Chandra Archives

December 17, 2007December 26, 2015 by Fraser Cain

Galactic Black Hole Fires a Jet at a Nearby Neighbour

Ouch, that’s going to leave a mark. A new photograph captured by NASA’s Chandra X-Ray Observatory shows a powerful jet blasting out of one galaxy, and colliding with another. As the jet tears through the galaxy, it could have serious implications for planetary formation, and trigger a wave of new star formation.

The image contains two galaxies, collectively known as 3C321, in orbit around one another. X-ray images from Chandra show that they both have supermassive black holes at their centres.

The black hole in the larger galaxy is actively feeding, and has an enormous jet of radiation and material blasting out into space. Unfortunately, the smaller galaxy has gotten caught right in the crossfire of this jet.

“We’ve seen many jets produced by black holes, but this is the first time we’ve seen one punch into another galaxy like we’re seeing here,” said Dan Evans, a scientist at the Harvard-Smithsonian Center for Astrophysics and leader of the study. “This jet could be causing all sorts of problems for the smaller galaxy it is pummeling.”

So what kinds of problems? For starters, the jet has a tremendous amount of radiation, especially high-energy X-rays and gamma-rays. An ongoing blast of this radiation could strip away planetary atmospheres and blow away newly forming stellar nurseries. In other cases, the jet could cause a cloud of gas and dust to collapse in the first place, setting the stage for new star formation.

Since the two galaxies are only 20,000 light years apart – the same distance of the Solar System to the middle of the Milky Way – the effect of the jet will be extreme. One bright part of the image shows where the jet is colliding with the galaxy, and then getting disrupted and deflected away.

This event is probably very short-lived. Astronomers estimate that the jet only began impacting the galaxy about a million years ago; a blink of the eye in cosmological terms.

Original Source: Chandra News Release

November 28, 2007December 26, 2015 by Fraser Cain

Neutron Star Seen Hurtling Out of the Milky Way

Like a baseball struck by a bat, there’s a neutron star out there that’s going, going, gone. Discovered using the Chandra X-Ray Observatory, the neutron star appears to be the result of a lopsided supernova explosion. It’s now hurtling away from the Milky Way faster than 4.8 million km/h (3 million mph). And it’s never coming back.

Astronomers think that the Puppis A supernova remnant was created about 3,700 years ago when a massive star detonated in a supernova explosion. Instead of exploding evenly, it was one-sided. A blast of material went in one direction, and the resulting neutron star was given a powerful kick in the opposite direction – like a natural rocket.

The neutron star’s position was measured in December 1999, and then again in April 2005. Based on the distance that it had moved, astronomers were able to calculate its velocity. With that kind of speed, it should be easy to spot, but it’s so far away that the difference is quite tiny from our vantage point. It’s impressive that Chandra was able to make the observation at all.

A detailed composite optical/X-ray image of the region near the neutron star shows clumps of oxygen drifting away from what is thought to be the centre of the explosion. The cloud is moving in the opposite direction of the neutron star.

The Puppis A neutron star is a bit of a mystery. Even the most sophisticated supernova explosion models can’t predict the speed and radiation coming from the neutron star.

“The problem with discovering this cosmic cannonball is we aren’t sure how to make the cannon powerful enough.” said Frank Winkler of Middlebury College in Vermont. “The high speed might be explained by an unusually energetic explosion, but the models are complicated and hard to apply to real explosions.”

Original Source: Chandra News Release

November 15, 2007December 26, 2015 by Fraser Cain

Chandra Sees Star Formation in NGC 281

Here’s a short little post about the star forming nebula NGC 281, captured by NASA’s Chandra X-Ray Observatory. This photograph is actually a composite of several wavelengths, imaged by ground and space-based observatories.

The optical data (red, orange and yellow) shows the clouds of gas and dust, and the dark lanes of obscuring dust where stars may be forming. The Chandra X-Ray data is in purple, and reveals more than 300 individual X-ray sources – most of them are associated with the central star forming region.

There’s another group of X-ray sources on the other side of the molecular cloud. Based on the elements in the region, astronomers think that a supernova went off in the region recently.

But really, it’s a pretty picture.

Original Source: Chandra News Release

October 23, 2007December 26, 2015 by Fraser Cain

Chandra Sees the Death of a Star in Detail

This absolutely beautiful object has a big of a bizarre name: G292.0+1.8. But don’t let that astronomical jargon throw you, you’re looking at a supernova remnant, captured by NASA’s Chandra X-Ray Observatory and ground-based observatories. It’s considered a textbook example of what remains after a massive star blows itself apart as a supernova. But it’s got a few surprises too.

Near the core of G292.0+1.8 is a pulsar wind nebula, revealed by the X-rays pouring out of it. This is the magnetized bubble of high energy particles that surround the rapidly spinning pulsar at the heart of the nebula. The pulsar is all that remains of the star before it detonated as a supernova.

Here’s one of the surprises. Instead of being right at the centre of the nebula, the pulsar is located slightly below and to the left. It possible that the supernova explosion was lopsided, and the recoil sent the pulsar shooting off to its current location. That would be a fine explanation, except the kick direction and pulsar spin direction aren’t aligned like you would expect.

Another interesting feature is that long white line running across the centre of the remnant called the equatorial belt. Imagine this is ring of material that unraveled from the star as it was coming apart. Once again, the orientation of this belt suggests that the parent star had the same spin axis before and after it exploded.

Astronomers find it puzzling that the remnant is missing thin filaments of high energy X-ray emission. These are thought to be a source of cosmic ray acceleration, and have been seen in many other well known supernova remnants. It’s possible that G292.0+1.8 is just too old now, and that stage only happens when the remnant is young.

Original Source: Chandra News Release

October 3, 2007December 26, 2015 by Fraser Cain

Hubble and Chandra View the Orion Nebula Together

It’s not a huge story, just some cool science and a pretty picture. Here’s a newly released image of the Orion Nebula, captured by two of the great observatories: the Chandra X-Ray Observatory and the Hubble Space Telescope. The bright blue and orange points are young stars, blazing out the X-rays visible to Chandra, while the diffuse glow is the surrounding gas and dust revealed by Hubble.

The Orion Nebula is located 1,500 light years away, and it’s one of the closest star forming regions to the Earth. Amateur astronomers often direct their telescopes towards this nebula, since it’s so close, large and bright.

This image was made by combining photographs captured by both Hubble and Chandra. The Chandra data was built up from almost 13 days of continuous observations, and they allowed astronomers to watch the activity of newborn stars, just 1-10 million years old. During the observation period, the stars flared in their X-ray output. Unlike our own Sun, which is pretty boring as stars go, these young stars are violent and chaotic; demonstrated by the fluctuations of radiation pouring off of them. You wouldn’t want to be living on a planet orbiting one of these monsters.

The wispy clouds of gas and dust (seen in pink and purple) are visible light images captured by Hubble. Right now they’re wispy filaments, but their gravitational interaction is bringing together new stars. One day these too will ignite in the warm glow of newly formed stars.

Original Source: Chandra News Release

August 31, 2007December 26, 2015 by Fraser Cain

Supernovae Blowing Superbubbles in the Small Magellanic Cloud

At a distance of only 200,000 light years, the Small Magellanic Cloud is one of the Milky Way’s closest galactic neighbours. Thanks to its brutal treatment by our galaxy’s gravity, the galaxy has massive regions of active star formation, and regular supernova explosions. Astronomers studied the region with the Chandra X-Ray Observatory, and saw superbubbles formed by stars and supernovae working together.

The region that Chandra focused in on is known as LHa115-N19, or N19 for short. It’s an area in the Small Magellanic Cloud which is rich in ionized hydrogen gas. There are many massive stars forming in the region, and many more supernova remnants – all that remain from the short-lived stars that formed in this rich nursery.

Astronomers combined images from Chandra with data gathered in other wavelengths. And when they did this, they found evidence for so-called superbubbles. These are formed when smaller cavities created by stars and detonating supernovae combine together to create gigantic cavities.

In just one small region, the Chandra data reveals three supernovae explosions clustered together; well, the supernova remnants, anyway. There are even hints in the data that the stars were associated with one another, forming together from the same interstellar cloud, and then dying together.

Original Source: Chandra News Release

August 9, 2007December 26, 2015 by Fraser Cain

Subtle Supernova Remnants

Here are two images of supernova remnants, made with combined data from NASA’s Chandra X-Ray Observatory and ESA’s XMM-Newton. For both of these images, XMM-Newton captured the wider field view, while Chandra focused in on key regions of interest to researchers.

The orange object on the right is RCW 86, one of the earliest supernovae ever recorded. Historians think that explosion of the central coincides with observations made by Chinese and Roman astronomers in 185 AD. Under the combined view of Chandra and XMM-Newton, you can see the expanding ring of debris that was created after massive star detonated.

The other object is G347.3-0.5; it was also observed by the Chinese in 393 AD. The exploding star was so bright, it was said to have blazed for months, and rivaled Jupiter in brilliance. The point source in the lower section of the image is probably the original neutron star; all that remains after the massive star’s core collapsed.

In both Chandra and XMM-Newton, the intensity of X-rays is represented by the brightness of the colour.

Original Source:Chandra News Release

July 25, 2007December 26, 2015 by Fraser Cain

Counting up the Active Black Holes with Chandra

The newest image released from NASA’s Chandra X-Ray Observatory is helping astronomers build up a census of the number of actively feeding supermassive black holes across the Universe. Scientists are hoping to build up a comprehensive picture of where (and thus when), these black holes were blasting out radiation.

It’s now thought that almost every galaxy in the Universe seems to contain a supermassive black hole at its centre. Perhaps the black holes came first and the rest of the galaxy formed around it, or maybe things evolved the other way around. Whatever the case, most of these black holes are in a quiescent state; apart from their gravitational influence on nearby stars, they’re all but invisible.

From time to time, however, the space surrounding these black holes flares up. Material falling into the black hole chokes up, and spreads out into a rapidly rotating accretion disk. Although the black hole itself is invisible, it’s this blocked up matter waiting to be consumed that shines hotly in the most energetic wavelengths.

This latest survey, gathered by NASA’s Chandra X-Ray Observatory seems to indicate that younger, more distant galaxy clusters contained many more active nuclei than the ones we see closer to us (and thus, closer to our current time). The more distant sample contains galaxies seen when the Universe was only 58% of its current age, while the closer sample shows galaxies at 82% of the galaxy’s current age. The more distant sample had 20x the number of active nuclei over the closer sample.

The research seems to point that the early Universe was much more likely to contain active galactic nuclei. This makes sense, since there was much more gas and dust in galaxies back then. This material was able to fuel the supermassive black holes. The research also points to a time in the future when there’ll be much less material to feed the black holes. It will become rarer and rarer to see these events.

Original Source: Chandra News Release

July 11, 2007December 26, 2015 by Fraser Cain

Supernova Remnant May Actually Have a Partner

When a star with at least 8 times the mass of our Sun detonates as a supernova, it leaves behind a neutron star. This tiny object has the mass of a star, but it’s compressed down to a ball only 10 km (6 miles) across – its protons and electrons have been compressed together to form neutrons. One of these objects has puzzled astronomers for years, but now researchers think they’ve found the solution: it’s got a friend.

New data gathered by NASA’s Chandra X-Ray Observatory is helping to explain the mystery in RCW 103. This supernova remnant, located 10,000 light-years away, detonated about 2,000 years ago (I know, that means it really exploded 12,000 years ago). The bright blue dot at the centre of the image is the neutron star, blasting out X-ray radiation.

The problem with this neutron star is that only rotates once every 6.7 hours. That sounds fast, but there are neutron stars out there that can rotate many times a second. It should be turning much faster.

One possible answer for the mystery is that the original star that detonated, leaving this remnant wasn’t alone. It might have had a much lower-mass companion which still remains. It was the magnetic field interaction between the neutron star and the low-mass companion slowed down its rotation.

Original Source:Chandra

June 28, 2007December 26, 2015 by Fraser Cain

Neutron Stars Have Jets Too

One time, astronomers thought that only black holes had jets of material pouring out of them. Something to do with the event horizon, and a lack of a solid surface. Well, step aside black holes, neutron stars seem to have them too.

This is according to new images captured by NASA’s Chandra X-Ray Observatory, which imaged a system called Circinus X-1. This is actually a binary system, consisting of a massive star with several times the mass of our Sun, and a neutron star. The neutron star is feeding on material from the star, and has gathered together an accretion disk around itself. It’s consuming so much material from the star that it backs up into this disk, which glows hot in the X-Ray spectrum.

And just like with a black hole, the centre of the accretion disk acts like an engine, firing material out into space along these jets. But the power from this engine comes from the neutron star.

In the Chandra image in the upper left, you can see what looks like cones on the two sides of the neutron star. This neutron star could be wobbling like a top, with the jets tracking out these larger arcs.

Original Source: Chandra News Release