The case of the neutron star with a wayward wake

Jun 01, 2006
The case of the neutron star with a wayward wake
Credit: Chandra X-ray: NASA/CXC/B.Gaensler et al; ROSAT X-ray: NASA/ROSAT/Asaoka & Aschenbach; Radio Wide: NRC/DRAO/D.Leahy; Radio Detail: NRAO/VLA; Optical: DSS

A long observation with NASA's Chandra X-ray Observatory revealed important new details of a neutron star that is spewing out a wake of high-energy particles as it races through space. The deduced location of the neutron star on the edge of a supernova remnant, and the peculiar orientation of the neutron star wake, pose mysteries that remain unresolved.

"Like a kite flying in the wind, the behavior of this neutron star and its wake tell us what sort of gas it must be plowing through," said Bryan Gaensler of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and lead author of a paper submitted to The Astrophysical Journal. "Yet we're still not sure how the neutron star got to its present location."

The neutron star, known as CXOU J061705.3+222127, or J0617 for short, appears to lie near the outer edge of an expanding bubble of hot gas associated with the supernova remnant IC 443. Presumably, J0617 was created at the time of the supernova -- approximately 30,000 years ago -- and propelled away from the site of the explosion at about 500,000 miles per hour.

However, the neutron star's wake is oriented almost perpendicularly to the direction expected if the neutron star were moving away from the center of the supernova remnant. This apparent misalignment had previously raised doubts about the association of the speeding neutron star with the supernova remnant.

Gaensler and his colleagues provide strong evidence that J0617 was indeed born in the same explosion that created the supernova remnant. First, the shape of the neutron star's wake indicates it is moving at the predicted pace, which is a little faster than the speed of sound in the remnant's multimillion-degree gas. In contrast, if the neutron star were outside the confines of the remnant, its inferred speed would be a sluggish 20,000 miles per hour. Also, the measured temperature of the neutron star matches that of one born at the same time of the supernova remnant.

What then, could cause the misaligned, or wayward, neutron star wake?

The authors speculate that perhaps the doomed progenitor star was moving at a high speed before it exploded, so that the explosion site was not at the observed center of the supernova remnant. Fast moving gusts of gas inside the supernova remnant have further pushed the neutron star's wake out of alignment.

Observations of J0617 in the next 10 years should put this idea to the test. "If the neutron star was born off-center and if the wake is being pushed around by cross-winds, the neutron star should be moving close to vertically, away from the center of the supernova remnant. Now we wait and see," said Gaensler.

Another group, led by Margarita Karovska, also of the Harvard-Smithsonian Center, has concentrated on other, previously unnoticed intriguing features of J0617. At a recent conference on neutron stars in London, England, they announced their findings, which include a thin filament of cooler gas that appears to extend from the neutron star along the long axis of its wake, and a second point-like feature embedded in the X-ray nebula around the neutron star

"There are a number of puzzling observational features associated with this system crying out for longer observations" said Karovska.

Source: Chandra X-ray Center

Explore further: Pulsar with widest orbit ever detected

Related Stories

Space station crew: Russia's spinning supply ship total loss

1 hour ago

A Russian supply capsule that went into an uncontrollable spin after launch was declared a total loss Wednesday, but the astronauts at the International Space Station said they will get by without the delivery of fresh food, ...

A phone with the ultimate macro feature

1 hour ago

If you thought scanning one of those strange, square QR codes with your phone was somewhat advanced, hold on to your seat. Researchers at the University of California, Los Angeles (UCLA) have recently developed ...

Recommended for you

Pulsar with widest orbit ever detected

May 01, 2015

A team of highly determined high school students discovered a never-before-seen pulsar by painstakingly analyzing data from the National Science Foundation's (NSF) Robert C. Byrd Green Bank Telescope (GBT). ...

New exoplanet too big for its stars

May 01, 2015

The Australian discovery of a strange exoplanet orbiting a small cool star 500 light years away is challenging ideas about how planets form.

Chandra suggests black holes gorging at excessive rates

Apr 30, 2015

A group of unusual giant black holes may be consuming excessive amounts of matter, according to a new study using NASA's Chandra X-ray Observatory. This finding may help astronomers understand how the largest ...

Unlocking the secrets of star creation

Apr 30, 2015

On April 1, 1995, the Hubble Space Telescope (link is external), now celebrating its 25th anniversary, captured the famous images of the "Pillars of Creation" in the Eagle Nebula. Twenty years later to the ...

NuSTAR captures possible 'screams' from zombie stars

Apr 30, 2015

Peering into the heart of the Milky Way galaxy, NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) has spotted a mysterious glow of high-energy X-rays that, according to scientists, could be the "howls" ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.