Accretion in strong field gravity with eXTP
In this paper we describe the potential of the enhanced X-ray Timing and Polarimetry (eXTP) mission for studies related to accretion flows in the strong field gravity regime around both stellar-mass and supermassive black-holes. eXTP has the unique capability of using advanced 'spectral-timing-polarimetry' techniques to analyze the rapid variations with three orthogonal diagnostics of the flow and its geometry, yielding unprecedented insight into the inner accreting regions, the effects of strong field gravity on the material within them and the powerful outflows which are driven by the accretion process.
High Resolution Spectroscopy of 4U 1728-34 from a Simultaneous Chandra-RXTE Observation
We report on a simultaneous Chandra and RossiXTE observation of the LMXB atoll bursting source 4U 1728-34 performed on 2002 March 3-5. We fitted the 1.2-35 keV continuum spectrum with a blackbody plus a Comptonized component. An overabundance of Si by a factor of ~2 with respect to Solar abundance is required for a satisfactory fit. Large residuals at 6-10 keV can be fitted by a broad (FWHM ~ 1.6 keV) Gaussian emission line, or, alternatively, by absorption edges associated with Fe I and Fe XXV at ~7.1 keV and ~9 keV, respectively. In this interpretation, we find no evidence of a broad, or narrow Fe Kalpha line, between 6 and 7 keV. We tested our alternative modeling of the iron Kalpha regi…
X-ray spectroscopy of the high-mass X-ray binary 4U 1700-37
We present the first results of a monitoring campaign of the high-mass X-ray binary system 4U 1700-37/HD 153919, carried out with XMM-Newton.We have observed the high-mass X-ray binary (HMXB) 4U 1700-37 with XMM-Newton at four orbital phases in February 2001. 4U 1700-37 is powered by the dense stellar wind of the O supergiant HD 153919. Numerous X-ray flares are observed with a typical duration, of the order of half an hour. We focus on three intervals in which the data are not affected by pile up: the eclipse, the eclipse egress and a low-flux part around orbital phase ϕ ~ 0.28.
Observatory science with eXTP
Disponible preprint en: arXiv:1812.04023v1 [astro-ph.HE] [v1] Mon, 10 Dec 2018 19:00:52 UTC (4,376 KB)
The iron K-shell features of MXB 1728-34 from a simultaneous Chandra-RXTE observation
We report on a simultaneous Chandra and RossiXTE observation of the low-mass X-ray binary atoll bursting source MXB 1728-34 performed on 2002 March 3-5. We fit the 1.2-35 keV continuum spectrum with a blackbody plus a Comptonized component. Large residuals at 6-10 keV can be fitted by a broad (FWHM ~ 2 keV) Gaussian emission line or, alternatively, by two absorption edges associated with lowly ionized iron and Fe XXV/XXVI at ~7.1 keV and ~9 keV, respectively. In this interpretation, we find no evidence of broad, or narrow, emission lines between 6 and 7 keV. We test our alternative modelling of the iron K shell region by reanalysing a previous BeppoSAX observation of MXB 1728-34, finding a …
Dense matter with eXTP
In this White Paper we present the potential of the Enhanced X-ray Timing and Polarimetry (eXTP) mission for determining the nature of dense matter; neutron star cores host an extreme density regime which cannot be replicated in a terrestrial laboratory. The tightest statistical constraints on the dense matter equation of state will come from pulse profile modelling of accretion-powered pulsars, burst oscillation sources, and rotation-powered pulsars. Additional constraints will derive from spin measurements, burst spectra, and properties of the accretion flows in the vicinity of the neutron star. Under development by an international Consortium led by the Institute of High Energy Physics o…