The inner mass distribution of late-type spiral galaxies from SAURON stellar kinematic maps. Issue 2 (27th September 2016)

• Record Type: Journal Article
• Authors: Kalinova, Veselina; van de Ven, Glenn; Lyubenova, Mariya; Falcón-Barroso, Jesús; Colombo, Dario; Rosolowsky, Erik
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 464:Issue 2(2017)
• Page Start: 1903
• Page End: 1922
• Publication Date: 2016-09-27
• Subjects: methods: analytical -- methods: statistical -- galaxies: bulges -- galaxies: kinematics and dynamics -- galaxies: spiral -- galaxies: structure; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stw2448
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: We infer the central mass distributions within 0.4–1.2 disc scalelengths of 18 late-type spiral galaxies using two different dynamical modelling approaches – the asymmetric drift correction (ADC) and axisymmetric Jeans anisotropic multi-Gaussian expansion (JAM) model. ADC adopts a thin-disc assumption, whereas JAM does a full line-of-sight velocity integration. We use stellar kinematics maps obtained with the integral-field spectrograph $\rm {SAURON}$ to derive the corresponding circular velocity curves from the two models. To find their best-fitting values, we apply the Markov Chain Monte Carlo (MCMC) method. ADC and JAM modelling approaches are consistent within 5 per cent uncertainty when the ordered motions are significant comparable to the random motions, i.e. $\overline{v_{\phi }}/\sigma _R$ is locally greater than 1.5. Below this value, the ratio v c, JAM / v c, ADC gradually increases with decreasing $\overline{v_{\phi }}/\sigma _R$, reaching v c, JAM ≈ 2 × v c, ADC . Such conditions indicate that the stellar masses of the galaxies in our sample are not confined to their disc planes and likely have a non-negligible contribution from their bulges and thick discs.