Pulsar encased in supernova bubble
Copyright: ESA/XMM-Newton/ L. Oskinova/M. Guerrero; CTIO/R. Gruendl/Y.H. Chu
Copyright: ESA/XMM-Newton/ L. Oskinova/M. Guerrero; CTIO/R. Gruendl/Y.H. Chu
Massive stars end their lives with a bang: exploding as spectacular
supernovas, they release huge amounts of mass and energy into space.
These explosions sweep up any surrounding material, creating bubble
remnants that expand into interstellar space. At the heart of bubbles
like these are small, dense neutron stars or black holes, the remains of
what once shone brightly as a star.
Since supernova-carved
bubbles shine for only a few tens of thousands of years before
dissolving, it is rare to come across neutron stars or black holes that
are still enclosed within their expanding shell. This image captures
such an unusual scene, featuring both a strongly magnetised, rotating
neutron star – known as a pulsar – and its cosmic cloak, the remains of
the explosion that generated it.
This pulsar, named SXP 1062, lies
in the outskirts of the Small Magellanic Cloud, one of the satellite
galaxies of our Milky Way galaxy. It is an object known as an X-ray
pulsar: it hungrily gobbles up material from a nearby companion star and
burps off X-rays as it does so. In the future, this scene may become
even more dramatic, as SXP 1062 has a massive companion star that has
not yet exploded as a supernova.
Most pulsars whirl around
incredibly quickly, spinning many times per second. However, by
exploring the expanding bubble around this pulsar and estimating its
age, astronomers have noticed something intriguing: SXP 1062 seems to be
rotating far too slowly for its age. It is actually one of the slowest
pulsars known.
While the cause of this weird sluggishness is still
a mystery, one explanation may be that the pulsar has an unusually
strong magnetic field, which would slow the rotation.
The diffuse
blue glow at the centre of the bubble in this image represents X-ray
emission from both the pulsar and the hot gas that fills the expanding
bubble. The other fuzzy blue objects visible in the background are
extragalactic X-ray sources.
This image combines X-ray data from
ESA’s XMM-Newton (shown in blue) with optical observations from the
Cerro Tololo Inter-American Observatory in Chile. The optical data were
obtained using two special filters that reveal the glow of oxygen (shown
in green) and hydrogen (shown in red). The size of the image is
equivalent to a distance of 457 light-years on a side.
This image was first published on ESA’s Science and Technology website in 2011. It is based on data from the paper “Discovery of a Be/X-ray pulsar binary and associated supernova remnant in the Wing of the Small Magellanic Cloud” by V. Hénault-Brunet, et al. 2012.
Source: ESA
