Spectral and temporal properties of X-ray emission from the ultra-luminous source X-9 in M81

V. La Parola; G. Fabbiano; D. W. Kim; G. Peres

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Spectral and temporal properties of X-ray emission from the ultra-luminous source X-9 in M81

V. La Parola·G. Fabbiano·D. W. Kim·G. Peres

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Abstract

We have analysed the spectra and the variability of individual X-ray sources in the M-81 field using data from the available ROSAT-PSPC and ROSAT-HRI observations of this nearby spiral galaxy. Here we present the results on the second brightest source in the field (X-9 - Fabbiano, 1988 ApJ 325 544), whose identification and interpretation is still unclear. Our work includes the study of the shape of X-9 from HRI data, the light curve and hardness ratio evolution, and the spectral analysis.

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V. La Parola, G. Fabbiano, D. W. Kim, G. Peres. 2001-02-14. Spectral and temporal properties of X-ray emission from the ultra-luminous source X-9 in M81. https://arxiv.org/abs/astro-ph/0102111

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