BeppoSAX observations of XTE J1946+274

We report on the BeppoSAX monitoring of a giant outburst of the transient X-ray pulsar XTE J1946+274 in 1998. The source was detected with a flux of ~ 4 x 10^(-9) erg cm^(-2) s^(-1) (in 0.1 - 120 keV range). The broadband spectrum, typical for accreting pulsars, is well described by a cutoff power law with a cyclotron resonance scattering feature (CRSF) at ~ 38 keV. This value is consistent with earlier reports based on the observations with Suzaku at factor of ten lower luminosity, which implies that the feature is formed close to the neutron star surface rather than in the accretion column. Pulsations with P ~ 15.82 s were observed up to ~ 70 keV. The pulse profile strongly depends on energy and is characterised by a "soft" and a "hard" peaks shifted by half period, which suggests a strong phase dependence of the spectrum, and that two components with roughly orthogonal beam patterns are responsible for the observed pulse shape. This conclusion is supported by the fact that the CRSF, despite its relatively high energy, is only detected in the spectrum of the soft peak of the pulse profile. Along with the absence of correlation of the line energy with luminosity, this could be explained in the framework of the recently proposed "reflection" model for CRSF formation. However more detailed modelling of both line and continuum formation are required to confirm this interpretation

The Antitrust Implications of Going Private and Other Changes of Corporate Control

Public shareholders likely have suffered billions of dollars in losses in recent years as a result of collusion among potential purchasers in change-of-control transactions. Unfortunately, the federal courts have been unable to devise an appropriate antitrust approach to collusion in change-of-control transactions. This article proposes a new approach to the antitrust regulation of the market for the control of public and private companies. Collusion among purchasers in that market has occurred in nearly every American industry The proposed approach will effectively deter the three types of anticompetitive conduct most likely to occur in these circumstances: (1) express agreements to allocate bids among potential purchasers, (2) implicit bid rigging by potential purchasers, and (3) consortiums among potential purchasers to submit single bids in company auctions. This Article illustrates the advantages of the proposed approach by applying it to going private transactions, which in recent years have become the most popular—and the most controversial—of all types of acquisitions