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Title: Scientists Discover Mysterious New X-Ray Objects 'Unlike Any They Have
Seen Before'

Link: https://science.slashdot.org/story/26/09/12/1...

An anonymous reader quotes a report from Space.com: NASA's Chandra X-ray
Observatory has found a brand new type of an otherwise familiar object --
compact binary systems that steal gas from other stars, but which do so while
emitting very low-energy X-rays but copious amounts of ultraviolet. Chandra
spotted 84 suspicious object emitting very low-energy X-rays in six galaxies -
- four evolved ellipticals and two spirals, namely our near-neighbor the
Andromeda Galaxy (M31) and the Pinwheel Galaxy (M101). "We've never
encountered a group of objects that act like this," said Mustafa Muhibullah
of the University of Alabama in a statement. Compact objects, in the form of
black holes, neutron stars and white dwarfs, are the remains of stars that
have died. Their small size and powerful gravity means that they're adept at
getting close to orbiting companion stars and ripping the stars' outer layers
of gas away. The gas swirls around the compact object, falling onto its
surface, and this accretionary process usually produces torrents of high-
energy X-rays because the stolen gas becomes superheated by the compact
object's gravitational vice-like grip. Because of their weak X-rays,
Muhibullah's team refer to them as 'hypersoft X-ray sources'. Since low-
energy X-rays and ultraviolet light are next to each other on the
electromagnetic spectrum, Muhibullah and his team suspect that the low-energy
X-rays are spillover from objects emitting prodigious amounts of ultraviolet.
Moreover, they think that these objects are lower-level compact binaries.
They're hard to find though, because the interstellar medium of hydrogen and
helium gas between the stars absorbs ultraviolet light. This could be why we
have yet to find any hypersoft X-ray sources in our own galaxy, because we
have to look through the interstellar medium through the plane of the Milky
Way. Consequently, there could be a large population of hypersoft X-ray
sources that remain undiscovered and they could have an important effect on
the universe around them. The findings have been published in the journal
Nature Astronomy.

Read more of this story at Slashdot.

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