smallie
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 (#1570604) Verfasst am: 13.11.2010, 01:17 Titel: Bubbles of Energy Are Found in Galaxy |
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Diese Meldung geht gerade durch die Medien:
| Zitat: | Bubbles of Energy Are Found in Galaxy
Something big is going on at the center of the galaxy, and astronomers are happy to say they don’t know what it is.
A group of scientists working with data from NASA’s Fermi Gamma-Ray Space Telescope said Tuesday that they had discovered two bubbles of energy erupting from the center of the Milky Way galaxy. The bubbles, they said at a news conference and in a paper to be published Wednesday in The Astrophysical Journal, extend 25,000 light years up and down from each side of the galaxy and contain the energy equivalent to 100,000 supernova explosions.
“They’re big,” said Doug Finkbeiner of the Harvard-Smithsonian Center for Astrophysics, leader of the team that discovered them.
The source of the bubbles is a mystery. One possibility is that they are fueled by a wave of star births and deaths at the center of the galaxy. Another option is a gigantic belch from the black hole known to reside, like Jabba the Hutt, at the center of the Milky Way. What it is apparently not is dark matter, the mysterious something that astronomers say makes up a quarter of the universe and holds galaxies together.
“Wow,” said David Spergel, an astrophysicist at Princeton who was not involved in the work.
“And we think we know a lot about our own galaxy,” Dr. Spergel added, noting that the bubbles were almost as big as the galaxy and yet unsuspected until now.
Jon Morse, head of astrophysics at NASA headquarters, said, “This shows again that the universe is full of surprises.”
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http://www.nytimes.com/2010/11/10/science/space/10galaxy.html?_r=2&hp |
Mehr Text im Link.
Mein Bauchgefühl sagt mir: das ist Unsinn. Wenn es soetwas gäbe, hätte man das bereits bei anderen Galaxien beobachtet. Oder sollte der Effekt so klein sein, daß er sich nur lokal beobachten läßt? 
Sicher gibt es Jets, die von Schwarzen Löchern ausgehen und es ist neuerdings bekannt, daß diese Jets auch Effekte wie Sternbildung in nahen Nachbar-Galaxien bewirken können. (Kann den Link, in dem das beschrieben wird, gerade nicht finden, der hier tut's ansatzweise auch: http://www.nasa.gov/mission_pages/chandra/news/07-139.html )
Wer weiß mehr?
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smallie
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Anmeldungsdatum: 02.04.2010
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| (#1572433) Verfasst am: 16.11.2010, 23:49 Titel: |
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Scientific American hat's inzwischen auch aufgegriffen: Hidden in Plain Sight Sehr viel schlauer werde ich daraus auch nicht. Immerhin sind die "bubbles of energy" aus dem NY-Times-Artikel zu "bubbles of plasma" geworden.
Ich bin immer noch skeptisch, vielleicht haben die Leute einfach nur einen Fehler in ihrem Modell.
| Zitat: | From its orbital perch hundreds of kilometers above Earth's surface, Fermi has charted the location of gamma-ray sources with its Large Area Telescope (LAT). But just where the gamma rays originate is not always clear; the foreground of Fermi's view is clouded with emission from events such as cosmic rays striking dust in the Milky Way's disk. To get a better picture of the gamma-ray environment, Douglas Finkbeiner of the Harvard–Smithsonian Center for Astrophysics and his colleagues carefully subtracted those sources based on maps showing locations of cosmic dust, models of the galactic disk, and known emitters of gamma rays, such as active black holes in other galaxies.
"There are many kinds of emission in the Fermi maps—there are things that we're expecting to see, like the dust-correlated emission," Finkbeiner said in an interview during the May meeting of the American Astronomical Society. Finkbeiner presented at the conference an early version of the research, which has now been finalized and readied for publication. "But then we saw some other things that we weren't expecting," Finkbeiner said in the interview. |
Oder vielleicht habe ich mich nur von der künstlerischen Darstellung der zwei Blasen blenden lassen. Im oben verlinkten arxiv-PDF sieht das Ganze wesentlich weniger symmetrisch aus. Und auch wesentlich weniger augenfällig.
Nebenher: bei sowas:
| Zitat: | | "When stuff falls into that black hole, as you can imagine, it makes a big mess," Finkbeiner said. |
frage ich mich dann auch immer, ob ich etwas falsch verstanden habe, oder ob Finkbeiner physikalische Details der Allgemeinverständlichkeit wegen unterschlägt. Es fällt nichts in ein Schwarzes Loch - jedenfalls nicht von aussen gesehen. Nichts kann den Ereignishorizont erreichen. Oder doch?
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