India's pioneering space astronomy observatory, AstroSat, has facilitated an international team of scientists in uncovering the enigmatic nature of the X-ray binary system known as MAXI J1820+070, home to a black hole, announced ISRO. X-ray binaries, named for their emission of X-rays, comprise a normal star and a collapsed star, which may manifest as a white dwarf, neutron star, or a black hole, as per NASA. MAXI J1820+070 is identified as a low-mass X-ray binary housing a black hole as a compact entity.
The study, titled "A Multi-Wavelength Spectral Study of MAXI J1820+070 in the Soft and Hard States," conducted by an international team, "provides distinctive insights into the behavior of this transient black hole X-ray binary during its 2018 outburst," said a statrement from the ISRO.
The team, spearheaded by researchers from the Inter-University Centre for Astronomy and Astrophysics, Pune, incorporates scientists from India, the United Kingdom, Abu Dhabi, and Poland. This comprehensive analysis has been accepted for publication in The Astrophysical Journal. Positioned at a distance of 9,800 light-years from Earth, MAXI J1820+070 was initially detected during its outburst in 2018 utilizing the MAXI instrument aboard the International Space Station (ISS), ISRO revealed. Owing to its proximity to Earth and its remarkable luminosity upon discovery, emerging as the second brightest object in the X-ray sky, MAXI J1820+070 garnered substantial attention within the astronomy community, prompting numerous observation campaigns across various electromagnetic bands, elucidated the agency.
Equipped with three X-ray payloads and a UV telescope, AstroSat captured soft and hard X-ray emissions as well as far ultraviolet radiation, portraying an intricate depiction of the nearby and distant regions encompassing the black hole in MAXI J1820+070. Through collaboration with the Las Cumbres Observatory on optical data and NASA's NICER mission on soft X-ray data, the team comprehended the dynamics of the X-ray binary system, as reported by ISRO. "The study uncovers compelling revelations about the accretion states of MAXI J1820+070. Black hole X-ray binaries such as MAXI J1820+070 frequently exhibit multiple accretion states throughout an outburst," ISRO added.
Employing advanced techniques, the researchers disclosed the black hole's spin, shedding light on its fundamental properties. "The significance of this study extends beyond MAXI J1820+070, underscoring the pivotal role of AstroSat in advancing the understanding of transient black hole X-ray binaries," noted ISRO.
