A brand-new ultra-bright source of X-rays has actually awakened in between our stellar next-door neighbors the Magellanic Clouds, after a 26-year rest. This is the second-closest such things understood to date, with a brightness higher than a million Suns. The discovery is released in the journal Monthly Notices of the Royal Astronomical Society.
The things, called RX J0209.6-7427, was very first found throughout a 6-month long outburst in 1993. Though it was at first recognized as a Be-type X-ray binary, its real nature stayed a secret as it remained in an inactive state for the next 26 years, just flaring once again in November in 2015.
Now, a group of Indian researchers have actually utilized AstroSat, India’s very first devoted area observatory, to expose the severe nature of the source, and have actually found broad-energy X-ray pulsations in the things for the very first time. This categorizes it as a kind of things called an ultra-luminous X-ray pulsar (ULXP).
The pulsar lies in the Magellanic Bridge, a stream of gas and stars connecting the Magellanic Clouds. These are 2 of our nearby stellar buddies, and a few of the most remote things noticeable to the naked eye. The brand-new X-ray source is the second-closest ULXP understood to date, after a 2018 discovery in our own Milky Way galaxy, and is just the 8th such things ever found.
Ultra-luminescent X-ray sources are observable as single points in the sky, however with brightnesses equivalent to whole galaxies. “The conventional theory is that in order to shine so brightly, ULXPs must be glowing accretion discs around black holes,” stated Amar Deo Chandra, lead author on the brand-new research study. “However, recent discoveries of pulsations in these objects suggest that they may in fact have neutron stars at their heart.”
A neutron star is the residue of a dead star which contains as much matter as our Sun, however is compressed into a small radius of just 10km – the size of a little city. The neutron star in this things is believed to be spinning as quickly as 100 times per 2nd, and discharges pulses of energetic X-rays from its magnetic poles, causing the brand-new ‘X-ray pulsar’ category.
The group of astronomers, from IISER Kolkata, IUCAA Pune and the Center for Excellence in Basic Sciences (UM-DAE CEBS) Mumbai, have actually likewise discovered that the pulsar might even be accelerating, triggering brilliant X-ray ‘fireworks’. This is believed to take place when the neutron star catches product from a buddy star, injecting energy into the system and accelerating the rotation.
The shortage of comparable sources makes identifying and studying brand-new ULXPs vital for X-ray astronomers looking for to comprehend the Universe.
“This is only the eighth ULXP detected so far, and the first one near the Magellanic Clouds,” Chandra includes. “It raises the interesting possibility that a significant fraction of ultra-luminous X-ray sources may really be neutron stars accreting at super Eddington rates, rather than black holes as previously thought.”
Reference: “Study of recent outburst in the Be/X-ray binary RX J0209.6−7427 with AstroSat: a new ultraluminous X-ray pulsar in the Magellanic Bridge?” by Amar Deo Chandra, Jayashree Roy, P C Agrawal and Manojendu Choudhury, 3 June 2020, Monthly Notices of the Royal Astronomical Society.