Principal Research Topics
Dr Philipp Podsiadlowski
1. Binaries Containing Compact Objects
- The theory of low- and intermediate-mass
X-ray binaries (LMXBs/IMXBs) and their relation to millisecond pulsars .
- Recent studies have shown that the majority of
LMXBs may in fact be descendants of IMXBs and that the standard model
is wholly inappropriate.
- Possible solution: irradiation-driven
mass-transfer cycles: requires the modelling of irradiated
secondaries (Sam Phillips) and
in particular of the irradiation-driven circulation
- The evolution of black-hole binaries (e.g. Nova Sco, GRS 1915+105).
- The origin of ultracompact
binaries, binaries with periods as short as 11 min
(e.g. X1820-303, AM CVn binaries).
- Collaborators: Saul Rappaport
(M.I.T.), Eric Pfahl (CfA, Harvard), Rosemary Mardling (Monash)
2. Supernovae in Binaries
- Modelling the evolution of the progenitors of
(i.e. the explosion of massive stars), in particular SN 1987A and
SN 1993J (SN 2000cl).
- SN 1987A was the first naked-eye supernova
since Kepler's Supernova in 1604 and is most likely the result
of the merger of two massive stars
inside a common envelope (press release).
- Hydrodynamical modelling of the formation of the triple-ring nebula around SN 1987A (Thomas Morris).
3. Type Ia Supernovae
- Type Ia supernovae, the thermonuclear
explosions of a massive white dwarf leading to its complete
disruption, have been used in recent years to measure the acceleration
of the Universe.
- However, the nature of their progenitors has remained a major
- Study progenitor models and the presupernova structure
- Model their population using binary population synthesis (Zhanwen Han [Kunming]).
4. Gamma-Ray Bursts (GRBs) and Hypernovae
- Gamma-ray bursts are short flashes of mainly gamma-rays,
lasting from a fraction of a second to tens of minutes.
- The identification of optical
counterparts in 1998 has shown that they may be
the most energetic events in the Universe, visible throughout the
- Some GRBs are now known to be associated with
hypernovae, very energetic
supernovae, possibly caused by the
collapse of a massive helium core into a black hole.
- Study possible progenitor
models for both hypernovae and GRBs and understand
their implications for galaxy formation
(with Joe Silk).
- Collaborators: Enrico Ramirez-Ruiz
(Princeton), Martin Rees (Cambridge), Ken Nomoto (Tokyo), Paolo Mazzali (Trieste)
List of abstracts and published papers