ATTENZIONE! IL REPOSITORY E’ APERTO ESCLUSIVAMENTE ALL’IMMISSIONE DEI RAPPORTI TECNICI (COLLEZIONE 4.01). NON E’ POSSIBILE INSERIRE PRODOTTI IN TUTTE LE ALTRE COLLEZIONI, A CAUSA DI PROBLEMI TECNICI. THE REPOSITORY IS OPEN EXCLUSIVELY FOR THE SUBMISSION OF TECHNICAL REPORTS (COLLECTION 4.01). SUBMISSIONS TO ALL OTHER COLLECTIONS ARE TEMPORARILY UNAVAILABLE, DUE TO TECHNICAL ISSUES.
 

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

Journal
Date Issued
2018
Author(s)
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
•
•
Sánchez, Sebastian F.
DOI
Abstract
Galaxy formation entails the hierarchical assembly of mass, along with the condensation of baryons and the ensuing, self-regulating star formation1,2. The stars form a collisionless system whose orbit distribution retains dynamical memory that can constrain a galaxy's formation history3. The orbits dominated by ordered rotation, with near-maximum circularity λz ≈ 1, are called kinematically cold, and the orbits dominated by random motion, with low circularity λz ≈ 0, are kinematically hot. The fraction of stars on `cold' orbits, compared with the fraction on `hot' orbits, speaks directly to the quiescence or violence of the galaxies' formation histories4,5. Here we present such orbit distributions, derived from stellar kinematic maps through orbit-based modelling for a well-defined, large sample of 300 nearby galaxies. The sample, drawn from the CALIFA survey6, includes the main morphological galaxy types and spans a total stellar mass range from 108.7 to 1011.9 solar masses. Our analysis derives the orbit-circularity distribution as a function of galaxy mass and its volume-averaged total distribution. We find that across most of the considered mass range and across morphological types, there are more stars on `warm' orbits defined as 0.25 ≤ λz ≤ 0.8 than on either `cold' or `hot' orbits. This orbit-based `Hubble diagram' provides a benchmark for galaxy formation simulations in a cosmological context.
Volume
2
Start page
233
Uri
Url
Issn Identifier
2397-3366
Ads BibCode
2018NatAs...2..233Z
Rights
open.access
File(s)
Loading...
Thumbnail Image
Name

1711.06728.pdf

Description
preprint
Size

2.7 MB

Format

Adobe PDF

Checksum (MD5)

05e936a6e6eca8fc54571a4a4407bc75

Loading...
Thumbnail Image
Name

Nature astr.s41550-017-0348-1.pdf

Description
[Administrators only]
Size

3.61 MB

Format

Adobe PDF

Checksum (MD5)

b6b90af0aee8a474b241891a760ca7c8