Large and dramatically shaped
, this cosmic cloud spans nearly 7 degrees or 14 full moons across planet
Earth's sky toward the southern constellation Ara. Difficult to image, the
filamentary apparition is cataloged as RCW 114 and traced in this telescopic
mosaic by the telltale reddish emission of ionized hydrogen atoms. In fact,
RCW 114 has been recognized as a supernova remnant. Its extensive filaments
of emission are produced as the still expanding shockwave from the death explosion
of a massive star sweeps up the surrounding interstellar medium. Consistent
estimates place its distance at over 600 light-years, indicating a diameter of about 100
light-years or so. Light from the supernova explosion that created RCW 114 would
have reached Earth around 20,000 years ago. A neutron star or pulsar has recently
been identified as the collapsed remains of the stellar core.
Nice A close pic of a solar flare
X-ray: NASA/CXO/Oxford University/J. Conlon et al.; Radio
Why does the Perseus galaxy cluster shine so strangely in one specific color
of X-rays? No one is sure, but a much-debated hypothesis holds that these X-
rays are a clue to the long-sought identity of dark matter. At the center of this
mystery is a 3.5 Kilo-electronvolt (KeV) X-ray color that appears to glow
excessively only when regions well outside the cluster center are observed
, whereas the area directly surrounding a likely central supermassive black hole
is actually deficient in 3.5 keV X-rays. One proposed resolution -- quite controversial -
- is that something never seen before might be present: fluorescent dark matter (FDM)
. This form of particle dark matter might be able to absorb 3.5 keV X-radiation. If operating
, FDM, after absorption, might later emit these X-rays from all over the cluster, creating an
emission line. However, when seen superposed in front of the central region surrounding
the black hole, FDM's absorption would be more prominent, creating an absorption line.
Pictured, a composite image of the Perseus galaxy cluster shows visible and radio light in red,
and X-ray light from the Earth-orbiting Chandra Observatory in blue.
source. https://www.nickczj.com/