The purpose of the University of California High-Performance AstroComputing Center (UC-HiPACC) is to realize the full potential of the University of California world class resources in computational astronomy. Read the letter from the Director
July 2014 AstroShort: Magnetically Levitating Black Holes
Loud and twisted: some supermassive black holes at the centers of galaxies have twisted magnetic fields so powerful they counteract the colossal pull of their gravity—allowing clouds of accreting gas or other objects literally to levitate temporarily in place above the black hole instead of plunging into the maw. That’s the conclusion of one UC Berkeley researcher and three coauthors after comparing their computational model to empirical measurements of not just one or two, but of 76 supermassive black holes in loud radio galaxies and blazars. The new findings may mean that theorists must re-evaluate their understanding of how supermassive black holes behave. Read the AstroShort “Magnetically Levitating Black Holes.”
A computer simulation shows gas (yellow) falling in the direction of a central black hole (too small to be seen). Twin jets (blue), strongly focused by spiral magnetic field lines, shoot out towards the top and bottom, perpendicular to the plane of the rotating accretion disk. Credit: Alexander Tchekhovskoy / LBNL
May 2014 AstroShort: Drying Out the Moon?
Moon rocks brought back by the Apollo astronauts revealed that the lunar mineral apatite is everywhere, from the ancient lunar highlands to the young lunar maria (lava seas). Much of it is rich in hydrogen. Taking hydrogen as a proxy for water, the evidence suggested that the material from which the Moon formed might have been as wet as that which formed Earth. Apatite became widely adopted as a yardstick for measuring hydrogen—and thus water—in the Moon. But a new computational model of how apatite crystalized from lunar magmas, devised by Jeremy W. Boyce at UC Los Angeles and four coauthors, now reveals that apatite, the mineral on which scientists have long relied, “cannot be trusted.” See the AstroShort “Drying Out the Moon?”
Photomicrograph of Apollo 11 lunar sample 10044,644 maps density of its polished surface: denser materials reflect more electrons and look lighter gray. Pinkscale version of image highlights density variations for a crystal of apatite. Credit: Jeremy Boyce, UCLA
April 2014 AstroShort: Not-So-Rare Earths
If the stars observed by NASA’s Kepler spacecraft are statistically representative of those in our own solar neighborhood of the Milky Way galaxy, then “Earth-size planets are common around nearby Sun-like stars,” conclude Erik A. Petigura and Geoffrey W. Marcy from the University of California, Berkeley and Andrew W. Howard from the University of Hawaii. They were led to that conclusion by a monumental statistical analysis of Kepler data completed with the help of the Carver supercomputer at the Department of Energy’s (DOE’s) National Energy Research Scientific Computing Center (NERSC). Read AstroShort
Field of view of the Kepler space telescope, located in the constellation Cygnus, just above the plane of the Milky Way Galaxy. Credit: NASA
March 2014 AstroShort: Discovered: Stellar Dinosaurs!
Arrow points to supernova SNLS 06D4eu and its host galaxy, both about 10 billion light-years away. Big objects with spikes are stars in our own Milky Way; every other bright dot is a distant galaxy. Credit: University of California, Santa Barbara
“We had no idea what these things were,” recounted D. Andrew Howell, staff scientist at Las Cumbres Observatory Global Telescope Network and adjunct assistant professor at UC Santa Barbara. Two objects caught by the detectors of the Supernova Legacy Survey looked like supernovae—stars exploding in cataclysmic stellar suicide—but did not act like familiar supernovae. The finding launched Howell along with Daniel Kasen, computational astrophysicist at UC Berkeley, and 16 colleagues into detective sleuthing that led to the discovery of … Read AstroShort
January 2014 AstroShort: A Black Hole is Born
Astrophysicists had unusual ringside seats to the birth of a black hole in an inconspicuous galaxy relatively nearby, watching across all wavelengths from initial gamma ray burst and optical flash through fading afterglow. Read AstroShort
Los Alamos National Laboratory astrophysicist Tom Vestrand poses with the fast-slew array of telescopes for RAPTOR (RAPid Telescopes for Optical Response) system. RAPTOR is an intelligent visual system that scans the skies for optical anomalies and zeroes in on them when it detects them. This unique capability allowed astronomers to witness the birth of a black hole in the constellation Leo.