English
Related papers

Related papers: Millijansky Radio Variability in SDSS Stripe 82

200 papers

We present the results of a 2-epoch variability survey in the Hubble Deep Field with the goal of investigating the population of AGN to z=1. The primary data sets analyzed for galactic variability are the original HDF observations obtained…

Astrophysics · Physics 2009-11-10 Vicki L. Sarajedini , Ronald L. Gilliland , Christina Kasm

We provide a quantitative description and statistical interpretation of the optical continuum variability of quasars. The Sloan Digital Sky Survey (SDSS) has obtained repeated imaging in five UV-to-IR photometric bands for 33,881…

The optically variable source SDSS J124602.54+011318.8 first appears in Sloan Digital Sky Survey (SDSS) data as a bright point source with nonstellar colors. Subsequent SDSS imaging and spectroscopy showed that the point source declined or…

Astrophysics · Physics 2009-11-07 Avishay Gal-Yam , Eran O. Ofek , Alexei V. Filippenko , Ryan Chornock , Weidong Li

We present a catalog of 110 variable stars within ~1' of Sgr A* based on image subtraction of near-infrared (H and K) photometry. Our images were obtained over 133 nights from 2000--2002 in H-band and over 134 nights from 2001--2002 in…

Astrophysics · Physics 2007-08-06 Molly S. Peeples , K. Z. Stanek , D. L. DePoy

Short time-scale radio variations of compact extragalactic radio quasars and blazars known as IntraDay Variability (IDV) can be explained in at least some sources as a propagation effect; the variations are interpreted as scintillation of…

We report quasi-simultaneous GMRT observations of seven extragalactic radio sources at 150, 325, 610 and 1400 MHz, in an attempt to accurately define their radio continuum spectra, particularly at frequencies below the observed spectral…

Astrophysics of Galaxies · Physics 2019-02-13 Mukul Mhaskey , Gopal-Krishna , Pratik Dabhade , Surajit Paul , Sameer Salunkhe , S. K. Sirothia

This is the third in a series of papers that present observations and results for a sample of 76 ultra-steep-spectrum radio sources designed to find galaxies at high redshift. Here we present multi-frequency radio observations, from the…

Astrophysics · Physics 2009-11-11 I. J. Klamer , R. D. Ekers , J. J. Bryant , R. W. Hunstead , E. M. Sadler , C. De Breuck

The compact radio source Sgr\,A*, associated with the super massive black hole at the center of the Galaxy, has been studied with VLBA observations at 3 frequencies (22, 43, 86\,GHz) performed on 10 consecutive days in May 2007. The total…

Astrophysics of Galaxies · Physics 2015-05-20 R. -S. Lu , T. P. Krichbaum , A. Eckart , S. König , D. ~Kunneriath , G. Witzel , A. Witzel , J. A. Zensus

We present new, simultaneous, multifrequency observations of 45 out of the 55 candidate High Frequency Peakers (HFP) selected by Dallacasa et al. (2000), carried out 3 to 4 years after a first set of observations. Our sub-sample consists of…

Astrophysics · Physics 2009-11-10 S. Tinti , D. Dallacasa , G. De Zotti , A. Celotti , C. Stanghellini

We have obtained single-epoch optical photometry for 201 quasars, taken from the FIRST Bright Quasar Survey, which span a wide range in radio loudness. Comparison with the magnitudes of these objects on the POSS-I plates provides by far the…

We present the first results of a wide area X-ray survey within the Sloan Digital Sky Survey (SDSS) Stripe 82, a 300 deg$^2$ region of the sky with a substantial investment in multi-wavelength coverage. We analyzed archival {\it Chandra}…

Deep combination radio observations at 1.4GHz with the VLA and MERLIN have imaged a region 10 arcminutes square surrounding the Hubble Deep Field North (HDF-N). Initial studies of the weak radio source population have shown that the…

Astrophysics · Physics 2007-05-23 T. W. B. Muxlow , R. J. Beswick , H. Thrall , A. M. S Richards , S. T. Garrington , A. Pedlar

We present 1 - 12 GHz Karl G. Jansky Very Large Array observations of 9 off-nuclear persistent radio sources (PRSs) in nearby (z < 0.055) dwarf galaxies, along with high-resolution European very-long baseline interferometry (VLBI) Network…

We present a catalog of Faraday rotation measures (RMs) and redshifts for 4003 extragalactic radio sources detected at 1.4 GHz, derived by identifying optical counterparts and spectroscopic redshifts for linearly polarized radio sources…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-02 Alison M. Hammond , Timothy Robishaw , B. M. Gaensler

We report the discovery of a mid-infrared variable AGN which is hosted by an ultraluminous infrared galaxy (ULIRG) candidate in the Sloan Stripe 82 field. \textit{WISE} \textit{J030654.88+010833.6} is a red, extended galaxy, which we…

We use mid-infrared variability in galaxies to search for active galactic nuclei (AGN) in the local universe. We use a sample of 10,220 galaxies from the Mapping Nearby Galaxies at APO (MaNGA) survey, part of the Sloan Digital Sky Survey…

Astrophysics of Galaxies · Physics 2024-12-09 Aashay Pai , Michael R. Blanton , John Moustakas

Radio activity has been observed in a large variety of stellar objects, including in the last few years, ultra-cool dwarfs. To explore the extent of long-term radio activity in ultra-cool dwarfs, we use data taken over an extended period of…

Astrophysics · Physics 2009-11-13 A. Antonova , J. G. Doyle , G. Hallinan , A. Golden , C. Koen

We have formed a complete sample of 26 low redshift (z < 0.3) giant radio galaxies (GRGs) from the WENSS survey, selected at flux densities above 1 Jy at 325 MHz. We present 10.5-GHz observations with the 100-m Effelsberg telescope of 18…

The spectral variability of a sample of 44 flat-spectrum radio quasars (FSRQs) and 18 steep-spectrum radio quasars (SSRQs) in the SDSS stripe 82 region is investigated. Twenty-five of 44 FSRQs show a bluer-when-brighter trend (BWB), while…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Minfeng Gu

The low-frequency polarisation properties of radio sources are poorly studied, particularly in statistical samples. However, the new generation of low-frequency telescopes, such as the Murchison Widefield Array (MWA; the precursor for the…