Quantifying the stellar ages of dynamically-separated bulges and disks of CALIFA spiral galaxies

Autor(en)

Yunpeng Jin, Ling Zhu, Stefano Zibetti, Luca Costantin, Glenn van de Ven, Shude Mao

Abstrakt

We employ a recently developed population-orbit superposition technique to simultaneously fit the stellar kinematic and age maps of 82 CALIFA spiral galaxies and obtain the ages of stars in different dynamical structures. We first evaluated the capabilities of this method on CALIFA-like mock data created from the Auriga simulations. The recovered mean ages of dynamically cold, warm, and hot components match the true values well, with an observational error of up to 20% in the mock age maps. For CALIFA spiral galaxies, we find that the stellar ages of the cold, warm, and hot components all increase with the stellar mass of the galaxies, from t

_cold ∼ 2.2 Gyr, t

_warm ∼ 2.3 Gyr, and t

_hot ∼ 2.6 Gyr for galaxies with stellar mass M

_∗ < 10

¹⁰ M, to t

_cold ∼ 4.0 Gyr, t

_warm ∼ 5.1 Gyr, and t

_hot ∼ 5.9 Gyr for galaxies with M

_∗ > 10

¹¹ M. About 80% of the galaxies in our sample have t

_hot > t

_cold, and the mean values of t

_hot − t

_cold also increase with stellar mass, from 0.7

⁺

₋

⁰

₀

_.

⁶

₂ Gyr in low-mass galaxies (10

^8.9 M < M

_∗ ≤ 10

^10.5 M) to 1.7

⁺

₋

⁰

₀

_.

⁷

₂ Gyr in high-mass galaxies (10

^10.5 M < M

_∗ < 10

^11.3 M). The stellar age is younger in disks than in bulges, on average. This suggests that either the disks formed later and/or that they experienced a more prolonged and extensive period of star formation. Lower-mass spiral galaxies have younger bulges and younger disks, while higher-mass spiral galaxies generally have older bulges, and their disks span a wide range of ages. This is consistent with the scenario in which the bulges in more massive spirals formed earlier than those in less massive spirals.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

Chinese Academy of Sciences (CAS), INAF - Osservatorio Astrofisico di Arcetri, INAF Osservatorio Astronomico di Brera, Tsinghua University, Centro de Astrobiología (CSIC-INTA)

Journal

Astronomy & Astrophysics

Band

681

Anzahl der Seiten

21

ISSN

0004-6361

DOI

https://doi.org/10.1051/0004-6361/202347197

Publikationsdatum

01-2024

Peer-reviewed

Ja

ÖFOS 2012

103003 Astronomie, 103004 Astrophysik

Schlagwörter

ASJC Scopus Sachgebiete

Astronomy and Astrophysics, Space and Planetary Science

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/1ec8f773-6ac3-4df1-a1e8-c553b10dfa24