Wide coverage for persistent and mysterious blast, neutron star merger, black hole gobbler, what’s-it billions of l.y. away
(Late addition – sheesh. I composed this yesterday and somehow forgot to push the little <publish> command. It was already late, now even later)
Last week we got a burst of news, and burst is the term to use, over a strangely prolonged and tumultuous stream of X-rays and gamma rays detected to have suddenly spewed from something or other in a galaxy some 3.8 billion light years away.
It lasted more than a week, flaring, sputtering and hiccupping erratically and for all I know is still going on. That rules out any variant of a gamma ray burst – which has a peak that lasts typically only a second or two tops and then goes into a steady fade. Theorists see two ways to make them, and hence two kinds of gamma ray bursts – jets of tortured radiation and matter spewed from near the core of a large, exhausted star collapsing into a black hole and bouncing most of itself into a supernova explosion, or jets of tortured radiation and matter spewing from the merger of two neutron stars that also form a black hole remnant.
The new and puzzling news is such a jet, but one that went on and on and that NASA’s Swift satellite detected March 28 in the constellation Draco. It got a catalog number(GRB) 110328A. GRB is just a catalog heading and stands for gamma ray burst even though this is not, nearly all agree, a GRB. Other space telescopes joined the inspection, including the Hubble and the Chandra X-ray Observatory. That’s an all-star lineup.
The news was released April 7. Much speculation ensued in print. Most followed NASA’s press release declaration that the leading explanation is the tidal shredding and consumption of a star by a supermassive black hole at the center of a galaxy.
Stories:
- Wired-UK – Mark Brown: Nasa’s telescopes team up over puzzling cosmic explosion ;
- New Scientist – Caitlin Stier: Black hole unleashes enduring cosmic blast ; Nice, except it uses imagery one often encounters but seems amiss to these eyes. A star, it says, “wandered too close” to a black hole, as though it were a little antelope strolling along nibbling daisies and suddenly POUNCE, a leopard grabbed it by the throat. Stars don’t wander when they get anywhere near black holes, they follow sharply prescribed orbits and only when they get swept up in an accretion disk and lose energy do they spiral inward to destruction. It’s a drawn out thing. That’s unless they are unlucky enough to get somehow aimed straight at the black hole. Then it’s a straight line until doom is upon them and frame dragging or other weird physics whip them to bits.
- Science News – Ron Cowen : Baffling Blowup in distant Galaxy ; This has the standard black hole and star eating scenario, plus Cowen stirs himself to call a famed UC Santa Cruz supernova authority and is rewarded with an alternative to the hypothesis that NASA spoon fed to media in its press release.
- Universe Today – Nancy Atkinson: Space Telescopes Observe Unprecedented Explosion;
- ScienceNOW – Yudhijit Bhattacharjee: Star-Eating Black Hole May Be Producing Universe Biggest Blast ; Emphasizes that while ordinary GRBs are huge blasts, this is like a firecracker string of them – an immense total energy output.
- Popular Science – Clay Dillow: Unprecedented Cosmic Explosion Spawns an Intergalactic Mystery ; Another rewrite of handouts, iwth a mystery in the headline of PopSci’s making. Yes, this is fussy. But how can one event in one galaxy be an intergalactic mystery? It seems not to be among or between galaxies. It’s inside just one, an intragalactic mystery at most unless and until it is shown to have some collective, galactic significance.
- Bad Astronomy blog via Discover Magazine – Phil Plait: two posts, Astronomers May Have Witnessed a Star Torn Apart by a Black Hole ; which explains that this event looks like the opposite of a GRB in which a star makes a black hole. Here, a black hole unmakes a star. Second post , Followup on the star torn apart by a black hole: Hubble Picture ;
Grist for the Mill: NASA Press Release ; arXiv paper ;
- Charlie Petit
