We report the discovery of possible periodic X-ray dips in a pulsating ultraluminous source, M51 ULX-7, with archival Changra observations. With ~20 days monitoring superorbital descending state, we discovered three separations ~2 and ~8 via Bayesian block technique. A phase-dispersion minimization $\chi^2$ test suggest that dip is likely recurrent period days, consistent orbital ULX-7. interpr...

We make a quantitative prediction for the detection rate of orphan gamma-ray burst (GRB) afterglows as a function of flux sensitivity in X-ray, optical, and radio wavebands, based on a recent model of collimated GRB afterglows. We find that the orphan afterglow rate strongly depends on the opening angle of the jet (roughly ∝ θ−2 jet ), as expected from simple geometrical consideration, if the t...

We present a brief overview of the basic concepts and important experimental observations of the effect of light localization near the surfaces of truncated periodic photonic structures. In particular, we discuss the formation of nonlinear localized modes and discrete surface solitons near the edges of nonlinear optical waveguide arrays and two-dimensional photonic lattices. We draw an analogy ...

The realization that the total energy of GRBs is correlated to their jet break angles motivates the search for a similar relation between the peak luminosity, L, and the jet break angles, L ∝ θ. Such a relation implies that the GRB luminosity function determines the angular distribution. We re-derive the GRB luminosity function using the BATSE peak flux distribution and compare the predicted di...

We present an analysis of thermal emission from comet 162P/Siding Spring (P/2004 TU12) measured during its discovery apparition in December 2004. The comet showed no dust coma at this time, so we have sampled emission from the comet’s nucleus. Observations using the “Mid-Infrared Spectrometer and Imager” (“MIRSI”) were performed at NASA’s Infrared Telescope Facility, where the peak of the comet...

We discuss the compact radio sources associated with quasars and AGN with particular emphasis on the implications of their structure and kinematics for relativistic beaming models.

Electromagnetic scattering caused by the site environment of airports will cause multipath effect. In the presence of multipath, the measured angle position, which is derived through the measuring of the time interval between “From” and “To” scanning pulse pairs, will deviate from the actual position, leading lower system guidance accuracy and higher risk. An error research method based on the ...