Stellar Dynamics

Open positions

Bachelor's and Master's projects

A complete listing of all publications by members of our group can be found at ADS. Below we list a few key papers that highlight the work done by our group.

Total mass slopes and enclosed mass constrained by globular cluster system dynamics

2024, A&A, 681, A46

Veršič, Tadeja; Thater, Sabine; van de Ven, Glenn; Watkins, Laura L.; Jethwa, Prashin; Leaman, Ryan; Zocchi, Alice

Discrete Jeans modelling using globular cluster systems.

Effect of the initial mass function on the dynamical SMBH mass estimate in the nucleated early-type galaxy FCC 47

2023, A&A, 675, A18

Thater, Sabine; Lyubenova, Mariya; Fahrion, Katja; Martín-Navarro, Ignacio; Jethwa, Prashin; Nguyen, Dieu D.; van de Ven, Glenn

Effects of the initial mass function on the dynamical SMBH mass estimate.

Testing the robustness of DYNAMITE triaxial Schwarzschild modelling: The effects of correcting the orbit mirroring

2022, A&A, 667, A51

Thater, Sabine; Jethwa, Prashin; Tahmasebzadeh, Behzad; Zhu, Ling; den Brok, Mark; Santucci, Giulia; Ding, Yuchen; Poci, Adriano; Lilley, Edward; Tim de Zeeuw, P.; Zocchi, Alice; Maindl, Thomas I.; Rigamonti, Fabio; Yang, Meng; Fahrion, Katja; van de Ven, Glenn

The effects of correcting the orbit mirroring.

The stellar orbit distribution in present-day galaxies inferred from the CALIFA survey

2018, NatAs, 2, 233

Zhu, Ling; van de Ven, Glenn; van den Bosch, Remco; Rix, Hans-Walter; Lyubenova, Mariya; Falcón-Barroso, Jesús; Martig, Marie; Mao, Shude; Xu, Dandan; Jin, Yunpeng; Obreja, Aura; Grand, Robert J. J.; Dutton, Aaron A.; Macciò, Andrea V.; Gómez, Facundo A.; Walcher, Jakob C.; García-Benito, Rubén; Zibetti, Stefano; Sánchez, Sebastian F.

Characterization of the internal dynamical strucuture of a large sample of galaxies.

Triaxial orbit based galaxy models with an application to the (apparent) decoupled core galaxy NGC 4365

2008, MNRAS, 385, 647

van den Bosch, R. C. E.; van de Ven, G.; Verolme, E. K.; Cappellari, M.; de Zeeuw, P. T.

Introduction of the Triaxial Schwarzschild model and application to an elliptical galaxy.

Recovery of the internal orbital structure of galaxies

2008, MNRAS, 385, 614

van de Ven, G.; R.C.E. de Zeeuw, P. T.; van den Bosch, R. C. E.

Testing the Schwarzschild orbit recovery.

The Dynamical Distance and Intrinsic Structure of the Globular Cluster omega Centauri

2006, A&A, 445, 513

van de Ven, G.; R.C.E. van den Bosch; E.K. Verolme; P.T. de Zeeuw

An application of the Triaxial Schwarzschild code.

Annoucements

No new annoucments.

Last updated: 26.9.2020

Workshops and Meeting Organisation

Periodically we organise workshops for researchers interested in running dynamical models. Find out more information here.

Members of our group have organised conferences and workshops on a variety of topics:

Dynamical Reconstruction of Galaxies

Lorentz Center, Leiden, The Netherlands - 17-21 February 2020

Survival of Dense Star Clusters in the Milky Way System

Haus der Astronomie, Heidelberg - 19-21 November 2018

The Exciting Lives of Galactic Nuclei

Ringberg Castle - 26 February - 3 March 2017

MPIA Summer Conference 2015

Haus der Astronomie & MPIA, Heidelberg - 6-10 July 2015

3rd DAGAL Annual Meeting

MPIA Heidelberg - 23-27 March 2015

Gaia Challenge II

Haus der Astronomie / MPIA, Heidelberg - 27-31 October 2014

3rd CALIFA Busy Week

Haus der Astronomie, Heidelberg - 11-15 June 2012

Dynamics Meets Kinematic Tracers

Ringberg Castle - 10-14 April 2012

Large Collaborations

Members of our group are active in a number of collaborations.

• Fornax-3D
• SAURON Project
• CALIFA Survey
• SDSS-IV / MaNGA Survey
• SFB881 The Milky Way System
• DAGAL EU-ITN
• SMAKCED Survey
• HSTPROMO Collaboration

The stellar dynamics group at the University of Vienna has been busy developing our dynamical modelling code into a new form called DYNAMITE - i.e. dynamics, age and metallicity indicators tracing evolution. The latest release is available on the github page here. The documentation for the Dynamite code is available here.

ArcheoDyn

Globular clusters (GCs) are the living fossils of the history of their native galaxies and the record keepers of the violent events that made them change their domicile. This project aims to mine GCs as living fossils of galaxy evolution to address fundamental questions in astrophysics:

• Do satellite galaxies merge as predicted by the hierarchical build-up of galaxies? ⟷ Can we recover disrupted satellite galaxies from the GCs they left in their host?
• What are the seeds of supermassive black holes in the centres of galaxies? ⟷ Do GCs harbour the intermediate mass black holes?
• How did star formation originate in the earliest phases of galaxy formation? ⟷ Can the origin of multiple stellar populations in GCs be uncovered from distinct dynamical fossil signatures?

Background

GCs are dynamically complex stellar systems, with internal rotation and velocity dispersions that depend on both the intrinsic positions and masses of their stars. Yet it is unknown if this complexity is a signature of a central intermediate mass black hole (IMBH), relates to the observed multiple stellar populations in GCs, or arises from external gravitational effects. Following the tidal disruption of satellite galaxies, their GCs, and possibly their nuclei, remain as abundant and easily observed relics of the hierarchical build-up of galaxies. The evolution of galaxies to the present day can thus be unearthed by recovering the orbits of the GCs that are surrounding them.

In the next few years, astrometric data from ESA’s Gaia mission will allow for high-precision measurements of the 6D position-velocity vectors of the GCs in the Milky Way (MW). At the same time, numerous imaging and spectroscopy surveys are providing extensive catalogues of colours, metallicities and radial velocities of hundreds of GCs around nearby galaxies. To make use of this data, we are building tools to ascertain which GCs are accretion survivors and to recover their orbits.

The presence (or absence) of a central intermediate mass black hole (IMBH) or of multiple stellar populations might tell which GCs are accreted, and among these which are former galaxy nuclei. At the same time, detection of IMBHs is important as they are predicted seeds for supermassive black holes in the centres of galaxies; while the multiple stellar populations in GCs are crucial witnesses to the extreme modes of star formation in the early universe. However, for every putative dynamical IMBH detection in a GC so far, the expected kinematic and emission signatures have not been seen; also, the origin of multiple stellar populations within GCs still lacks any uncontrived explanation.

The quantity and quality of chemical and kinematical measurements of individual stars in GCs in the MW is currently dramatically increasing. This includes precision proper motion measurements of tens of thousands of stars in the inner parts of GCs based on Hubble Space Telescope (HST) data. Soon this will be complemented by Gaia proper motions of thousands of giant stars in the outer parts of the GCs. With the novel tools developed in this group, we aim to fully exploit this data to firmly establish the (non)presence of IMBHs and to disentangle the internal dynamics of the multiple stellar populations to decipher their origin.

With the synergy of new population-dynamics tools and exquisite chemo-kinematic data, the ArcheoDyn project aims to unlock the full potential of GCs as living fossils of the past of galaxies.

SFB: Tomography Across the Scales

As of 2022, our group is a member of the FWF-funded SFB project Tomography Across the Scales. This project connects scientists and mathematicians to tackle common challenges of extracting physical information from complex datasets using modern computing technology. The experimental groups have expertise spanning from applied optics to biophysics, medicine, and astrophysics. The mathematical groups are proficient in modelling, regularisation, and numerical optimisation. The mission of this consortium is to enable analysis of dynamic processes in nature across physical scales.

Advancing Extragalactic Archaeology through Novel Inversion Techniques

The goal of galactic archaeology is to reveal a galaxy’s past from observations in the present day i.e. viewed in the local Universe. By observing local galaxies we have access to the most precise data. In this SFB sub-project we will develop and apply novel inversion techniques to make accordingly precise inferences about a galaxy’s history. The proposed techniques will address short-comings of the current state-of-the-art techniques however they come at a much higher computational cost. Therefore, this work requires an interdisciplinary team with expertise in both galactic archeology and inverse problems.