IPAC

Home

NASA/IPAC Extragalactic Database

  • Home
  • Search Objects
    • By Name
    • Near Name or Position (Cone)
    • In Refcode
    • By Parameters
  • Literature
    • References by Author Name
    • Reference Lookup
    • Nomenclature
  • Services
    • Gravitational Wave Followup
      • Overview
      • Events
    • Ticket Status
    • Level5
      • Knowledge Base
      • Glossary
    • Classic Home Page
  • Tools
    • Coordinate Calculator
    • Extinction Calculator
    • Velocity Calculator
  • Information
    • Overview
      • News
      • Archived Release Notes
    • User Guides
      • Search Objects
      • Calculators
      • Program Interfaces
      • Database
      • Tutorials
      • Best Practices
      • Search & Retrieval FAQ
      • Scientific Calculations FAQ
      • Known Issues
      • Discontinuing Services
    • Holdings
      • Nomenclature
      • Counts
      • Graphics
      • Data Sets
    • References
      • Articles about NED
      • Brochure (pdf)
      • Cosmology Calculators
      • Extinction-Law Calculators
      • Related Sites
    • Community
      • Users Committee
      • Ambassadors
    • Team
    • Contact Us

You are here

Home » Literature » Reference Lookup

Help Reference Information

TitleIdentification of X-ray sources <1° from Seyfert galaxies.
AuthorsArp, H.
Bibcode

1997A&A...319...33A   Search ADS ↗

AbstractExcess numbers of X-ray sources around bright Seyfert galaxies have been demonstrated with significances of association up to 7.4-sigma (Radecke, preceding paper). The optical identification of these sources is shown here to be predominantly blue stellar objects (BSO's) of which some are already catalogued as quasars. Excluding the two brightest Seyferts, a subset of 24 with apparent magnitudes between 8.04<=B_T_^o,i^<=12.90mag. show a minimum excess of >46 bright X-ray sources. These excess X-ray sources are generally distributed between 10'
Objects

51 Objects    Search NED ↙

Reload form

The NASA/IPAC Extragalactic Database (NED) is funded by the
National Aeronautics and Space Administration under
Award Number 80NSSC21M0037, and operated by the California Institute of Technology.

  • IPAC
  • Caltech
  • NASA
  • About NED
  • Acknowledging NED
  • Connect with NED:
    • EMail
    • facebook
    • youtube
Copyright © 2025, California Institute of Technology
back up ↑