Michigan Technological University

Department of Physics

is pleased to announce a colloquium

with

Haihong Che

Michigan Technological University

Graduate Student

On Jets and Luminosity Function of GRBs Associated with Supernovae

If Gamma-ray Bursts (GRBs) are generally associated with supernovae, a relatively wide intrinsic luminosity function is implied. If it is assumed that the intrinsic luminosity function of GRBs is a power-law: fL proportional to Lb, data from the BATSE 4B catalog can be used to constrain slope index b and the dynamic range width Log (Lmax / Lmin). Using a K-S test comparison with the observational Log N - Log P, we find constraints on the GRB fireball model, GRB jets. We find acceptable dynamic range for 102 < (Lmax / Lmin) < 107. Our results show that jet model is more likely to be related more highly energetic explosion than fireball model. Our studies also show that the luminosity function provided by a purely special relativistic effect on a jet would dominate.

Wellesley Pereira

Michigan Technological University

Graduate Student

CONtinuous CAMeras (CONCAMs)

CONCAMs are a series of automated passive sky monitors, capable of creating a continuous record of the sky down to about 10th magnitude. They are extremely inexpensive, contain few or no moving parts, and are small enough to fit into a briefcase. They tend to be both continuous and passive. They are passive in the sense that since they see all available sky all the time, they do not need to be pointed. Variability is discovered in the archived data. They are continuous in the sense that they are always on. They only cease observations when they break. It is hoped that, eventually, much of the sky can be recorded much of the time. Possible scientific returns may also include noting or limiting the existence of transient Astronomical phenomena at night such as comets, meteors, bright novae, and even bright optical counterparts to Gamma-Ray Bursts. When run during the day, a useful meteorological record may also be recorded.

Thursday, February 10, 2000

4:00 p.m. Fisher Hall 139

Refreshments will be served