Speaker
Mr
Francesco Coti Zelati
(Anton Pannekoek Institute for Astronomy, University of Amsterdam)
Description
In 2013 April a new magnetar, SGR 1745−2900, was discovered as it entered an outburst at
only 2.4 arcsec angular distance from Sagittarius A∗, the supermassive black hole at the centre of the Milky Way. The new source was detected both in the radio and X-ray bands, with a peak X-ray luminosity L_X ∼ 5 × 10^{35} erg s^{−1}. I will present the results of the long-term Chandra (25 observations) and XMM–Newton (eight observations) X-ray monitoring campaign of SGR 1745−2900 from the onset of the outburst in 2013 April until 2014 September. This unprecedented data set has unveiled an extremely slow flux decay for the source, and a rather inefficient surface cooling. I will show how starquake-induced
crustal cooling models alone have difficulty in explaining the prolonged high luminosity of the source for the first ∼200 days of its outburst. Additional heating of the star surface from currents flowing in a twisted magnetic bundle is probably playing an important role in the outburst evolution.
Primary author
Mr
Francesco Coti Zelati
(Anton Pannekoek Institute for Astronomy, University of Amsterdam)
