The quiescent phase of galactic disc growth
We perform a series of controlled N-body simulations of growing disc galaxies within non-growing, live dark matter haloes of varying mass and concentration. Our initial conditions include either a low-mass disc or a compact bulge. New stellar particles are continuously added on near-circular orbits...
| Main Authors: | , , |
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| Format: | Journal article |
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Oxford University Press
2015
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| _version_ | 1797089473925742592 |
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| author | Aumer, M Binney, J Schönrich, R |
| author_facet | Aumer, M Binney, J Schönrich, R |
| author_sort | Aumer, M |
| collection | OXFORD |
| description | We perform a series of controlled N-body simulations of growing disc galaxies within non-growing, live dark matter haloes of varying mass and concentration. Our initial conditions include either a low-mass disc or a compact bulge. New stellar particles are continuously added on near-circular orbits to the existing disc, so spiral structure is continuously excited. To study the effect of combined spiral and giant molecular cloud (GMC) heating on the discs, we introduce massive, short-lived particles that sample a GMC mass function. An isothermal gas component is introduced for a subset of the models. We perform a resolution study and vary parameters governing the GMC population, the histories of star formation and radial scale growth. Models with GMCs and standard values for the disc mass and halo density provide the right level of self-gravity to explain the age–velocity dispersion relation of the solar neighbourhood (Snhd). GMC heating generates remarkably exponential vertical profiles with scaleheights that are radially constant and agree with observations of galactic thin discs. GMCs are also capable of significantly delaying bar formation. The amount of spiral-induced radial migration agrees with what is required for the metallicity distribution of the Snhd. However, in our standard models, the outward-migrating populations are not hot enough vertically to create thick discs. Thick discs can form in models with high baryon fractions, but the corresponding bars are too long, the young stellar populations too hot and the discs flare considerably. |
| first_indexed | 2024-03-07T03:04:35Z |
| format | Journal article |
| id | oxford-uuid:b20f1bc9-6c3d-4639-a7ab-ff05f0ce2106 |
| institution | University of Oxford |
| last_indexed | 2024-03-07T03:04:35Z |
| publishDate | 2015 |
| publisher | Oxford University Press |
| record_format | dspace |
| spelling | oxford-uuid:b20f1bc9-6c3d-4639-a7ab-ff05f0ce21062022-03-27T04:09:01ZThe quiescent phase of galactic disc growthJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:b20f1bc9-6c3d-4639-a7ab-ff05f0ce2106Symplectic Elements at OxfordOxford University Press2015Aumer, MBinney, JSchönrich, RWe perform a series of controlled N-body simulations of growing disc galaxies within non-growing, live dark matter haloes of varying mass and concentration. Our initial conditions include either a low-mass disc or a compact bulge. New stellar particles are continuously added on near-circular orbits to the existing disc, so spiral structure is continuously excited. To study the effect of combined spiral and giant molecular cloud (GMC) heating on the discs, we introduce massive, short-lived particles that sample a GMC mass function. An isothermal gas component is introduced for a subset of the models. We perform a resolution study and vary parameters governing the GMC population, the histories of star formation and radial scale growth. Models with GMCs and standard values for the disc mass and halo density provide the right level of self-gravity to explain the age–velocity dispersion relation of the solar neighbourhood (Snhd). GMC heating generates remarkably exponential vertical profiles with scaleheights that are radially constant and agree with observations of galactic thin discs. GMCs are also capable of significantly delaying bar formation. The amount of spiral-induced radial migration agrees with what is required for the metallicity distribution of the Snhd. However, in our standard models, the outward-migrating populations are not hot enough vertically to create thick discs. Thick discs can form in models with high baryon fractions, but the corresponding bars are too long, the young stellar populations too hot and the discs flare considerably. |
| spellingShingle | Aumer, M Binney, J Schönrich, R The quiescent phase of galactic disc growth |
| title | The quiescent phase of galactic disc growth |
| title_full | The quiescent phase of galactic disc growth |
| title_fullStr | The quiescent phase of galactic disc growth |
| title_full_unstemmed | The quiescent phase of galactic disc growth |
| title_short | The quiescent phase of galactic disc growth |
| title_sort | quiescent phase of galactic disc growth |
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