A possible x-ray periodicity at several tens of hours of an ultraluminous compact x-ray source in IC 342

M. Sugiho, J. Kotoku, K. Makishima, Aya Kubota, T. Mizuno, Y. Fukazawa, M. Tashiro

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

A long (155 hr) ASCA observation was performed of two ultraluminous compact X-ray sources, source 1 and source 2, in the spiral galaxy IC 342. While source 1, which was in a hard spectral state, varied little, source 2, which was in its soft spectral state, varied significantly on a timescale of about 1 day. The rms variation amplitude amounts to 5% in the 2-10 keV band but is less than 4% in 0.7-2 keV. The variation involves statistically significant changes in the parameters describing multicolor disk blackbody emission from this source. The variation is possibly periodic, with a period of either 31 ± 2 or 41 ± 3 hr. Both are consistent with the orbital period of a semidetached binary formed by a black hole and a main-sequence star of several tens of solar masses. These results reinforce the interpretation of these X-ray objects in terms of accreting massive stellar black holes.

Original languageEnglish
JournalAstrophysical Journal
Volume561
Issue number1 PART 2
DOIs
Publication statusPublished - 2001 Nov 1
Externally publishedYes

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x ray sources
periodicity
periodic variations
x rays
timescale
main sequence stars
spiral galaxies
orbitals
parameter

Keywords

  • Black hole physics
  • Galaxies: spiral
  • X-rays: galaxies

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

A possible x-ray periodicity at several tens of hours of an ultraluminous compact x-ray source in IC 342. / Sugiho, M.; Kotoku, J.; Makishima, K.; Kubota, Aya; Mizuno, T.; Fukazawa, Y.; Tashiro, M.

In: Astrophysical Journal, Vol. 561, No. 1 PART 2, 01.11.2001.

Research output: Contribution to journalArticle

Sugiho, M. ; Kotoku, J. ; Makishima, K. ; Kubota, Aya ; Mizuno, T. ; Fukazawa, Y. ; Tashiro, M. / A possible x-ray periodicity at several tens of hours of an ultraluminous compact x-ray source in IC 342. In: Astrophysical Journal. 2001 ; Vol. 561, No. 1 PART 2.
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AU - Mizuno, T.

AU - Fukazawa, Y.

AU - Tashiro, M.

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