Yearly Archives: 2013

american astronomical society, Gemini Observatory, Orion, Orion Nebula

Bullets of Star Formation

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Clumps of Supersonic Gas Point Back to Hot Young Stars

 

 

This image reveals exquisite details in the outskirts of the Orion Nebula. The large adaptive optics field-of-view (85 arcseconds across) demonstrates the system’s extreme resolution and uniform correction across the entire field. The three filters used for this composite color image include [Fe II], H2, and, K(short)-continuum (2.093 microns) for blue, orange, and white layers respectively. The natural seeing while these data were taken ranged from about 0.8 to 1.1 arcseconds, with AO corrected images ranging from 0.084 to 0.103 arcsecond. Each filter had a total integration (exposure) of 600 seconds. In this image, the blue spots are clouds of gaseous iron “bullets” being propelled at supersonic speeds from a region of massive star formation outside, and below, this image’s field-of-view. As these “bullets” pass through neutral hydrogen gas it heats up the hydrogen and produces the pillars that trace the passage of the iron clouds.
Principal Investigator(s): John Bally and Adam Ginsberg, University of Colorado and the GeMS/GSAOI commissioning team; Data processing/reduction: Rodrigo Carrasco, Gemini Observatory; Color image composite: Travis Rector, University of Alaska Anchorage. Image Courtesy: Gemini Observatory/AURA
The universe is not a static place. Things change all the time. So, the more often you look at an object or process in the cosmos, the more information you’ll get about how it changes over time. Astronomers take advantage of this to get what you might call a “time varying” view of something like the Sun or a planet or a star-forming region (for example). The process gets very interesting when they use newer technology to study something that seems familiar, like the Orion Nebula.

The Gemini Observatory observed a region of the Orion Nebula in 2007 and imaged what are called “bullets”. These almost look like tunnels through the clouds of gas and dust that make up the nebula. They are actually strong winds blowing gas off of massive stars at incredibly high speeds. As these “wind bullets” speed out, they carve out these tubular wakes as much as a fifth of a light-year long.

Those original images were some of the best taken of this region at the time, and they showed dynamic action surrounding hot young stars in the nebula.

Now, the Gemini Observatory has studied these again, this time using an a technology called adaptive optics and laser guide stars to gain a sharp clear image of these bullets in the Orion Nebula. The laser guide stars are artificial stars that are made using a special laser that shoots into the sky and provides astronomers a guide to aim at. They read those stars and use what they see to “adapt” the telescope system to account for the atmospheric aberration between the telescope and the sky. The process provides very clear, almost Hubble-like images, but from the ground.

The new images show more detail and, if you look closely between the originals and the new ones, you can make out a little bit of dynamic motion in the clouds themselves.

Check out the new image here, and then go over to the Gemini page and look at a previous image of the bullets — you can see clear improvements that are giving astronomers a great new tool to check out the Orion Nebula better than ever before.

 

 

american astronomical society, Milky Way, Milky Way Galaxy

Rattling the Galaxy’s Bones

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Dark Cloud in the Milky Way

The galactic “bone” was identified while studying a dust cloud that in 2010 was nicknamed “Nessie” after the Loch Ness Monster. Nessie turns out to be at least twice, and perhaps as much as eight times, longer than originally claimed. Both the original 2010 “Nessie” and the extended structure are outlined and labeled here on a Spitzer infrared image.
Credit: NASA/JPL/SSC

Once in a while a story really grabs my attention, like yesterday’s census of planets in the Milky Way.  It really opened up a galaxy of possible worlds to explore. Today, I was sitting in a press conference, listening to astronomers talking about using radio astronomy to study a cloud of gas and dust that they described as the one of the Milky Way’s “bones”, meaning an important part of its structure.

The structure is nicknamed “Nessie” because it bears a resemblance to the Loch Ness Monster. That right there was enough to grab my attention because as CEO of Loch Ness Productions, I’m quite used to being called one of the “Nessies” by our colleagues in the field. So, I approve of my monstrous namesake in the sky!

It’s a cool name and a memorable mental visual.

So, what’s Nessie all about?

Think about our galaxy. It’s what’s known as a barred spiral galaxy. That means it is a typical spiral — with two principal spiral arms wrapping around, and a bar cutting across the middle.

The central region of our the Milky Way has tantalized astronomers since forever, but it’s tough to see because it’s hidden by clouds of gas and dust. However, if you look at it in infrared light or using radio telescopes, you can make out structures not only in the core but along the plane of the Milky Way.

Astronomers have done that using a variety of techniques. In the case of Nessie, they used the Spitzer Space Telescope to probe along the plane (a line drawn across the central region from edge to edge) and found this cloud feature that got nicknamed Nessie by James Jackson of Boston University.

Alyssa Goodman at Harvard Center for Astrophysics and her team looked at Nessie and analyzed it using various data set. It’s really a long tendril of dust and gas that they called a “bone.”

Goodman gave a talk at the AAS today about Nessie. “This is the first time we’ve seen such a delicate piece of the galactic skeleton,” she said, and pointed out that other spiral galaxies also display internal bones or endoskeletons. Observations, especially at infrared wavelengths of light, have found long skinny features jutting between galaxies’ spiral arms. These relatively straight structures are much less massive than the curving spiral arms.

Computer simulations of galaxy formation show webs of filaments within spiral disks. It is very likely that the newly discovered Milky Way feature is one of these “bone-like” filaments.

Radio emissions from clouds of molecular gas in the center of the Milky Way region show that Nessie is in the galactic plane, and is more than 300 light-years long but only 1 or 2 light-years wide. The amount of mass is enough to make about  100,000 Suns. It’s possible that this odd feature bone is part of a spiral arm, or maybe is part of a web connecting other spiral features. Goodman and her colleagues hope to find more of these bones, and once they have enough data, it will give them enough information to create a cool 3D version of the galaxy and its skeleton.