The Stellar Kinematics of Extragalactic Bulges

Falcón-Barroso, J.

doi:10.1007/978-3-319-19378-6_7

Cited by 10 publications

(6 citation statements)

References 145 publications

(177 reference statements)

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“…In the JAM approach, two basic assumptions are made for the stellar population: a constant velocity anisotropy (βz = 1 − σ 2 z /σ 2 R ) and a constant dynamical mass-tolight ratio (Υ dyn ). The parameters βz and Υ dyn have been defined after fitting the observed second-order velocity moment Vrms = √ V 2 + σ 2 calculated from the stellar kinematics of the galaxies (Falcón- Barroso et al 2016). The best-fit model of the observed Vrms, the corresponding fitting parameters (βz and Υ dyn ), and their uncertainties are obtained by applying the Markov Chain Monte Carlo (MCMC) method as described in Kalinova et al (2017b).…”

Section: Dynamical Models Circular Velocity Curves and Orbital Timesmentioning

confidence: 99%

The EDGE–CALIFA survey: the influence of galactic rotation on the molecular depletion time across the Hubble sequence

Colombo

Kalinova

Utomo

et al. 2017

Monthly Notices of the Royal Astronomical Society

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We present a kpc-scale analysis of the relationship between the molecular depletion time (τ mol dep ) and the orbital time (τ orb ) across the field of 39 face-on local galaxies, selected from the EDGE-CALIFA sample. We find that, on average, 5% of the available molecular gas is converted into stars per orbital time, or τ mol dep ∼ 20 τ orb . The resolved relation shows a scatter of ∼ 0.5 dex. The scatter is ascribable to galaxies of different morphologies that follow different τ mol dep −τ orb relations which decrease in steepness from early-to late-types. The morphologies appear to be linked with the star formation rate surface density, the molecular depletion time, and the orbital time, but they do not correlate with the molecular gas content of the galaxies in our sample. We speculate that in our molecular gas rich, early-type galaxies, the morphological quenching (in particular the disc stabilization via shear), rather than the absence of molecular gas, is the main factor responsible for their current inefficient star formation.

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Section: Dynamical Models Circular Velocity Curves and Orbital Timesmentioning

confidence: 99%

The EDGE–CALIFA survey: the influence of galactic rotation on the molecular depletion time across the Hubble sequence

Colombo

Kalinova

Utomo

et al. 2017

Monthly Notices of the Royal Astronomical Society

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“…We notice that higher order GH coefficients h k 1,l (m=3,4) have larger values when 3 < |∆V /σ| < 5, while h k 1,l = 0 (m=3,4) keeps for orbit k. Thus including higher order of GH coefficient h 3,l , h 4,l helps to distinguish these two orbits. However, the quality of CALIFA data can only provide realiable h m,l (m=1,2) (Falcón- Barroso et al 2016).…”

Section: A2 Option Amentioning

confidence: 99%

Orbital decomposition of CALIFA spiral galaxies

Zhu

Bosch

Ven

et al. 2017

Monthly Notices of the Royal Astronomical Society

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Schwarzschild orbit-based dynamical models are widely used to uncover the internal dynamics of early-type galaxies and globular clusters. Here we present for the first time the Schwarzschild models of late-type galaxies: an SBb galaxy NGC 4210 and an S0 galaxy NGC 6278 from the CALIFA survey. The mass profiles within 2 R e are constrained well with 1σ statistical error of ∼ 10%. The luminous and dark mass can be disentangled with uncertainties of ∼ 20% and ∼ 50% respectively. From R e to 2 R e , the dark matter fraction increases from 14 ± 10% to 18 ± 10% for NGC 4210 and from 15 ± 10% to 30 ± 20% for NGC 6278. The velocity anisotropy profiles of both σ r /σ t and σ z /σ R are well constrained. The inferred internal orbital distributions reveal clear substructures. The orbits are naturally separated into three components: a cold component with near circular orbits, a hot component with near radial orbits, and a warm component in between. The photometrically-identified exponential disks are predominantly made up of cold orbits only beyond ∼ 1 R e , while they are constructed mainly with the warm orbits inside. Our dynamical hot components are concentrated in the inner regions, similar to the photometrically-identified bulges. The reliability of the results, especially the orbit distribution, are verified by applying the model to mock data.

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“…A radial anisotropy of stellar velocity dispersion would be difficult to identify and to interpret as evidence of recent AGN activity due to difficulties in modelling stellar orbits and their anisotropies in external galaxies (Cappellari et al 2013;Falcón-Barroso 2016). Nevertheless, we predict that galaxies showing evidence of recent AGN activity, such as hot gas bubbles on galactic outskirts (analogous to the Fermi bubbles, Su et al 2010) or young stars very close to the nucleus (analogous to the disc of young stars in the Galactic centre, Paumard et al 2006) may also have radiallybiased stellar velocity dispersions.…”

Section: Kinematics Of Young Starsmentioning

confidence: 99%

Do AGN outflows quench or enhance star formation?

Zubovas

Bourne

2017

Monthly Notices of the Royal Astronomical Society

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AGN outflows can remove large quantities of gas from their host galaxy spheroids, potentially shutting off star formation. On the other hand, they can compress this gas, potentially enhancing or triggering star formation, at least for short periods. We present a set of idealised simulations of AGN outflows affecting turbulent gas spheres, and investigate the effect of the outflow and the AGN radiation field upon gas fragmentation. We show that AGN outflows of sufficient luminosity shut off fragmentation while the nucleus is active, but gas compression results in a burst of fragmentation after the AGN switches off. Self-shielding of gas against the AGN radiation field allows some fragmentation to occur during outbursts, but too much shielding results in a lower overall fragmentation rate. For our idealised simulation setup, there is a critical AGN luminosity which results in the highest fragmentation rate, with outflows being too efficient at removing gas when L > L crit and not efficient enough to compress the gas to high densities otherwise. These results, although preliminary, suggest that the interaction between AGN and star formation in their host galaxies is particularly complex and requires careful study in order to interpret observations correctly.

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The Stellar Kinematics of Extragalactic Bulges

Cited by 10 publications

References 145 publications

The EDGE–CALIFA survey: the influence of galactic rotation on the molecular depletion time across the Hubble sequence

The EDGE–CALIFA survey: the influence of galactic rotation on the molecular depletion time across the Hubble sequence

Orbital decomposition of CALIFA spiral galaxies

Do AGN outflows quench or enhance star formation?

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