Bildquelle: http://www.scinexx.de/wissen-aktuell-bi ... 25596.html
Quelle und ganzer Text: http://www.scinexx.de/wissen-aktuell-18 ... 11-07.htmlRätselhaftes Flackern: Ein Schwarzes Loch im Herzen einer fernen Galaxie sendet Gammastrahlen-Lichtblitze aus, die schneller flackern, als es nach bisherigen Vorstellungen möglich schien. Das Rätsel dieses "unmöglichen" Wetterleuchtens haben Astronomen nun gelöst: Die flackernden Blitze stammen nicht von der in das Loch stürzenden Materie, sondern enstehen im Plasmajet, so die Forscher im Fachmagazin "Science".
Quelle und ganzer Text: http://www.sciencemag.org/content/early ... 3.abstract / http://www.sciencemag.org/content/early ... /suppl/DC1Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry but still suffer from insufficient angular resolution. An alternative method to resolve small structures is to measure the time variability of their emission. Here we report on gamma-ray observations of the radio galaxy IC 310 obtained with the MAGIC telescopes, revealing variability with doubling time scales faster than 4.8 min. Causality constrains the size of the emission region to be smaller than 20% of the gravitational radius of its central black hole. We suggest that the emission is associated with pulsar-like particle acceleration by the electric field across a magnetospheric gap at the base of the radio jet.
Quelle und ganzer Text: https://magic.mpp.mpg.de/The MAGIC Telescopes captured an extreme event coming from the regions immediately surrounding a supermassive black hole located in the heart of the radio galaxy IC310. During the extraordinary outburst of gamma rays the source showed the very rapid flux variations. Ancillary observations using the European VLBI network of radio telescopes showed a remarkably straight plasma jet emerging from the vicinity of a supermassive black hole at the center of the galaxy. The flickering of the gamma-ray flare on time scales of less than five minutes shows that it originated from a region smaller than the event horizon of the black hole. The finding supports the idea that the observed emission was due to particles accelerated in an extremely narrow region located near the event horizon of the black hole and permeated by strong electric fields. Such structures are expected to form near rapidly-spinning black holes that power radio jets by their rotational energy loss.
This exceptional result obtained by using the MAGIC and EVN telescopes has been published on the issue of November 6th, 2014 of magazine Science Express