ASCA observation of a radio-loud quasar and a new candidate for a cluster of galaxies

Fumie Akimoto, Akihiro Furuzawa, Yuzuru Tawara, Yuichi Kamata, Koujun Yamashita

Research output: Contribution to journalArticlepeer-review


During an X-ray observation of the distant galaxy cluster CL 0107+31 (z = 0.69) with ASCA, an extended X-ray source was detected in the field of view. Based on an image analysis in two different energy bands of 1-3 keV and 3-10 keV, we found that this source consists of a hard point-like component and an additional soft diffuse X-ray source extended over ≥ 3′ in radius. However, due to poor photon statistics, we could not distinguish whether their X-ray spectra are thermal or non-thermal. The peak position of the central X-ray source coincides with a radio-loud quasar, NRAO 58. NRAO 58 is found to have a power-law spectrum with a photon index 1.6+0.3-0.2 and a (2-10 keV) luminosity of ∼ 4×1046 erg s-1 (in the quasar rest frame). The extended component is likely to be a candidate for a nearby galaxy group which accidentally coincides with the quasar.

Original languageEnglish
Pages (from-to)677-681
Number of pages5
JournalPublications of the Astronomical Society of Japan
Issue number5
Publication statusPublished - 1999
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


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