RECORD
Stellar orbits in cosmological galaxy simulations: the connection to formation history and line-of-sight kinematics
Astrophysics of Galaxies · Submitted 25 Jun 2014
abstract compiled · 2026-09-23 · no language-model review
The authors' main claim We connect the orbital structure to the formation histories and specific features (e.g. disk, counter-rotating core, minor axis rotation) in two-dimensional kinematic maps.
The compiled record
The paper's own sentences, arranged. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.
Open the compiled record
The abstract, sentence by sentence
We analyze orbits of stars and dark matter out to three effective radii for 42 galaxies formed in cosmological zoom simulations. Box orbits always dominate at the centers and $z$-tubes become important at larger radii. We connect the orbital structure to the formation histories and specific features (e.g. disk, counter-rotating core, minor axis rotation) in two-dimensional kinematic maps. Globally, fast rotating galaxies with significant recent in situ star formation are dominated by $z$-tubes. Slow rotators with recent mergers have significant box orbit and $x$-tube components. Rotation, quantified by the $\lambda_R$-parameter often originates from streaming motion of stars on $z$-tubes but sometimes from figure rotation. The observed anti-correlation of $h_3$ and $V_0 / \sigma$ in rotating galaxies can be connected to a dissipative formation history leading to high $z$-tube fractions. For galaxies with recent mergers in situ formed stars, accreted stars and dark matter particles populate similar orbits. Dark matter particles have isotropic velocity dispersions. Accreted stars are typically radially biased ($\beta \approx 0.2 - 0.4$). In situ stars become tangentially biased (as low as $\beta \approx -1.0$) if dissipation was relevant during the late assembly of the galaxy. We discuss the relevance of our analysis for integral field surveys and for constraining galaxy formation models.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | We analyze orbits of stars and dark matter out to three effective radii for 42 galaxies formed in cosmological zoom simulations. | contribution 0.55 | 0.97 | 0.04 | asserted 0.96 |
| s1 | Box orbits always dominate at the centers and $z$-tubes become important at larger radii. | result 1.00 | 0.85 | 0.13 | asserted 1.00 |
| s2 | We connect the orbital structure to the formation histories and specific features (e.g. disk, counter-rotating core, minor axis rotation) in two-dimensional kinematic maps. | contribution 0.87 | 0.93 | 0.18 | asserted 0.99 |
| s3 | Globally, fast rotating galaxies with significant recent in situ star formation are dominated by $z$-tubes. | result 1.00 | 0.89 | 0.24 | asserted 1.00 |
| s4 | Slow rotators with recent mergers have significant box orbit and $x$-tube components. | result 0.99 | 0.89 | 0.13 | asserted 1.00 |
| s5 | Rotation, quantified by the $\lambda_R$-parameter often originates from streaming motion of stars on $z$-tubes but sometimes from figure rotation. | result 0.70 | 0.77 | 0.13 | asserted 0.65 |
| s6 | The observed anti-correlation of $h_3$ and $V_0 / \sigma$ in rotating galaxies can be connected to a dissipative formation history leading to high $z$-tube fractions. | interpretation 0.84 | 0.72 | 0.13 | asserted 0.55 |
| s7 | For galaxies with recent mergers in situ formed stars, accreted stars and dark matter particles populate similar orbits. | result 1.00 | 0.86 | 0.08 | asserted 0.98 |
| s8 | Dark matter particles have isotropic velocity dispersions. | result 1.00 | 0.82 | 0.04 | asserted 1.00 |
| s9 | Accreted stars are typically radially biased ($\beta \approx 0.2 - 0.4$). | result 1.00 | 0.87 | 0.05 | asserted 0.97 |
| s10 | In situ stars become tangentially biased (as low as $\beta \approx -1.0$) if dissipation was relevant during the late assembly of the galaxy. | result 0.99 | 0.85 | 0.10 | asserted 0.79 |
| s11 | We discuss the relevance of our analysis for integral field surveys and for constraining galaxy formation models. | future work 0.61 | 0.43 | 0.04 | unclear 0.82 |
What was examined, and what was not
- arXiv listing abstract v2
- full text
- figures and tables
- references and citing sentences
- relations to other papers
- P abstract
- S sections
- T body sentences
- C citations
- R cross-paper relations
The paper
Original abstract
We analyze orbits of stars and dark matter out to three effective radii for 42 galaxies formed in cosmological zoom simulations. Box orbits always dominate at the centers and $z$-tubes become important at larger radii. We connect the orbital structure to the formation histories and specific features (e.g. disk, counter-rotating core, minor axis rotation) in two-dimensional kinematic maps. Globally, fast rotating galaxies with significant recent in situ star formation are dominated by $z$-tubes. Slow rotators with recent mergers have significant box orbit and $x$-tube components. Rotation, quantified by the $\lambda_R$-parameter often originates from streaming motion of stars on $z$-tubes but sometimes from figure rotation. The observed anti-correlation of $h_3$ and $V_0 / \sigma$ in rotating galaxies can be connected to a dissipative formation history leading to high $z$-tube fractions. For galaxies with recent mergers in situ formed stars, accreted stars and dark matter particles populate similar orbits. Dark matter particles have isotropic velocity dispersions. Accreted stars are typically radially biased ($\beta \approx 0.2 - 0.4$). In situ stars become tangentially biased (as low as $\beta \approx -1.0$) if dissipation was relevant during the late assembly of the galaxy. We discuss the relevance of our analysis for integral field surveys and for constraining galaxy formation models.
Human review
How the literature uses it
2 arXiv papers cite this in 2 sentences
What it cites · 11 sentences without a confident label
Uses the method or tool of 1 paper
-
The maps are constructed in a similar way to observations and all details can be found in [ref] .
The ATLAS$^{\rm{3D}}$ project - XXV: Two-dimensional kinematic analysis of simulated galaxies and the cosmological origin of fast and slow rotators · Line-of-sight kinematics · 0.97
Discussion
Know something about this paper? Leave a comment, or highlight any passage above to comment on it.