Articles written in Journal of Astrophysics and Astronomy
Volume 32 Issue 1-2 March 2011 pp 193-196 Part 4. Emission Models and Theory
The observed broadband spectral energy distributions (SEDs) of 22 hot spots and 45 knots are modelled with single-zone lepton models. Considering the sources at rest, the X-rays of some hot spots can be explained by the SSC model with magnetic field being consistent with the equipartition magnetic field in magnitude of order 1, but at the same time an unreasonably low magnetic field is required to model the X-rays for all knots. When considering the relativistic bulk motion of the sources, the IC/CMB model well explains the X-ray emission for most of them under the equipartition condition. We show that the ratio of observational luminosity 𝑅𝐿 is tentatively correlated with the co-moving equipartition magnetic field 𝐵'eq and the beaming factor 𝛿. These facts suggest that the observational differences of the X-rays from the knots and hot spots may be mainly due to the differences in the Doppler boosting effect and the co-moving magnetic field of the two kinds of source.
Volume 35 Issue 3 September 2014 pp 267-270 Part II: Blazar Observations in Infrared and Optical
A statistical analysis of gamma-ray burst host galaxies is presented and a clear metallicity-stellar mass relation is found in our sample. A trend that a more massive host galaxy tends to have a higher star-formation rate is also found. No correlation is found between 𝐴V and 𝑁H. GRB host galaxies at a higher redshift also tend to have a higher star formation rate, however, even in the same redshift, the star formation rate may vary for three orders of magnitude.
Volume 35 Issue 3 September 2014 pp 457-461 Part VI: Combined Multi-Waveband Observations
Four well-sampled Spectral Energy Distributions (SEDs) of PMN J0948+0022 are fitted with the syn+SSC+EC model to derive the physical parameters of its jets and to investigate the spectral variations of its SEDs. A tentative correlation between the peak luminosity (𝐿c) and peak frequency (𝑣c) of its inverse Compton (IC) bump is found in both the observer and co-moving frames, indicating that the variations of luminosity are accompanied by the spectral shift. A correlation between 𝐿cs and 𝛿 is found, and thus the magnification of external photon field by the bulk motion of the radiation regions is an essential reason for the spectral variation since, IC bump of PMN J0948+0022 is dominated by the EC process.
Volume 40 | Issue 6
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