We report on temporal and spectral analysis performed on 4U 1907 + 09 observed by BeppoSAX. We found a new measurement of the pulse period, that indicates that the source is still spinning-down at a rate of (P) over dot = +0.243 s/yr. The pulse profile is double peaked in the soft X-ray range, while the first peak disappears in the hard range (above 20 keV). The pulse phase averaged spectrum shows the presence of two absorption features at similar to 20 and 40 keV, tentatively identified with the fundamental and the second harmonic cyclotron lines respectively. The pulse phase resolved analysis is also reported. The second harmonic is clearly visible at the phases of the hard peak and the minimum.
Temporal and spectral analysis of 4U 1907+09 observed by BeppoSAX
BURDERI, LUCIANO;
1999-01-01
Abstract
We report on temporal and spectral analysis performed on 4U 1907 + 09 observed by BeppoSAX. We found a new measurement of the pulse period, that indicates that the source is still spinning-down at a rate of (P) over dot = +0.243 s/yr. The pulse profile is double peaked in the soft X-ray range, while the first peak disappears in the hard range (above 20 keV). The pulse phase averaged spectrum shows the presence of two absorption features at similar to 20 and 40 keV, tentatively identified with the fundamental and the second harmonic cyclotron lines respectively. The pulse phase resolved analysis is also reported. The second harmonic is clearly visible at the phases of the hard peak and the minimum.
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