February 20, 2014
This week, a group of astronomers published the discovery of a fast moving pulsar, designated IGR J11014-6103. The pulsar is moving away from a residue of a supernova and it is producing a record-breaking jet made of high-energy particles.
Supernova remnant is on the left, speeding pulsar IGR J11014-6103 is bottom-right. You can notice both the jet (purple) and the tail (white) quite clearly. Credit: X-ray: NASA/CXC/ISDC/L.Pavan et al, Radio: CSIRO/ATNF/ATCA O
A pulsar is a type of neutron star (which is dense, compact star left after its supernova) that rotates really fast and emits a beam of electromagnetic radiation, like a lighthouse. IGR J11014-6103 was first observed with INTEGRAL satellite. It is located 60 light-years from the center of the supernova remnant SNR MSH 11-61A, in the constellation of Carina, and it is moving away from it at estimated speed somewhere between 4 and 8 million km/h. This makes it one of the fastest pulsars observed.
Upon a closer look with Chandra X-ray Observatory, astronomers noticed there's something special about IGR J11014-6103 – the jet that it ejects is estimated to be about 40 light-years long, making it the longest object in our galaxy. As you can notice in the image above, the jet's shape indicate that the pulsar is most likely wobbling as it spins.
"We've never seen an object that moves this fast and also produces a jet," said Lucia Pavan, University of Geneva, Switzerland. He is the lead author of a paper published 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."
It gets better! Normally, you would expect a pulsar to fire a jet in the direction it is moving. However, there is a "tail" behind the IGR J11014-6013 that shows us the direction in which the pulsar is moving and this "tail" is perpendicular to the jet.
Pulsars often have nebulae made of charged particles around them, called pulsar wind nebula and if the pulsar is moving, the accompanying nebula drags behind it like a tail. Jet is made of same particles, but they are emitted from the star's magnetic poles, along the magnetic axis which approximately correspond rotational axis. So, the jet indicates where the poles are and the tail indicates in which direction the pulsar is moving.
"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, the University of Tübingen, Germany. "The question is, why is the jet pointing off in this other direction?"
The supernova remnants left behind the pulsar is elongated diagonally on the image above, in the same direction as the pulsar's jet. This could be an indication that the star's jet played an important role in the supernova of the star.
"This gives us clues that exotic physics can occur when some stars collapse," said Gerd Pühlhofer, also of the University of Tübingen, Germany.