Browsing by Autor "Antonio Parravano"

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    Hα and FUV luminosities from a stochastically formed stellar population
    (Cambridge University Press, 2011) Nidia Danigza Lugo-López; G. Magris; Antonio Parravano
    Abstract It has been observed that the ratio of Hα to FUV luminosity (L H α /L FUV ) is lower in low surface brightness galaxies. This behaviour has been attributed to systematic variations of the upper mass end and/or the slope of the Initial Mass Function (IMF) Meurer et al . (2009) and Lee et al . (2009)). However these hypotheses do not explain the observed scatter in luminosity ratio (L H α /L FUV ). We present a model for the total L H α and L FUV luminosity arising from a randomly populated IMF following the Salpeter power law and the clustering law of Oey & Clarke (2007).
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    Self-Regulating Star Formation in Isolated Galaxies
    (Cambridge University Press, 1988) Antonio Parravano
    Abstract Recent investigation (Parravano, 1987) shows that the diffuse phases of the ISM condense mainly by the transition from warm gas to small cool clouds (WG → SC). In this work we introduce the new hypothesis that the star formation rate (SFR) in isolated galaxies is self-regulated in such a way that it maintains Pmax close to the ISM gas pressure. Here Pmax is the gas pressure at the marginal state of stability for the transition WG → SC. This hypothesis leads to a relation between global galactic parameters which appears to be applicable to various morphological groups of isolated galaxies.
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    Thermal Instabilities in the Warm Interstellar Gas as a Regulating Mechanism of Star Formation
    (Springer Nature (Netherlands), 1990) Antonio Parravano