【6.6; Seminar】2025年粒子天体物理全国重点实验室系列学术报告 #10：Accretion disc winds in X-ray binaries；#11：Galactic magnetized halo related to the eROSITA Bubbles

时间/Time: 6月6日周五下午2:00/Friday, June 6, 2:00 p.m.

地点/Location: 多学科楼229会议室/Meeting Room 229, Multidisciplinary building

报告人/Speaker: Dr. Gabriele Ponti and Dr. Heshou Zhang (INAF Osservatorio Astronomico di Brera)

主持人/Host: 陈松战/Songzhan Chen

腾讯会议号/ meeting.tencent：973-986-894

https://meeting.tencent.com/dm/ZkbYJa0Qygyh

题目1/Title 1: Accretion disc winds in X-ray binaries

摘要1/Abstract 1:

The detection of X-ray binaries at PeV energies has renewed interest in outflows from these systems and their interaction on interstellar medium. Over the past decades, high-resolution X-ray observations have revealed narrow absorption lines in the Fe K band in several X-ray binaries, indicating the presence of highly ionised plasma. Grating spectroscopy has shown that this plasma is often outflowing, forming equatorial winds typically detected during the soft spectral state. On the contrary, these highly ionised winds are typically absent during the hard state. The mass outflow rate associated with these winds is often comparable or larger than the mass accretion rate, suggesting that these winds may play a fundamental role in regulating accretion physics. Evidence of lower ionisation winds has also been observed in the optical and infrared bands, further strengthening their importance in the broader context of X-ray binary physics. I will present an historical overview of wind studies in X-ray binaries and I will discuss their relevance for accretion physics.

个人简介1/Biography 1:

Dr. Gabriele Ponti, first researcher (Primo Ricercatore) in INAF Osservatorio Astronomico di Brera. He is the PI of ERC Consolidate project "The Hot phase of the Milky Way". He is an X-ray astronomer with world-leading results on X-ray emission from AGN, X-ray binaries, the Galactic center, the hot circumgalactic medium of the Milky Way and of external galaxies, as well as of the X-ray background. Recently, he got especially interested in the X-ray counterparts of the ultra high energy sources that the team in IHEP have been finding. He is looking forward to meeting and discussing with experts in IHEP during his visit.

题目2/Title 2: Galactic magnetized halo related to the eROSITA Bubbles

摘要2/Abstract 2:

The large-scale structures such as Fermi Bubbles and eROSITA Bubbles provide a unique opportunity to study our Milky Way. However, the nature and origin of these large structures are still under debate. In this talk, I will present the identification of several kpc-scale magnetised structures based on their polarized radio emission and their gamma-ray counterparts, which can be interpreted as the radiation of relativistic electrons in the Galactic magnetic halo. These non-thermal structures extend far above and below the Galactic plane and are spatially coincident with the thermal X-ray emission from the eROSITA Bubbles. Multi-wavelength spectral energy distribution analyses have revealed that both thermal and non-thermal extended structures can be explained by Galactic outflows driven by the active star-forming regions located at 3 − 5 kpc from the Galactic Centre. These results reveal how X-ray-emitting and magnetised halos of spiral galaxies can be related to intense star formation activities.

个人简介2/Biography 2:

Dr. Heshou Zhang, researcher in INAF Osservatorio Astronomico di Brera working with Dr. Ponti. His expertise includes magnetic field measurements in the universe, Galactic Center outflows and multi-wavelength observational analysis on gamma-ray sources. The presentation is based on our recent work Zhang, Ponti et al. 2024 Nature Astronomy, https://ui.adsabs.harvard.edu/abs/2024NatAs...8.1416Z/abstract.