ESA Voyage 2050 white paper: A Polarized View of the Hot and Violent Universe

Paolo Soffitta; Niccolò Bucciantini; Eugene Churazov; Enrico Costa; Michal Dovciak; Hua Feng; Jeremy Heyl; Adam Ingram; Keith Jahoda; Philip Kaaret; Timothy Kallman; Vladimir Karas; Ildar Khabibullin; Henric Krawczynski; Julien Malzac; Frederic Marin; Herman Marshall; Giorgio Matt; Fabio Muleri; Carole Mundell; Mark Pearce; Pierre-Olivier Petrucci; Juri Poutanen; Roger Romani; Andrea Santangelo; Gianpiero Tagliaferri; Roberto Taverna; Roberto Turolla; Jacco Vink; Silvia Zane

arXiv · 1910.10092

ESA Voyage 2050 white paper: A Polarized View of the Hot and Violent Universe

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Abstract

Since the birth of X-ray Astronomy, spectacular advances have been seen in the imaging, spectroscopic and timing studies of the hot and violent X-ray Universe, and further leaps forward are expected in the future. On the other hand, polarimetry is very much lagging behind: after the measurements of the Crab Nebula and Scorpius X-1, obtained by OSO-8 in the 70s, no more observations have been performed in the classical X-ray band, even if some interesting results have been obtained in hard X-rays and in soft gamma-rays. The NASA/ASI mission IXPE, scheduled for the launch in 2021, is going to provide for the first time imaging X-ray polarimetry in the 2-8 keV band thanks to its photoelectric polarimeter, coupled with ~25'' angular resolution X-ray mirrors. Its orders of magnitude improvement in sensitivity with respect to the OSO-8 Bragg polarimeter implies scientifically meaningful polarimetric measurements for at least the brightest specimens of most classes of X-ray sources. In 2027, the Chinese-led mission eXTP should also be launched. In addition to timing and spectroscopic instruments, eXTP will have on board photoelectric polarimeters very similar to those of IXPE, but with a total effective area 2-3 times larger. Building on IXPE results, eXTP will increase the number of sources for which significant polarimetric measurements could be obtained. However, further progresses, such as exploring a broader energy range, considering a larger effective area, improving the angular resolution, and performing wide-field polarization measurements, are needed to reach a mature phase for X-ray polarimetry. In the first part of this White Paper we will discuss a few scientific cases in which a next generation X-ray Polarimetry mission can provide significant advances. In the second part, a possible concept for a medium-class Next Generation X-ray Polarimetry (NGXP) mission will be sketched.

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Paolo Soffitta, Niccolò Bucciantini, Eugene Churazov, Enrico Costa, Michal Dovciak, Hua Feng, Jeremy Heyl, Adam Ingram, Keith Jahoda, Philip Kaaret, Timothy Kallman, Vladimir Karas, Ildar Khabibullin, Henric Krawczynski, Julien Malzac, Frederic Marin, Herman Marshall, Giorgio Matt, Fabio Muleri, Carole Mundell, Mark Pearce, Pierre-Olivier Petrucci, Juri Poutanen, Roger Romani, Andrea Santangelo, Gianpiero Tagliaferri, Roberto Taverna, Roberto Turolla, Jacco Vink, Silvia Zane. 2019-10-22. ESA Voyage 2050 white paper: A Polarized View of the Hot and Violent Universe. https://arxiv.org/abs/1910.10092

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