Dynamical Modeling of the Stellar Nucleus of M31

Abstract

We present stellar dynamical models of the lopsided, double-peaked nucleus of M31, derived from Hubble Space Telescope (HST) photometry. A Schwarzscild-type method, in conjunction with Richardson-Lucy deconvolution, was employed to construct steadily rotating, hot, stellar disks. The stars orbit a massive dark object, on prograde and retrograde quasi-periodic loop orbits. Our results support Tremaine's eccentric disk model, extended to include a more massive disk, non zero pattern speed ($\Omega$), and different viewing angle. Most of the disk mass populated prograde orbits, with $\simeq 3.4$ on retrograde orbits. The best fits to photometric and kinematic maps were disks with $Ω\approx 16\kmspc $. We speculate on the origins of the lopsidedness, invoking recent work on the linear overstability of nearly Keplerian disks, that possess even a small amount of a counter-rotating component. Accretion of material-no more massive than a globular cluster-onto a preexisting stellar disk, will account for the mass in our retrograde orbits, and could have stimulated the lopsidedness seen in the nucleus of M31.

6 pages, 5 figures, revised. To appear in Astronomy and Astrophysics

References in corpus (3)

• Slow modes in Keplerian disks
• Eccentric Nuclear Disks with Self Gravity: Predictions for the Double Nucleus of M31
• Long-lived lop-sided modes of annular disks orbiting a central mass

Cited by in corpus (27)

• How Do Massive Black Holes Get Their Gas?
• HST STIS spectroscopy of the triple nucleus of M31: two nested disks in Keplerian rotation around a Supermassive Black Hole
• The Nuclear Stellar Disk in Andromeda: A Fossil from the Era of Black Hole Growth
• Lopsided Spiral Galaxies
• Dynamics of galaxy cores and supermassive black holes
• Eccentric-disk models for the nucleus of M31
• Why Are AGN and Host Galaxies Misaligned?
• The Origin of the Young Stars in the Nucleus of M31
• A Schwarzschild model of the Galactic bar with initial density from N-body simulations
• The Binary Nucleus in VCC 128: A Candidate Supermassive Black Hole in a Dwarf Elliptical Galaxy
• Self-Gravitating Eccentric Disk Models for the Double Nucleus of M31
• Three-dimensional Keplerian orbit-superposition models of the nucleus of M31
• Counter-rotating stellar discs around a massive black hole: self-consistent, time-dependent dynamics
• Stellar Dynamics around a Massive Black Hole I: Secular Collisionless Theory
• The Effect of General Relativistic Precession on Tidal Disruption Events from Eccentric Nuclear Disks
• A Slowly Precessing Disk in the Nucleus of M31 as the Feeding Mechanism for a Central Starburst
• The Doubling of Stellar Black Hole Nuclei
• Secular Evolution Driven by Massive Eccentric Disks/Rings: An Apsidally Aligned Case
• Evolution of eccentric stellar disks around supermassive black holes: the complex disk disruption dynamics and the milliparsec stars
• The molecular H2 and stellar discs in the nuclear region of NGC 4258
• Slow m=1 instabilities of softened gravity Keplerian discs
• Unstable $m=1$ modes of counter-rotating Keplerian discs
• On the formation of an eccentric disk via disruption of a bulge core near a massive black hole
• Chaotic orbits in a 3D galactic dynamical model with a double nucleus
• Recovery of transverse velocities of steadily rotating patterns in flat galaxies
• Modal analysis of gravitational instabilities in nearly Keplerian, counter-rotating collisionless discs
• From the Circumnuclear Disk in the Galactic Center to thick, obscuring tori of AGNs -- Modelling the molecular emission of a parsec-scale torus as found in NGC1068