The so-called Magnificent Seven neutron stars
like RXJ1856.5-3754 and RXJ0720.4-3125 are of particular
interest, because one can observe directly the
surface and, hence, one can in principle
determine mass, radius, and spin, in order
to constrain the equation-of-state.
We investigate isolated neuron stars such as the Magnificent Seven in various ways:
X-ray spectroscopy, proper motion
by deep optical and X-ray imaging, deep radio
observations.
We also search for more such radio-quiet neutron stars,
which can be found by their large X-ray to optical flux
ratio with soft X-ray and blue optical emission:
We use deep X-ray pointings from ROSAT and XMM and
perform deep optical follow-up observations of unidentified
soft sources.
In addition, we also use deep optical pointings of large
telescopes, found in public archives, to search for very
faint objects, which are blue and/or fast moving.
Furthermore, we model the neutron star population
of the Galactic disk and the Gould Belt, using cooling
curves and a 3D absorption model.
We also consider the relevance of such neutron stars to
gravitational wave astronomy regarding both the equation
of state and the emission of gravitational waves.
We participate in the SFB / TR 7 "Gravitational Wave Astronomy" with one project on neutron stars.
We closely collaborate with G. Hasinger, F. Haberl, J. Trümper (MPE Garching), K. Werner (Uni Tübingen), as well as S. Popov (Sternberg, Moskau) and B. Posselt (CFA Harvard).
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