<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Vasilopoulos, G.</style></author><author><style face="normal" font="default" size="100%">Haberl, F.</style></author><author><style face="normal" font="default" size="100%">Carpano, S.</style></author><author><style face="normal" font="default" size="100%">Maitra, C.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">NGC 300 ULX1: A test case for accretion torque theory</style></title><short-title><style face="normal" font="default" size="100%">Astronomy and Astrophysics</style></short-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Astrophysics - High Energy Astrophysical Phenomena</style></keyword><keyword><style  face="normal" font="default" size="100%">galaxies: individual: NGC 300</style></keyword><keyword><style  face="normal" font="default" size="100%">pulsars: individual: NGC 300 ULX1</style></keyword><keyword><style  face="normal" font="default" size="100%">stars: neutron</style></keyword><keyword><style  face="normal" font="default" size="100%">X-rays: binaries</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2018</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2018/12/1</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://ui.adsabs.harvard.edu/abs/2018A&amp;A...620L..12V</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">620</style></volume><pages><style face="normal" font="default" size="100%">L12</style></pages><isbn><style face="normal" font="default" size="100%">0004-6361</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">NGC 300 ULX1 is a newly identified ultra-luminous X-ray pulsar. The system is associated with the supernova impostor SN 2010da that was later classified as a possible supergiant Be X-ray binary. In this work we report on the spin period evolution of the neutron star based on all the currently available X-ray observations of the system. We argue that the X-ray luminosity of the system has remained almost constant since 2010, at a level above ten times the Eddington limit. Moreover, we find evidence that the spin period of the neutron star evolved from ∼126 s down to ∼18 s within a period of about 4 years. We explain this unprecedented spin evolution in terms of the standard accretion torque theory. An intriguing consequence for NGC 300 ULX1 is that a neutron star spin reversal should have occurred a few years after the SN 2010da event.</style></abstract></record></records></xml>