时间：2018年5月9日（周三）上午10：30

　　地点：主楼415会议室

　　报告人：Prof. Dieg. F. Torres

　　主持人：张澍 研究员

　　题目：Unifying interpretation of the high-energy spectra of pulsars

　　摘要：

　　From the hundreds of gamma-ray pulsars known, only a handful show non-thermal X-ray pulsations. Instead, nine objects pulse in non-thermal X-rays but lack counterparts at higher energies. I will present a physical model for the non-thermal emission of pulsars above 1 keV. With just four physical parameters, I fit the spectrum of the gamma/X-ray pulsars along eight orders of magnitude in energy. I find that all detections can be encompassed in a continuous variation of the model parameters, and pose that their values could likely relate to the closure mechanism operating in the accelerating region. The model explains the appearance of sub-exponential cutoffs at high energies as a natural consequence of synchro-curvature dominated losses, unveiling that curvature-only emission may play a relatively minor role --if any-- in the spectrum of most pulsars. The model also explains the flattening of the X-ray spectra at soft energies as a result of propagating particles being subject to synchrotron losses all along their trajectories. Using this model, I show how observations in gamma-rays can predict the detectability of the pulsar in X-rays, and viceversa.

　　个人简介：

　　I was born in Buenos Aires, Argentina, where I studied up to obtaining my doctoral degree in physics from the National University at La Plata, working on cosmology and astrophysics of extended gravitational theories. After several years in fellowships (Astronomy Centre of Sussex University in UK, Institute for Radioastronomy in Argentina, Princeton University and the Lawrence Livermore Laboratory in the USA) and some stays in Italy (International Center for Theoretical Physics at Trieste, Salerno University at Baronissi), I moved to Barcelona, to work at the Institute of Space Sciences and start a research group on high-energy astrophysics in 2006. My research focuses on compact objects and cosmic rays. Lately, I have mostly focused on pulsars, pulsar wind nebulae, transitional pulsars, and gamma-ray binaries. My earlier research includes gravitation and cosmology; particularly, scalar-tensor theories and non-minimal couplings, scalar dark matter, boson stars, gravitational lensing, and wormholes. I published several papers on all these topics. I became Director of the Institute of Space Sciences in March, 2016.