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Related papers: Kinematic Age Estimates for 4 Compact Symmetric Ob…

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We have studied the kinematics traced by the water masers located at the centre of the planetary nebula (PN) K3-35, using data from previous Very Large Array (VLA) observations. An analysis of the spatial distribution and line-of-sight…

Here we discuss evolution and broad-band emission of compact (< kpc) lobes in young radio sources. We propose a simple dynamical description for these objects, consisting of a relativistic jet propagating into a uniform gaseous medium in…

Astrophysics · Physics 2009-11-13 L. Stawarz , L. Ostorero , M. C. Begelman , R. Moderski , J. Kataoka , S. Wagner

We aim at a detailed description of the kinematic properties of the old, (several Gyrs) late-type CO-absorption star population among the Galactic centre (GC) cluster stars. We applied AO-assisted, near-infrared imaging and integral-field…

We report on a VLBA imaging study of the nearby bright southern blazar PKS 1921 - 293 (OV - 236). High resolution VLBA observations, made at four frequencies (5, 12, 15, and 43 GHz) over the period 1994 - 2000, have revealed a strongly…

Astrophysics · Physics 2007-05-23 Z. -Q. Shen , J. M. Moran , K. I. Kellermann

A direct measurement of the expansion of W 3(OH) is made by comparing Very Large Array images taken about 10 yr apart. The expansion is anisotropic with a typical speed of 3 to 5 km/s, indicating a dynamical age of only 2300 yr. These…

Astrophysics · Physics 2009-10-30 Jonathan H. Kawamura , Colin R. Masson

We report on analysis of X-ray, optical and radio observations of the previously overlooked X-ray source 2CXO\,J174517.0$-$321356 located just 3.2$^{\circ}$ away from the Galactic center. Timing analysis of X-ray observations of the source…

High Energy Astrophysical Phenomena · Physics 2023-09-13 Hang Gong

Compact Symmetric Objects (CSOs) are thought to represent the first step in the evolutionary path of radio galaxies. In this work, we investigate the X-ray emission of two CSOs confirmed to emit at GeV energies: PKS 1718-649 and TXS…

High Energy Astrophysical Phenomena · Physics 2024-01-31 E. Bronzini , G. Migliori , C. Vignali , M. Sobolewska , Ł. Stawarz , A. Siemiginowska , M. Orienti , F. D'Ammando , M. Giroletti , G. Principe , K. Balasubramaniam

We want to understand the kinematic and thermal properties of young massive gas clumps prior to and at the earliest evolutionary stages of high-mass star formation. Do we find signatures of gravitational collapse? Do we find temperature…

Solar and Stellar Astrophysics · Physics 2015-07-01 S. Bihr , H. Beuther , H. Linz , S. E. Ragan , M. Hennemann , J. Tackenberg , R. J. Smith , O. Krause , Th. Henning

Density perturbations at the decoupling epoch produce angular fluctuations in the temperature of the Cosmic Microwave Background (CMB) radiation that may appear as hot and cold spots. Observational data of the CMB includes instrumental…

Astrophysics · Physics 2009-10-28 Laura Cayon , George Smoot

We present sensitive ($\sigma<10{\rm \mu Jy \, beam^{-1}}$), radio continuum observations using the Australian telescope compact array (ATCA) at frequencies of $6$ and $9$ GHz towards 4 MYSOs. From a previous, less sensitive work, these…

Astrophysics of Galaxies · Physics 2018-09-27 S. J. D. Purser , S. L. Lumsden , M. G. Hoare , N. Cunningham

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

Using multi-epoch VLA observations, covering a time baseline of 29.1 years, we have measured the proper motions of 88 young stars with compact radio emission in the core of the Orion Nebula Cluster (ONC) and the neighboring BN/KL region.…

The remarkable astrometric capabilities of Chandra offer the possibility to measure proper motions of X-ray sources with an unprecedented accuracy in this wavelength range. We recently completed a proper motion survey of three of the seven…

High Energy Astrophysical Phenomena · Physics 2009-11-13 C. Motch , A. M. Pires , F. Haberl , A. Schwope , V. E. Zavlin

We are carrying out multi-frequency radio continuum observations, using the Australia Telescope Compact Array, to systematically search for collimated ionized jets towards high-mass young stellar objects (HMYSOs). Here we report…

Solar and Stellar Astrophysics · Physics 2012-06-15 Andrés E. Guzmán , Guido Garay , Kate J. Brooks , Maxim A. Voronkov

We report the results of a 15 GHz (2 cm) multi-epoch VLBA program, begun in 1994 to study the outflow in radio jets ejected from quasars and active galaxies. The observed flow of 208 distinct features measured in 110 quasars, active…

Compact Symmetric Objects (CSO) are considered to be the young version of Fanaroff-Riley type I and type II radio galaxies, with typical sizes smaller than 1 kpc and ages of the order of a few thousand years. Before the launch of the Fermi…

High Energy Astrophysical Phenomena · Physics 2019-08-14 F. D'Ammando , M. Orienti , M. Giroletti

Extended radio emission detected around a sample of GHz Peaked Spectrum (GPS) radio sources is discussed. Evidence for extended emission which is related to the GPS source is found in 6 objects out of 33. Three objects are associated with…

Astrophysics · Physics 2009-11-11 C. Stanghellini , C. P. O'Dea , D. Dallacasa , P. Cassaro , S. A. Baum , R. Fanti , C. Fanti

We observed the thirteen extragalactic radio sources of the complete S5 polar cap sample at 15.4 GHz with the Very Long Baseline Array, on 27 July 1999 (1999.57) and 15 June 2000 (2000.46). We present the maps from those two epochs, along…

Astrophysics · Physics 2007-05-23 M. A. Perez-Torres , J. M. Marcaide , J. C. Guirado , E. Ros

We present an improved proper motion measurement of the central compact object RX J0822-4300, located in the supernova remnant Puppis A. By employing a new data set taken in February 2019 by the High Resolution Camera aboard the Chandra…

High Energy Astrophysical Phenomena · Physics 2020-09-02 Martin Mayer , Werner Becker , Daniel Patnaude , P. Frank Winkler , Ralph Kraft

Multifrequency VLBA observations of the final group of ten objects in a sample of FIRST-based compact steep spectrum (CSS) sources are presented. The sample was selected to investigate whether objects of this kind could be relics of…

Astrophysics · Physics 2009-11-13 Magdalena Kunert-Bajraszewska , Andrzej Marecki