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Related papers: Spatially-Offset AGN Candidates in the CLASS Surve…

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In a recent paper Lehnert & Bremer have photometrically selected a sample of galaxies at z>4.8 from a single VLT/FORS2 pointing and spectroscopically confirmed half of them to be at 4.8<z<5.8. To study the properties of such galaxies…

Astrophysics · Physics 2009-11-10 M. N. Bremer , M. D. Lehnert , I. Waddington , M. J. Hardcastle , P. J. Boyce , S. Phillipps

We estimate the incidence of multiply-imaged AGNs among the optical counterparts of X-ray selected point-like sources in the XXL field. We also derive the expected statistical properties of this sample, such as the redshift distribution of…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-06 F. Finet , A. Elyiv , O. Melnyk , O. Wertz , C. Horellou , J. Surdej

We have used the Very Large Array to search for compact milliarcsecond-size radio sources near methanol masers in high-mass star-forming regions. Such sources are required for Very Long Baseline Interferometry phase-referencing…

Astrophysics · Physics 2009-11-11 Y. Xu , M. J. Reid , K. M. Menten , X. W. Zheng

We present a new sample of 84 large angular size radio galaxies selected from the NRAO VLA Sky Survey. Radio sources with declination above +60 degrees, total flux density greater than 100 mJy at 1.4 GHz and angular size larger than 4…

Astrophysics · Physics 2009-11-06 L. Lara , W. D. Cotton , L. Feretti , G. Giovannini , J. M. Marcaide , I. Marquez , T. Venturi

We have compiled a sample of 234 ultra-steep-spectrum (USS) selected radio sources in order to find high-redshift radio galaxies. The sample covers the declination range -40deg < DEC < -30deg in the overlap region between the 1400-MHz NRAO…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 J. J. Bryant , J. W. Broderick , H. M. Johnston , R. W. Hunstead , B. M. Gaensler , C. De Breuck

Many radio galaxies show the presence of dense and dusty gas near the active nucleus. This can be traced by both 21cm HI absorption and soft X-ray absorption, offering new insight into the physical nature of the circumnuclear medium of…

Using Chandra imaging spectroscopy and VLA L-band maps, we have identified radio galaxies at P(1.4 GHz) >= 3x10^{23} W Hz^{-1} and X-ray point sources (XPSs) at L(0.3-8 keV) >= 10^{42} ergs s^{-1} in 11 moderate redshift (0.2<z<0.4)…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-16 Quyen N. Hart , John T. Stocke , Eric J. Hallman

We have constrained the extragalactic source count distributions over a broad range of X-ray fluxes and in various energy bands to test whether the predictions from X-ray background synthesis models agree with the observational constraints…

We present and discuss two catalogues of UV-selected (NUV $< 22.8$ mag) galaxies that lie within a 200 deg$^2$ area of sky covered by the ASKAP FLASH survey and have an impact parameter of less than 20 arcsec to a FLASH radio continuum…

Astrophysics of Galaxies · Physics 2024-11-15 Sophie L. Eden , Elaine M. Sadler , Kevin A. Pimbblet , Elizabeth K. Mahony , Hyein Yoon

We report the result of optical identifications of FIRST radio sources with the Hyper Suprime-Cam Subaru Strategic Program survey (HSC-SSP). The positional cross-match within 1" between the FIRST and HSC-SSP catalogs (i ~< 26) produced more…

We report on our search for distant clusters of galaxies based on optical and X-ray follow up observations of X-ray candidates from the SHARC survey. Based on the assumption that the absence of bright optical or radio counterparts to…

Astrophysics · Physics 2009-11-13 C. Adami , M. P. Ulmer , F. Durret , G. Covone , E. Cypriano

Giant radio galaxies (GRGs) are one of the largest astrophysical sources in the Universe with an overall projected linear size of ~0.7 Mpc or more. Last six decades of radio astronomy research has led to the detection of thousands of radio…

Astrophysics of Galaxies · Physics 2017-06-16 Pratik Dabhade , Madhuri Gaikwad , Joydeep Bagchi , M. Pandey-Pommier , Shishir Sankhyayan , Somak Raychaudhury

Mid-IR colour selection techniques have proved to be very efficient in finding AGN. This is because the AGN heats the surrounding dust producing warm mid-IR colours. Using the WISE 3.6, 4.5 and 12 $\mu m$ colours, the largest sample of IR…

We have analyzed galaxy properties in the environment of a sample of 70 Ultra Steep Spectrum (USS) radio sources selected from the Sydney University Molonglo sky Survey and the NRAO VLA Sky Survey catalogues, using near-IR data complete…

Astrophysics · Physics 2009-11-13 Carlos G. Bornancini , Diego G. Lambas , Carlos De Breuck

Submillimetre-selected galaxies (SMGs) at high redshift ($z$ $\sim$ 2) are potential host galaxies of active galactic nuclei (AGN). If the local Universe is a good guide, $\sim$ 50$\%$ of the obscured AGN amongst the SMG population could be…

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…

Astrophysics of Galaxies · Physics 2018-01-31 A. Saxena , P. Jagannathan , H. J. A. Röttgering , P. N. Best , H. T. Intema , M. Zhang , K. J. Duncan , C. L. Carilli , G. K. Miley

A new sample of very large angular size radio sources has been selected from the 1.4 GHz VLA surveys: FIRST and NVSS. This sample will be very useful for an observational constraint on the time evolution of double radio sources, especially…

Astrophysics · Physics 2009-11-06 J. Machalski , M. Jamrozy , S. Zola

We have analyzed new, archival and published high resolution radio and X-ray observations of a sample of composite LINER/HII galaxies known to exhibit AGN-like properties. Five of the 16 AGN candidates have milliarcsecond-scale detections…

Astrophysics · Physics 2009-11-10 M. E. Filho , F. Fraternali , S. Markoff , N. M. Nagar , P. D. Barthel , L. C. Ho , F. Yuan

Searches for slow radio transients and variables have generally focused on extragalactic populations, and the basic parameters of Galactic populations remain poorly characterized. We present a large 3 GHz survey performed with the Allen…

The optical identification of large number of X-ray sources such as those from the ROSAT All-Sky Survey is challenging with conventional spectroscopic follow-up observations. We investigate two ROSAT All-Sky Survey fields of size 10 * 10…

High Energy Astrophysical Phenomena · Physics 2015-02-25 J. Greiner , G. A. Richter
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