NASA's Chandra X-ray Observatory has seen a fast-moving pulsar
escaping from a supernova remnant while spewing out a record-breaking
jet – the longest of any object in the Milky Way galaxy -- of
high-energy particles.
The pulsar, a type of neutron star, is known as IGR J11014-6103. IGR
J11014-6103's peculiar behavior can likely be traced back to its birth
in the collapse and subsequent explosion of a massive star.
Originally discovered with the European Space Agency satellite
INTEGRAL, the pulsar is located about 60 light-years away from the
center of the supernova remnant SNR MSH 11-61A in the constellation of
Carina. Its implied speed is between 2.5 million and 5 million mph,
making it one of the fastest pulsars ever observed.
"We've never seen an object that moves this fast and also produces a
jet," said Lucia Pavan of the University of Geneva in Switzerland and
lead author of a paper published Tuesday,in the journal Astronomy and
Astrophysics. "By comparison, this jet is almost 10 times longer than
the distance between the sun and our nearest star."
The X-ray jet in IGR J11014-6103 is the longest known in the Milky
Way galaxy. In addition to its impressive span, it has a distinct
corkscrew pattern that suggests the pulsar is wobbling like a spinning
top.
IGR J11014-6103 also is producing a cocoon of high-energy particles
that enshrouds and trails behind it in a comet-like tail. This
structure, called a pulsar wind nebula, has been observed before, but
the Chandra data show the long jet and the pulsar wind nebula are almost
perpendicular to one another.
"We can see this pulsar is moving directly away from the center of
the supernova remnant based on the shape and direction of the pulsar
wind nebula," said co-author Pol Bordas, from the University of
Tuebingen in Germany. "The question is, why is the jet pointing off in
this other direction?"
Usually, the spin axis and jets of a pulsar point in the same
direction as they are moving, but IGR J11014-6103's spin axis and
direction of motion are almost at right angles.
"With the pulsar moving one way and the jet going another, this gives
us clues that exotic physics can occur when some stars collapse," said
co-author Gerd Puehlhofer also of the University of Tuebingen..
One possibility requires an extremely fast rotation speed for the
iron core of the star that exploded. A problem with this scenario is
that such fast speeds are not commonly expected to be achievable.
The supernova remnant that gave birth to IGR J11014-6013 is elongated
from top-right to bottom-left in the image roughly in line with the
jet's direction. These features and the high speed of the pulsar are
hints that jets could have been an important feature of the supernova
explosion that formed it.
NASA's Marshall Space Flight Center in Huntsville, Ala., manages the
Chandra program for NASA's Science Mission Directorate in Washington.
The Smithsonian Astrophysical Observatory in Cambridge, Mass., controls
Chandra's science and flight operations.
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