Podcaster: Richard Drumm
Title: Space Scoop: The Brightest Galaxy in the Universe is Tearing Itself Apart
Organization: 365 Days Of Astronomy
Link : astrosphere.org ; http://unawe.org/kids/unawe1602/
Description: Space scoop, news for children.
Bio: Richard Drumm is President of the Charlottesville Astronomical Society and President of 3D – Drumm Digital Design, a video production company with clients such as Kodak, Xerox and GlaxoSmithKline Pharmaceuticals. He was an observer with the UVa Parallax Program at McCormick Observatory in 1981 & 1982. He has found that his greatest passion in life is public outreach astronomy and he pursues it at every opportunity.
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Transcript:
This is 365 Days of Astronomy. Today we bring you a new episode in our Space Scoop series. This show is produced in collaboration with Universe Awareness, a program that strives to inspire every child with our wonderful cosmos.
Today’s story is:
The Brightest Galaxy in the Universe is Tearing Itself Apart
It’s often said that fame comes with a hefty price, but never has the price tag been as expensive as it is for the galaxy in the pictures in today’s album artwork. This galaxy is literally tearing itself apart to shine as brightly as it does!
The picture in the lower right hand corner was drawn by an artist. It shows us what we think we’d see if we got an up-close view of the quasar W2246-0526. Let’s call it W2246 for short. It’s what would be the winner of the Brightest Galaxy in the Entire Visible Universe Award, uh, if there was such an award.
A quasar is a galaxy that has a very active SMBH, a supermassive black hole, in its core. This SMBH, because it is actively sucking up gas & dust in large quantities, is what we astronomers call an AGN or active galactic nucleus. Science is full of abbreviations, innit?
It’s thought that quasars represent an early phase of galactic evolution as they seem to largely be at great distances from us. One of the closest, 3C 273, is 2.4 billion light years away. W2246, on the other hand, lies over 12 billion light years away. So of course, we’re seeing it as it was 12 billion years ago when the Universe was very young.
Although W2246 is bright as quasars go, heck, it’s the brightest galaxy in the visible Universe, it’s impossible to take a detailed photograph, even with the most powerful telescope, because it’s just so darn far away.
The inset window in the upper right hand corner of the album artwork is as good a photograph as we can get, from the Hubble Space Telescope. Even so, there’s a lot of scientific information in that image.
The ALMA radio telescope array in Chile was used for the main part of the research and it’s contribution is shown as lines that look like a topographic map in the lower center and lower right images of that inset window. You can see that the resolution of the ALMA portion exceeds the Hubble by a good bit.
There’s a simple rule in astrophysics: the brighter an object is, the more violent and powerful it is. W2246 blasts out as much light as roughly 350 trillion Suns! So it is about a thousand times brighter than the Milky Way. A typical quasar is on the order of 100 times as luminous as the Milky Way.
The central SMBH’s accretion disk has injected a huge amount of X-ray energy into the ISM, the inter-stellar medium, the gas & dust that you make new stars from. This appears to be causing the ISM to blow out of the galaxy in all directions. In the words of the scientific paper, it’s “… an unprecedented, homogeneous, large-scale turbulent outflow…” with some parts traveling at 2 million kilometers per hour!
Often galaxies (like the starburst galaxy M82 in Ursa Major) will have 2 jets of material hurled out by their central SMBH, but in the case of W2246 the evidence points toward a uniform, high velocity expansion in all directions. It also appears that it’s likely that all the gas is going to be blown away from the galaxy. If so, then star formation will cease permanently.
While this violent behavior may have made this galaxy a cosmic celebrity, it has shortened its star forming life dramatically. It’s possible that it will eventually mature into a very large but otherwise typical quasar, time will tell. Heh. LOTS of time!
Hey, Here’s A Cool Fact:
Most quasars shine brightly, but a small number are amazingly dusty, W2246 included. We call these Hot DOGS, which is short for Hot, Dust-Obscured GalaxieS.
Thank you for listening to 365 Days of Astronomy!
End of podcast:
365 Days of Astronomy
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The 365 Days of Astronomy Podcast is produced by Astrosphere New Media. Audio post-production by Richard Drumm. Bandwidth donated by libsyn.com and wizzard media. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. This year we will celebrate more discoveries and stories from the universe. Join us and share your story. Until tomorrow! Goodbye!