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dc.contributor.advisorBonnell, Ian Alexander
dc.contributor.authorRamon Fox, Felipe Gerardo
dc.coverage.spatialxxiii, 223 p.en_US
dc.description.abstractStar formation begins on the large scales of a galaxy and takes place on the smallest scales. As the interstellar gas flows into a spiral arm, it forms a shock where the change in density, coupled to self-gravity and thermal instabilities, leads to the formation of high density structures where molecular clouds grow. It is important to understand the role of large-scale flows in assembling these clouds. This work explores the gas flows in spiral arms to understand its role on molecular cloud formation comparing between grand-design and flocculent galaxies. A set of high-resolution smoothed particle hydrodynamics (SPH) simulations are used. One simulation evolves the gas in a potential including a halo, stellar disc, and spiral arms. The second simulation evolves the gas in an N-body stellar disc and bulge within a fixed halo potential. The first and second models are representative of grand-design and flocculent galaxies, respectively. The third simulation is a high-resolution simulation of a region of gas flowing in a spiral arm based on the simulations of Bonnell et al. (2013), which follows in more detail the local cloud dynamics. In the global models, the mass resolution is about 45M⊙ per gas particle and in the spiral simulation, about 0.6M⊙. The results show that in both the grand-design and flocculent models, the gas is shocked as it flows through an arm. The N-body model shows flow characteristics qualitatively similar to the spiral potential model but with more variations due to the potentials arm-to-arm variations. Clouds are identified using a friends-of-friends algorithm to catalogue clumps above a given density threshold. These have non-negligible streaming motions and their properties are consistent with observed mass-radius and size-velocity dispersion relations.en_US
dc.description.sponsorship"This work was supported by the ERC ECOGAL project under grant number 291277. I also thank the University of St. Andrews for supporting me with a St. Leonards Scholarship." -- Acknowledgementsen
dc.publisherUniversity of St Andrews
dc.relationThe role of large scale flows in molecular cloud formation in spiral galaxies (Thesis data) Ramon Fox, F.G., University of St Andrews, 22 May 2019 DOI:
dc.rightsAttribution-NonCommercial-NoDerivatives 4.0 International*
dc.subjectInterstellar medium -- Kinematics and dynamicsen_US
dc.subjectInterstellar medium -- Molecular clouds -- Formationen_US
dc.subjectGalaxies -- Kinematics and dynamicsen_US
dc.subjectMilky Way -- Structureen_US
dc.subjectAstrophysics -- Astrophysics of galaxiesen_US
dc.subject.lcshMolecular cloudsen
dc.subject.lcshGalactic dynamicsen
dc.subject.lcshSpiral galaxiesen
dc.titleThe role of large scale flows in molecular cloud formation in spiral galaxiesen_US
dc.contributor.sponsorEuropean Research Council (ERC)en_US
dc.contributor.sponsorUniversity of St Andrews. St Leonard's Collegeen_US
dc.type.qualificationnamePhD Doctor of Philosophyen_US
dc.publisher.institutionThe University of St Andrewsen_US

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