We investigate the well‐known correlations between the dynamical mass‐to‐light ratio (M/L) and other global observables of elliptical (E) and lenticular (S0) galaxies. We construct two‐integral Jeans and three‐integral Schwarzschild dynamical models for a sample of 25 E/S0 galaxies with SAURON integral‐field stellar kinematics to about one effective (half‐light) radius Re. They have well‐calibrated I‐band Hubble Space Telescope WFPC2 and large‐field ground‐based photometry, accurate surface brightness fluctuation distances, and their observed kinematics is consistent with an axisymmetric intrinsic shape. All these factors result in an unprecedented accuracy in the M/L measurements. We find a tight correlation of the form (M/L) = (3.80 ± 0.14) × (σe/200 km s−1)0.84±0.07 between the M/L (in the I band) measured from the dynamical models and the luminosity‐weighted second moment σe of the LOSVD within Re. The observed rms scatter in M/L for our sample is 18 per cent, while the inferred intrinsic scatter is ∼13 per cent. The (M/L)–σe relation can be included in the remarkable series of tight correlations between σe and other galaxy global observables. The comparison of the observed correlations with the predictions of the Fundamental Plane (FP), and with simple virial estimates, shows that the ‘tilt’ of the FP of early‐type galaxies, describing the deviation of the FP from the virial relation, is almost exclusively due to a real M/L variation, while structural and orbital non‐homology have a negligible effect. When the photometric parameters are determined in the ‘classic’ way, using growth curves, and the σe is measured in a large aperture, the virial mass appears to be a reliable estimator of the mass in the central regions of galaxies, and can be safely used where more ‘expensive’ models are not feasible (e.g. in high‐redshift studies). In this case the best‐fitting virial relation has the form (M/L)vir= (5.0 ± 0.1) ×Reσ2e/(LG), in reasonable agreement with simple theoretical predictions. We find no difference between the M/L of the galaxies in clusters and in the field. The comparison of the dynamical M/L with the (M/L)pop inferred from the analysis of the stellar population, indicates a median dark matter fraction in early‐type galaxies of ∼30 per cent of the total mass inside one Re, in broad agreement with previous studies, and it also shows that the stellar initial mass function varies little among different galaxies. Our results suggest a variation in M/L at constant (M/L)pop, which seems to be linked to the galaxy dynamics. We speculate that fast‐rotating galaxies have lower dark matter fractions than the slow‐rotating and generally more‐massive ones. If correct, this would suggest a connection between the galaxy assembly history and the dark matter halo structure. The tightness of our correlation provides some evidence against cuspy nuclear dark matter profiles in galaxies.

We present an overview of self-report scales for measuring schizotypy and a review of factor-analytical studies of these scales. These studies show that schizotypy is a multidimensional construct consisting of three or four factors. Positive Schizotypy, Negative Schizotypy, Nonconformity, and possibly Social Anxiety/Cognitive Disorganization. Clinical and external validation studies provide support for the construct validity of the Positive Schizotypy and Negative Schizotypy factors, but as yet fail to support the Nonconformity and Social Anxiety/Cognitive Disorganization factors. In accordance with this multidimensional structure, the scales for measuring schizotypy can be classified as factor-specific scales. We consider the striking similarities between the multidimensionality of schizotypal traits and the multidimensionality of schizophrenic symptoms. We also look at the similarities and differences between schizotypy and normal personality traits. Some practical and theoretical implications of these relationships are discussed.

We present new models for the formation of disc galaxies that improve upon previous models by following the detailed accretion and cooling of the baryonic mass, and by using realistic distributions of specific angular momentum. Under the assumption of detailed angular momentum conservation, the discs that form have density distributions that are more centrally concentrated than an exponential. We examine the influence of star formation, bulge formation, and feedback on the outcome of the surface brightness distributions of the stars. Low angular momentum haloes yield disc galaxies with a significant bulge component and with a stellar disc that is close to exponential, in good agreement with observations. High angular momentum haloes, on the other hand, produce stellar discs that are much more concentrated than an exponential, in clear conflict with observations. At large radii, the models reveal distinct truncation radii in both the stars and the cold gas. The stellar truncation radii result from our implementation of star formation threshold densities, and are in excellent agreement with observations. The truncation radii in the density distribution of the cold gas reflect the maximum specific angular momentum of the gas that has cooled. We find that these truncation radii occur at H i surface densities of roughly 1 M⊙ pc−2, in conflict with observations. We examine various modifications to our models, including feedback, viscosity, and dark matter haloes with constant‐density cores, but show that the models consistently fail to produce bulge less discs with exponential surface brightness profiles. This signals a new problem for the standard model of disc formation: if the baryonic component of the protogalaxies out of which disc galaxies form has the same angular momentum distribution as the dark matter, discs are too compact.

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