| Autor: |
Crowther, P. A., Barnard, R., Carpano, S., Clark, J. S., Dhillon, V. S., Pollock, A. M. T. |
| Předmět: |
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| Zdroj: |
Monthly Notices of the Royal Astronomical Society: Letters; Mar2010, Vol. 403 Issue 1, pL41-L45, 5p |
| Abstrakt: |
We present Very Large Telescope/FORS2 time-series spectroscopy of the Wolf–Rayet (WR) star #41 in the Sculptor group galaxy NGC 300. We confirm a physical association with NGC 300 X-1, since radial velocity variations of the He iiλ4686 line indicate an orbital period of 32.3 ± 0.2 h which agrees at the 2σ level with the X-ray period from Carpano et al. We measure a radial velocity semi-amplitude of 267 ± 8 km s−1, from which a mass function of is obtained. A revised spectroscopic mass for the WN-type companion of yields a black hole mass of for a preferred inclination of . If the WR star provides half of the measured visual continuum flux, a reduced WR (black hole) mass of ) would be inferred. As such, #41/NGC 300 X-1 represents only the second extragalactic WR plus black hole binary system, after IC 10 X-1. In addition, the compact object responsible for NGC 300 X-1 is the second highest stellar-mass black hole known to date, exceeded only by IC 10 X-1. [ABSTRACT FROM AUTHOR] |
| Databáze: |
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