Search results for "radio astronomy"
showing 10 items of 28 documents
A search for short-period pulsars
1985
On utilise le radiotelescopede Parkes pour rechercher des pulsars de courte periode a 1,4 GHz de frequence. On trouve quatre nouveaux pulsar radio
The parkes Southern pulsar Survey -- I. Observing and data analysis systems and initial results
1996
'Australia Telescope National Facility, CSIRO, PO Box 76, Epping NSW 2121, Australia Wuffield Radio Astronomy Laboratories, University of Manchester, lodrell Bank, Macclesfield, Cheshire SKII 9DL 3Istituto di Radioastronomia del CNR, Via Gobetti 101, 40129 Bologna, Italy 4Istituto di Fisica dell'Universita, Via Archirafi 36, 90123 Palermo, Italy 'Research Centre for Theoretical Astrophysics, University of Sydney, NSW 2006, Australia 6Mount Stromlo and Siding Spring Observatories, Australian National University, Private Bag, Weston ACT 2611, Australia
PKS1830-211 HDO, ND and NH_2_D spectra
2020
VizieR online Data Catalogue associated with article published in journal Astronomy & Astrophysics with title 'Detection of deuterated molecules, but not of lithium hydride, in the z=0.89 absorber toward PKS 1830-211.' (bibcode: 2020A&A...637A...7M)
S5 0836+710 image at 1.6GHz
2012
VizieR online Data Catalogue associated with article published in journal Astronomy & Astrophysics with title 'S5 0836+710: An FRII jet disrupted by the growth of a helical instability?' (bibcode: 2012A&A...545A..65P)
BALDONE OBSERVATORY IN THE CIRCLES OF TIME
2019
1957 – The first laboratory building, known as the White House, was built near Baldone on the Riekstu hill, in the territory of the next Observatory. 01.01.1958 – The Astronomy Sector was separated from the Institute of Physics and commenced independent activi- ty as the Laboratory of Astrophysics at the Latvian Acade- my of Sciences (LAS). In 1967, with the decision of the Presidium of the Latvian SSR LAS the Laboratory of As- trophysics was transformed into the Radioastrophysic Ob- servatory at LAS. Under the leadership of the first director, Janis Ikaunieks, an instrumental observation base develops – a 1.2m Schmidt telescope was installed in 1966 for opti- cal observations. The project …
MOJAVE. VI. Kinematic analysis of blazar jets
2012
We discuss the jet kinematics of a complete flux-density-limited sample of 135 radio-loud active galactic nuclei (AGNs) resulting from a 13 year program to investigate the structure and evolution of parsec-scale jet phenomena. Our analysis is based on new 2cm Very Long Baseline Array (VLBA) images obtained between 2002 and 2007, but includes our previously published observations made at the same wavelength, and is supplemented by VLBA archive data. In all, we have used 2424 images spanning the years 1994-2007 to study and determine the motions of 526 separate jet features in 127 jets. Cone search capability for table J/AJ/138/1874/agn (AGN sample)
22GHz image of 3C 273
2017
RadioAstron is a 10m orbiting radio telescope mounted on the Spektr-R satellite, launched in 2011, performing Space Very Long Baseline Interferometry (SVLBI) observations supported by a global ground array of radio telescopes. With an apogee of ~350000km, it is offering for the first time the possibility to perform as-resolution imaging in the cm-band. The RadioAstron Active Galactic Nuclei (AGN) polarization Key Science Project (KSP) aims at exploiting the unprecedented angular resolution provided by RadioAstron to study jet launching/collimation and magnetic-field configuration in AGN jets. The targets of our KSP are some of the most powerful blazars in the sky. We present observations at…
LOFAR images of blazar S5 0836+710
2019
The emission and proper motion of the terminal hotspots of active galactic nucleus (AGN) jets can be used as a powerful probe of the intergalactic medium. However, measurements of hotspot advance speeds in active galaxies are difficult, especially in the young universe, because of the low angular velocities and the low brightness of distant radio galaxies. Our goal is to study the termination of an AGN jet in the young universe and to deduce physical parameters of the jet and the intergalactic medium. We used the LOw Frequency ARray (LOFAR) to image the long-wavelength radio emission of the high-redshift blazar S5 0836+710 on arcsecond scales between 120MHz and 160MHz. The LOFAR image shows…
S5 0836+710 Ground and Space VLBI images
2020
Detailed studies of relativistic jets in active galactic nuclei (AGN) require high-fidelity imaging at the highest possible resolution. This can be achieved using very long baseline interferometry (VLBI) at radio frequencies, combining worldwide (global) VLBI arrays of radio telescopes with a space-borne antenna on board a satellite. We present multiwavelength images made of the radio emission in the powerful quasar S5 0836+710, obtained using a global VLBI array and the antenna Spektr-R of the RadioAstron mission of the Russian Space Agency, with the goal of studying the internal structure and physics of the relativistic jet in this object. The RadioAstron observations at wavelengths of 18…
ALMA third image of lensed quasar PKS 1830-211
2020
Strong gravitational lensing distorts our view of sources at cosmological distances but brings invaluable constraints on the mass content of foreground objects and on the geometry and properties of the Universe. We report the detection of a third continuum source toward the strongly lensed quasar PKS 1830-211 in ALMA multi-frequency observations of high dynamic range and high angular resolution. This third source is point-like and located slightly to the north of the diagonal joining the two main lensed images, A and B, 0.3" away from image B. It has a flux density that is 140 times weaker than images A and B and a similar spectral index, compatible with synchrotron emission. We conclude th…