Spectral Indices of Stars at Super-solar Regime

We derived Lick narrow-band indices for 139 candidate super metal-rich stars of different luminosity class previously studied in Malagnini et al. (2000). Indices include Iron Fe50, Fe52, Fe53, and Magnesium Mgb and Mg2 features. By comparing observations with Kurucz' synthetic model atmospheres, no evidence is found for non-standard Mg vs. Fe relative abundance (i.e. [Mg/Fe]~ 0, on the average, for our sample). A comparison with the Worthey et al.(1994) and Buzzoni et al.(1992, 1994) fitting function predictions for [Fe/H] > 0 is performed and briefly discussed.Comment: 4 pages, 3 figures; proceedings of "New Quests in Stellar Astrophysics: The link between Stars and Cosmology", 26-30 March, 2001, Puerto Vallarta, Mexico, eds. M. Chavez, A. Bressan, A. Buzzoni & D. Mayya, to be published by the Kluwer Academic Publisher

Population Synthesis and the Diagnostics of High-redshift Galaxies

The effect of redshift on the observation of distant galaxies is briefly discussed emphasizing the possible sources of bias in the interpretation of high-z data. A general energetic criterion to assess physical self-consistency of evolutionary population synthesis models is also proposed, for a more appropriate use of this important tool to investigate distinctive properties of primeval galaxies.Comment: 8 pages and 6 color figures. Invited talk at the conference "New Quests in Stellar Astrophysics: The link between Stars and Cosmology", 26-30 March, 2001, Puerto Vallarta, Mexico, eds. M. Chavez et al., to be published by Kluwe

Teleologie und Kausalit\ue4t in der Biologie

Il progetto, che \ue8 stato finanziato dalla fondazione internazionale di ricerca Alexander von Humboldt e che \ue8 stato condotto presso l'universit\ue0 di Essen insieme col prof. Dirk Hartmann, ha affrontato il problema dello statuto epistemologico della biologia, precisando il punto di raccordo epistemologico fra meccanicismo e teleologia

Is Technology an Autonomous Process? Technology, Scientific Experiment, and Human Person

Despite the many turns that philosophy of technology has undergone in recent decades, the question of the nature and limits of technological determinism (TD) has been neglected, because it was considered as solved and overcome, and therefore not worth further discussion. This paper once again raises the problem of TD, by trying to save the opposing, but complementary elements of truth of the two main forms of TD that I shall call \u201cnomological\u201d and \u201cnormative\u201d: (a) technology is all-pervasive and has an inexorable capacity for extending itself into every field of human life, and (b) we have a capacity to counteract and orient technology, at least in some measure. In order to reconcile these seemingly inconsistent claims, the key move for my argument is a brief analysis of the notion of scientific experiment from the perspective of the distinction between the context of discovery and the context of justification. As a result, two senses of technology are distinguished, which I shall call respectively \u201creflective\u201d and \u201cmethodological.\u201d From the point of view of this distinction, the all-pervasiveness and inexorability of technology and the in principle irreducibility of human persons to technology\u2014which nomological and normative TD assert dialectically one against the other\u2014can be reconciled. Among other things, this requires the rejection (in one fundamental sense) of the widely held assumption, made both by nomological and normative TD, that technology is a cultural field whose contents can be neatly separated from the rest of human culture. This thesis should be replaced by the more qualified claim of the reflective unity and the methodological multiplicity of technology

The Janus-Faced Nature of Philosophy of Science: Eleven Theses

Elsewhere I have tried to provide the justification of both the irreducible (transcendental) distinction of science and philosophy and their inevitable (naturalistic) complementarity. Unlike empirical science, philosophy has no limit whatever as far as its possible objects are concerned. To say that there is no limit whatever to the possible objects of philosophy is to say that, strictly speaking, it has no object at all and must find its object outside itself, that is, in common sense knowledge and the natural and human sciences. Against the background of this conception, the paper argues that philosophy of science, as a critical reflection on common sense knowledge and the natural or human sciences, inherits from philosophy in general this two-faced Janus nature, which in the philosophy of science shapes the epistemological status of the discipline in an even more prominent way. To show this in detail, the paper enunciates eleven theses that derive from the intimate connection of unity and distinction that exists between philosophy of science on the one hand and the particular and specialized scientific knowledge on the other

A critical appraisal of ATLAS9 and NextGen 5 model atmospheres

The fitting atmosphere parameters (Teff, g, and [Fe/H]) for over 300 stars in the Gunn & Striker and Jacoby et al. catalogs have been obtained relying on the Kurucz (1992) ATLAS9 and Hauschildt et al (1999) NextGen5 synthesis models. The output results are compared, and a critical appraisal of both theoretical codes is performed.Comment: 2 pages, 2 figures; proceedings of "New Quests in Stellar Astrophysics: The link between Stars and Cosmology", 26-30 March, 2001, Puerto Vallarta, Mexico, eds. M. Chavez, A. Bressan, A. Buzzoni & D. Mayya, to be published by the Kluwer Academic Publisher

Synthesis models in a probabilistic framework: metrics of fitting

In general, synthesis models provide the mean value of the distribution of possible integrated luminosities, this distribution (and not only its mean value) being the actual description of the integrated luminosity. Therefore, to obtain the closest model to an observation only provides confi- dence about the precision of such a fit, but not information about the accuracy of the result. In this contribution we show how to overcome this drawback and we propose the use of the theoretical mean-averaged dispersion that can be produced by synthesis models as a metric of fitting to infer accurate physical parameters of observed systems.Comment: Invited talk in "New Quests in stellar astrophysics II. Ultraviolet properties of evolved stellar populations" in press. 8 pages, 5 figures. (Part II on metric of fitting for population synthesis

Deep Studies of the Resolved Stellar Populations in the Outskirts of M31

We discuss the first results from ongoing studies of the resolved stellar populations in the outskirts of our nearest large neighbour, M31. Deep HST/WFPC2 archival observations are used to construct colour-magnitude-diagrams which reach well below the horizontal branch at selected locations in the outer disk and halo, while a panoramic ground-based imaging survey maps spatial density variations through resolved star counts to a projected radius of ~50 kpc.Comment: 4 pages, to appear in proc of "New Quests in Stellar Astrophysics: The Link Between Stars and Cosmology", eds. M. Chavez, A. Bressan, A. Buzzoni, D. Mayy