Marius Hertfelder

• The Boundary Layer in Compact Binaries

I am currently working on my PhD in the group of Wilhelm Kley. In my work I mainly deal with Accretion Disk Boundary Layers (BL).

Context. The Boundary Layer (BL) is an ubiquitous phenomenon which occurs when accretion processes in astrophysical problems take place. Albeit a large fraction of the total luminosity of the system (the BL may contribute as much as one half of the accretion luminosity) originates from this tiny layer connecting the accretion disk and the accreting object, it has, however, not yet been accomplished to find a generally accepted description of this area.
Aims. It is the aim of my studies to get more insight into the structure of the BL and develop a model which meets the yet known requirements and is in good accordance with the experimental (observational) data. Further aims are the clarification of the mechanism, that transports angular momentum within the BL and the possible contribution of the BL to phenomena like rapid oscillations in cataclysmic variables (DNOs, QPOs) and outbursts in a variety of systems.
Methods. Since the governing equations of the problem are the Navier-Stokes-Equations (the gas flow in an accretion disk can obviously be treated by means of fluid dynamics), which are nonlinear partial differential equations of order 2, we are not (yet) capable of solving the problem in an analytical manner. Instead we rely on numerical codes based on finite differences and finite volumes methods in order to simulate the region of interest. This field of science is called Computational Fluid Dynamics (CFD) and combines physics with both numerics and computer science.

• Accretion Processes in Astrophysics
• Cataclysmic Variables
• Computational Fluid Dynamics
• Computer Science / Programming

• M. Hertfelder, W. Kley:
  The vertical structure of the boundary layer around compact objects
  Accepted by Astronomy & Astrophysics
  (ArXiv: 170507658H)

• M. Hertfelder:
  The boundary layer in compact binaries
  Proceedings of Science (Golden2015) 044
  (ArXiv: 170206726H)

• M. Hertfelder, W. Kley:
  Wave mediated angular momentum transport in astrophysical boundary layers
  Astronomy & Astrophysics, Volume 579, id.A54, 07/2015
  (ADS: 2015A&A...579A..54H)

• V. Suleimanov, M. Hertfelder, K. Werner, W. Kley:
  Modeling the EUV spectra of optically thick boundary layers of dwarf novae in outburst
  Astronomy & Astrophysics, Volume 571, id.A55, 11/2014
  (ADS: 2014A&A...571A..55S)

• M. Hertfelder, W. Kley, V. Suleimanov, K. Werner:
  The boundary layer in compact binaries
  Astronomy & Astrophysics, Volume 560, id.A56, 12/2013
  (ADS: 2013A&A...560A..56H)

• M. Hertfelder:
  Die Grenzschicht von Akkretionsscheiben um junge Sterne
  Diploma Thesis, University of Tübingen, 2012.
  (Résumé/Short Version)

• WS 2016/2017: Physikalisches Praktikum für Mediziner und Zahnmediziner
• SS 2016: Physikalisches Praktikum für Mediziner und Zahnmediziner
• WS 2015/2016: Übungen zur Vorlesung Physik Integrierter Kurs 1
• SS 2015: Übungen zur Vorlesung Physik Integrierter Kurs 2
• WS 2014/2015: Übungen zur Vorlesung Physik Integrierter Kurs 1
• SS 2014: Übungen zur Vorlesung Physik Integrierter Kurs 2
• WS 2013/2014: Übungen zur Vorlesung Physik Integrierter Kurs 1
• SS 2013: Übungen zur Vorlesung Physik Integrierter Kurs 2
• WS 2012/2013: Physikalisches Praktikum für Mediziner und Zahnmediziner
• SS 2012: Physikalisches Praktikum für Mediziner und Zahnmediziner
• WS 2011/12: Physikalisches Praktikum für Mediziner und Zahnmediziner
• SS 2011: Physikalisches Praktikum für Mediziner und Zahnmediziner
• WS 2010/11: Physikalisches Praktikum für Mediziner und Zahnmediziner