| | |
| | |
Stat |
Members: 3643 Articles: 2'487'895 Articles rated: 2609
28 March 2024 |
|
| | | |
|
Article overview
| |
|
INTEGRAL and XMM-Newton observations of IGR J16418-4532: evidence of accretion regime transitions in a supergiant fast X-ray transient | S. P. Drave
; A. J. Bird
; L. Sidoli
; V. Sguera
; V. A. McBride
; A. B. Hill
; A. Bazzano
; M. E. Goossens
; | Date: |
2 May 2013 | Abstract: | We report on combined INTEGRAL and XMM-Newton observations of the supergiant
fast X-ray transient IGR J16418-4532. The observations targeted the X-ray
eclipse region of IGR J16418-4532s orbit with continuous INTEGRAL observations
across ~25% of orbital phase and two quasi-simultaneous XMM-Newton observations
of length 20ks and 14ks, occurring during and just after the eclipse
respectively. An enhanced INTEGRAL emission history is provided with 19
previously unreported outbursts identified in the archival 18-60 keV data set.
The XMM-Newton eclipse observation showed prominent Fe-emission and a flux of
2.8*10^-13 erg cm^-2 s^-1 (0.5 - 10 keV). Through the comparison of the
detected eclipse and post eclipse flux, the supergiant mass loss rate through
the stellar wind was determined as dot{M}_{w} = 2.3-3.8*10^-7 M_{odot} yr^-1.
The post eclipse XMM-Newton observation showed a dynamic flux evolution with
signatures of the X-ray pulsation, a period of flaring activity, structured nH
variations and the first ever detection of an X-ray intensity dip, or
’off-state’, in a pulsating supergiant fast X-ray transient. Consideration is
given to the origin of the X-ray dip and we conclude that the most applicable
of the current theories of X-ray dip generation is that of a transition between
Compton cooling dominated and radiative cooling dominated subsonic accretion
regimes within the ’quasi-spherical’ model of wind accretion. Under this
interpretation, which requires additional confirmation, the neutron star in IGR
J16418-4532 possesses a magnetic field of ~10^14 G, providing tentative
observational evidence of a highly magnetised neutron star in a supergiant fast
X-ray transient for the first time. The implications of these results on the
nature of IGR J16418-4532 itself and the wider SFXT class are discussed. | Source: | arXiv, 1305.0430 | Services: | Forum | Review | PDF | Favorites |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser claudebot
|
| |
|
|
|
| News, job offers and information for researchers and scientists:
| |