Penn State is a major center of activity on the theory of gamma-ray bursts, as well as on developing instrumentation for detecting GRB, e.g. Swift, HET, LIGO , ICECUBE , etc. ON the theoretical side, we are also involved in a major way in ultra-high energy neutrino astrophysics, and in problems of gravitational wave generation in compact objects (including GRB). Other active areas of research are neutron stars , and cosmology, in particular as related to GRB and other high energy sources.. The GRB, high-energy and GW theory group as of 2004 includes, besides Peter Meszaros, postdoctoral fellows Dr. Soeb Razzaque, Dr. Xiang-Yu Wang and graduate student Mr. LiJun Gou. We have ongoing collaborations with Dr. Eli Waxman (Weizmann Inst.), with Prof. Martin Rees (Cambridge), and Dr. Tim Kallman (NASA-GSFC). Recent short-term theory visitors have included Dr. Zigao Dai (summer 02); Dr. Jaime Alvarez-Muniz (Su. 2004); Dr. Asaf Pe'er (Spring 05, Fall 05); Dr. Felix Ryde (Fall 05; Spring 06). We collaborate also with other Penn State faculty primarily involved in GRB observations, e.g. Dr. Derek Fox, Dr. John Nousek and Dr. David Burrows, with at least five or six other faculty involved part-time, including Profs. Steinn Sigurdsson and Pablo Laguna. Previous members of the GRB theory group include Dr. Shiho Kobayashi (now Senior Lecturer at John Moores University, Liverpool); Dr. Kunihito Ioka (now Assistant Prof. of Physics at Kyoto University, Japan); Dr. Bing Zhang (now Assistant Prof. of Physics at U. Nevada); Dr. Maddalena Spada (now U. Florence, Italy), Mr. Chriss Weth (now U. Tuebingen, Germany); Dr. Alin Panaitescu (now Los Alamos Nat. Lab.); Dr. Hara Papathanassiou (U. Portsmouth, UK); Dr. Jorg Rachen (U. Utrecht, Netherlands); Prof. Istvan Horvath (Budapest); and Prof. Dan Reichart (U. North Carolina). Among current research topics being investigated are the properties of X-ray and optical afterglows of GRB; the gravitational wave signatures of GRB and massive black hole systems, the radiation and pehenomenology of jets in GRB; the propagation and dynamics of relativistic jets inside progenitors; the GeV-TeV photon signatures of bursts and afterglows, and the ultra-high energy (TeV to ZeV) neutrino signals from GRB and AGN jets. On the top photo, L to R top: Peter Meszaros, Soeb Razzaque, Kunihito Ioka, Lijun Gou; L to R bottom: Jaime Alvarez-Muniz, Shiho Kobayashi, Bing Zhang.
On the experimental side, Penn State and NASA/Goddard are the main partners in Swift, a GRB Afterglow Midex satellite, successfully launched in November 2004. 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. Other teams involved include Mullard Space Science Lab, London; Brera Observatory, Milano; and Leicester University, UK. GRB optical afterglow work is also being carried out with the Hobby-Eberly 10-meter telescope, in operation in west Texas, led by Prof. Michael Eracleous from Penn State. Other Penn State GRB activities include participation in the development of the AMANDA and ICECUBE ultra-high energy neutrino detectors in Antartica, and the Auger cosmic ray array in Argentina, involving Profs. Douglas Cowen, Paul Sommers and Stephane Coutu from Penn State. 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, Pablo Laguna, Peter Meszaros, Steinn Sigurdsson.
Research sponsors: NASA, NSF