Astronomers have some (more) good evidence that  their favorite explanations for a major class of cosmic rays is on target. It is a bit indirect, but detection of gamma rays from galaxies chock-a-block with big, young, supernova-prone stars indicates strongly that they are prime sources of high energy cosmic rays too. The rays themselves – ionized atomic nuclei – get switcherooed in direction as they carom through magnetic fields, so one can hardly tell where they started from the direction from which they arrive at Earth. But theory says that their presumed birth places – the core collapses and supernova rebounds of giant worn out stars – should generate  gamma rays too as the dense gusts of cosmic rays wham through the thin gases of the intragalactic medium. Or so they say. The new data finds lots of gamma rays in galaxies that have lots of such exploding stars. Ergo….

The latest evidence is from a new set of telescopes at Arizona’s Whipple Observatory called the Veritas Array plus data from NASA’s  Fermi Gamma-ray Space Telescope. It is in Nature on line this week. Its authors reported it as well in Washington DC at the Fermi Science Symposium.

To appreciate media coverage, for a switch let’s start with a press release from the Harvard-Smithsonian Ctr. for Astrophysics, as rendered by the news release aggregating service ScienceDaily. The reason, if you look at that page, is that it includes links to press releases on the same gemeral topic and going back several years. The basic hypothesis has been bolstered, although perhaps not as emphatically as now, in 2004 and in June this year. This is not to say the new stuff does not merit coverage. But it is a useful reminder that science is cumulative via small steps more often than in the giant leaps that journalists are instinctively prone to see.

For all that, if one looks at the lineup of press releases down there in Grist, and the relatively light pickup for what is rather interesting news on the fundamentals of the universe, it’s too bad more reporters did not bite.

Stories:

• Science News (via Wired) Ron Cowen: Gamma-Ray Mystery Traced to Star-Birth Frenzy ; Well explained piece on the news. But the hed that Wired puts on it says the mystery centered on gamma rays. Aren’t the gamma rays the (indirect) key to settling the mystery – of cosmic rays? A: Yes. Sci News’s own hed is Cosmic Rays Traced to Centers of Star Birth.
• USA Today – Dan Vergano (brief): Exploding stars shoot out cosmic rays ; Such a short piece on a complicated topic reminds one of the old joke about USA Today in its early days: as birthplace of a new genre, the investigative paragraph.
• The MinnPost site in Minneapolis-St. Paul carries an Inside Science News Service account by Devin Powell, filed in Washington and, apparently, from the Fermi symposium where the users of the telescopes reported their results. Aside from being a solid piece this is worth noting for two other reasons – MinnPost is one of the fairly new startup, non-profit outlets trying to step into the gap left by the fading of traditional media, and it includes science in its menu. The last link goes to its health-science page, heavy on health while including some decent enviro and phys. science reporting as well. It’s also of interest to see it using material from ISNS,  maintained by the American Institute of Physics.
• Nat’l Geographic News – Victoria Jaggard: GALAXY PICTURE: Cosmic Ray Mystery Solved?

More Grist for the Mill:

Original Harvard-Smithsonian CfA Press Release;

NASA Goddard Space Flight Ctr Press Release ;

NSF Press Release ;

University of Delaware Press Release ;

Iowa State University Press Release ;

Fermi Gamma Ray Space Telescope Press Release ;

VERITAS Array ;

Other Gamma Ray News:

Recently the Fermi telescope has been in the news for other reasons. One, already tracked in this previous post, was its indication that the speed of light pays no measurable attention to wavelength in the near vacuum of space. Another is detection of a gamma ray haze within the Milky Way that just might be an indirect signature for dark matter. Here are two stories on that:

• Scientific American – John Matson: Emission Impossible? Is Dark Matter Behind the Hazy Radiation at the Milky Way’s Center? ;
• NYTimes – Dennis Overbye: Findings on Mysterious Haze at Galaxy’s Center ;

- Charlie Petit

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