A Binary Orbit for the Massive, Evolved Star HDE 326823, a WR+O System Progenitor

The hot star HDE 326823 is a candidate transition-phase object that is evolving into a nitrogen-enriched Wolf-Rayet star. It is also a known low-amplitude, photometric variable with a 6.123 d period. We present new, high and moderate resolution spectroscopy of HDE 326823, and we show that the absorption lines show coherent Doppler shifts with this period while the emission lines display little or no velocity variation. We interpret the absorption line shifts as the orbital motion of the apparently brighter star in a close, interacting binary. We argue that this star is losing mass to a mass gainer star hidden in a thick accretion torus and to a circumbinary disk that is the source of the emission lines. HDE 326823 probably belongs to a class of objects that produce short-period WR+O binaries.Comment: 32 pages, 10 figures, accepted to the Astronomical Journa

Asset Price Shocks, Real Expenditures, and Financial Structure: A Multi-Country Analysis

This paper examines the responses of private consumption, residential investment, and business investment in 11 EU countries, Japan, and the United States to shocks in housing and equity prices. The effects are assessed with a Structural Vector Auto Regressive (SVAR) model, and four key findings emerge. First, the impacts of asset price shocks are heterogeneous across countries. Second, these heterogeneous responses are systematically related to cross-country variation in financial structure. We are thus able to document the importance of a wealth/balance sheet channel for private consumption and residential investment and an equity finance channel for business investment. Third, for a given country, housing shocks have a much greater impact than equity shocks. Fourth, variance decompositions indicate that monetary policy reacts to equity price shocks but not to housing price shocks. These results highlight the important role played by asset prices on real activity and fuel the debate about the inclusion of asset prices in the formulation of monetary policy.monetary policy, asset prices, structural VAR

Asset Price Shocks, Real Expenditures, and Financial Structure:A Multi-Country Analysis

This paper examines the response of the economies of 11 EU countries, Japan, and the United States to shocks in housing and equity prices. The effects are assessed with a Structural Vector Auto Regressive (SVAR) model, and four key findings emerge. First, the impacts of asset price shocks are heterogeneous across countries. Second, these heterogeneous responses are systematically related to cross-country variation in financial structure, and we are thus able to document the importance of a wealth/balance sheet channel for consumption and an equity finance channel for investment. Third, for a given country, housing shocks have a much greater impact than equity shocks. Fourth, variance decompositions indicate that monetary policy reacts to equity price shocks but not to housing price shocks. These results highlight the important role played by asset prices on real activity, and fuel the debate about the inclusion of asset prices in the formulation of monetary policy.

Investor Protections and Concentrated Ownership: Assessing Corporate Control Mechanisms in the Netherlands

The Berle-Means problem - information and incentive asymmetries disrupting relations between knowledgeable managers and remote investors - has remained a durable issue engaging researchers since the 1930's. However, the Berle-Means paradigm - widely-dispersed, helpless investors facing strong, entrenched managers - is under stress in the wake of the cross-country evidence presented by La Porta, Lopez-de-Silanes, Shleifer, and Vishny and their legal approach to corporate control. This paper continues to investigate the roles of investor protections and concentrated ownership by examining firm behaviour in the Netherlands. Our within country analysis generates two key results. First, the role of investor protections emphasized in the legal approach is not sustained. Rather, we find that performance is enhanced when the firm is freed of equity market constraints, a result that we attribute to the relaxation of the myopia constraints imposed by relatively uninformed investors. Second, ownership concentration does not have a discernible impact on firm performance, which may reflect large shareholders' dual role in lowering the costs of managerial agency problems but raising the agency costs of expropriation.

Firm Performance, Financial Institutions and Corporate Governance in the Netherlands

This paper analyses the impact of share ownership, creditorship and networking by financial institutions on the performance of 94 Dutch non-financial firms in the period 1992-1996. We find a nonlinear relationship between firm performance and ownership by banks. Because of various defense mechanisms the role of the shareholder is very limited in the Netherlands. Financial institutions are, however, in a position to discipline firm management through other channels. It turns out that there is a direct positive link between share o wnership by banks and the firms` short-term bank loans, which indicates the existence of a financing channel. Financial institutions are also represented on the supervisory boards of firms and vice versa, which is an example of networking. This suggests that besides creditorship networking may be an additional disciplinary device for financial institutions. Here we find that there is a significant positive relationship between share ownership by insurance companies and pension funds and the probability of networking.

Photometric study of selected cataclysmic variables II. Time-series photometry of nine systems

We present time-series photometry of nine cataclysmic variables: EI UMa, V844Her, V751 Cyg, V516 Cyg, GZ Cnc, TY Psc, V1315 Aql, ASAS J002511+1217.12, V1315 Aql and LN UMa. The observations were conducted at various observatories, covering 170 hours and comprising 7,850 data points in total. For the majority of targets we confirm previously reported periodicities and for some of them we give, for the first time, their spectroscopic orbital periods. For those dwarf-nova systems which we observed during both quiescence and outburst, the increase in brightness was followed by a decrease in the amount of flickering. Quasi-periodic oscillations have either been discovered, or were confirmed. For the eclipsing system V1315 Aql we have covered 9 eclipses, and obtained a refined orbital ephemeris. We find that, during its long baseline of observations, no change in the orbital period of this system has occurred. V1315 Aql also shows eclipses of variable depth.Comment: 30 pages, 16 figures, 4 tables. Submitted to JA

Investigations of the Non-Linear LMC Cepheid Period-Luminosity Relation with Testimator and Schwarz Information Criterion Methods

In this paper, we investigate the linearity versus non-linearity of the Large Magellanic Cloud (LMC) Cepheid period-luminosity (P-L) relation using two statistical approaches not previously applied to this problem: the testimator method and the Schwarz Information Criterion (SIC). The testimator method is extended to multiple stages for the first time, shown to be unbiased and the variance of the estimated slope can be proved to be smaller than the standard slope estimated from linear regression theory. The Schwarz Information Criterion (also known as the Bayesian Information Criterion) is more conservative than the Akaike Information Criterion and tends to choose lower order models. By using simulated data sets, we verify that these statistical techniques can be used to detect intrinsically linear and/or non-linear P-L relations. These methods are then applied to independent LMC Cepheid data sets from the OGLE project and the MACHO project, respectively. Our results imply that there is a change of slope in longer period ranges for all of the data sets. This strongly supports previous results, obtained from independent statistical tests, that the observed LMC P-L relation is non-linear with a break period at/around 10 days.Comment: 9 pages, 5 figures and 3 tables, PASP accepte

Firm Performance, Financial Institutions and Corporate Governance in the Netherlands

This paper analyses the impact of share ownership, creditorship and networking by financial institutions on the performance of 94 Dutch non-financial firms in the period 1992-1996. We find a nonlinear relationship between firm performance and ownership by banks. Because of various defense mechanisms the role of the shareholder is very limited in the Netherlands. Financial institutions are, however, in a position to discipline firm management through other channels. It turns out that there is a direct positive link between share o wnership by banks and the firms` short-term bank loans, which indicates the existence of a financing channel. Financial institutions are also represented on the supervisory boards of firms and vice versa, which is an example of networking. This suggests that besides creditorship networking may be an additional disciplinary device for financial institutions. Here we find that there is a significant positive relationship between share ownership by insurance companies and pension funds and the probability of networking

X-ray Light Curves and Accretion Disk Structure of EX Hydrae

We present X-ray light curves for the cataclysmic variable EX Hydrae obtained with the Chandra High Energy Transmission Grating Spectrometer and the Extreme Ultraviolet Explorer Deep Survey photometer. We confirm earlier results on the shape and amplitude of the binary light curve and discuss a new feature: the phase of the minimum in the binary light curve, associated with absorption by the bulge on the accretion disk, increases with wavelength. We discuss several scenarios that could account for this trend and conclude that, most likely, the ionization state of the bulge gas is not constant, but rather decreases with binary phase. We also conclude that photoionization of the bulge by radiation originating from the white dwarf is not the main source of ionization, but that it is heated by shocks originating from the interaction between the inflowing material from the companion and the accretion disk. The findings in this paper provide a strong test for accretion disk models in close binary systems.Comment: 19 pages, 4 figures, accepted for publication in the Ap