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相关论文: Sensitive Search For Radio Variables And Transient…

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We present the evolutionary properties and luminosity functions of the radio sources belonging to the Chandra Deep Field South VLA survey, which reaches a flux density limit at 1.4 GHz of 43 microJy at the field center and redshift ~5, and…

宇宙学与河外天体物理 · 物理学 2015-05-28 P. Padovani , N. Miller , K. I. Kellermann , V. Mainieri , P. Rosati , P. Tozzi

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

We report on the results of a search for radio transients between 115 and 190\,MHz with the LOw-Frequency ARray (LOFAR). Four fields have been monitored with cadences between 15 minutes and several months. A total of 151 images were…

[ABRIDGED] We report the results of a 944-epoch survey for transient sources with archival data from the Very Large Array spanning 22 years with a typical epoch separation of 7 days. Observations were obtained at 5 or 8.4 GHz for a single…

We present Chandra point-source catalogs for the Extended Chandra Deep Field-South (E-CDF-S) survey. The E-CDF-S consists of four contiguous 250 ks Chandra observations covering an approximately square region of total solid angle ~0.3…

We have carried out a dedicated transient survey of 300 deg$^2$ of the SDSS Stripe 82 region using the Giant Meterwavelength Radio Telescope (GMRT) at 150 MHz. Our multi-epoch observations, together with the TGSS survey, allow us to probe…

天体物理仪器与方法 · 物理学 2019-10-24 A. Hajela , K. P. Mooley , H. T. Intema , D. A. Frail

We report on a blind survey for extragalactic radio variability that was carried out by comparing two epochs of data from the FIRST survey with a third epoch from a new 1.4 GHz survey of SDSS Stripe 82. The three epochs are spaced seven…

宇宙学与河外天体物理 · 物理学 2015-06-15 Jacqueline A. Hodge , Robert H. Becker , Richard L. White , Gordon T. Richards

We present a search for transient and highly variable sources at low radio frequencies (150-200 MHz) that explores long timescales of 1-3 years. We conducted this search by comparing the TIFR GMRT Sky Survey Alternative Data Release 1 (TGSS…

We study the Extended Chandra Deep Field South (E-CDFS) Very Large Array sample, which reaches a flux density limit at 1.4 GHz of 32.5 microJy at the field centre and redshift ~ 4, and covers ~ 0.3 deg^2. Number counts are presented for the…

星系天体物理 · 物理学 2015-08-06 P. Padovani , M. Bonzini , K. I. Kellermann , N. Miller , V. Mainieri , P. Tozzi

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 a survey for transient and variable sources, on timescales from 28 seconds to $\sim$1 year, using the Murchison Widefield Array (MWA) at 182 MHz. Down to a detection threshold of 0.285 Jy, no transient candidates were identified,…

Radio activity has been observed in a large variety of stellar objects, including in the last few years, ultra-cool dwarfs. To explore the extent of long-term radio activity in ultra-cool dwarfs, we use data taken over an extended period of…

天体物理学 · 物理学 2009-11-13 A. Antonova , J. G. Doyle , G. Hallinan , A. Golden , C. Koen

We report on sensitive radio observations made with the VLA at 8.5 GHz, centered on the Hubble Deep Field (HDF). We collected data in the A, CnB, C, DnC, and D configurations, corresponding to angular resolutions ranging from 0.3" to 10".…

天体物理学 · 物理学 2008-11-26 E. A. Richards , K. I. Kellermann , E. B. Fomalont , R. A. Windhorst , R. B. Partridge

8.4-GHZ radio imaging study of an optically selected sample of early type Seyfert galaxies; comparison of images taken at two epochs reveals possible variation in the nuclear radio flux density in five of them over a seven year period. It…

宇宙学与河外天体物理 · 物理学 2011-07-25 C. G. Mundell , N. Nagar , P. Ferruit

We present the main results from our 940 ksec observation of the Chandra Deep Field South (CDFS), using the source catalog described in an accompanying paper (Giacconi et al. 2001). We extend the measurement of source number counts to…

We present a pilot search for variable and transient sources at 1.4 GHz with the Australian Square Kilometre Array Pathfinder (ASKAP). The search was performed in a 30 deg$^{2}$ area centred on the NGC 7232 galaxy group over 8 epochs and…

A comprehensive search for variable and transient radio sources has been conducted using ~55,000 snapshot images of the FIRST survey. We present an analysis leading to the discovery of 1,627 variable and transient objects down to mJy levels…

宇宙学与河外天体物理 · 物理学 2015-05-30 Nithyanandan Thyagarajan , David J. Helfand , Richard L. White , Robert H. Becker

A new generation of radio telescopes with excellent sensitivity, instantaneous {\it uv} coverage, and large fields of view, are providing unprecedented opportunities for performing commensal transient searches. Here we present such a…

高能天体物理现象 · 物理学 2023-09-18 S. I. Chastain , A. J. van der Horst , A. Rowlinson , L. Rhodes , A. Andersson , R. Diretse , R. P. Fender , P. A. Woudt

[abridged] We present point-source catalogs for the 4Ms Chandra Deep Field-South (CDF-S), which is the deepest Chandra survey to date and covers an area of 464.5 arcmin^2. We provide a main source catalog, which contains 740 X-ray point…

We present the results of the first transient survey from the Owens Valley Radio Observatory Long Wavelength Array (OVRO-LWA) using 31 hr of data, in which we place the most constraining limits on the instantaneous transient surface density…