Mass models of disc galaxies from the DiskMass Survey in modified Newtonian dynamics

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dc.contributor.authorAngus, G W
dc.contributor.authorGentile, G
dc.contributor.authorSwaters, R
dc.contributor.authorFamaey, B
dc.contributor.authorDiaferio, A
dc.contributor.authorMcGaugh, S S
dc.contributor.authorHeyden, K J van der
dc.date.accessioned2021-10-08T07:08:22Z
dc.date.available2021-10-08T07:08:22Z
dc.date.issued2015
dc.description.abstractThis article explores the agreement between the predictions of modified Newtonian dynamics (MOND) and the rotation curves and stellar velocity dispersion profiles measured by the DiskMass Survey (DMS). A bulge-disk decomposition was made for each of the thirty published galaxies, and a MOND Poisson solver was used to simultaneously compute, from the baryonic mass distributions, model rotation curves and vertical velocity dispersion profiles, which were compared to the measured values. The two main free parameters, the stellar disk's mass-to-light ratio (M/L) and its exponential scaleheight (h(z)), were estimated by Markov Chain Monte Carlo modelling. The average best-fitting K-band stellar mass-to-light ratio was M/L a parts per thousand integral 0.55 +/- A 0.15. However, to match the DMS data, the vertical scaleheights would have to be in the range h(z) = 200-400 pc which is a factor of 2 lower than those derived from observations of edge-on galaxies with a similar scalelength. The reason is that modified gravity versions of MOND characteristically require a larger M/L to fit the rotation curve in the absence of dark matter and therefore predict a stronger vertical gravitational field than Newtonian models. It was found that changing the MOND acceleration parameter, the shape of the velocity dispersion ellipsoid, the adopted vertical distribution of stars, as well as the galaxy inclination, within any realistic range, all had little impact on these results.
dc.identifier.apacitationAngus, G. W., Gentile, G., Swaters, R., Famaey, B., Diaferio, A., McGaugh, S. S., & Heyden, K. J. v. d. (2015). Mass models of disc galaxies from the DiskMass Survey in modified Newtonian dynamics. <i>Monthly Notices of the Royal Astronomical Society</i>, 451(4), 3551 - 3580. http://hdl.handle.net/11427/34568en_ZA
dc.identifier.chicagocitationAngus, G W, G Gentile, R Swaters, B Famaey, A Diaferio, S S McGaugh, and K J van der Heyden "Mass models of disc galaxies from the DiskMass Survey in modified Newtonian dynamics." <i>Monthly Notices of the Royal Astronomical Society</i> 451, 4. (2015): 3551 - 3580. http://hdl.handle.net/11427/34568en_ZA
dc.identifier.citationAngus, G.W., Gentile, G., Swaters, R., Famaey, B., Diaferio, A., McGaugh, S.S. & Heyden, K.J.v.d. 2015. Mass models of disc galaxies from the DiskMass Survey in modified Newtonian dynamics. <i>Monthly Notices of the Royal Astronomical Society.</i> 451(4):3551 - 3580. http://hdl.handle.net/11427/34568en_ZA
dc.identifier.issn0035-8711
dc.identifier.issn1365-2966
dc.identifier.ris TY - Journal Article AU - Angus, G W AU - Gentile, G AU - Swaters, R AU - Famaey, B AU - Diaferio, A AU - McGaugh, S S AU - Heyden, K J van der AB - This article explores the agreement between the predictions of modified Newtonian dynamics (MOND) and the rotation curves and stellar velocity dispersion profiles measured by the DiskMass Survey (DMS). A bulge-disk decomposition was made for each of the thirty published galaxies, and a MOND Poisson solver was used to simultaneously compute, from the baryonic mass distributions, model rotation curves and vertical velocity dispersion profiles, which were compared to the measured values. The two main free parameters, the stellar disk's mass-to-light ratio (M/L) and its exponential scaleheight (h(z)), were estimated by Markov Chain Monte Carlo modelling. The average best-fitting K-band stellar mass-to-light ratio was M/L a parts per thousand integral 0.55 +/- A 0.15. However, to match the DMS data, the vertical scaleheights would have to be in the range h(z) = 200-400 pc which is a factor of 2 lower than those derived from observations of edge-on galaxies with a similar scalelength. The reason is that modified gravity versions of MOND characteristically require a larger M/L to fit the rotation curve in the absence of dark matter and therefore predict a stronger vertical gravitational field than Newtonian models. It was found that changing the MOND acceleration parameter, the shape of the velocity dispersion ellipsoid, the adopted vertical distribution of stars, as well as the galaxy inclination, within any realistic range, all had little impact on these results. DA - 2015 DB - OpenUCT DP - University of Cape Town IS - 4 J1 - Monthly Notices of the Royal Astronomical Society LK - https://open.uct.ac.za PY - 2015 SM - 0035-8711 SM - 1365-2966 T1 - Mass models of disc galaxies from the DiskMass Survey in modified Newtonian dynamics TI - Mass models of disc galaxies from the DiskMass Survey in modified Newtonian dynamics UR - http://hdl.handle.net/11427/34568 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/34568
dc.identifier.vancouvercitationAngus GW, Gentile G, Swaters R, Famaey B, Diaferio A, McGaugh SS, et al. Mass models of disc galaxies from the DiskMass Survey in modified Newtonian dynamics. Monthly Notices of the Royal Astronomical Society. 2015;451(4):3551 - 3580. http://hdl.handle.net/11427/34568.en_ZA
dc.language.isoeng
dc.publisher.departmentDepartment of Astronomy
dc.publisher.facultyFaculty of Science
dc.sourceMonthly Notices of the Royal Astronomical Society
dc.source.journalissue4
dc.source.journalvolume451
dc.source.pagination3551 - 3580
dc.source.urihttps://dx.doi.org/10.1093/mnras/stv1132
dc.subject.othernumerical – galaxies
dc.subject.otherkinematics and dynamics
dc.subject.otherdark matter
dc.titleMass models of disc galaxies from the DiskMass Survey in modified Newtonian dynamics
dc.typeJournal Article
uct.type.publicationResearch
uct.type.resourceJournal Article
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