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相关论文: A survey of Low Luminosity Compact sources

200 篇论文

We report an ASKAP search for associated HI 21-cm absorption against bright radio sources from the Molonglo Reference Catalogue (MRC) 1-Jy sample. The search uses pilot survey data from the ASKAP First Large Absorption Survey in \hi (FLASH)…

A sample of high-frequency peaker (HFP) candidates was formed from the AT20G catalog radio sources with spectral indices of the optically thick emission region $\alpha_{below}$ exceeding +0.5. A study of the spectral properties of the…

宇宙学与河外天体物理 · 物理学 2025-08-12 Elena Majorova , Olga Zhelenkova

Evidence has been mounting recently that activity in some radio-loud AGNs (RLAGNs) can cease shortly after ignition and that perhaps even a majority of very compact sources may be short-lived phenomena because of a lack of stable fuelling…

天体物理学 · 物理学 2009-11-11 Magdalena Kunert-Bajraszewska , Andrzej Marecki , Peter Thomasson

We discuss our current understanding of the nature of the faint, high-frequency radio sky. The Tenth Cambridge (10C) survey at 15.7 GHz is the deepest high-frequency radio survey to date, covering 12 square degrees to a completeness limit…

星系天体物理 · 物理学 2016-03-01 Imogen H. Whittam , Julia M. Riley , David A. Green , Matt J. Jarvis

Using a nondegenerate four-wave mixing (FWM) process based on a double-{\Lambda} scheme in hot cesium vapor, we demonstrate a compact diode-laser-pumped quantum light source for the generation of quantum correlated twin beams with a maximum…

量子物理 · 物理学 2018-03-09 Rong Ma , Wei Liu , Zhongzhong Qin , Xiaolong Su , Xiaojun Jia , Junxiang Zhang , Jiangrui Gao

We address the question of why low-luminosity radio sources with similar flat radio spectra show a range of optical activity. The investigation is based on the spectral energy distributions (SEDs) of objects from the 200 mJy sample. We…

天体物理学 · 物理学 2015-06-11 S. Anton , I. W. A. Browne , M. J. M. Marcha , M. Bondi , A. Polatidis

Unlike at lower redshift, where there is a 40% detection rate, surveys for 21-cm absorption arising within the hosts of z > 1 radio galaxies and quasars have been remarkably unsuccessful. Curran et al.(2008) suggest that this is due to the…

宇宙学与河外天体物理 · 物理学 2015-06-11 S. J. Curran , M. T. Whiting , E. M. Sadler , C. Bignell

We present results of multifrequency polarimetric VLBA observations of 34 compact radio sources. The observations are part of a large survey undertaken to identify CSOs Observed in the Northern Sky (COINS). Compact Symmetric Objects (CSOs)…

天体物理学 · 物理学 2009-10-31 A. B. Peck , G. B. Taylor

We present a radio survey carried out with the Australia Telescope Compact Array. A motivation for the survey was to make a complete inventory of the diffuse emission components as a step towards a study of the cosmic evolution in radio…

宇宙学与河外天体物理 · 物理学 2015-05-14 R. Subrahmanyan , R. D. Ekers , L. Saripalli , E. M. Sadler

We present e-MERLIN and EVN observations which reveal unambiguous jet activity within radio quiet quasar HS~0810+2554. With an intrinsic flux density of 880~nJy, this is the faintest radio source ever imaged. The findings present new…

星系天体物理 · 物理学 2019-03-06 P. Hartley , N. Jackson , D. Sluse , H. R. Stacey , H. Vives-Arias

We have analyzed sensitive high spatial resolution archival radio continuum data at 1.3, 2.0, 3.6 and 6.0 cm as well as the H2O maser molecular line data obtained using the Very Large Array (VLA) in its hybrid AB configuration toward the…

天体物理学 · 物理学 2009-11-13 Luis A. Zapata , Silvia Leurini , Karl M. Menten , Peter Schilke , Rainer Rolffs , Carolin Hieret

There is quite a clear anticorrelation between the intrinsic peak frequency and the overall radio source size in Compact Steep Spectrum (CSS) and GHz Peaked Spectrum (GPS) radio sources as shown by O'Dea (1998). This feature is interpreted…

天体物理学 · 物理学 2009-11-07 Daniele Dallacasa

We present sub-arcsecond resolution multi-frequency (8 and 22 GHz) VLA images of five low power compact (LPC) radio sources, and phase referenced VLBA images at 1.6 GHz of their nuclear regions. At the VLA resolution we resolve the…

天体物理学 · 物理学 2009-11-11 M. Giroletti , G. Giovannini , G. B. Taylor

Several samples have been proposed in the last years in order to study the properties of intrinsically small sources. In this paper, we review the properties of the main samples that are currently available, both selected on the basis of…

宇宙学与河外天体物理 · 物理学 2011-08-31 M. Giroletti , A. Polatidis

We present Very Large Array observations at 1.4 and 5 GHz of a sample of 16 quasi-stellar objects (QSOs) at z = 1.78 to 2.71. Half of the chosen quasars are bright at mm wavelengths (250 or 350 GHz) while the other half were not detected at…

天体物理学 · 物理学 2008-11-26 A. Petric , C. L. Carilli , F. Bertoldi , A. Beelen , P. Cox , A. Omont

Data from the Spitzer Space Telescope (the First Look Survey - FLS) have recently been made public. We have compared the 24 micron images with very deep WSRT 1.4 GHz observations (Morganti et al. 2004), centred on the FLS verification strip…

天体物理学 · 物理学 2007-05-23 M. Orienti , M. A. Garrett , C. Reynolds , R. Morganti

Compact Symmetric Objects (CSOs) show radio features such as jets, lobes, hot spots that are contained within the central 1 kpc region of their host galaxy. Thus, they are thought to be among the progenitors of large-scale radio galaxies. A…

Using the Alternative Data Release of the TIFR GMRT Sky Survey (TGSS), we studied the low-frequency properties of FR0 radio galaxies, the large population of compact radio sources associated with red massive early-type galaxies revealed by…

星系天体物理 · 物理学 2019-11-20 Alessandro Capetti , Ranieri D. Baldi , Marisa Brienza , Raffaella Morganti , Gabriele Giovannini

We present a comprehensive multi-frequency catalogue of radio sources behind the Large Magellanic Cloud between 0.2 and 20 GHz, gathered from a combination of new and legacy radio continuum surveys. This catalogue covers an area of…

The compact steep spectrum (CSS) and gigahertz peaked spectrum (GPS) sources are widely believed to be young radiosources, with ages <10^6 yr. If the activity in the nucleus is fuelled by the supply of gas, one might find evidence of this…

天体物理学 · 物理学 2009-11-07 D. J. Saikia , S. Jeyakumar , F. Mantovani , C. J. Salter , R. E. Spencer , P. Thomasson , P. J. Wiita