Photoionization instability of the Fe K absorbing plasma in the neutron star transient AX J1745.6-2901
Date Issued
2017
Author(s)
Abstract
AX J1745.6-2901 is a low-mass X-ray binary with an accreting neutron star, showing clear evidence for highly ionized absorption. Strong ionized Fe Kα and Kβ absorption lines are always observed during the soft state, whereas they disappear during the hard state. We computed photoionization stability curves for the hard and the soft states, under different assumptions on the adopted spectral energy distributions and the physical parameters of the plasma. We observe that the ionized absorber always lies on a stable branch of the photoionization stability curve during the soft state, while it becomes unstable during the hard state. This suggests that photoionization instability plays a key role in defining the observable properties of the ionized absorber. The same process might explain the disappearance of the high ionization absorber/wind during the hard state in other accreting neutron stars and black holes.
Volume
472
Issue
2
Start page
2454
Issn Identifier
0035-8711
Ads BibCode
2017MNRAS.472.2454B
Rights
open.access
File(s)![Thumbnail Image]()
![Thumbnail Image]()
Loading...
Name
1709.00860.pdf
Description
preprint
Size
1.76 MB
Format
Adobe PDF
Checksum (MD5)
5c90e0d6d023f3babc313ee6d5972760
Loading...
Name
stx2173.pdf
Description
pdf editoriale
Size
1.29 MB
Format
Adobe PDF
Checksum (MD5)
f4b8128910ff9464c85347c185ce8597
