by
Albert Kong(Institute of Astronomy, National Tsing Hua University, Taiwan)
→
Europe/Stockholm
Description
The evolutionary and formation of millisecond pulsars (MSPs) has long
been a subject of inquiry, and one widely accepted version is that an
old neutron star has been spun up to a spin period on the order of
millisecond via accretion from a late-type companion which transferred
mass and angular momentum to the pulsar. Once the accretion has
stopped, the relativistic, strongly magnetized pulsar wind will
possibly carry away the pulsar rotational energy and angular momentum, meanwhile ablate and eventually evaporate its companion. It is generally believed that radio MSPs can only be turned on when the mass transfer from the companion star is extremely low. However, the
observational evidence of such transition has not been found until
recently. In this talk, I will review recent discoveries of "transformer" MSPs that switch between low-mass X-ray binaries and radio MSPs. I will also discuss how multi-wavelength observations reveal a new population of black widow/redback MSPs that provides new
insight into MSP's emission mechanisms and the physics of compact
objects.