The seminar of the Astro & Theory Section takes place Thursdays (alternating with the Journal Club) in E3-128 and on zoom, starting normally at 14.15. If you would like to suggest a seminar speaker or want to be added to the email list, please contact the organizer (Michael.Kachelriess@ntnu.no).
A list of seminars in the previous and the current years can be accessed in the sidebar; the (planned) seminars in 2021 are
- 17.02., Marco Turchetta (IFY, NTNU): Searches and characterisation of optical and X-ray pulsations from candidate millisecond pulsars
Abstract: In recent years three transitional millisecond pulsars (tMSPs) have been identified, showing transitions between rotation and accretion-powered pulsar state. In 2016 the SiFAP2/TNG (INAF) optical photometer unveiled for the first time optical pulsations from one of these systems, PSR J1023 + 0038 (J1023). The issues in explaining this phenomenon in terms of emission fed by either rotation or accretion power have fostered the formulation of new models, in which both the two mechanisms conspire to yield the emission of optical pulsations. During this talk I will present the results obtained in my master thesis work, which was aimed to gain insight into the nature of these optical pulsations. At this purpose, I have performed periodicity searches in optical and X-ray band from five candidate tMSPs, all showing the same multi-wavelength emission features observed in both the two states of J1023. - 21.02., Patrick Reichherzer (RUB Bochum): Influence of diffusive cosmic-ray transport on multimessenger observables
Abstract: Cosmic-ray transport in astrophysical environments is often dominated by diffusion in a magnetic field with a turbulent component. The diffusion properties of charged particles directly influence observable properties, such as the spectrum of cosmic rays and their secondaries produced in interactions. In many diffusion scenarios, the simplified assumption of fully resonant Kolmogorov diffusion in the quasi-linear limit results in a parallel diffusion coefficient D ~ E^(1/3). A quantitative investigation of the scattering regimes, however, shows that the diffusion coefficient tensor can deviate significantly from this behaviour. In this talk, the complex dependencies of charged particle diffusion on the turbulence level of the magnetic field are presented. Examples of how this affects observational signatures will be shown in the context of galaxies or the transient sky, i.e., flaring Blazars. - 10.03., Robert Plantey (NTNU):
23.03., Gabriela Barcenas Enrique (Universidad de Guanajuato; NTNU):
- 07.04., Inga Strumke (AI Lab, NTNU):