The Diversity of Thick Galactic Discs

  title={The Diversity of Thick Galactic Discs},
  author={Anastasia V Kasparova and Ivan Yu. Katkov and Igor V. Chilingarian and Olga K. Silchenko and Alexey V. Moiseev and S. Borisov},
  journal={Monthly Notices of the Royal Astronomical Society},
Although thick stellar discs are detected in nearly all edge-on disc galaxies, their formation scenarios still remain a matter of debate. Due to observational difficulties, there is a lack of information about their stellar populations. Using the Russian 6m telescope BTA we collected deep spectra of thick discs in three edge-on S0-a disc galaxies located in different environments: NGC4111 in a dense group, NGC4710 in the Virgo cluster, and NGC5422 in a sparse group. We see intermediate age (4 5… 

Figures and Tables from this paper

An excessively massive thick disc of the enormous edge-on lenticular galaxy NGC 7572
Galactic discs are known to have a complex multilayer structure. An in-depth study of the stellar population properties of the thin and thick components can elucidate the formation and evolution of
The kinematics of local thick discs do not support an accretion origin
Thick discs are nearly ubiquitous components of the discs of present-day galaxies. It has been proposed that a fraction of their stars have been accreted. Here, we aim to find whether accretion of
A prediction about the age of thick discs as a function of the stellar mass of the host galaxy
One of the suggested thick disc formation mechanisms is that they were born quickly and in situ from a turbulent clumpy disc. Subsequently, thin discs formed slowly within them from leftovers of the
NGC 5746: Formation history of a massive disc-dominated galaxy
The existence of massive galaxies lacking a classical bulge has often been proposed as a challenge to ΛCDM. However, recent simulations propose that a fraction of massive disc galaxies might have
NGC 7457: evidence for merger-driven cylindrical rotation in disc galaxies
We construct Schwarzschild orbit-based models of NGC 7457, known as a peculiar low-mass lenticular galaxy. Our best-fitting model successfully retrieves most of the unusual kinematics behaviours of
On the flaring of thick discs of galaxies: insights from simulations
Using simulated galaxies in their cosmological context, we analyse how the flaring of mono-age populations (MAPs) influences the flaring and the age structure of geometrically defined thick discs.
The Fornax 3D project: Thick disks in a cluster environment
We have used deep MUSE observations to perform a stellar-kinematic and population analysis of FCC 153 and FCC 177, two edge-on S0 galaxies in the Fornax cluster. The geometrical definition of the
The reports of thick discs’ deaths are greatly exaggerated : thick discs are NOT artefacts caused by diffuse scattered light
Recent studies have made the community aware of scattered light when examining low-surface-brightness galaxy features such as thick discs. In our past studies of the thick discs of edge-on galaxies
Thick Disks in the Hubble Space Telescope Frontier Fields
Thick disk evolution is studied using edge-on galaxies in two Hubble Space Telescope Frontier Field Parallels. The galaxies were separated into 72 clumpy types and 35 spiral types with bulges.
The Fornax 3D project: Unveiling the thick disk origin in FCC 170; possible signs of accretion
We present and discuss the stellar kinematics and populations of the S0 galaxy FCC 170 (NGC 1381) in the Fornax cluster, using deep MUSE data from the Fornax 3D survey. We show the maps of the first


Large scale nested stellar discs in NGC 7217
NGC 7217 is an unbarred early-type spiral galaxy having a multisegment exponential light profile and a system of star-forming rings of the unknown origin; it also possesses a circumnuclear gaseous
Ages and abundances in large-scale stellar discs of nearby S0 galaxies†
By undertaking deep long-slit spectroscopy with the focal reducer SCORPIO of the Russian 6m telescope, we studied stellar population properties and their variation with radius in 15 nearby S0
Kinematics and stellar populations of the dwarf elliptical galaxy IC 3653
We present the first 3D observations of a diffuse elliptical galaxy (dE). The good quality data (S/N up to 40) reveal the kinematical signature of an embedded stellar disc, reminiscent of what is
Characteristics of thick disks formed through minor mergers: stellar excesses and scale lengths
By means of a series of N-body/SPH simulations we investigate the morphological properties of thick stellar disks formed through minor mergers with, e.g. a range of gas-to-stellar mass rati os. We
On the Formation of Galactic Thick Disks
Recent spectroscopic observations in the Milky Way suggest that the chemically defined thick disk (stars that have high [α/Fe] ratios and are thus old) has a significantly smaller scale-length than
The formation of thick stellar disks in spiral galaxies is studied. Simulations of gas-rich young galaxies show formation of internal clumps by gravitational instabilities, clump coalescence into a
The evolution of disk galaxies and the origin of S0 galaxies
We reconsider the relation between spiral and SO galaxies in the light of recent data on the colors and morphology of disk systems, and on the content of clusters at different redshifts. Star
Lick Indices in the Thin and Thick Disks of Edge-On Disk Galaxies
We have measured Lick index equivalent widths to derive luminosity weighted stellar ages and metallicities for thin- and thick-disk-dominated regions of nine edge-on disk galaxies with the ARC 3.5 m
NGC 6340: an old S0 galaxy with a young polar disc. Clues from morphology, internal kinematics and
Context. Lenticular galaxies are believed to form by a combination of environmental effects and secular evolution. Aims. We study the nearby disc-dominated S0 galaxy NGC 6340 photometrically and
A Structural and Dynamical Study of Late-Type, Edge-on Galaxies. II. Vertical Color Gradients and the Detection of Ubiquitous Thick Disks
We present an analysis of optical (B-R) and optical-infrared (R-Ks) color maps for 47 extremely late-type edge-on unwarped, bulgeless disk galaxies spanning a wide range of mass. The color maps show