Penn State is a major center of activity on the theory of gamma-ray bursts, as well as related activities in neutrino, cosmic ray, and gravitational wave astrophysics. Penn State is also heavily involved in observations, data analysis and instrumentation development targeting GRB, AGNs, SNe and other high energy sources, e.g. Swift, Auger , ICECUBE , LIGO , etc. Other active areas of research are neutron stars , and cosmology, in particular as related to GRB and other high energy sources. The GRB, particle astrophysics and GW theory group as of 2008 includes Peter Meszaros, postdoctoral fellows Dr. Xuefeng Wu, Dr. Kenji Toma, Dr. Alessandra Corsi, and graduate students Prakash Arumugasamy, Shan Gao, Xihao Deng, Xuesong Wang. We have ongoing collaborations with Profs. Eli Waxman (Weizmann Inst.), Martin Rees (Cambridge), and the SWIFT, FERMI and ICECUBE groups. Recent short-term theory visitors have included Dr. Katsuaki Asano (winter 08), Dr. Shin'ichiro Ando (winter 08); Dr. Kunihito Ioka (Spring 08); Dr. Asaf Pe'er (Fall 08). We collaborate also with other Penn State faculty primarily involved in GRB observations, e.g. Dr. Derek Fox, Dr. David Burrows, etc. Some recent previous members of the GRB theory group include Dr. Lijun Gou (now postdoc, Harvard-Smihtsonian Center for Astrophysics); Dr. Shiho Kobayashi (now Senior Lecturer at John Moores University, Liverpool); Dr. Kunihito Ioka (now Associate Prof. of Physics, KEK-Japan Nat. Accelerator Lab); Dr. Bing Zhang (now Associate Prof. of Physics at U. Nevada); Dr. Alin Panaitescu (now Director's Fellow, Los Alamos Nat. Lab.);
Among current research topics are: (a) the properties of the GeV and TeV photon emission of GRB, related to our group's affiliation with the FERMI satellite collaboration; (b) the MeV prompt emission and the X-ray and optical afterglows of GRB, related to our role in the SWIFT satellite consortium; (c) the TeV to EeV neutrino signals from GRB and AGN jets, related to our affiliation with the ICECUBE ultra-high energy neutrino detector; (d) the cosmic ray astrophysics of GRB and AGN, which benefits from osmosis with the local AUGER group; (e) the gravitational wave signatures of GRB and massive black hole systems, related to our involvement with the CGWP; (f) and the general properties of relativistic jets and compact object systems, with their related cosmological and funadamental physics questions. An example of the latter is the calculation of a new lower limit to the quantum gravity (or Lorentz invariance violation) energy scale, based on analysis of FERMI data on GRB 080916C (Science, 2009, in press). On the top photo, L to R: Nino Cucciara, Derek Fox, Alessandra Corsi, Peter Meszaros, Xuefeng Wu, Kenji Toma.
On the experimental side, Penn State and NASA/Goddard are the main partners in Swift, a GRB Afterglow Midex satellite launched in November 2004, which has been revolutionizing the field of GRB. Swift is equipped with gamma-ray, x-ray and optical detectors for on-board follow-up, and is capable of relaying to the ground arc-second quality burst coordinates within less than a minute from the burst trigger, allowing even mid-size ground-based telescopes to obtain prompt spectra and redshifts. This has permitted much more detailed studies of the burst environment, the host galaxy, and the intergalactic medium between galaxies. The Penn State Swift activities (involving Drs. John Nousek, Dave Burrows, Derek Fox, Marg Chester, Peter Roming and others) include developing and running the Ground Control Center for the satellite, housed at Penn State; building and running the X-ray CCD detectors and camera; and assembling, testing and running the Optical Monitor flown on Swift. The Gamma-ray monitor was built and is operated by the NASA Swift team. Penn State is also the lead institution for a new proposed ``Nascent Universe" high-redshift GRB satellite proposal called JANUS, with all-sky gamma-ray detectors and autonomously repointing infra-red telescopes (Peter Roming, Derek Fox, David Burrows, Abe Falcone). GRB optical afterglow work is also being carried out with the Hobby-Eberly 10-meter telescope, in operation in west Texas, led by Prof. Derek Fox from Penn State. Other Penn State GRB activities include participation in the development of the ICECUBE ultra-high energy neutrino detectors in Antartica, the Auger cosmic ray array in Argentina, involving Profs. Douglas Cowen, Paul Sommers Stephane Coutu and Tyce DeYoung from Penn State, and the VERITAS TeV gamma-ray air Chereknov observatory, involving Abe Falcone. Another GRB experimental effort is aimed at detection of gravitational wave signals from compact sources and GRB with LIGO , and from massive black holes and galactic systems with LISA, carried out through the Center for Gravitational Wave Physics, involving Profs. E. Sam Finn, Ben Owen, Peter Meszaros, Steinn Sigurdsson. These various activities are coordinated through the Penn State Center for Particle Astrophysics ,
Research sponsors: NASA, NSF