The x-ray timing and polarization satellite - 1, 2, 3: uncovering the mysteries of black holes and extreme physics in the universe

Abstract

on behalf of the XTP collaboration ABSTRACT The X-ray Timing and Polarization (XTP) satellite, planned for launch in ~2020, is dedicated to the study of 1-singularity (Black Hole), 2-stars (normal neutron star and magnetar) and 3-extremes (the physics under extreme gravity, density and magnetism). With an effective area of ~1 m 2 and a combination of various types of X-ray telescopes, XTP is expected to make the most sensitive temporal and polarization observations with good energy resolution in 1-30 keV. XTP will open a new window using its powerful capability of polarization observations; its minimum detectable polarization will be 3% (1 mCrab, 1e6 s).

Radiative transfer simulations of magnetar flare beaming

“…However, an improved model that computes the properties of the outflow self-consistently from the radiation field, i.e., incorporating the influences of Compton drag on the wind dynamics, would provide constraints on these properties. The angular dependence of the photon polarization degree, and how it changes over time as the properties of the system change, is potentially observable with future X-ray polarimetry missions (Soffitta et al 2013;Weisskopf et al 2014;Dong 2014;Jahoda et al 2015). Our results also show that in general the O-mode is beamed slightly more strongly than the E-mode.…”

“…However, the distribution of photons between the two polarization modes is strongly variable with the various physical parameters (velocity, density, seed photon temperature, magnetic field strength) of our model. This means that future X-ray polarimetry missions, such as XIPE (Soffitta et al 2013), IXPE (Weisskopf et al 2014), XTP (Dong 2014) and PRAXyS (Jahoda et al 2015) could be able to add significant value to magnetar flare observations, by tracking what happens to the polarization signature during the tail of a magnetar flare. Because the photon mode distribution may change while the pulse profile does not, this would add valuable constraints to any attempt to fit magnetar flare light curves using the model set out in this paper.…”

“…However, we can track differences in the spectrum for different angular directions, to test whether we can recreate the spectral variations with rotation found in some magnetar flares (Feroci et al 2001;Boggs et al 2007). We also test whether the pulse profile is significantly different between the two polarization modes, something which might be observable with proposed X-ray polarimetry missions (see for example Fernández & Davis 2011), such as XIPE (Soffitta et al 2013), IXPE (Weisskopf et al 2014), XTP (Dong 2014) and PRAXyS (Jahoda et al 2015). Such information offers the prospect for better understanding the geometrical relationship between the outflow, nozzle and fireball zones in future models that are more self-consistent.…”

The enhanced X-ray Timing and Polarimetry mission—eXTP

“…The science payload consists of four instruments: the focused SFA and PFA telescopes arrays, the large area instrument LAD, and the WFM to monitor a large fraction of the sky. The eXTP mission is an enhanced version of the Chinese X-ray Timing and Polarimetry mission [6], which in 2011 was selected and funded for a Phase 0/A study as one of the background concept missions in the Strategic Priority Space Science Program of the Chinese Academy of Sciences (CAS). Also in 2011, the Large Observatory for Timing (LOFT) mission concept [7,8] was selected for an assessment study in the context of the ESA's Announcement of Opportunity for the third of the medium size missions (M3) foreseen in the framework of the Agency's Cosmic Vision programme.…”

Development of imaging x-ray telescopes at Tongji University

“…For over the past 10 years, China has proposed and is currently leading several IXT missions. The X-ray Timing and Polarization satellite 13 and the enhanced X-ray Timing and Polarimetry 14 are proposed as the successors of the Insight-HXMT, dedicated to study black hole, neutron star, and then get more information in the physics under extreme gravity, density, and magnetism. The Einstein Probe 15 mission aims at discovering transients and monitoring variable objects in the 0.5 to 4 keV xrays, at a sensitivity higher by 1 order of magnitude than those of missions currently in orbit.…”