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Related papers: Variability of Late-time Radio Emission in SLSN PT…

200 papers

We present multiwavelength observations of supernova (SN) 2017hcc with the Chandra X-ray telescope and the X-ray telescope onboard Swift (Swift-XRT) in X-ray bands, with the Spitzer and the TripleSpec spectrometer in near-infrared (IR) and…

High Energy Astrophysical Phenomena · Physics 2022-10-26 Poonam Chandra , Roger A. Chevalier , Nicholas J. H. James , Ori D. Fox

We searched a short-term radio variability in an active galactic nucleus PKS 1510-089. A daily flux monitoring for 143 days at 8.4 GHz was performed, and VLBI observations at 8.4, 22, and 43 GHz were carried out 4 times during the flux…

High Energy Astrophysical Phenomena · Physics 2017-02-22 Akiko Kadota , Kenta Fujisawa , Satoko Sawada-Satoh , Kiyoaki Wajima , Akihiro Doi

Magnetars have been considered as progenitors of magnetar giant flares (MGFs) and fast radio bursts (FRBs). We present detailed studies on afterglow emissions caused by bursts that occur in their wind nebulae and surrounding baryonic…

High Energy Astrophysical Phenomena · Physics 2023-08-10 Yujia Wei , B. Theodore Zhang , Kohta Murase

We investigate the radio afterglows of gamma-ray bursts (GRBs) and hypernovae (HNe) at high redshifts and quantify their detectability, as well as their potential usefulness for 21 cm absorption line studies of the intergalactic medium…

Astrophysics · Physics 2009-11-10 Kunihito Ioka , Peter Meszaros

We report on VLBI observations of supernova 1986J in the spiral galaxy NGC 891 at two new epochs, 1990 July and 1999 February, t=7.4 and 15.9 yr after the explosion, and on a comprehensive analysis of these and earlier observations from t~4…

Astrophysics · Physics 2009-11-07 M. F. Bietenholz , N. Bartel , M. P. Rupen

We present high sensitivity Very Long Baseline Interferometry (VLBI) observations 806 days after the gamma-ray burst of 2003 March 29 (GRB030329). The angular diameter of the radio afterglow is measured to be 0.347 +- 0.09 mas,…

Astrophysics · Physics 2010-11-11 Y. M. Pihlström , G. B. Taylor , J. Granot , S. Doeleman

We investigate the radio spectral energy distributions (SEDs) of young star-forming galaxies and how they evolve with time. The duration and luminosity of the nonthermal radio emission from supernova remnants (SNRs) are constrained by using…

Astrophysics · Physics 2009-11-11 H. Hirashita , L. K. Hunt

(abridged) We use the 1.4 GHz VIMOS-VLA Deep Survey and the optical VVDS and the CFHT-LS to compare the properties of radio loud galaxies with respect to the whole population of optical galaxies. The availability of multiband photometry and…

Some solar-type stars are known to present faint, time-variable radio continuum emission whose nature is not clearly established. We report on Jansky Very Large Array observations of the nearby star $\epsilon$ Eridani at 10.0 and 33.0 GHz.…

Solar and Stellar Astrophysics · Physics 2023-10-25 Luis F. Rodriguez , Susana Lizano , Jorge Canto , Ricardo F. Gonzalez

SN1993J in M81 is the best studied young radio-luminous supernova in the Northern Hemisphere. We recently reported results from the analysis of a complete set of VLBI observations of this supernova at 1.7, 2.3, 5.0, and 8.4 GHz, covering a…

High Energy Astrophysical Phenomena · Physics 2015-06-16 I. Marti-Vidal , J. M. Marcaide

At bright radio powers ($P_{\rm 1.4 GHz} > 10^{25}$ W/Hz) the space density of the most powerful sources peaks at higher redshift than that of their weaker counterparts. This paper establishes whether this luminosity-dependent evolution…

Astrophysics of Galaxies · Physics 2015-09-16 E. E. Rigby , J. Argyle , P. N. Best , D. Rosario , H. J. A. Röttgering

We present extensive optical observations of a Type IIn supernova (SN) 2010jl for the first 1.5 years after the discovery. The UBVRI light curves demonstrated an interesting two-stage evolution during the nebular phase, which almost flatten…

We present a complete numerical model of the afterglow of a laterally structured relativistic ejecta from the radio to very high energies (VHE). This includes a self-consistent calculation of the synchrotron radiation, with its maximum…

High Energy Astrophysical Phenomena · Physics 2024-11-05 Clément Pellouin , Frédéric Daigne

We report the discovery of a radio counterpart to GRB 990123. In contrast to previous well-studied radio afterglows which rise to peak flux on a timescale of a week and then decay over several weeks to months, the radio emission from this…

We have studied the flare characteristics of 55 AGN at 8 different frequency bands between 4.8 and 230 GHz. Our extensive database enables us to study the various observational properties of flares in these sources and compare our results…

Astrophysics · Physics 2009-11-13 T. Hovatta , E. Nieppola , M. Tornikoski , E. Valtaoja , M. F. Aller , H. D. Aller

We summarize results from flux density monitoring campaigns performed with the 100 meter radio-telescope at Effelsberg and the VLA during the past 15 yrs. We briefly discuss some of the statistical properties of the rapid variability from…

Astrophysics · Physics 2009-11-07 T. P. Krichbaum , A. Kraus , L. Fuhrmann , G. Cimo , A. Witzel

We present the results of an eight-year long monitoring of the radio emission from the Luminous Infrared Galaxy (LIRG) NGC 7469, using 8.4 GHz Very Large Array (VLA) observations at 0.3'' resolution. Our monitoring shows that the late time…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 M. A. Perez-Torres , A. Alberdi , L. Colina , J. M. Torrelles , N. Panagia , A. Wilson , E. Kankare , S. Mattila

We report here on 5 GHz global very-long-baseline interferometry (VLBI) observations of SN 1986J, 16 yr after its explosion. We obtained a high-resolution image of the supernova, which shows a distorted shell of radio emission, indicative…

We have carried out a multifrequency analysis of the radio variability of blazars, exploiting the data obtained during the extensive monitoring programs carried out at the University of Michigan Radio Astronomy Observatory (UMRAO, at 4.8,…

We report on a set of 5 GHz Urumqi observations of the galaxy M82, made between August 2005 and May 2009. From the resulting flux densities, we detect a strong flare, starting in March or April and peaking in June 2008. We identify this…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 N. Marchili , I. Marti-Vidal , A. Brunthaler , T. P. Krichbaum , P. Mueller , X. Liu , H. -G. Song , U. Bach , R. Beswick , J. A. Zensus