Articles written in Journal of Astrophysics and Astronomy
Volume 32 Issue 1-2 March 2011 pp 1-2
Volume 32 Issue 1-2 March 2011 pp 59-60 Part 1. Blazar Observations in Radio
In this work, we investigate the correlation between the luminosity and the core-dominance parameter for a sample of X-ray selected BL Lacertae objects (XBLs), and found that the extended luminosity is strongly anti-correlated with the core-dominance parameter while the core (or the total) luminosity is not correlated with the core-dominance parameter. If this is the case, then we can expect that the lower extended luminosity XBLs and their core luminosity is relatively higher. This can be explained by a relativistic beaming model since in this case, the viewing angle is smaller and the emissions dominate the extended emissions. Therefore, the anti-correlation is in fact the result of the relativistic beaming model.
Volume 32 Issue 1-2 March 2011 pp 67-71 Part 2. Blazar Observations in Infrared and Optical
Variability is one of the characteristics of blazars. The rapid variability is superposed on the long term variation. In this work, the variability on different time scales, such as intra-day (IDV), short-term (STV) and long-term (LTV) variations are presented for some sources. We also presented our own observations of some selected objects, for which the historical data were compiled for periodicity analysis using several methods. The parameters of the binary black hole system OJ 287 are determined.
Volume 32 Issue 1-2 March 2011 pp 79-86 Part 2. Blazar Observations in Infrared and Optical
In this work, four methods are introduced to analyse the unevenly sampled data. The four methods are power spectral density, autocorrelation function, structure function and Jurkevich method. Some interesting mathematical links are derived amongst the four methods. These links show that the four methods have the same performance. For the Jurkevich method, the effect of the width of bins is apparent. If the width is half the time scale, the method has better performance.
Volume 32 Issue 1-2 March 2011 pp 331-332 Part 7. Other Topics
Astronomy is a very interesting subject for undergraduate students studying physics. In this paper, we report astronomy education for undergraduate students in the Physics Department of Guangzhou University, and how we are teaching astronomy to the students. Astrophysics has been rapidly developing since 1994, when the center for astrophysics was founded. Now, astrophysics has become a key subject in Guangdong Province, and the Astronomy Science and Technology Research Laboratory one of the key laboratories of the Department of Education of the Guangdong Province. Many undergraduate students, working under the tutorship of faculty members completed their thesis at the Center for Astrophysics in Guangzhou.
Volume 35 Issue 3 September 2014 pp 201-202
Volume 35 Issue 3 September 2014 pp 231-235 Part II: Blazar Observations in Infrared and Optical
The most identified sources observed by Fermi/LAT are blazars, based on which we can investigate the emission mechanisms and beaming effect in the 𝛾-ray bands for blazars. Here, we used the compiled around 450 Fermi blazars with the available X-ray observations to estimate their Doppler factors and compared them with the integral 𝛾-ray luminosity in the range of 1–100 GeV. It is interesting that the integral 𝛾-ray luminosity is closely correlated with the estimated Doppler factor, log 𝑣𝛾 𝐿𝑣𝛾 = (2.95 ± 0.09) log 𝛿 + 43.59 ± 0.08 for the whole sample. When the dependence of the correlation between them and the X-ray luminosity is removed, the correlation is still strong, which suggests that the 𝛾-ray emissions are strongly beamed.
Volume 35 Issue 3 September 2014 pp 257-260 Part II: Blazar Observations in Infrared and Optical
OJ 287 is a BL Lac object at redshift 𝑧 = 0.306 that has shown double-peaked bursts at regular intervals of 12 yr during the last 40 yr according to previous research. Some of the AGN 𝛾 ray power density shows a white noise process, while some others shows a red noise process. Some AGN flux presents normal or log-normal distribution. The two processes have an intrinsic relationship with centre black hole emission mechanism. We present the results of the analysis of the Fermi-LAT data. We review some problems concerning the random process.
Volume 35 Issue 3 September 2014 pp 585-586 Part VII: Other Topics
Guangdong province is an active area in China for astronomy education and popularization. The current status and problems of astronomy education in high schools are reviewed. To tackle these problems, an astronomy education project for high school teachers and students was initiated by Guangzhou University in 2013. The purpose and key points of the projects are introduced in this paper.
Volume 40 | Issue 3
Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science immediately. All these have helped shorten the publication time and have improved the visibility of the articles.