Hai-Ming Zhang

Extremely Bright GRB 160625B with Multiple Emission Episodes: Evidence for Long-term Ejecta Evolution

GRB 160625B is an extremely bright GRB with three distinct emission episodes. By analyzing its data observed with the GBM and LAT on board the {\em Fermi} mission, we find that a multi-color black body (mBB) model can be used to fit the spectra of initial short episode (Episode I) very well within the hypothesis of photosphere emission of a fireball model. The time-resolved spectra of its main episode (Episode II), which was detected with both GBM and LAT after a long quiet stage (

Multiple-wavelength Variability and Quasi-periodic Oscillation of PMN J0948+0022

\sim 180

Examining the High-energy Radiation Mechanisms of Knots and Hotspots in Active Galactic Nucleus Jets

seconds) of the initial episode, can be fitted with a model composing of an mBB component plus a cutoff power-law (CPL) component. This GRB was detected again in the GBM and LAT bands with a long extended emission (Episode III) after a quiet period of

Characteristics of Two-episode Emission Patterns in Fermi Long Gamma-Ray Bursts

\sim 300

GRB 120729A: External Shock Origin for Both the Prompt Gamma-Ray Emission and Afterglow

seconds. The spectrum of Episode III is adequately fitted with a CPL plus a single power-law models, and no mBB component is required. These features may imply that the emission of three episodes are dominated by distinct physics process, i.e., Episode I is possible from cocoon emission surrounding the relativistic jet, Episode II may be from photosphere emission and internal shock of relativistic jet, and Episode III is contributed by internal and external shocks of relativistic jet. On the other hand, both X-ray and optical afterglows are consistent with standard external shocks model.

Jet Radiation Properties of 4C +49.22: from the Core to Large-Scale Knots

We present a comprehensive analysis of multiple wavelength observational data of the first GeV-selected narrow-line Seyfert 1 galaxy PMN J0948+0022. We derive its lightcurves in the \gamma-ray and X-ray bands from the data observed with Fermi/LAT and Swift/XRT, and make the optical and radio lightcurves by collecting the data from the literature. These lightcurves show significant flux variations. With the LAT data we show that this source is analogue to typical flat spectrum radio quasars in the

Fermi/LAT observations of lobe-dominant radio galaxy 3C 207 and possible radiation region of γ-rays

L_\gamma-\Gamma_\gamma

Similarity of jet radiation between flat spectrum radio quasars and GeV narrow-line Seyfert 1 galaxies: a universal δ- L c correlation

plane, where

Extremely Bright GRB160625B with Short-Soft Precursor and long-hard extended emission: Hints for long-term evolution of the GRB Ejecta

L_\gamma

Adsorption of chromium (VI) from aqueous solution by the iron (III)-impregnated sorbent prepared from sugarcane bagasse

and