of Optical Counterparts in the Chandra Galactic Bulge Survey

We present optical lightcurves of variable stars consistent with the positions of X-ray sources identified with the Chandra X-ray Observatory for the Chandra Galactic Bulge Survey. Using data from the Mosaic-II instrument on the Blanco 4m…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Christopher T. Britt , R. I. Hynes , C. B. Johnson , A. Baldwin , P. G. Jonker , G. Nelemans , M. A. P. Torres , T. Maccarone , D. Steeghs , S. Greiss , C. Heinke , C. G. Bassa , A. Collazzi , A. Villar , M. Gabb , L. Gossen

SDSS low z quasar companion galaxies

We investigate the relationship between quasars and close companion galaxies using photometry and spectroscopy from the large data set of the SDSS DR16 survey. From the SDSS-QSO catalog of quasars, we selected objects with 0.1 < z < 0.35…

Astrophysics of Galaxies · Physics 2025-10-29 D. Bettoni , R. Falomo , S. Paiano

The OmegaWhite survey for Short-Period Variable Stars III: Follow-up Photometric and Spectroscopic Observations

We present photometric and spectroscopic follow-up observations of short-period variables discovered in the OmegaWhite survey: a wide-field high-cadence g-band synoptic survey targeting the Galactic Plane. We have used fast photometry on…

Solar and Stellar Astrophysics · Physics 2016-12-14 S. A. Macfarlane , P. A. Woudt , P. J. Groot , G. Ramsay , R. Toma , M. Motsoaledi , L. A. Crause , D. G. Gilbank , D. O'Donoghue , S. B. Potter , A. A. Sickafoose , C. van Gend , H. L. Worters

Variability-selected quasars behind the Small Magellanic Cloud

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

The OmegaWhite Survey for short period variable stars II: An overview of results from the first four years

OmegaWhite is a wide-field, high cadence, synoptic survey targeting fields in the southern Galactic plane, with the aim of discovering short period variable stars. Our strategy is to take a series of 39 s exposures in the g band of a 1…

Solar and Stellar Astrophysics · Physics 2016-08-31 Ruxandra Toma , Gavin Ramsay , Sally MacFarlane , Paul Groot , Patrick Woudt , Vik Dhillon , C. Simon Jeffery , Tom Marsh , Gijs Nelemans , Danny Steeghs

Measurement of Very-high-energy Diffuse Gamma-ray Emissions from the Galactic Plane with LHAASO-WCDA

The diffuse Galactic gamma-ray emission is a very important tool used to study the propagation and interaction of cosmic rays in the Milky Way. In this work, we report the measurements of the diffuse emission from the Galactic plane,…

High Energy Astrophysical Phenomena · Physics 2026-01-08 The LHAASO Collaboration , Zhen Cao , F. Aharonian , Y. X. Bai , Y. W. Bao , D. Bastieri , X. J. Bi , Y. J. Bi , W. Bian , A. V. Bukevich , C. M. Cai , W. Y. Cao , Zhe Cao , J. Chang , J. F. Chang , A. M. Chen , E. S. Chen , H. X. Chen , Liang Chen , Long Chen , M. J. Chen , M. L. Chen , Q. H. Chen , S. Chen , S. H. Chen , S. Z. Chen , T. L. Chen , X. B. Chen , X. J. Chen , Y. Chen , N. Cheng , Y. D. Cheng , M. C. Chu , M. Y. Cui , S. W. Cui , X. H. Cui , Y. D. Cui , B. Z. Dai , H. L. Dai , Z. G. Dai , Danzengluobu , Y. X. Diao , X. Q. Dong , K. K. Duan , J. H. Fan , Y. Z. Fan , J. Fang , J. H. Fang , K. Fang , C. F. Feng , H. Feng , L. Feng , S. H. Feng , X. T. Feng , Y. Feng , Y. L. Feng , S. Gabici , B. Gao , C. D. Gao , Q. Gao , W. Gao , W. K. Gao , M. M. Ge , T. T. Ge , L. S. Geng , G. Giacinti , G. H. Gong , Q. B. Gou , M. H. Gu , F. L. Guo , J. Guo , X. L. Guo , Y. Q. Guo , Y. Y. Guo , Y. A. Han , O. A. Hannuksela , M. Hasan , H. H. He , H. N. He , J. Y. He , X. Y. He , Y. He , S. Hernández-Cadena , Y. K. Hor , B. W. Hou , C. Hou , X. Hou , H. B. Hu , S. C. Hu , C. Huang , D. H. Huang , J. J. Huang , T. Q. Huang , W. J. Huang , X. T. Huang , X. Y. Huang , Y. Huang , Y. Y. Huang , X. L. Ji , H. Y. Jia , K. Jia , H. B. Jiang , K. Jiang , X. W. Jiang , Z. J. Jiang , M. Jin , S. Kaci , M. M. Kang , I. Karpikov , D. Khangulyan , D. Kuleshov , K. Kurinov , B. B. Li , Cheng Li , Cong Li , D. Li , F. Li , H. B. Li , H. C. Li , Jian Li , Jie Li , K. Li , L. Li , R. L. Li , S. D. Li , T. Y. Li , W. L. Li , X. R. Li , Xin Li , Y. Z. Li , Zhe Li , Zhuo Li , E. W. Liang , Y. F. Liang , S. J. Lin , B. Liu , C. Liu , D. Liu , D. B. Liu , H. Liu , H. D. Liu , J. Liu , J. L. Liu , J. R. Liu , M. Y. Liu , R. Y. Liu , S. M. Liu , W. Liu , X. Liu , Y. Liu , Y. Liu , Y. N. Liu , Y. Q. Lou , Q. Luo , Y. Luo , H. K. Lv , B. Q. Ma , L. L. Ma , X. H. Ma , J. R. Mao , Z. Min , W. Mitthumsiri , G. B. Mou , H. J. Mu , Y. C. Nan , A. Neronov , K. C. Y. Ng , M. Y. Ni , L. Nie , L. J. Ou , P. Pattarakijwanich , Z. Y. Pei , J. C. Qi , M. Y. Qi , J. J. Qin , A. Raza , C. Y. Ren , D. Ruffolo , A. Sáiz , M. Saeed , D. Semikoz , L. Shao , O. Shchegolev , Y. Z. Shen , X. D. Sheng , Z. D. Shi , F. W. Shu , H. C. Song , Yu. V. Stenkin , V. Stepanov , Y. Su , D. X. Sun , H. Sun , Q. N. Sun , X. N. Sun , Z. B. Sun , N. H. Tabasam , J. Takata , P. H. T. Tam , H. B. Tan , Q. W. Tang , R. Tang , Z. B. Tang , W. W. Tian , C. N. Tong , L. H. Wan , C. Wang , G. W. Wang , H. G. Wang , H. H. Wang , J. C. Wang , K. Wang , Kai Wang , Kai Wang , L. P. Wang , L. Y. Wang , L. Y. Wang , R. Wang , W. Wang , X. G. Wang , X. J. Wang , X. Y. Wang , Y. Wang , Y. D. Wang , Z. H. Wang , Z. X. Wang , Zheng Wang , D. M. Wei , J. J. Wei , Y. J. Wei , T. Wen , S. S. Weng , C. Y. Wu , H. R. Wu , Q. W. Wu , S. Wu , X. F. Wu , Y. S. Wu , S. Q. Xi , J. Xia , J. J. Xia , G. M. Xiang , D. X. Xiao , G. Xiao , Y. L. Xin , Y. Xing , D. R. Xiong , Z. Xiong , D. L. Xu , R. F. Xu , R. X. Xu , W. L. Xu , L. Xue , D. H. Yan , J. Z. Yan , T. Yan , C. W. Yang , C. Y. Yang , F. F. Yang , L. L. Yang , M. J. Yang , R. Z. Yang , W. X. Yang , Y. H. Yao , Z. G. Yao , X. A. Ye , L. Q. Yin , N. Yin , X. H. You , Z. Y. You , Y. H. Yu , Q. Yuan , H. Yue , H. D. Zeng , T. X. Zeng , W. Zeng , M. Zha , B. B. Zhang , B. T. Zhang , F. Zhang , H. Zhang , H. M. Zhang , H. Y. Zhang , J. L. Zhang , Li Zhang , P. F. Zhang , P. P. Zhang , R. Zhang , S. R. Zhang , S. S. Zhang , W. Y. Zhang , X. Zhang , X. P. Zhang , Yi Zhang , Yong Zhang , Z. P. Zhang , J. Zhao , L. Zhao , L. Z. Zhao , S. P. Zhao , X. H. Zhao , Z. H. Zhao , F. Zheng , W. J. Zhong , B. Zhou , H. Zhou , J. N. Zhou , M. Zhou , P. Zhou , R. Zhou , X. X. Zhou , X. X. Zhou , B. Y. Zhu , C. G. Zhu , F. R. Zhu , H. Zhu , K. J. Zhu , Y. C. Zou , X. Zuo

A near-infrared catalogue of the Galactic novae in the VVV survey area

Near-IR data of Classical Novae contain useful information about the ejected gas mass and the thermal emission by dust formed during eruption, and provide independent methods to classify the objects according to the colour of their…

Astrophysics of Galaxies · Physics 2015-06-15 R. K. Saito , D. Minniti , R. Angeloni , M. Catelan , J. C. Beamin , J. Borissova , I. Dekany , E. Kerins , R. Kurtev , R. E. Mennickent

High redshift quasars in the COSMOS survey: the space density of z>3 X-ray selected QSOs

We present a new measurement of the space density of high redshift (3.0<z<4.5), X-ray selected QSOs obtained by exploiting the deep and uniform multiwavelength coverage of the COSMOS survey. We have assembled a statistically large (40…

Astrophysics · Physics 2009-11-13 M. Brusa , A. Comastri , R. Gilli , G. Hasinger , K. Iwasawa , V. Mainieri , M. Mignoli , M. Salvato , G. Zamorani , A. Bongiorno , N. Cappelluti , F. Civano , F. Fiore , A. Merloni , J. Silverman , J. Trump , C. Vignali , P. Capak , M. Elvis , O. Ilbert , C. Impey , S. Lilly

Variables in the Southern Polar Region Evryscope 2016 Dataset

The regions around the celestial poles offer the ability to find and characterize long-term variables from ground-based observatories. We used multi-year Evryscope data to search for high-amplitude (~5% or greater) variable objects among…

Solar and Stellar Astrophysics · Physics 2019-07-10 Jeffrey K. Ratzloff , Henry T. Corbett , Nicholas M. Law , Brad N. Barlow , Amy Glazier , Ward S. Howard , Octavi Fors , Daniel del Ser , Trifon Trifonov

Gaia Data Release 3: Surface brightness profiles of galaxies and host galaxies of quasars

Since July 2014, the Gaia space mission has been continuously scanning the sky and observing the extragalactic Universe with unprecedented spatial resolution in the optical domain ($\sim$ 180 mas by the end of the mission). Gaia provides an…

Astrophysics of Galaxies · Physics 2023-06-21 C. Ducourant , A. Krone-Martins , L. Galluccio , R. Teixeira , J. -F. Le Campion , E. Slezak , R. de Souza , P. Gavras , F. Mignard , J. Guiraud , W. Roux , S. Managau , D. Semeux , A. Blazere , A. Helmer , D. Pourbaix

A Simple Method To Find All Lensed Quasars

We demonstrate that gravitationally lensed quasars are easily recognized using image subtraction methods as time variable sources that are spatially extended. For Galactic latitudes |b|>20 deg, lensed quasars dominate the population of…

Astrophysics · Physics 2009-11-13 C. S. Kochanek , B. Mochejska , N. D. Morgan , K. Z. Stanek

Joint Analysis of Optical, Near-Infrared And Mid-Infrared Variability of 4 Quasars at Redshift < 1

Amid rapid advances in time-domain astronomy, multi-wavelength (e.g., optical and infrared) time-domain studies of quasars remain scarce. Here we present a systematic analysis of four quasars initially selected by their Ks-band variability…

Astrophysics of Galaxies · Physics 2025-10-31 Lin Long , Zhen-ya Zheng , Ning Jiang , Chun Xu , Jiaqi Lin , Fang-Ting Yuan , Chunyan Jiang , Ruqiu Lin , Hai-Cheng Feng , Hengxiao Guo , Xiang Ji

New quasars behind the Magellanic Clouds. II. Spectroscopic confirmation of 136 near-infrared selected candidates

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.…

Astrophysics of Galaxies · Physics 2024-04-30 Valentin D. Ivanov , Maria-Rosa L. Cioni , Michel Dennefeld , Richard de Grijs , Jessica E. M. Craig , Jacco Th. van Loon , Clara Pennock , Chandreyee Maitra , Frank Haberl

The Sloan Digital Sky Survey Quasar Lens Search. II. Statistical Lens Sample from the Third Data Release

We report the first results of our systematic search for strongly lensed quasars using the spectroscopically confirmed quasars in the Sloan Digital Sky Survey (SDSS). Among 46,420 quasars from the SDSS Data Release 3 (~4188 deg^2), we…

Astrophysics · Physics 2008-11-26 Naohisa Inada , Masamune Oguri , Robert H. Becker , Min-Su Shin , Gordon T. Richards , Joseph F. Hennawi , Richard L. White , Bartosz Pindor , Michael A. Strauss , Christopher S. Kochanek , David E. Johnston , Michael D. Gregg , Issha Kayo , Daniel Eisenstein , Patrick B. Hall , Francisco J. Castander , Alejandro Clocchiatti , Scott F. Anderson , Donald P. Schneider , Donald G. York , Robert Lupton , Kuenley Chiu , Yozo Kawano , Ryan Scranton , Joshua A. Frieman , Charles R. Keeton , Tomoki Morokuma , Hans-Walter Rix , Edwin L. Turner , Scott Burles , Robert J. Brunner , Erin Scott Sheldon , Neta A. Bahcall , Masataka Fukugita

Measuring Quasar Variability with Pan-STARRS1 and SDSS

We measure quasar variability using the Panoramic Survey Telescope and Rapid Response System 1 Survey (Pan-STARRS1 or PS1) and the Sloan Digital Sky Survey (SDSS) and establish a method of selecting quasars via their variability in 10,000…

High Energy Astrophysical Phenomena · Physics 2015-06-22 E. Morganson , W. S. Burgett , K. C. Chambers , P. J. Green , N. Kaiser , E. A. Magnier , P. J. Marshall , J. S. Morgan , P. A. Price , H. -W. Rix , E. F. S Chlafly , J. L. Tonry , F. Walter

Variable stars in the dwarf irregular galaxy NGC 6822: the photometric catalogue

Deep B,V time-series photometry obtained with the ESO Very Large Telescope has been used to identify variable stars in the dwarf irregular galaxy NGC 6822. We surveyed a 6.8x6.8 arcmin area of the galaxy and detected a total number of 390…

Astrophysics · Physics 2009-11-10 L. Baldacci , L. Rizzi , G. Clementini , E. V. Held