出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We present here X-ray observations of the high mass X-ray binary LS I +61 303 carried out during
50 ks with the ACIS-I array aboard the Chandra X-ray Observatory. The source count rate and
hardness ratio was found to be moderately variable on timescales of hours, confirming previous
results. No clear correlation between the hardness ratio and the total count rate is present in the
data, in contrast to previous results. We produced a single spectrum of the source, which could be
properly fitted with an absorbed power-law model after considering pileup effects. The resulting
parameters are NH = (0.68±0.06)×1022 cm−2 and G = 1.25±0.09. The flux of the source in
the 0.3–10 keV range is (7.8±2.2)×10−12 erg cm−2 s−1. Assuming a distance to the source of
2.0 kpc the intrinsic X-ray luminosity is found to be LX (0.3−10 keV) = (3.7±1.1)×1033 erg s−1.
Hints of extended and hard X-ray emission forming a ring-like structure around LS I +61 303
are also found. If this extended X-ray emission is produced by synchrotron radiation, efficient
particle acceleration up to scales of ∼ 104 AU takes place in LS I +61 303.
