Stochastic angular momentum slews and flips and their effect on discs in galaxy formation models

dc.creatorPadilla, Nelson David
dc.creatorSalazar Albornoz, Salvador
dc.creatorContreras, Sergio
dc.creatorCora, Sofía Alejandra
dc.creatorRuiz, Andrés Nicolás
dc.date2014-08
dc.date2020-04-16T16:23:21Z
dc.date.accessioned2023-07-14T19:19:18Z
dc.date.available2023-07-14T19:19:18Z
dc.identifierhttp://sedici.unlp.edu.ar/handle/10915/93561
dc.identifierhttp://mnras.oxfordjournals.org/content/443/3/2801.full
dc.identifierhttps://ri.conicet.gov.ar/handle/11336/35185
dc.identifierissn:0035-8711
dc.identifier.urihttps://repositorioslatinoamericanos.uchile.cl/handle/2250/7434847
dc.descriptionThe angular momentum of galactic discs in semi-analytic models of galaxy formation is usually updated in time as material is accreted to the disc by adopting a constant dimensionless spin parameter and little attention is paid to the effects of accretion with misaligned angular momenta. These effects are the subject of this paper, where we adopt a Monte Carlo simulation for the changes in the direction of the angular momentum of a galaxy disc as it accretes matter based on accurate measurements from dark-matter haloes in the Millennium II simulation. In our semi-analytic model implementation, the flips seen in the dark-matter haloes are assumed to be the same for the cold baryons; however, we also assume that in the latter the flip also entails a difficulty for the disc to increase its angular momentum which causes the disc to become smaller relative to a no-flip case. This makes star formation to occur faster, especially in low-mass galaxies at all redshifts allowing galaxies to reach higher stellar masses faster. We adopt a new condition for the triggering of starbursts during mergers. As these produce the largest flips it is natural to adopt the disc instability criterion to evaluate the triggering of bursts in mergers instead of one based on mass ratios as in the original model. The new implementation reduces the average lifetimes of discs by a factor of ∼2, while still allowing old ages for the present-day discs of large spiral galaxies. It also provides a faster decline of star formation in massive galaxies and a better fit to the bright end of the luminosity function at z = 0.
dc.descriptionInstituto de Astrofísica de La Plata
dc.descriptionFacultad de Ciencias Astronómicas y Geofísicas
dc.formatapplication/pdf
dc.format2801-2814
dc.languageen
dc.rightshttp://creativecommons.org/licenses/by-nc-sa/4.0/
dc.rightsCreative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
dc.subjectAstronomía
dc.subjectgalaxies: evolution
dc.subjectgalaxies: fundamental parameters
dc.subjectgalaxies: general
dc.subjectgalaxies: structure
dc.titleStochastic angular momentum slews and flips and their effect on discs in galaxy formation models
dc.typeArticulo
dc.typeArticulo


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