Bulge properties and dark matter content of early-type barred galaxies

The dynamics of a barred galaxy depends on the pattern speed of its bar. The only direct method for measuring the pattern speed of a bar is the Tremaine-Weinberg technique. This method is best suited to the analysis of the distribution and dynamics of the stellar component. Therefore it has been mostly used for early-type barred galaxies. Most of them host a classical bulge. On the other hand, a variety of indirect methods, which are based on the analysis of the distribution and dynamics of the gaseous component, has been used to measure the bar pattern speed in late-type barred galaxies. Nearly all the measured bars are as rapidly rotating as they can be. By comparing this result with high-resolution numerical simulations of bars in dark matter halos, it is possible to conclude that these bars reside in maximal disks.Comment: 4 pages. To appear in the proceedings of IAU Symposium 245 "Formation and Evolution of Galaxy Bulges", M. Bureau, E. Athanassoula, and B. Barbuy, ed

Institutions, Technological Change and the Wage Differentials Between Skilled and Unskilled Workers: Theory and Evidence from Europe

We study the evolution of the wage differentials between graduate (skilled) and non graduate (unskilled) workers in several european countries in the period that range from the beginning of the nineties to the beginning of this century. The starting point is that all european countries show an increasing relative supply of skilled workers but different behaviours of the wage differentials. The standard explanation for non decreasing differentials in the face of rising relative supply is that technological progress is skill biased. This in turn would imply that technological progress differs in its magnitude and effects across Europe. Our finding shows that what is relevant in the determination of the differentials it is the pace and intensity at which technological progress takes place. We turn then to institutions and we build a model of imperfect competition and wage bargaining which relate the differentials to the technological progress but also to several labour market institutions. The empirical analysis on this aspect reveal that employment rates of different groups as well as the union density and the generosity of unemployment benefits are indeed important and help in explaining the evolution of the wage differentials between skilled and unskilled workers.Wage Differentials ; Technological Changes ; Labor Market Institutions

Counter-Rotation in Disk Galaxies

Counter-rotating galaxies host two components rotating in opposite directions with respect to each other. The kinematic and morphological properties of lenticulars and spirals hosting counter-rotating components are reviewed. Statistics of the counter-rotating galaxies and analysis of their stellar populations provide constraints on the formation scenarios which include both environmental and internal processes.Comment: 10 pages, 2 figures. To appear in ASP Conf. Ser., Multi-Spin Galaxies, E. Iodice and E. M. Corsini (eds.

Direct measurements of bar pattern speeds

The dynamics of a barred galaxy depends on the angular velocity or pattern speed of its bar. Indeed, it is related to the location of corotation where gravitational and centrifugal forces cancel out in the rest frame of the bar. The only direct method for measuring the bar pattern speed is the Tremaine-Weinberg technique. This method is best suited to the analysis of the distribution and kinematics of the stellar component in absence of significant star formation and patchy dust obscuration. Therefore, it has been mostly used for early-type barred galaxies. The main sources of uncertainties on the directly-measured bar pattern speeds are discussed. There are attempts to overcome the selection bias of the current sample of direct measurements by extending the application of the Tremaine-Weinberg method to the gaseous component. Furthermore, there is a variety of indirect methods which are based on the analysis of the gas distribution and kinematics. They have been largely used to measure the bar pattern speed in late-type barred galaxies. Nearly all the bars measured with direct and indirect methods end close to their corotation radius, i.e., they are as rapidly rotating as they can be.Comment: 8 pages, 1 figure. To appear in "Tumbling, twisting, and winding galaxies: Pattern speeds along the Hubble sequence", E. M. Corsini and V. P. Debattista (eds.), Memorie della Societa` Astronomica Italian

Unemployment Insurance Schemes, Liquidity Constraints and Re-employment: a three Country Comparison

We examine how unemployment schemes and liquidity constraints affect re-employment probabilities and unemployment duration. In particular we investigate to which extent those schemes, through employment services and search requirements, can offset the expected perverse effect of benefits on reservation wages and search effort. Similarly, given that liquidity constraints and financial pressure should also affect reservation wage and search effort we analyze whether better economic conditions of individuals actually increase duration. We perform the analysis on Finland, Italy and Poland, countries that displays significant differences both in the UI schemes generosity and eligibility criteria and in the overall degree of social wealth and economic prosperity. Using a sample of newly unemployed from these countries, we perform and estimation of Cox hazard models and assess what variables are important in determining unemployment duration. Our findings suggest that even correctly designed UI schemes have a mixed effect: initially they give incentive to increase search effort, as the eligibility criteria impose certain search requirements, but with time they simply reduces liquidity constraints and thus increase duration. As for the direct effect of liquidity constraints and financial pressure we found that in Italy and Poland they appear to reduce unemployment duration but they are not relevant in Finland, suggesting that these aspects are not so important in countries that are particularly rich and with a developed welfare system.Unemployment Insurance, Liquidity constraints, Re-employment, Unemployment Duration

Robust, High-speed, All-Optical Atomic Magnetometer

A self-oscillating magnetometer based on the nonlinear magneto-optical rotation effect with separate modulated pump and unmodulated probe beams is demonstrated. This device possesses a bandwidth exceeding 1\khz. Pump and probe are delivered by optical fiber, facilitating miniaturization and modularization. The magnetometer has been operated both with vertical-cavity surface-emitting lasers (VCSELs), which are well suited to portable applications, and with conventional edge-emitting diode lasers. A sensitivity of around $3 {\rm nG}$ is achieved for a measurement time of 1\s.Comment: 8 pages, 5 fig

CLIC Drive Beam and LHC Based Fel-Nucleus Collider

The feasibility of a CLIC-LHC based FEL-nucleus collider is investigated. It is shown that the proposed scheme satisfies all requirements of an ideal photon source for the Nuclear Resonance Fluorescence method. The physics potential of the proposed collider is illustrated for a beam of Pb nuclei.Comment: Presented at PAC05, 16-20 May 2005, Knoxville, TN, US

The dark matter content of early-type barred galaxies

The dynamics of a barred galaxy depends on the pattern speed of its bar. The only direct method for measuring the pattern speed of a bar is the Tremaine-Weinberg technique. This method relies on the analysis of the distribution and dynamics of the stellar component. It is best suited to gas-poor galaxies and therefore it has been restricted to early-type barred galaxies. On the other hand, a variety of indirect methods, which are based on the analysis of the distribution and dynamics of the gaseous component, has been used to measure the bar pattern speed in late-type barred galaxies. The complete sample of galaxies for which the bar pattern speed has been directly measured with the Tremaine-Weinberg method is given. Nearly all the measured bars are as rapidly rotating as they can be. By comparing this result with recent high-resolution N-body simulations of bars in cosmologically-motivated dark matter halos, it is possible to conclude that these bars are not located inside centrally-concentrated halos.Comment: 5 pages. Proceedings of "Baryons in Dark Matter Halos". Novigrad, Croatia, 5-9 Oct 2004. Editors: R. Dettmar, U. Klein, P. Salucci. Published by SISS

An Assessment of the Italian 2007 Second Pillar Reform: a simulation approach

In this paper we aim at assessing the outcomes of the 2007 Italian reform of the complementary social security and to identify the determinants behind them. The reform gave relevant incentives to workers to switch from investing about 7% of their gross wages into a compulsory defned benefit scheme inside the firm (which took the form of a termination indemnity payment, the TFR scheme) to an external pension fund. We provide a theoretical framework to model workers' choice problem of switching between these pension schemes and we then perform an agent-based simulation taking into account all the details of the reform. Our simulations are able to replicate the Italian data in term of adhesion rates to complementary social security and also to identify some of the key determinants of that outcome, like the fiscal incentives, the financial literacy and the expectations on the rate of returns of pension funds.Agent Based Simulation, Pension Schemes, Second Pillar