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相关论文: Spectral index properties of milliJansky radio sou…

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We present the low frequency (610 MHz) radio source counts of the VVDS-VLA field and investigate the radio spectral index properties of the sub-mJy population. We use new deep (r.m.s.$\simeq 50$ $\mu$Jy/beam) observations of the VVDS-VLA…

We have studied a sample of 296 faint (> 0.5 mJy) radio sources selected from an area of the Tenth Cambridge (10C) survey at 15.7 GHz in the Lockman Hole. By matching this catalogue to several lower frequency surveys (e.g. including a deep…

宇宙学与河外天体物理 · 物理学 2013-02-06 I. H. Whittam , J. M. Riley , D. A. Green , M. J. Jarvis , I. Prandoni , G. Guglielmino , R. Morganti , H. J. A. Röttgering , M. A. Garrett

The redshift distribution of flat-spectrum radio sources with 5 GHz flux densities S>5 mJy is a key component in using current radio lens surveys to probe the cosmological model. We have constructed the first flat-spectrum radio sample in…

天体物理学 · 物理学 2009-11-07 J. A. Munoz , E. E. Falco , C. S. Kochanek , J. Lehar , E. Mediavilla

We use the recent releases of sensitive VLA/LOFAR large-area surveys at 340 MHz and 54 MHz, in conjunction with the 1.4 GHz NVSS, to accurately determine the `spectral index - flux density relation' ($\alpha$ - S) for extragalactic radio…

星系天体物理 · 物理学 2023-07-05 Pratik Dabhade , Gopal-Krishna

[Abridged] The nature and evolutionary properties of the faint radio population, responsible for the steepening observed in the 1.4 GHz source counts below 1 milliJy, are not yet entirely clear. Radio spectral indices may help to constrain…

天体物理学 · 物理学 2009-11-11 I. Prandoni , P. Parma , M. H. Wieringa , H. R. de Ruiter , L. Gregorini , A. Mignano , G. Vettolani , R. D. Ekers

Infrared-faint radio sources (IFRS) are objects that have flux densities of several mJy at 1.4GHz, but that are invisible at 3.6um when using sensitive Spitzer observations with uJy sensitivities. Their nature is unclear and difficult to…

As a constraint for new starburst/AGN models of IRAS bright galaxies we determine the radio spectra of 31 luminous and ultraluminous IRAS galaxies (LIRGs/ULIRGs). We construct the radio spectra using both new and archival data. From our…

天体物理学 · 物理学 2009-11-13 M. S. Clemens , O. Vega , A. Bressan , G. L. Granato , L. Silva , P. Panuzzo

(abridged) We present multiwavelength observations for a large sample of microjansky radio sources detected in ultradeep 1.4GHz maps centered on the Hubble Deep Field-North (HDF-N) and the Hawaii Survey Fields SSA13 and SSA22. Our…

This is the first of a series of papers based on sensitive 610 MHz observations of the ELAIS N1 field using the Giant Metrewave Radio Telescope. We describe the observations, processing and source catalogue extraction from a deep image with…

星系天体物理 · 物理学 2019-11-06 E. F. Ocran , A. R. Taylor , M. Vaccari , C. H. Ishwara-Chandra , I. Prandoni

Understanding the spectral properties of sources is crucial for the characterization of the radio source population. In this work, we have extensively studied the ELAIS N1 field using various low-frequency radio observations. For the first…

星系天体物理 · 物理学 2023-08-11 Akriti Sinha , Sarvesh Mangla , Abhirup Datta

We have conducted a deep radio survey with the Very Large Array at 1.4 GHz of a region containing the Hubble Deep Field. This survey overlaps previous observations at 8.5 GHz allowing us to investigate the radio spectral properties of…

天体物理学 · 物理学 2009-10-31 E. A. Richards

A detailed understanding of how the activity of a galactic nucleus regulates the growth of its host is still missing. To understand the activity and the types of accretion of supermassive black holes in different hosts, it is essential to…

By combining high-sensitivity LOFAR 150MHz, uGMRT 400MHz and 1,250MHz, GMRT 610MHz, and VLA 5GHz data in the ELAIS-N1 field, we study the radio spectral properties of radio-detected star-forming galaxies (SFGs) at observer-frame frequencies…

Star forming galaxies are thought to dominate the sub-mJy radio population, but recent work has shown that low luminosity AGN can still make a significant contribution to the faint radio source population. Spectral indices are an important…

宇宙学与河外天体物理 · 物理学 2015-06-11 M. T. Huynh , A. M. Hopkins , E. Lenc , M. Y. Mao , E. Middelberg , R. P. Norris , K. E. Randall

We present the results from two radio integrations at 8.4 GHz using the VLA. One of the fields, at 13h,+43d (SA13 field), has an rms noise level of 1.49 microJy and is the deepest radio image yet made. Thirty-four sources in a complete…

天体物理学 · 物理学 2009-11-07 E. B. Fomalont , K. I. Kellermann , R. B. Partridge , R. A. Windhorst , E. A. Richards

One of the most debated issues about sub-mJy radio sources, which are responsible for the steepening of the 1.4 GHz source counts, is the origin of their radio emission. Particularly interesting is the possibility of combining radio…

天体物理学 · 物理学 2009-11-13 A. Mignano , I. Prandoni , L. Gregorini , P. Parma , H. R. de Ruiter , M. H. Wieringa , G. Vettolani , R. D. Ekers

To explore the high frequency radio spectra of galaxies in clusters, we used NRAO's Very Large Array at four frequencies, 4.9-43 GHz, to observe 139 galaxies in low redshift (z<0.25), X-ray detected, clusters. The clusters were selected…

The search for compact components of strong ($S_{int} \ge 5$ Jy at 102.5 MHz) discrete radio sources from the Pushchino catalogue was carried out using the method of interplanetary scintillation. A total of 3620 sources were examined, and…

高能天体物理现象 · 物理学 2022-07-18 S. A. Tyul'bashev , I. V. Chashei , I. A. Subaev , M. A. Kitaeva

Infrared-faint radio sources (IFRSs) are a rare class of object which are relatively bright at radio wavelengths but very faint at infrared and optical wavelengths. Here we present sensitive near-infrared observations of a sample of these…

Radio surveys with the Australia Telescope Compact Array have been carried out at 1.4 and 2.4 GHz with a limiting flux of 0.2 mJy at each frequency in the Marano Field, in which deep optical and X-ray (ROSAT) data are also available. In…

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