Evolution of X-ray spectra of Cygnus X-3 with radio flares

Cygnus X-3, among the X-ray binaries, is one of the brightest in the radio band, repeatedly exhibiting huge radio flares. The X-ray spectra shows two definite states, low (correspondingly hard) and high (correspondingly soft). During the hard state the X-ray spectra shows a pivoting behaviour correlated to the radio emission. In the high state the X-ray spectra shows a gamut of behaviour which controls the radio flaring activity of the source. The complete evolution of the X-ray spectra along with the radio flaring activity is reported here, for the first time for this source.Comment: Bibliography has been correctly adde

Detection of anti-correlated hard X-ray time lag in Cygnus X-3

The wide-band X-ray spectra of the high mass X-ray binary Cygnus X-3 exhibits a pivoting behavior in the `low' (as well as `hard') state, correlated to the radio emission. The time scale of the soft and hard X-rays' anti-correlation, which gave rise to the pivoting feature, was found to be less than a day from the monitoring observations by RXTE--ASM and CGRO--BATSE. In this Letter we report the detection of a lag of $\lesssim$ 1000s in the anti-correlation of the hard X-ray emission (20--50 keV) to that of the soft X-ray emission (2--7 keV), which may be attributed to the viscous time scale of flow of matter in the accretion disk. This suggests the geometrical picture of a truncated accretion disc with a Compton cloud inside the disc, the relative sizes of which determine the spectral shape. Any change in the disc structure will take place in a viscous time scale, with corresponding anti-correlated change in the Compton cloud. We also report the pivoting in the spectra in one span of a pointed observation when an episode of the rearranging of the accretion system is serendipitously observed. This is the first such observation of hard X-ray delay seen in the persistent Galactic microquasars, within the precincts of the hard state.Comment: Accepted in The Astrophysical Journal (Letters): in pres

Emergence of a non-scaling degree distribution in bipartite networks: a numerical and analytical study

We study the growth of bipartite networks in which the number of nodes in one of the partitions is kept fixed while the other partition is allowed to grow. We study random and preferential attachment as well as combination of both. We derive the exact analytical expression for the degree-distribution of all these different types of attachments while assuming that edges are incorporated sequentially, i.e., a single edge is added to the growing network in a time step. We also provide an approximate expression for the case when more than one edge are added in a time step. We show that depending on the relative weight between random and preferential attachment, the degree-distribution of this type of network falls into one of four possible regimes which range from a binomial distribution for pure random attachment to an u-shaped distribution for dominant preferential attachment

An analysis of the Isgur-Wise Function and its derivatives within a Heavy-Light QCD Quark Model

In determining the mesonic wave function from QCD inspired potential model, if the linear confinement term is taken as parent (with columbic term as perturbation), Airy's function appears in the resultant wave function - which is an infinite series. In the study of Isgur-Wise function (IWF) and its derivatives with such a wave function, the infinite upper limit of integration gives rise to divergence. In this paper, we have proposed some reasonable cut-off values for the upper limit of such integrations and studied the subsequent effect on the results. We also study the sensitivity of the order of polynomial approximation of the infinite Airy series in calculating the derivatives of IWF.Comment: 14 pages,6 tables 8 figure

The association of shift work and coronary heart disease risk factors among male factory workers in Kota Bharu, Kelantan

Shift work is one of the work hour systems in which a relay of employees extends the period of production beyond the conventional 8-hour working day. It has been found to be associated with various health problems and there is concern that shift workers are at higher risk to develop risk factors for coronary heart disease (CHD). The study was undertaken to examine relationships between shift work and CHD risk factors, namely hypertension, dyslipidaemia (either hypercholesterolaemia, hyper-low density lipoprotein-cholesterolaemia, hypo-high density lipoprotein-cholesterolaemia or hypertriglyceridaemia), high body mass index (BMI), hyperglycemia and physical inactivity among male factory workers in a factory in Kota Bharu, Kelantan. METHODS: This study was a contrived cross-sectional study of 76 shift and 72 day workers from one ofthe factories in Kota Bharu, Kelantan. Data was collected through a questionnaire on psychosocial and life-style factors, anthropometric and blood pressure measurement, fasting blood sugar and fasting lipid proJiles analyses. RESULTS: The prevalence of hypertension, hypercholesterolaemia, hypertriglyceridaemia and high body mass index (BMO were significantly higher among shift workers compared to day workers. There was no difference in the prevalence of hyperg[ycemia, hypo-high-density lipoprotein-cholesterolaemia, hyper-high-density lipoprotein-cholesterolaemia and physical inactivity. When the shiji workers were compared with the day workers, the aajusted odds ratio (OR) for hypertension, high BMI andphysical inactivity were 9.1 (95% CI 1.4-56.8), 2.9 (95% CI 1.3-6.1) and 7.7 (95% CI 2.1-27.5) respectively. There was neither association of shift work with dyslipidaemia, nor with hyperglycemia. CONCLUSIONS: There were positive association between shiji work and hypertension, high BMI andphysical inactivity which denotes a higher risk of CHD risk factors among shift workers compared to day workers

A study of the Haor areas of Sylhet-Mymensing districts with ERTS imageries (winter crop estimation)

There are no author-identified significant results in this report

New limits on top squark NLSP from ATLAS 4.7 fb−1fb^{-1} data

Using the ATLAS 4.7 $fb^{-1}$ data on new physics search in the jets + \met channel, we obtain new limits on the lighter top squark ($\tilde t_1$) considering all its decay modes assuming that it is the next to lightest supersymmetric particle (NLSP). If the decay \lstop \ra c \lspone dominates and the production of dark matter relic density is due to NLSP - LSP co-annihilation then the lower limit on \mlstop is 240 GeV. The limit changes to 200 GeV if the decay \lstop \ra b W \lspone dominates. Combining these results it follows that \lstop NLSP induced baryogenesis is now constrained more tightly.Comment: 9 pages, 2 figures, published in MPL