New type of cosmic explosion:

Discussion in 'Astronomy, Exobiology, & Cosmology' started by paddoboy, Nov 15, 2017.

  1. paddoboy Valued Senior Member

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    https://phys.org/news/2017-11-astronomers-cosmic-explosion.html

    Astronomers discover new type of cosmic explosion

    An international team of astronomers, including a University of Southampton expert, has discovered a new type of explosion in a distant galaxy.

    The explosion, called PS1-10adi, seems to prefer active galaxies that house supermassive black holes consuming the gas and material around them.

    Using telescopes on La Palma and Hawaii, the team detected an explosion that was so energetic it must have originated from one of two sources: an extremely massive star – up to several hundred times more massive than our Sun – exploding as a supernova, or from a lower mass star that has been shredded by the ultra-strong gravitational forces close to the supermassive black hole.

    The explosion – detailed in a study published in Nature Astronomy – occurred 2.4 billion years ago, but the enormous distance that light from the event had to travel to reach Earth meant it wasn't observed by astronomers until 2010. The slow evolution of the explosion allowed scientists to monitor it for several years.



    Read more at: https://phys.org/news/2017-11-astronomers-cosmic-explosion.html#jCp

    the paper:

    https://www.nature.com/articles/s41550-017-0290-2

    A population of highly energetic transient events in the centres of active galaxies

    Abstract
    Recent all-sky surveys have led to the discovery of new types of transients. These include stars disrupted by the central supermassive black hole, and supernovae that are 10–100 times more energetic than typical ones. However, the nature of even more energetic transients that apparently occur in the innermost regions of their host galaxies is hotly debated1,2,3. Here we report the discovery of the most energetic of these to date: PS1-10adi, with a total radiated energy of ~2.3 × 1052 erg. The slow evolution of its light curve and persistently narrow spectral lines over ∼ 3 yr are inconsistent with known types of recurring black hole variability. The observed properties imply powering by shock interaction between expanding material and large quantities of surrounding dense matter. Plausible sources of this expanding material are a star that has been tidally disrupted by the central black hole, or a supernova. Both could satisfy the energy budget. For the former, we would be forced to invoke a new and hitherto unseen variant of a tidally disrupted star, while a supernova origin relies principally on environmental effects resulting from its nuclear location. Remarkably, we also discover that PS1-10adi is not an isolated case. We therefore surmise that this new population of transients has previously been overlooked due to incorrect association with underlying central black hole activity.

    https://www.nature.com/articles/s41550-017-0290-2
     

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