Milky Way Galaxey Harboring a Black Hole as of September 5, 2001

The Chandra X-ray Observatory, NASA's flagship mission for X-ray astronomy, has played a significant role in confirming the active accretion of matter in Sagittarius A (Sgr A), the supermassive black hole at the centre of our Milky Way galaxy.

In October 2000, the observatory detected a powerful X-ray flare from Sgr A, an event that provided definitive evidence of its active accretion of matter. This discovery resolved prior ambiguity regarding the nature of Sgr A.

Astronomers from the Smithsonian Astrophysical Observatory and other collaborating institutions, led by scientists such as Frederick K. Baganoff, were involved in observing this rapid and strong X-ray flare in 2001. The sharpness of the imagery from Chandra and the violence of the flare dispelled any doubts about the presence of a supermassive black hole at the centre of the Milky Way.

Sgr A had long been assumed to be at the centre of the Milky Way based on infrared and radio observations. The existence of Sgr A was previously inferred from these data. The observation of the X-ray flare confirmed its existence.

Subsequent Chandra-based research indicated that Sgr A's relatively faint X-ray emissions are due to the ejection of a majority of infalling material. In fact, less than 1% of the infalling material reaches the event horizon of Sgr A.

The active consumption of matter by Sgr A* is a phenomenon known for its occurrence in supermassive black holes. This activity, also known as accretion, involves the black hole pulling in matter from its surroundings, a process that releases a tremendous amount of energy.

The Chandra X-ray Observatory continues to be used for research related to Sgr A*, providing valuable insights into the behaviour of this enigmatic celestial object. The observations made by Chandra have significantly contributed to our understanding of the supermassive black hole at the centre of our galaxy.