Hubble Peers at the Heart of NGC 5793
This new Hubble image is centered on NGC 5793, a spiral galaxy over
150 million light-years away in the constellation of Libra. This galaxy has two
particularly striking features: a beautiful dust lane and an intensely bright
center — much brighter than that of our own galaxy, or indeed those of most
spiral galaxies we observe.
NGC 5793 is a Seyfert galaxy. These galaxies have incredibly
luminous centers that are thought to be caused by hungry supermassive black
holes — black holes that can be billions of times the size of the sun — that
pull in and devour gas and dust from their surroundings.
This galaxy is of great interest to astronomers for many reasons.
For one, it appears to house objects known as masers. Whereas lasers emit
visible light, masers emit microwave radiation. The term "masers" comes from the
acronym Microwave Amplification by Stimulated Emission of Radiation. Maser
emission is caused by particles that absorb energy from their surroundings and
then re-emit this in the microwave part of the spectrum.
Naturally occurring masers, like those observed in NGC 5793, can
tell us a lot about their environment; we see these kinds of masers in areas
where stars are forming. In NGC 5793 there are also intense mega-masers, which
are thousands of times more luminous than the sun.
Credit: NASA, ESA, and E. Perlman (Florida Institute of
Technology)
NASA
Guillermo Gonzalo Sánchez Achutegui
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