The VIRUS-dE Survey I: Stars in dwarf elliptical galaxies - 3D dynamics and radially resolved stellar initial mass functions

Fuente: arXiv
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Main Authors: Lipka, Mathias, Thomas, Jens, Saglia, Roberto, Bender, Ralf, Fabricius, Maximilian, Hill, Gary J., Kluge, Matthias, Landriau, Martin, Mazzalay, Ximena, Noyola, Eva, Parikh, Taniya, Snigula, Jan
Format: Preprint
Published: 2024
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author Lipka, Mathias
Thomas, Jens
Saglia, Roberto
Bender, Ralf
Fabricius, Maximilian
Hill, Gary J.
Kluge, Matthias
Landriau, Martin
Mazzalay, Ximena
Noyola, Eva
Parikh, Taniya
Snigula, Jan
author_facet Lipka, Mathias
Thomas, Jens
Saglia, Roberto
Bender, Ralf
Fabricius, Maximilian
Hill, Gary J.
Kluge, Matthias
Landriau, Martin
Mazzalay, Ximena
Noyola, Eva
Parikh, Taniya
Snigula, Jan
contents We analyse the stellar structure of a sample of dwarf ellipticals (dE) inhabiting various environments within the Virgo cluster. Integral-field observations with a high spectral resolution allow us to robustly determine their low velocity dispersions ($\sim25$ km s$^{-1}$) and higher-order kinematic moments out to the half-light radius. We find the dEs exhibit a diversity in ages with the younger dEs being less enhanced than the older, suggesting a complex star formation history for those dEs that recently entered Virgo while others have been quenched shortly after reionization. Orbit-superposition modeling allowed us to recover viewing angles, stellar mass-to-light ratios (with gradients), as well as the intrinsic orbit structure. We find that the angular momentum of the dEs is strongly suppressed compared to ordinary early-type galaxies and correlates with the environment. Flattened dEs are so because of a suppressed kinetic energy perpendicular to their equatorial plane. Combining population and dynamical modeling results, we find an age-dependent stellar initial mass function (IMF) or, alternatively, evidence for a more extended star formation history for those galaxies that have had higher initial mass and/or inhabited lower density environments. dEs appear to have a spatially homogeneous stellar structure but the state they were `frozen' in as they stopped forming stars varies dramatically according to their initial conditions.
format Preprint
id arxiv_https___arxiv_org_abs_2409_10518
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle The VIRUS-dE Survey I: Stars in dwarf elliptical galaxies - 3D dynamics and radially resolved stellar initial mass functions
Lipka, Mathias
Thomas, Jens
Saglia, Roberto
Bender, Ralf
Fabricius, Maximilian
Hill, Gary J.
Kluge, Matthias
Landriau, Martin
Mazzalay, Ximena
Noyola, Eva
Parikh, Taniya
Snigula, Jan
Astrophysics of Galaxies
We analyse the stellar structure of a sample of dwarf ellipticals (dE) inhabiting various environments within the Virgo cluster. Integral-field observations with a high spectral resolution allow us to robustly determine their low velocity dispersions ($\sim25$ km s$^{-1}$) and higher-order kinematic moments out to the half-light radius. We find the dEs exhibit a diversity in ages with the younger dEs being less enhanced than the older, suggesting a complex star formation history for those dEs that recently entered Virgo while others have been quenched shortly after reionization. Orbit-superposition modeling allowed us to recover viewing angles, stellar mass-to-light ratios (with gradients), as well as the intrinsic orbit structure. We find that the angular momentum of the dEs is strongly suppressed compared to ordinary early-type galaxies and correlates with the environment. Flattened dEs are so because of a suppressed kinetic energy perpendicular to their equatorial plane. Combining population and dynamical modeling results, we find an age-dependent stellar initial mass function (IMF) or, alternatively, evidence for a more extended star formation history for those galaxies that have had higher initial mass and/or inhabited lower density environments. dEs appear to have a spatially homogeneous stellar structure but the state they were `frozen' in as they stopped forming stars varies dramatically according to their initial conditions.
title The VIRUS-dE Survey I: Stars in dwarf elliptical galaxies - 3D dynamics and radially resolved stellar initial mass functions
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2409.10518