Recent observations by According to a release, this week, at the annual meeting of the
Swift's seven-year campaign to monitor the center of the
Sgr A* sits in the center of the
"Given its size, this supermassive black hole is about a billion times fainter than it could be," said
To better understand the black hole's behavior over time, the Swift team began making regular observations of the
The Swift XRT team expects 2014 to be a banner year for the campaign. A cold gas cloud named G2, about three times the mass of Earth, will pass near Sgr A* and already is being affected by tides from the black hole's powerful gravitational field. Astronomers expect G2 will swing so close to the black hole during the second quarter of the year that it will heat up to the point where it produces X-rays.
If some of the cloud's gas actually reaches Sgr A*, astronomers may witness a significant increase in activity from the black hole. The event will unfold over the next few years, giving scientists a front-row seat to study the phenomena.
"Astronomers around the world are eagerly awaiting the first sign that this interaction has begun," said Jamie Kennea, a team member at
Scientists saw what they thought was a sign in April, when Swift detected a powerful high-energy burst and a dramatic rise in the X- ray brightness of the Sgr A* region. They were excited to discover the activity came from separate source very near the black hole: a rare subclass of neutron star.
A neutron star is the crushed core of a star destroyed by a supernova explosion, packing the equivalent mass of a half-million Earths into a sphere no wider than
The discovery of SGR J1745-29 may aid scientists in their exploration of important properties of the Sgr A* black hole. As it spins, the magnetar emits regular X-ray and radio pulses. As it orbits Sgr A*, astronomers could detect subtle changes in the pulse timing because of the black hole's gravitational field, a prediction of Einstein's theory of general relativity.
"This long-term program has reaped many scientific rewards, and due to a combination of the spacecraft's flexibility and the sensitivity of its XRT, Swift is the only satellite that can carry out such a campaign," said
Goddard manages Swift, which was launched in
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Recent observations by
According to a release, this week, at the annual meeting of the