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APOD: 2023 September 13 Á NGC 4632: Galaxy with a Hidden Polar Ring
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Credit & Copyright: Jayanne English
(U. Manitoba),
Nathan Deg
(Queen's University) &
WALLABY Survey,
CSIRO/ASKAP,
NAOJ/Subaru Telescope;
Text:
Jayanne English (U. Manitoba)
Explanation:
Galaxy NGC 4632 hides a secret from optical telescopes.
It is surrounded by a ring of cool
hydrogen
gas orbiting at 90 degrees to its spiral disk.
Such polar ring galaxies
have previously been discovered using starlight.
However, NGC 4632 is among the first in which a
radio
telescope survey
revealed a polar ring.
The featured composite image
combines this gas ring, observed with the highly sensitive
ASKAP telescope, with optical data from the
Subaru telescope.
Using virtual reality, astronomers separated out the
gas in the main disk of the galaxy from the ring,
and the subtle color gradient traces its orbital motion.
Why do
polar rings exist?
They could be material
pulled from one galaxy as it
gravitationally interacts with a companion.
Or hydrogen gas flows along the
filaments of the cosmic web and accretes into a ring around a galaxy,
some of which gravitationally contracts into stars.
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NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: polar ring
Publications with words: polar ring
See also: