Other
Scientific paper
Dec 2009
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009aas...21460201u&link_type=abstract
American Astronomical Society, AAS Meeting #214, #602.01
Other
Scientific paper
Supergiant Fast X-ray Transients (SFXTs) are one of the most interesting (and unexpected) results of the INTEGRAL mission. They are a new class of HMXBs displaying short hard X-ray outbursts (duration less tha a day) characterized by fast flares (few hours timescale) and large dinamic range (10E3-10E4). The physical mechanism driving their peculiar behaviour is still unclear and highly debated: some models involve the structure of the supergiant companion donor wind (likely clumpy, in a spherical or non spherical geometry) and the orbital properties (wide separation with eccentric or circular orbit), while others involve the properties of the neutron star compact object and invoke very low magnetic field values (B < 1E10 G) or alternatively very high (B>1E14 G, magnetars).
The picture is still highly unclear from the observational point of view as well: no cyclotron lines have been detected in the spectra, thus the strength of the neutron star magnetic field is unknown. Orbital periods have been measured in only 4 systems, spanning from 3.3 days to 165 days. Even the duty cycle seems to be quite different from source to source.
The Energetic X-ray Imaging Survey Telescope (EXIST), with its hard X-ray all-sky survey and large improved limiting sensitivity, will allow us to get a clearer picture of SFXTs. A complete census of their number is essential to enlarge the sample. A long term and continuous as possible X-ray monitoring is crucial to -(1) obtain the duty cycle, -(2 )investigate their unknown orbital properties (separation, orbital period, eccentricity),- (3) to completely cover the whole outburst activity, (4)-to search for cyclotron lines in the high energy spectra.
EXIST observations will provide crucial informations to test the different models and shed light on the peculiar behaviour of SFXTs.
Bazzano Angela
Sguera Vito
Sidoli Lara
Ubertini Pietro
No associations
LandOfFree
EXIST Perspective for SFXTs does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with EXIST Perspective for SFXTs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and EXIST Perspective for SFXTs will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1766224