The mass and the radius of the neutron star in the transient low mass X-ray binary SAX J1748.9−2021

We use time resolved spectroscopy of thermonuclear X-ray bursts observed from SAX J1748.9−2021 to infer the mass and the radius of the neutron star in the binary. Four X-ray bursts observed from the source with RXTE enable us to measure the angular size and the Eddington limit on the neutron star surface. Combined with a distance measurement to the globular cluster NGC 6440, in which SAX J1748.9−2021 resides, we obtain two solutions for the neutron star radius and mass, R = 8.18±1.62 km and M = 1.78±0.3 M_sun or R = 10.93±2.09 km and M = 1.33 ± 0.33 M_sun

Multiwavelength observations of the black hole transient XTE J1752-223 during its 2010 outburst decay

Galactic black hole transients show many interesting phenomena during outburst decays. We present simultaneous X-ray (RXTE, Swift, and INTEGRAL), and optical/near-infrared (O/NIR) observations (SMARTS), of the X-ray transient, XTE J1752-223 during its outburst decay in 2010. The multi- wavelength observations of 150 days in 2010 cover the transition from soft to hard spectral state. The evolution of ATCA/VLBI radio observations are shown to confirm the compact jet appearance. The source shows flares in O/NIR during changes in X-ray and radio properties. One of those flares is bright and long, and starts about 20 days after the transition in timing. Other, smaller flares occur along with the transition in timing and increase in power-law flux, and also right after the detection of the core with VLBI. Furthermore, using the simultaneous broadband X-ray spectra including IN- TEGRAL, we found that a high energy cut-off is necessary with a folding energy at around 250 keV around the time that the compact jet is forming. The broad band spectrum can also be fitted equally well with a Comptonization model. In addition, using photoelectric absorption edges in the XMM– Newton RGS X-ray spectra and the extinction of red clump giants in the direction of the source, we found a lower limit on the distance of > 5 kpc

The relationship between inflation, output growth, and their uncertainties: Nonlinear Multivariate GARCH-M evidence

In this paper, we propose a nonlinear multivariate GARCH-M model. We have illustrated the actual modelling by applying the models to inflation and output growth variables and found that the effects of real and nominal uncertainties are regime-dependent.Nonlinear multivariate GARCH-M, STVAR-GARCH, inflation, growth, uncertainty

Low/hard state of microquasars at low luminosities

Galactic black hole transients (GBHTs) spend most of their time in the low/hard spectral state during the outburst decay. This state exhibits a hard X-ray spectrum with X-ray flux correlating with both the radio and the infrared flux. As the luminosity declines, the spectra of the GBHTs got harder. However, for a few sources at very low luminosity levels a softening of the spectrum has been observed. In this work we discuss the evolution of GBHTs at the very lowest luminosity levels using RXTE data and discuss the behavior of the X-ray spectrum, as well as the reported correlations

The Term Structure of Interest Rate as a Predictor of Inflation and Real Economic Activity: Nonlinear Evidence from Turkey

This study investigates whether the term structure of interest rates contains useful information about future real economic activity and inflation in Turkey during the 1991:7-2004:3 periods. In order to analyze these relationships, we have employed the Generalized Impulse Response (GIRF) analysis to the Logistic Smooth Transition Vector Autoregressive (LSTVAR) model. We have determined that the results of a GIRF analysis are consistent with the recursive Chow test and parameter stability tests. Besides, we have found out that the relationships between spread-real economic activity and spread-inflation are negative. These negative relationships have also been examined by GIRF analysis; because of a negative reverse relationship between Expectation Hypothesis and Interest Transmission Channel, a negative correlation between real economic activity and spread has occurred.Term Structure of Interest Rates; Monetary Policy; LSTVAR; GIRF; Real Economic Activity; Inflation

The Reaction of Stock Returns to News about Fundamentals

This paper analyzes the reaction of stock returns to news about the state of the economy. We develop a general equilibrium asset pricing model where the investor learns about the growth rate of the economy through two sources of information, dividend realizations and regularly scheduled announcements about the state of the economy. We distinguish between dividend news and the unexpected part of the external signal and characterize the reaction of stock returns to news from these two sources of information. We show that the reaction to these news variables can be quite different under different assumptions about their precisions in different states. Our model is able to account for several empirical facts about the reaction of stock returns to news, such as time-varying and state-dependent reaction, asymmetric reaction to extreme news and stronger reaction to more precise signals.Regime Switching, Asymmetric Reaction, Dividend News, Public Announcements

Broadband Technologies on Residential Acces

The diffusion of broadband technologies is a hot topic for developed and many developing countries. Although the provision of service has many similar aspects, the overall and specific penetration of broadband technologies varies significantly in these countries. This study aims to examine the place of users' perceptions in the broadband issue by studying the development of the selected technologies and national policies in the light of the general information technology diffusion aspects.Diffusion of Technology, Broadband Technologies, Development of National Policies and Pricing Issues

Technology and Demand for Skilled Labor in Turkish Private Manufacturing Industries

This paper examines the relationship between technology and demand for skilled labor both historically and empirically. First, it is pointed out that the Industrial Revolution substituted skilled labor with unskilled labor since it has a de-skilling characteristic. Second, the skill-bias feature of Information and Communication Technologies Revolution is suggested. Finally, the effect of technological progress on the demand for skilled labor is tested for Turkish Private Manufacturing Industries. According to the static panel data estimation results, there is a positive but weak relationship between technological progress and demand for skilled labor.Skill bias, Technological change, Manufacturing