UM Today: A kilonova in our neighbourhood
Not “super,” but still pretty good
FEBRUARY 4, 2019 — As UM Today reports:
An international team of researchers, led by U of M astrophysicist Dr. Samar Safi-Harb, proposes that the merging of two neutron stars relatively near the Earth has created a “kilonova remnant” – opening a new window to studying this astrophysical phenomenon.
Safi-Harb notes: “The X-ray emission from the kilonova event has been interpreted in the literature as something other than thermal emission. But we now have hints of thermal, hot glowing X-ray gas, that could arise from a newborn kilonova remnant (KNR).“
IMAGINE WHAT HAPPENS WHEN TWO NEUTRON STARS COLLIDE
When massive stars more than eight times the mass of our Sun reach the end of their lives, they explode. These supernova explosions release huge outbursts of energy that can outshine an entire galaxy, and can be detected by Earth-based telescopes, despite their immense distances from us.
Left behind, inside these supernovas, are stellar cores that are compressed to extreme densities, sometimes converted to neutron degenerate matter, or neutron stars. They are so dense and massive, a teaspoon of such matter would weigh tens of millions of tonnes.
Neutron stars can emit radiation across the electromagnetic spectrum and can have some of the strongest magnetic fields in nature. In fact, some have such strong magnetic fields, they are known as magnetars.
It gets weirder. Some neutron stars are in binary systems, and in such an arrangement can pull matter from their companion stars and increase their rotation periods to incredible levels, even to milliseconds. And because of their high density and gravity, neutron stars can bend light, create time dilation, and cause huge redshifts of the wavelengths of light trying to escape from their surface.
So imagine what happens when two neutron stars collide.