1. A Particle Physicist View of Particle Astrophysics Bill Atwood SCIPP/UCSC 18-Sept-2008

2. All good stories start with “….in the beginning…”  GLAST (now FERMI) began in 1992 one year after EGRET began revealing an extraordinary Gamma Ray Sky  HEP detector development for SSC in full swing  A re-do of EGRET with modern HEP detectors, saturating the launch capabilities of a Delta II rocket resulted in the GLAST design  Rapid simulation capability added credibility to design concept Marriage between High Energy Astro and HEP communities  Each brings a unique perspective and expertise.  And… each brings their own culture and “way of doing business” High Energy Astrophysics + HEP Particle Astrophysics Glast was amoung the first in the new interdisciplinary field….

3. HEP - Particle Astro Community Comparison HEPCollecting Particle decay modes (Br. Ratios) Particles & their parameters Cross-sectionsExploring Neutrino generations Parity Violation Searches – Higgs, SUSY, Extra Dimensions, etc. Particle-AstroCollecting Pulsars AGN Other exoticsExploring CMB Hubble expansion Dark Matter Lorentz Invariance Primordial relics Laboratories for GR Collecting in the two groups is quite disjoint Explorers are on similar quests My personal preference is Exploring

4. Furthermore the Keplerian velocities depend only the ratio r s /r So the inner edge of accretion disks have v ~ ~ parsecs Accretion Disk 3- 10 r s Black Hole Diameter = 2r s ~ 4 AU A Sketch of a Massive Black Hole……not-to-scale An example distinguishing Gathering/Exploring from Astrophysics A Laboratory for Exploring Extreme Environments

5. A Question for All: The Dark Matter Mystery Only visible effect due to Gravitational Interactions FERMI-LAT FERMI-LAT  Self Interactions could produce measurable effects in Gamma Ray and Cosmic Ray Spectra.  It is doubtful that it will positively identify the precise nature of the particles LHC: ATLAS / CMS  May find particle DM candidate(s).  If so, this will sharpen the search in FERMI A Plausible Scenario  LHC finds new particles  FERMI tells what their role is in the Universe at large For Explorers – this coming year is remarkable & exciting!!! IF… IF… Dark Matter has a particle component…