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Related papers: First Results from MASIV: The Micro-Arcsecond Scin…

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This paper presents the results of the 2009-2010 monitoring sessions of the starburst galaxy M82, obtained with the Multi-Element Radio-Linked Interferometer Network (MERLIN) at 5GHz and e-MERLIN at 6GHz. Combining several 5GHz MERLIN…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 M. A. Gendre , D. M. Fenech , R. J. Beswick , T. W. B. Muxlow , M. K. Argo

The X-ray source 3XMM~J150052.0+015452 was discovered as a spectacular tidal disruption event candidate during a prolonged ($>11$ yrs) outburst (Lin et al. 2017). It exhibited unique quasi-soft X-ray spectra of characteristic temperature…

We have shown previously that a broad correlation between the peak radio luminosity and the variability time-scales, approximately L ~ t^5, exists for variable synchrotron emitting sources and that different classes of astrophysical source…

High Energy Astrophysical Phenomena · Physics 2017-08-30 M. Pietka , T. D. Staley , M. L. Pretorius , R. P. Fender

We present a study of scintillation induced by the mid-latitude ionosphere. By implementing methods currently used in Interplanetary Scintillation studies to measure amplitude scintillation at low frequencies, we have proven it is possible…

Instrumentation and Methods for Astrophysics · Physics 2022-09-14 A. Waszewski , J. Morgan , C. H. Jordan

We demostrate that the measurement of fluctuations of polarization due to the galactic interstellar scintillations may be used to study the structure of the radiation field at compact radio sources. We develop a mathematical formalism and…

Astrophysics · Physics 2009-10-31 Mikhail V. Medvedev

We aim to search for evidence of annual modulation in the time scales of the BL Lac object S5 0716+714. The intra-day variability (IDV) observations were carried out monthly from 2005 to 2009, with the Urumqi 25m radio telescope at 4.8 GHz.…

High Energy Astrophysical Phenomena · Physics 2012-07-12 X. Liu , H. -G. Song , N. Marchili , B. -R. Liu , J. Liu , T. P. Krichbaum , L. Fuhrmann , J. A. Zensus

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…

We use the multi-epoch, mid-infrared Spitzer Deep, Wide-Field Survey to investigate the variability of 474,179 objects in 8.1 deg^2 of the NDWFS Bootes field. We perform a Difference Image Analysis of the four available epochs between 2004…

To locate and image the compact emission regions in quasars, which are closely connected to the phenomenon of IntraDay Variability (IDV), space VLBI observations are of prime importance. Here we report on VSOP observations of two prominent…

We present the first observations of magnetic cataclysmic variables with the Spitzer Space Telescope. We used the Infrared Array Camera to obtain photometry of the polars EF Eri, GG Leo, V347 Pav, and RX J0154.0-5947 at 3.6, 4.5, 5.8, and…

r-mode oscillations have been shown to have a significant potential to constrain the composition of fast spinning neutron stars. Due to their high rotation rates, millisecond pulsars (MSPs) provide a unique platform to constrain the…

High Energy Astrophysical Phenomena · Physics 2020-10-21 Tuğba Boztepe , Ersin Göğüs , Tolga Güver , Kai Schwenzer

I model the multi-phase interstellar medium (ISM) randomly heated and shocked by supernovae, with gravity, differential rotation and other parameters we understand to be typical of the solar neighbourhood. The simulations are 3D extending…

Astrophysics of Galaxies · Physics 2017-12-15 Frederick Gent

We have observed an area of approximatley 27 deg^2 to an rms noise level of less than 0.2 mJy at 15.7 GHz, using the Arcminute Microkelvin Imager Large Array. These observations constitute the most sensitive radio-source survey of any…

We derive the distribution of flux density of a compact source exhibiting strong diffractive scintillation. Our treatment accounts for arbitrary spectral averaging, spatially-extended source emission, and the possibility of intrinsic…

Instrumentation and Methods for Astrophysics · Physics 2012-08-09 Michael D. Johnson , Carl R. Gwinn

We present new radio observations of the large-separation gravitationally-lensed quasar SDSS J1004+4112, taken in a total of 6 hours of observations with the Extended Very Large Array (EVLA). The maps reach a thermal noise level of…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-18 Neal Jackson

Aims. The analysis of variability of astronomical sources is of extraordinary interest, as it allows the study of astrophysical phenomena in real time. This paper presents the Javalambre Variability Survey (J-VAR) which leverages the narrow…

The intra-day variable source 0917+624 displays annual changes in its timescale of variability. This is explained in terms of a scintillation model in which changes in the variability timescale are due to changes in the relative velocity of…

Astrophysics · Physics 2009-11-06 D. L. Jauncey , J. -P. Macquart

We report results based on the monitoring of the BL Lac object Mrk 501 in the optical (B, V and R) passbands from March to May 2000. Observations spread over 12 nights were carried out using 1.2 meter Mount Abu Telescope, India and 61 cm…

Astrophysics · Physics 2009-06-23 A. C. Gupta , W. G. Deng , U. C. Joshi , J. M. Bai , M. G. Lee

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

The precision of intensity measurements of the extragalactic X-ray Background (XRB) on an angular scale of about a degree is dominated by spatial fluctuations caused by source confusion noise. X-ray source counts at the flux level…

Astrophysics · Physics 2009-10-30 X. Barcons , A. C. Fabian , F. J. Carrera