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相关论文: A view of the sub-mJy populations, modelling and p…

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This is the second of a series of three papers exploring the connection between the multiwavelength properties of AGN in nearby early-type galaxies and the characteristics of their hosts. In Capetti et al. (2005) we presented a study of the…

天体物理学 · 物理学 2009-11-11 B. Balmaverde , A. Capetti

We present a systematic analysis of the mid-infrared (MIR) properties of the youngest radio galaxies, based on low-resolution data provided by the {\it WISE} and {\it IRAS} satellites. We restrict our analysis to sources with available…

Discerning the exact nature of the sub-mJy radio population has been historically difficult due to the low luminosity of these sources at most wavelengths. Using deep ground based optical follow-up and observations from the Spitzer Space…

天体物理学 · 物理学 2009-11-13 N. Seymour , T. Dwelly , D. Moss , I. McHardy , A. Zoghbi , G. Rieke , M. Page , A. Hopkins , N. Loaring

Identifying the optical/near-infrared (NIR) counterparts to the distant submillimeter (submm) source population has proved difficult due to poor submm spatial resolution. However, the proportionality of both centimeter and submm data to the…

天体物理学 · 物理学 2007-05-23 A. J. Barger , L. L. Cowie , E. A. Richards

Deep combination radio observations at 1.4GHz with the VLA and MERLIN have imaged a region 10 arcminutes square surrounding the Hubble Deep Field North (HDF-N). Initial studies of the weak radio source population have shown that the…

天体物理学 · 物理学 2007-05-23 T. W. B. Muxlow , R. J. Beswick , H. Thrall , A. M. S Richards , S. T. Garrington , A. Pedlar

We present an analysis of deep mid- to far-infrared (MFIR) Spitzer photometric observations of the southern 2Jy sample of powerful radio sources (0.05 < z < 0.7), conducting a statistical investigation of the links between radio jet, AGN,…

天体物理学 · 物理学 2011-02-11 D. Dicken , C. Tadhunter , D. Axon , R. Morganti , K. J. Inskip , J. Holt , R. Gonzalez Delgado , B. Groves

Deep radio surveys show a population of very red counterparts of microjansky radio sources, which are unidentified to I = 25 in ground based images and I = 28.5 in the Hubble Deep Field. This population of optically faint radio sources,…

天体物理学 · 物理学 2007-05-23 K. I. Kellermann , E. A. Richards

In this paper we use a 50ks XMM-Newton pointing overlapping with the Phoenix Deep Survey, a homogeneous radio survey reaching muJy sensitivities, to explore the X-ray properties and the evolution of star-forming galaxies. UV, optical and…

天体物理学 · 物理学 2008-12-18 A. Georgakakis , A. M. Hopkins , M. Sullivan , J. Afonso , I. Georgantopoulos , B. Mobasher , L. E. Cram

Ultra-steep spectrum (USS) radio sources are good tracers of powerful radio galaxies at $z > 2$. Identification of even a single bright radio galaxy at $z > 6$ can be used to detect redshifted 21cm absorption due to neutral hydrogen in the…

Abridged. We present high-quality optical spectra for 12 powerful radio sources at low and intermediate redshifts (z < 0.7) that show evidence for a substantial UV excess. These data were taken using the WHT and VLT to determine the…

We separate the extragalactic radio source population above ~50 uJy into active galactic nuclei (AGN) and star-forming sources. The primary method of our approach is to fit the infrared spectral energy distributions (SEDs), constructed…

A complete sample of 96 faint ($S > 0.5$ mJy) radio galaxies is selected from the Tenth Cambridge (10C) survey at 15.7~GHz. Optical spectra are used to classify 17 of the sources as high-excitation or low-excitation radio galaxies (HERGs…

星系天体物理 · 物理学 2016-08-31 Imogen H. Whittam , Julia M. Riley , David A. Green , Matt J. Jarvis

It has been speculated that low luminosity radio-loud AGN have the potential to serve as an important source of AGN feedback, and may be responsible for suppressing star-formation activity in massive elliptical galaxies at late times. As…

宇宙学与河外天体物理 · 物理学 2015-06-17 K. McAlpine , M. J. Jarvis , D. G. Bonfield

Infrared-Faint Radio Sources (IFRS) represent an unexpected class of objects relatively bright at radio wavelength, but unusually faint at infrared (IR) and optical wavelengths. A recent and extensive campaign on the radio-brightest IFRSs…

We describe multi-frequency data designed to probe the emission mechanism that dominates in faint radio sources. Our analysis is based on observations of the Lockman Hole using the GMRT - the deepest 610-MHz imaging yet reported - together…

宇宙学与河外天体物理 · 物理学 2015-05-13 Edo Ibar , R. J. Ivison , A. D. Biggs , D. V. Lal , P. N. Best , D. A. Green

We have formed a new sample which consists of extended extragalactic radio sources without obvious active galactic nuclei (AGN) in them. Most of these sources appear to be dead double radio sources. These sources with steep spectra ($\alpha…

星系天体物理 · 物理学 2011-02-11 K. S. Dwarakanath , Ruta Kale

The radio properties of 11 obscured `radio-intermediate' quasars at redshifts z>~2 have been investigated using the European Very-Long-Baseline-Interferometry Network (EVN) at 1.66 GHz. A sensitivity of ~25 micro Jy per 14x17 mas2 beam was…

宇宙学与河外天体物理 · 物理学 2015-05-13 H. -R. Kloeckner , A. Martinez-Sansigre , S. Rawlings , M. A. Garrett

We present deep L-Band observations of the equatorial field centered on the z=6.3 SDSS QSO, reaching a 1 sigma sensitivity of ~2.5 uJy at the center of the field. We extracted a catalog of 1489 radio sources down to a flux density of ~12.5…

We report the results of high-resolution 5 GHz Very Long Baseline Array and European VLBI Network observations of 36 nearby galaxies, an extension of the Legacy e-MERLIN Multi-band Imaging of Nearby Galaxies (LeMMINGs) survey. Our sample…

We use a physically motivated semi-analytic model, based on the mass function of dark matter halos, to predict the number of radio-loud quasars as a function of redshift and luminosity. Simple models in which the central BH mass scales with…

天体物理学 · 物理学 2009-11-10 Zoltan Haiman , Eliot Quataert , Geoffrey C. Bower