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We present new imaging observations of the remnant of Supernova (SN) 1987A at 44 GHz, performed in 2011 with the Australia Telescope Compact Array (ATCA). The $0\farcs35\times0\farcs23$ resolution of the diffraction-limited image is the…

High Energy Astrophysical Phenomena · Physics 2013-04-08 Giovanna Zanardo , L. Staveley-Smith , C. -Y. Ng , B. M. Gaensler , T. M. Potter , R. N. Manchester , A. K. Tzioumis

We present new radio observations of the binary neutron star merger GW170817 carried out with the Karl G. Jansky Very large Array (VLA) more than 3\,yrs after the merger. Our combined dataset is derived by co-adding more than…

We present deep 3.6 cm radio continuum observations of the HII region W40 obtained using the Very Large Array in its A and B configurations. We detect a total of 20 compact radio sources in a region of 4 x 4 arcmin, with 11 of them…

Astrophysics of Galaxies · Physics 2015-05-19 Luis F. Rodríguez , Steven A. Rodney , Bo Reipurth

Supernova 1987A in the Large Magellanic Cloud has proven a unique laboratory to investigate particle acceleration in young supernova remnants. Here we report the first detection of linear polarization of the supernova's synchrotron emission…

High Energy Astrophysical Phenomena · Physics 2018-07-18 Giovanna Zanardo , Lister Staveley-Smith , B. M. Gaensler , Remy Indebetouw , C. -Y. Ng , Mikako Matsuura , A. K. Tzioumis

We present the results of Karl G. Jansky Very Large Array (VLA) observations to study the properties of FR0 radio galaxies, the compact radio sources associated with early-type galaxies which represent the bulk of the local radio-loud AGN…

Astrophysics of Galaxies · Physics 2018-11-28 Ranieri D. Baldi , Alessandro Capetti , Gabriele Giovannini

We analyzed high angular resolution 45.5 GHz images of the W49 North massive star forming region obtained in 1998 and 2016 with the Very Large Array. Most of the ultracompact HII regions show no detectable changes over the time interval of…

Solar and Stellar Astrophysics · Physics 2020-03-04 Luis F. Rodriguez , Roberto Galvan-Madrid , Joel Sanchez-Bermudez , Christopher G. De Pree

The proximity of core-collapse Supernova 1987A (SN1987A) in the Large Magellanic Cloud (LMC) and its rapid evolution make it a unique case study of the development of a young supernova remnant. We aim at resolving the remnant of SN1987A for…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Masha Lakicevic , Giovanna Zanardo , Jacco Th. van Loon , Lister Staveley-Smith , Toby Potter , C. -Y. Ng , B. M. Gaensler

SDSSJ1539+3954 ($z\approx 1.935$), a radio-quiet weak-line quasar (WLQ), exhibited exceptional X-ray variability in 2019$-$2020, with its X-ray flux increasing by over 20 times from 2013 to 2019 and subsequently dropping by at least a…

The Andromeda galaxy (M\,31) hosts one of the nearest and most quiescent super-massive black holes, which provides a rare, but promising opportunity for studying the physics of black hole accretion at the lowest state. We have conducted a…

Astrophysics of Galaxies · Physics 2017-08-30 Yang Yang , Zhiyuan Li , Loránt O. Sjouwerman , Feng Yuan , Zhi-Qiang Shen

Modern radio telescopes are routinely reaching depths where normal starforming galaxies are the dominant observed population. Realising the potential of radio as a tracer of star formation and black hole activity over cosmic time involves…

Astrophysics of Galaxies · Physics 2020-07-01 I. Heywood , C. L. Hale , M. J. Jarvis , S. Makhathini , J. A. Peters , M. L. L. Sebokolodi , O. M. Smirnov

We present new spectroscopic observations of the southern radio galaxy PKS1549-79 (z =0.152).Despite the flat spectrum character of the radio emission from this source, our optical spectra show no sign of the broad permitted lines and…

Astrophysics · Physics 2009-11-06 C. Tadhunter , K. Wills , R. Morganti , T. Oosterloo , R. Dickson

We present Very Large Array (VLA) 8.5-GHz light curves of the two lens images of the Cosmic Lens All Sky Survey (CLASS) gravitational lens B1600+434. We find a nearly linear decrease of 18-19% in the flux densities of both lens images over…

Astrophysics · Physics 2007-05-23 L. V. E. Koopmans , A. G. de Bruyn , E. Xanthopoulos , C. D. Fassnacht

We present images of radio recombination lines (RRLs) at wavelengths around 17 cm from the star-forming region W49A to determine the kinematics of ionized gas in the THOR survey (The HI/OH/Recombination line survey of the inner Milky Way)…

We present Very Large Array (VLA) high resolution observations of the NH3(1,1) and NH3(2,2) molecular transitions towards the high mass star forming region AFGL 437. Our aim was to investigate if the poorly collimated CO molecular outflow…

Astrophysics of Galaxies · Physics 2015-06-03 G. Manjarrez , J. F. Gomez , I. de Gregorio-Monsalvo

We present 325 MHz (90 cm wavelength) radio observations of ultracool dwarfs TVLM 513-46546 and 2MASS J0036+1821104 using the Very Large Array (VLA) in June 2007. Ultracool dwarfs are expected to be undetectable at radio frequencies, yet…

Solar and Stellar Astrophysics · Physics 2012-01-31 T. R. Jaeger , R. A. Osten , T. J. Lazio , N. Kassim , R. L. Mutel

We present K-band spectra of newly born OB stars in the obscured Galactic giant H II region W51A and ~ 0.8'' angular resolution images in the J, H and K_S-bands. Four objects have been spectroscopically classified as O-type stars. The mean…

Astrophysics · Physics 2009-11-13 E. Figueredo , R. D. Blum , A. Damineli , P. S. Conti , C. L. Barbosa

RCW49 and its ionizing cluster form an extensive, complex region, widely studied at IR and optical wavelengths. Molonglo 843 MHz and ATCA data at 1.4 and 2.4 GHz showed two shells. Recent high-resolution IR imaging revealed a complex dust…

Optical CCD imaging and spectroscopic observations of three supernova remnants are presented. Optical emission from G 54.4-0.3 and G 59.8+1.2 is detected for the first time, while the first flux calibrated CCD images of the supernova…

Astrophysics · Physics 2009-11-11 P. Boumis , F. Mavromatakis , E. M. Xilouris , J. Alikakos , M. P. Redman , C. D. Goudis

Global VLBI observations at 5 GHz have been performed to study the source morphology in 10 compact steep-spectrum (CSS) sources selected from the Peacock & Wall catalogue with the aim of finding asymmetric structures produced by the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 D. Dallacasa , M. Orienti , C. Fanti , R. Fanti , C. Stanghellini

We report the results from a pilot search for radio recombination line (RRL) emission at millimeter wavelengths in a small sample of pre-planetary nebulae (pPNe) and young PNe (yPNe) with emerging central ionized regions. Observations of…

Solar and Stellar Astrophysics · Physics 2017-04-07 C. Sanchez Contreras , A. Baez-Rubio , J. Alcolea , V. Bujarrabal , J. Martin-Pintado