7,808 research outputs found
New Direct Observational Evidence for Kicks in SNe
We present an updated list of direct strong evidence in favour of kicks being
imparted to newborn neutron stars. In particular we discuss the new cases of
evidence resulting from recent observations of the X-ray binary Circinus X-1
and the newly discovered binary radio pulsar PSR J1141-6545. We conclude that
the assumption that neutron stars receive a kick velocity at their formation is
unavoidable (van den Heuvel & van Paradijs 1997).Comment: 2 pages, to appear in the proceedings of the IAU Colloq. 177 "Pulsar
Astronomy - 2000 and beyond
Comment on "A non-interacting low-mass black hole -- giant star binary system"
Thompson et al. (Reports, 1 November 2019, p. 637, Science) interpreted the
unseen companion of the red giant star 2MASS J05215658+4359220 as most likely a
black hole. We argue that if the red giant is about one solar mass, its
companion can be a close binary consisting of two main-sequence stars. This
would explain why no X-ray emission is detected from the system.Comment: 3 pages, Author version of Technical Comment published in Science on
8 May, 202
Exploring a multi-faceted framework for SOC: How to develop secure web-service interactions? (An extended abstract).
Discovery of Two Relativistic Neutron Star-White Dwarf Binaries
We have discovered two recycled pulsars in relativistic orbits as part of the
first high-frequency survey of intermediate Galactic latitudes. PSR J1157-5112
is a 44 ms pulsar and the first recycled pulsar with an ultra-massive (M > 1.14
Mo) white dwarf companion. Millisecond pulsar J1757-5322 is a relativistic
circular-orbit system which will coalesce due to the emission of gravitational
radiation in less than 9.5 Gyr. Of the ~40 known circular orbit pulsars,
J1757-5322 and J1157-5112 have the highest projected orbital velocities. There
are now three local neutron-star/white-dwarf binaries that will coalesce in
less than a Hubble time, implying a large coalescence rate for these objects in
the local Universe. Systems such as J1141-6545 (Kaspi et al. 2000) are
potential gamma-ray burst progenitors and dominate the coalescence rate, whilst
lighter systems make excellent progenitors of millisecond pulsars with
planetary or ultra-low mass companions.Comment: 4 pages, to appear in ApJ Letters. Uses aastex v 5.0,
emulateapj5.sty, apjfonts.st
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