Chandra observation of the Big Dipper X 1624-490
- Authors: IARIA R; LAVAGETTO G; D'AI' A; DI SALVO T; ROBBA N R
- Publication year: 2007
- Type: Articolo in rivista (Articolo in rivista)
- Key words: accretion, accretion disks; stars : individual : X 1624-490; stars : neutron; X-rays : stars; X-rays : binaries; X-rays : general
- OA Link: http://hdl.handle.net/10447/27006
Abstract
We present the results of a 73 ks long Chandra observation of the dipping source X 1624 - 490. During the observation a complex dip lasting 4 h is observed. We analyse the persistent emission detecting, for the first time in the 1st-order spectra of X 1624 - 490, an absorption line associated to Ca XX We confirm the presence of the Fe XXV K-alpha and Fe XXVI K-alpha absorption lines with a larger accuracy with respect to a previous XMM observation. Assuming that the line widths are due to a bulk motion or a turbulence associated to the coronal activity, we estimate that the lines have been produced in a photoionized absorber between the coronal radius and the outer edge of the accretion disk.