中文
相关论文

相关论文: The 2dF BL Lac Survey

200 篇论文

We present the results of a spectroscopic survey with the Keck I telescope of more than 280 star-forming galaxies and AGN at redshifts 1.4<z<3.0 in the GOODS-N field. Candidates are selected by their UGR colors using the ``BM/BX'' criteria…

天体物理学 · 物理学 2008-11-26 Naveen A. Reddy , Charles C. Steidel , Dawn K. Erb , Alice E. Shapley , Max Pettini

We present the results from a survey of i-dropout objects selected from ~1550 deg^2 of multicolor imaging data from the Sloan Digital Sky Survey, to search for luminous quasars at z>5.8. Objects with i*-z*>2.2 and z*<20.2 are selected, and…

We present radio observations for 29 southern Seyfert galaxies selected from a volume limited sample with cz<3600 km s^-1, and declination delta<0degr. Objects with declination -30degr<delta<0degr were observed with the Very Large Array…

天体物理学 · 物理学 2009-10-31 R. Morganti , Z. I. Tsvetanov , J. Gallimore , M. G. Allen

(abridged) We present a comprehensive study of a sample of 23 genuine radio-loud NLS1 galaxies which have the radio-loudness parameters greater than 100. The radio sources of the sample are ubiquitously compact. A significant fraction of…

天体物理学 · 物理学 2009-11-13 W. Yuan , H. Y. Zhou , S. Komossa , X. B. Dong , T. G. Wang , H. L. Lu , J. M. Bai

We utilize deep near-infrared survey data from the UltraVISTA fourth data release (DR4) and the VIDEO survey, in combination with overlapping optical and Spitzer data, to search for bright star-forming galaxies at $z \gtrsim 7.5$. Using a…

We present spectroscopic and eleven-band photometric redshifts for galaxies in the 100-uJy Subaru/XMM-Newton Deep Field radio source sample. We find good agreement between our redshift distribution and that predicted by the SKA Simulated…

We have used the 2dF instrument on the AAT to obtain redshifts of a sample of z<3, 18.0<g<21.85 quasars selected from SDSS imaging. These data are part of a larger joint programme: the 2dF-SDSS LRG and QSO Survey (2SLAQ). We describe the…

The parsec-scale radio properties of 232 active galactic nuclei (AGNs), most of which are blazars, detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed contemporaneously by the Very Long…

高能天体物理现象 · 物理学 2015-06-11 J. D. Linford , G. B. Taylor , F. K. Schinzel

The X-ray spectra of serendipitously observed AGN in the XMM-Newton fields of Mrk 205 and QSO 0130-403 are analysed. The sample consists of 23 objects, none of which is detected at radio frequencies, with a median X-ray luminosity of ~ 4 x…

天体物理学 · 物理学 2009-11-07 K. L. Page , M. J. L. Turner , J. N. Reeves , P. T. O'Brien , S. Sembay

We analyze the Parkes quarter-Jansky flat-spectrum sample of QSOs in terms of space density, including the redshift distribution, the radio luminosity function, and the evidence for a redshift cutoff. With regard to the luminosity function,…

天体物理学 · 物理学 2009-11-10 J. V. Wall , C. A. Jackson , P. A. Shaver , I. M. Hook , K. I. Kellermann

We present a determination of the optical/UV AGN luminosity function and its evolution, based on a large sample of faint (R<24) QSOs identified in the COMBO-17 survey. Using multi-band photometry in 17 filters within 350nm < lambda_obs <…

天体物理学 · 物理学 2010-04-06 C. Wolf , L. Wisotzki , A. Borch , S. Dye , M. Kleinheinrich , K. Meisenheimer

Our knowledge of the blazar surface densities and luminosity functions, which are fundamental parameters, relies still on samples at relatively high flux limits. As a result, our understanding of this rare class of active galactic nuclei is…

天体物理学 · 物理学 2011-02-11 P. Padovani , P. Giommi , H. Landt , E. S. Perlman

We obtained optical spectra of four objects identified with variable radio sources. Three objects (0029+0554, 0400+0550, 2245+0500) were found to be quasars with redshifts of 1.314, 0.761, and 1.091. One object (2349+0534) has a continuum…

天体物理学 · 物理学 2009-11-07 V. Chavushyan , R. Mujica , A. G. Gorshkov , V. K. Konnikova , M. G. Mingaliev

We have observed nine QSOs with redshifts 0.85 to 4.16 at near-IR wavelengths with the adaptive optics bonnette of the Canada-France-Hawaii telescope. Exposure times ranged from 1500 to 24000s (mostly near 7000s) in J, H, or K bands, with…

天体物理学 · 物理学 2009-10-31 J. B. Hutchings , D. Crampton , S. L. Morris , D. Durand , E. Steinbring

We present spectroscopic and polarimetric observations of a complete, optically unbiased sample of 2Jy radio galaxies at intermediate redshifts (0.15 < z < 0.7). These data -- which cover the nuclear regions of the target galaxies -- allow…

天体物理学 · 物理学 2009-11-07 C. Tadhunter , R. Dickson , R. Morganti , T. G. Robinson , K. Wills , M. Villar-Martin , M. Hughes

We present a detailed determination of the restframe B-band galaxy luminosity function (LF) as a function of redshift and star formation activity from z=0 to z=0.75. The dataset used for this purpose is a combined sample of over 1700…

天体物理学 · 物理学 2015-06-24 Richard S. Ellis , Matthew Colless , Tom Broadhurst , Jeremy Heyl , Karl Glazebrook

We have used the Very Large Array aperture synthesis telescope to conduct a radio continuum survey of polar-ring galaxies, at 20cm and 6cm. Forty objects were observed at 20cm with 5" resolution. Twenty (50%) of the program sources were…

天体物理学 · 物理学 2009-11-10 A. L. Cox , L. S. Sparke

Fermi has provided the largest sample of {\gamma}-ray selected blazars to date. In this work we use a complete sample of FSRQs detected during the first year of operation to determine the luminosity function (LF) and its evolution with…

宇宙学与河外天体物理 · 物理学 2015-05-30 M. Ajello , M. S. Shaw , R. W. Romani , C. D. Dermer , L. Costamante , O. G. King , W. Max-Moerbeck , A. Readhead , A. Reimer , J. L. Richards , M. Stevenson

We present the results of spectroscopic observations of the optical counterparts of 47 southern radio sources from the candidate International Celestial Reference Catalogue (ICRC), as part of a Very Long Baseline Interferometry (VLBI)…

宇宙学与河外天体物理 · 物理学 2015-05-30 O. Titov , D. L. Jauncey , H. M. Johnston , R. W. Hunstead , L. Christensen

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…

‹ 上一页 1 8 9 10 下一页 ›