Search Publications

The Hot--blackbody Spectral Excess in Low--luminosity High--Mass X--Ray Binaries

Tiengo, A.; Mereghetti, S.; Sidoli, L. +2 more

We report on the main results obtained thanks to an observation campaign with XMM-Newton of four persistent, low-luminosity (L_{X} ∼ 10^{34} erg s^{-1}) and long-period (P > 200 s) Be accreting pulsars. We found that all sources considered here are characterized by a spectral excess that can be described with a blackbody component of high tempe…

Observations of the Unique X--ray Emitting Subdwarf Stars HD 49798 and BD +37° 442

Tiengo, A.; Mereghetti, S.; Stella, L. +3 more

We report on the results we obtained with XMM observations of HD 49798 and BD +37° 442, the only two sdO stars for which X-ray emission has been observed so far. HD 49798 is a single-lined spectroscopic binary with orbital period of 1.5 days. We could establish that its companion is a massive white dwarf with M = 1.28 M_{⊙}, which makes it a candi…