New views of old galaxies

Davies, Roger L.

doi:10.1111/j.1468-4004.2011.52518.x

Cited by 2 publications

(1 citation statement)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finally, on larger scales, the classical V /σ vs. ellipticity diagram (Davies et al 1983) is now rich in spheroidal, rotation-supported early-type galaxies (see e.g. Davies (2011) for a summary), following major surveys such as SAURON (Bacon et al 2001) and ATLAS3D (Cappellari et al 2011). While these systems are often modelled with Jeans and Schwarzschild techniques, it is important to explore the stability properties of the equilibria identified in these studies.…”

Section: Introductionmentioning

confidence: 99%

Mapping the stability of stellar rotating spheres via linear response theory

Rozier

Fouvry

Breen

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Rotation is ubiquitous in the Universe, and recent kinematic surveys have shown that early type galaxies and globular clusters are no exception. Yet the linear response of spheroidal rotating stellar systems has seldom been studied. This paper takes a step in this direction by considering the behaviour of spherically symmetric systems with differential rotation. Specifically, the stability of several sequences of Plummer spheres is investigated, in which the total angular momentum, as well as the degree and flavour of anisotropy in the velocity space are varied. To that end, the response matrix method is customised to spherical rotating equilibria. The shapes, pattern speeds and growth rates of the systems' unstable modes are computed. Detailed comparisons to appropriate N -body measurements are also presented. The marginal stability boundary is charted in the parameter space of velocity anisotropy and rotation rate. When rotation is introduced, two sequences of growing modes are identified corresponding to radially and tangentially-biased anisotropic spheres respectively. For radially anisotropic spheres, growing modes occur on two intersecting surfaces (in the parameter space of anisotropy and rotation), which correspond to fast and slow modes, depending on the net rotation rate. Generalised, approximate stability criteria are finally presented.

show abstract

Section: Introductionmentioning

confidence: 99%

Mapping the stability of stellar rotating spheres via linear response theory

Rozier

Fouvry

Breen

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

Observational Evidence of Active Galactic Nuclei Feedback

Fabian

2012

Annu. Rev. Astron. Astrophys.

2,533

2,070

View full text Add to dashboard Cite

Radiation, winds and jets from the active nucleus of a massive galaxy can interact with its interstellar medium leading to ejection or heating of the gas. This can terminate star formation in the galaxy and stifle accretion onto the black hole. Such Active Galactic Nucleus (AGN) feedback can account for the observed proportionality between central black hole and host galaxy mass. Direct observational evidence for the radiative or quasar mode of feedback, which occurs when the AGN is very luminous, has been difficult to obtain but is accumulating from a few exceptional objects. Feedback from the kinetic or radio mode, which uses the mechanical energy of radio-emitting jets often seen when the AGN is operating at a lower level, is common in massive elliptical galaxies. This mode is well observed directly through X-ray observations of the central galaxies of cool core clusters in the form of bubbles in the hot surrounding medium. The energy flow, which is roughly continuous, heats the hot intracluster gas and reduces radiative cooling and subsequent star formation by an order of magnitude. Feedback appears to maintain a long-lived heating/cooling balance. Powerful, jetted radio outbursts may represent a further mode of energy feedback which affect the cores of groups and subclusters. New telescopes and instruments from the radio to X-ray bands will come into operation over the next few years and lead to a rapid expansion in observational data on all modes of AGN feedback.

show abstract

New views of old galaxies

Abstract: In his Presidential Address for 2011, Roger Davies reports results from the SAURON and ATLAS3D surveys that suggest a new paradigm for early‐type galaxies.

Cited by 2 publications

References 38 publications

Mapping the stability of stellar rotating spheres via linear response theory

Mapping the stability of stellar rotating spheres via linear response theory

Observational Evidence of Active Galactic Nuclei Feedback

Contact Info

Product

Resources

About