VLASS tagged posts

Stellar Collision Trggers Supernova Explosion

Credit: Bill Saxton, NRAO/AUI/NSF

Astronomers have found dramatic evidence that a black hole or neutron star spiraled its way into the core of a companion star and caused that companion to explode as a supernova. The astronomers were tipped off by data from the Very Large Array Sky Survey (VLASS), a multi-year project using the National Science Foundation’s Karl G. Jansky Very Large Array (VLA).

“Theorists had predicted that this could happen, but this is the first time we’ve actually seen such an event,” said Dillon Dong, a graduate student at Caltech and lead author on a paper reporting the discovery in the journal Science.

The first clue came when the scientists examined images from VLASS, which began observations in 2017, and found an object brightly emitting radio waves but ...

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Newborn Jets in Distant Galaxies – Jets ‘turned on’ in past two decades or so.

Credit: Sophia Dagnello, NRAO/AUI/NSF

Comparing data from VLA sky surveys made some two decades apart revealed that the black hole-powered ‘engines’ at the cores of some distant galaxies have launched new, superfast jets of material during the interval between the surveys.

Astronomers using data from the ongoing VLA Sky Survey (VLASS) have found a number of distant galaxies with supermassive black holes at their cores that have launched powerful, radio-emitting jets of material within the past two decades or so. The scientists compared data from VLASS with data from an earlier survey that also used the National Science Foundation’s Karl G. Jansky Very Large Array (VLA) to reach their conclusion.

“We found galaxies that showed no evidence of jets before but now show clear indicati...

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