An intergalactic acceleration lane?

The following press conference is scheduled for the American Physical Society (APS) April Meeting in Long Beach, California April 29-May 2, 2000.

Presenting the very first low-frequency (75 MHZ) radio telescope images of a region that is part of the Great Wall of galaxies, Phil Kronberg of the University of Toronto (416-978-4971, kronberg@physics.utoronto.ca) and his colleagues present the clearest, most unambiguous evidence yet for intergalactic magnetic fields outside galaxy clusters. The new images suggest the possibility (still speculative at this point) that vast intergalactic zones like these may serve as the mysterious acceleration sites for ultra-high energy cosmic rays, which have confounded physicists in recent years. In separate work to be published later this year, Kronberg and colleagues have found that the rarefied intergalactic regions in typical clusters have magnetic fields that are, amazingly, at least as strong as those within the much denser disk of our Milky Way. This means that a significant additional amount of energy, in a previously invisible form, is stored within the intergalactic gas in galaxy clusters.

Angela Olinto of the University of Chicago (773-702-8206, olinto@oddjob.uchicago.edu) will describe what is known about the history of magnetic fields in the universe. Studying the magnetic fields within galaxies, Russell Kulsrud of Princeton University (rkulsrud@astro.princeton.edu) will report on a new problem that has emerged: Evidence is ruling out the previously held scenario that a galaxy's magnetic field grows from a weaker field as it develops over billions of years. This only seems to leave the possibility that the precursors to galaxies billions of years ago must somehow have possessed magnetic fields roughly as strong as those in galaxies that we observe today. (Session B7, Saturday)

The press conference will be held in room 201A in the Long Beach Convention Center. Press conferences will be held in room 201B. Pressroom hours: Sat-Tues 8 AM to 5 PM. Pressroom phone numbers: 562-499-7780 and 81. Fax: 562-499-7784.

The meeting website, including all the abstracts, is http://www.aps.org/meet/APR00/#general. See also the APS virtual pressroom at http://www.aps.org/meet/APR00/baps/vpr. Journalists intending to attend the meeting should send in their request for a press badge, if they haven't already done so, to Ben Stein at bstein@aip.org.