Recently I came across this story – this ten year old story – on Tumblr.
Sept. 9, 2003: Astronomers using NASA’s Chandra X-ray Observatory have found, for the first time, sound waves from a supermassive black hole. The “note” is the deepest ever detected from any object in our Universe. The tremendous amounts of energy carried by these sound waves may solve a longstanding problem in astrophysics.
The black hole resides in the Perseus cluster of galaxies located 250 million light years from Earth. In 2002, astronomers obtained a deep Chandra observation that shows ripples in the gas filling the cluster. These ripples are evidence for sound waves that have traveled hundreds of thousands of light years away from the cluster’s central black hole.
“The Perseus sound waves are much more than just an interesting form of black hole acoustics,” says Steve Allen, of the Institute of Astronomy and a co-investigator in the research. “These sound waves may be the key in figuring out how galaxy clusters, the largest structures in the Universe, grow.”
Here is the story on Chandra’s website.
Chandra’s 53-hour observation of the central region of the Perseus galaxy cluster (left) has revealed wavelike features (right) that appear to be sound waves. Credit: NASA/CXC/IoA/A.Fabian et al.
Why this subject, albeit with an embedded audio joke, was making the rounds on Tumblr now, I don’t know. But what struck me was the comments on the post calling shenanigans – because if light can’t escape a black hole, then how can sound?
The answer is, you can “hear” black holes the same way you can “see” them – indirectly. Because it is true that nothing can escape a black hole – but that is only true of matter that crosses the event horizon, the gravitational point of no return. Black holes can and do affect their environments in detectible ways.
Despite what the “Impossible Planet” episode of Doctor Who will tell you, it is perfectly possible for something to orbit a black hole. In fact, one way we detect stellar-mass black holes is when they are part of a binary star system. The black hole’s effects on the companion star are observable by us here on Earth – effects like a black hole slowly cannibalizing its companion.
Read more »
Well, it happened again, guys! The 222nd biannual meeting of the American Astronomical Society (AAS) held at the Indiana Convention Center, that’s what. For those of you not in the loop, the American Astronomical Society is a professional society for astronomers devoted to promoting astronomy and like sciences as well as enhancing education. We’ve covered previous meetings and will definitely be involved in future ones – you can learn more about AAS press conferences, read Sara’s wrap-up of the last meeting, follow Maggie’s adventures at the 2011 AAS meeting in Seattle, or even listen to our podcast from a meeting in 2010.
This year, however, had a particularly special treat for everyone. On Monday, June 3rd, and Tuesday, June 4th, anyone with the gusto and interest could come to the meeting and attend special talks and events for public and amateur astronomers. To celebrate this, the Indiana Astronomical Society held a star party on June 3rd to get everyone ready for the exciting news unleashed in the following days. Now for the meat and potatoes…
Credit: NASA/JPL-Caltech/University of Wisconsin
Read more »
Capturing the beauty of this galaxy took a team of people – and to understand the galaxy takes a team of missions.
This gorgeous image of galaxy M106 was created by renowned astro-photographer Robert Gendler, who retrieved archival Hubble images to assemble a mosaic of the center of the galaxy. He then used his own and fellow astro-photographer Jay GaBany’s observations to fill in areas where there was little or no Hubble data.
Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), and R. Gendler (for the Hubble Heritage Team) Acknowledgment: J. GaBany
The NASA feature written about this image tells us that Hubble data from the Advanced Camera for Surveys, Wide Field Camera 3, and Wide Field Planetary Camera 2 detectors were used for the center of the galaxy. The outer spiral arms are also Hubble data, but colorized with ground-based data taken by Gendler’s and GaBany’s 12.5-inch and 20-inch telescopes, which was captured at dark, remote sites in New Mexico.
Also visible are the optical component of the so-called “anomalous arms” of M106, which in this image are a red color, from glowing hydrogen emission. They’re called “anomalous” because they don’t line up very well with the galaxy’s more prominent spiral arms.
Why is this hydrogen gas glowing?
Read more »
Each December, there’s a bit of a lull in astronomy news. Not only do the holidays slow things down, but astronomers are also getting ready for the winter meeting of the American Astronomical Society (AAS) in January. These AAS meetings (there’s also a summer meeting in May or June) are a particularly high-profile place to announce a groundbreaking discovery or other exciting piece of research – scientists are surrounded by their peers, with press conferences held daily throughout the week-long meeting. We’ve covered a few of these meetings in the past – you can learn more about AAS press conferences, follow Maggie’s adventures at the 2011 AAS meeting in Seattle, or even listen to our podcast from a meeting in 2010.
This year’s AAS winter meeting was held in Long Beach, CA, where astronomers got a bit of sunshine and sand as well as time to meet with their colleagues, present their research, and hear about the latest and greatest astronomy news. We wanted to share some of the highlights from the astrophysics press releases – and there are some particularly exciting ones in this meeting’s batch!
Credit: NASA, ESA, and A. Feild (STScI)
From a “zombie” to a “rogue” – the astronomy community still can’t get enough of the strange planet Fomalhaut b! First, there was controversy over whether it was a planet or a dust cloud, and now they’re looking at the planet’s unusual orbit within the debris disk of its host star, Fomalhaut. The planet’s highly elliptical, 2,000-year orbit leads astronomers to suspect that there may be other planet-like bodies hiding within the debris around Fomalhaut. One or more of these other bodies may have gravitationally disturbed Fomalhaut b, ejecting it from a position closer to the star and sending it on a wild and potentially destructive orbit through the debris disk. I’m sure this isn’t the last we’ve heard about Fomalhaut b, as astronomers are hoping to continue the hunt for other planets in its system, and to better understand its own characteristics.
Read more »
Welcome back to the -EST blog! This is where I chat about some of the astronomical superlatives that go the extra distance to make our universe so interesting and awesome. In this post I’m going to talk about a pretty popular topic, the darkest things in our universe – black holes. A lot of people think of black holes like giant outer space vacuum cleaners. While they do end up “sucking in” anything that gets too close, this isn’t the most correct way to think about them. Black holes are pretty seriously complex, but I am going to step back to some basics and try to build a decent picture.
Credit: Ute Kraus, Institute of Physics, Universität Hildesheim, Space Time Travel
Black holes are the darkest things in our universe because they emit no light whatsoever in any wavelength. The reason there are no images of black holes themselves is because it is a fact of their physics that they cannot be seen (The image above is an artists conception). Any light that gets too close falls in and can’t get back – this makes black holes problematic because that is how we see things, we see the light that comes back to our eyes. So if black holes produce no light and no light that falls in can ever get back out they can never be seen. But we can still study them and deduce how we think they work. Let’s take a few steps back to try and get our bigger picture.
Read more »
Welcome back to the -EST Blog! This is where we explore some of the astronomical superlatives that go the extra distance to make our universe so interesting. This time, I’ll be trying to tackle one of the brightest objects that we can see. We’re going to talk about Active Galactic Nuclei. These objects make up more than half of the bright objects we see when we observe the universe in high energy gamma rays. I talked with Dr. Dave Thompson about his work studying active galactic nuclei and why studying them is important.
Credit: ESA/NASA/AVO/Paolo Padovani
So what are active galactic nuclei? An active galactic nucleus (AGN for short) is a small region at the center of a galaxy that is much brighter than it would be in an average galaxy. A galaxy that holds one of these active nuclei is known as an “active galaxy.” The artist concept above show what these galaxies might look like up close. The active regions at the centers of active galaxies are believed to contain black holes that are millions or billions of times the mass of the sun – supermassive black holes.
Read more »
Click to listen! (7.5MB MP3, right-click to save)
Transcript (Text, PDF)
It’s an exciting experience for any space geek to watch a new satellite launch into orbit. Even through an online video feed, it’s thrilling to see something that Earthlings worked for years to create headed for its new home, to be our newest eyes on the Universe. These launches don’t happen so often, especially for astrophysics missions, where we see the launch of a new observatory every few years at most. Earlier in 2012, we were excited about the launch of NuSTAR, a small explorer X-ray mission collaboratively created by teams at Caltech, NASA, and over a dozen other institutions around the world.
NuSTAR advances the international astronomical community’s ability to observe some of the hottest, densest, and most energetic objects in the Universe. Its detectors are sensitive at significantly higher energies than other X-ray observatories such as Chandra and XMM-Newton, giving astronomers a chance to extend the range of data they collect. During its mission lifetime, NuSTAR will conduct a survey for massive black holes, study the particles accelerated in active galaxies, and observe the remnants of exploded stars and the chemical elements they’ve left behind.
We were interested to find out more about NASA Goddard’s involvement in the mission, so we interviewed post-doc Dr. Dan Wik about his work with the satellite’s optics and his interest in observing galaxy clusters with NuSTAR.
Credit: Dan Wik
Read more »
On Tuesday, June 5, Venus passed in front of the Sun – an event that was visible on seven continents for those that were fortunate enough to have clear weather. These “transits” of Venus are very rare, coming in pairs separated by more than a hundred years. This June’s transit, the second of a 2004-2012 pair, won’t be repeated until the year 2117.
Credit: NASA/SDO, AIA
Credit: JAXA/NASA/Lockheed Martin
The first image is a composite of images taken by the Solar Dynamics Observatory that shows the path that Venus took across the disk of the Sun. The second is a close-up image taken by Hinode – a joint JAXA/NASA mission to study the connections of the sun’s surface magnetism, primarily in and around sunspots.
Read more »
We posted once about NuSTAR, a new X-ray telescope. It was due to be launched in March, but that launch date is now scheduled for June. Below is a great new image of NuSTAR in the nose cone of the Pegasus rocket it will be launched on.
Using NASA’s Galaxy Evolution Explorer, a space-based observatory, and the Pan-STARRS1 telescope on the summit of Haleakala in Hawaii, astronomers have gathered the most direct evidence yet
of a supermassive black hole shredding a star that wandered too close.
Credit: NASA, S. Gezari (The Johns Hopkins University), and J. Guillochon (University of California, Santa Cruz)
“When the star is ripped apart by the gravitational forces of the black hole, some part of the star’s remains falls into the black hole while the rest is ejected at high speeds,” said project lead Suvi Gezari of the Johns Hopkins University. “We are seeing the glow from the stellar gas falling into the black hole over time. We’re also witnessing the spectral signature of the ejected gas, which we find to be mostly helium. It is like we are gathering evidence from a crime scene. Because there is very little hydrogen and mostly helium in the gas, we detect from the carnage that the slaughtered star had to have been the helium-rich core of a stripped star.”
The above image and this video are computer simulations:
The video shows a star being shredded by the gravity of a massive black hole. As the video caption says, “Some of the stellar debris falls into the black hole and some of it is ejected into space at high speeds. The areas in white are regions of highest density, with progressively redder colors corresponding to lower-density regions. The blue dot pinpoints the black hole’s location. The elapsed time corresponds to the amount of time it takes for a Sun-like star to be ripped apart by a black hole a million times more massive than the Sun.”
Read more »
Credit: NASA, ESA, CFHT, CXO, M.J. Jee (University of California, Davis), and A. Mahdavi (San Francisco State University)
Astronomers have observed what appears to be a clump of dark matter left behind from a wreck between massive clusters of galaxies. The result could challenge current theories about dark matter.
The above image shows the distribution of dark matter, galaxies, and hot gas in the core Abell 520, a merging galaxy cluster formed by violent collision. It is a composite of data from several sources. The natural-color image of the galaxies is from the Hubble Space Telescope and the Canada-France-Hawaii Telescope in Hawaii. Superimposed on it are false-color maps showing the concentration of starlight, hot gas, and dark matter in the cluster.
Starlight from galaxies, derived from observations by the Canada-France-Hawaii Telescope, is colored orange. The green-tinted regions show hot gas, as detected by the Chandra X-ray Observatory. The gas is evidence that a collision took place. The blue-colored areas pinpoint the location of most of the mass in the cluster, which is dominated by dark matter. Dark matter is an invisible substance that makes up most of the universe’s mass. The dark-matter map was derived from the Hubble Wide Field Planetary Camera 2 observations, by detecting how light from distant objects is distorted by the cluster galaxies, an effect called gravitational lensing.
The blend of blue and green in the center of the image reveals that a clump of dark matter resides near most of the hot gas, where very few galaxies are found. This could present a challenge to basic theories of dark matter, which predict that galaxies should be anchored to dark matter, even during the shock of a collision.
You can read more at the news release.
Read more »