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-Elizabeth Landau
Andromeda is the nearest large
galaxy to the Milky Way, and it is a spiral galaxy slightly larger than the
Milky Way. It resides 2.5 million light-years from our own galaxy, which is
considered very close, given the broader scale of the universe. Stargazers can
see Andromeda without a telescope on dark, clear nights. It features a dominant
source of high-energy X-ray emission. NASA's NuSTAR (Nuclear Spectroscopic
Telescope Array) mission has pinpointed an object responsible for this
high-energy radiation, but its identity was mysterious until now. The object,
called Swift J0042.6+4112, is a possible pulsar. Its spectrum is very similar
to known pulsars in the Milky Way, and It is likely in a binary system, in
which material from a stellar companion gets pulled onto the pulsar, spewing
high-energy radiation as the material heats up.
Many differences of the object
from various spacecraft that brings researchers to observers deeply. In 2013,
NASA's Swift satellite reported it as a high-energy source, but its
classification was unknown, as there are many objects emitting low energy
X-rays in the region. Other spacecraft, such as NASA's Chandra X-ray
Observatory and ESA's XMM-Newton had also detected it. However, it wasn't until
the new study by NuSTAR, aided by supporting Swift satellite data, that
researchers realized it was the same object as this likely pulsar that
dominates the high energy X-ray light of Andromeda.
"NuSTAR has made us realize
the general importance of pulsar systems as X-ray-emitting components of
galaxies, and the possibility that the high energy X-ray light of Andromeda is
dominated by a single pulsar system only adds to this emerging picture,"
said Ann Hornschemeier, co-author of the study and based at NASA's Goddard
Space Flight Center, Greenbelt, Maryland.
by Dini Dwintika Karuniati
16611042
Science Article
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