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Title: THE ABUNDANCE OF X-SHAPED RADIO SOURCES. I. VLA SURVEY OF 52 SOURCES WITH OFF-AXIS DISTORTIONS

Cheung identified a sample of 100 candidate X-shaped radio galaxies using the NRAO FIRST survey; these are small-axial-ratio extended radio sources with off-axis emission. Here, we present radio images of 52 of these sources that have been made from archival Very Large Array data with resolution of about 1″. Fifty-one of the 52 were observed at 1.4 GHz, 7 were observed at 1.4 and 5 GHz, and 1 was observed only at 5 GHz. We also present overlays of the Sloan Digital Sky Survey red images for 48 of the sources, and DSS II overlays for the remainder. Optical counterparts have been identified for most sources, but there remain a few empty fields. Our higher resolution VLA images along with FIRST survey images of the sources in the sample reveal that extended extragalactic radio sources with small axial ratios are largely (60%) cases of double radio sources with twin lobes that have off-axis extensions, usually with inversion-symmetric structure. The available radio images indicate that at most 20% of sources might be genuine X-shaped radio sources that could have formed by a restarting of beams in a new direction following an interruption and axis flip. The remaining 20% are in neithermore » of these categories. The implications of this result for the gravitational wave background are discussed in Roberts et al.« less
Authors:
; ;  [1] ; ;  [2]
  1. Department of Physics MS-057, Brandeis University, Waltham, MA 02454-0911 (United States)
  2. Raman Research Institute, C. V. Raman Avenue, Sadashivanagar, Bangalore 560080 (India)
Publication Date:
OSTI Identifier:
22520141
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal, Supplement Series; Journal Volume: 220; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABUNDANCE; AXIAL RATIO; GHZ RANGE; GRAVITATIONAL WAVES; IMAGES; RADIO GALAXIES; RESOLUTION; SKY