The diversity of thick galactic discs

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 6-m telescope BTA we collected deep spectra o...

Full description

Saved in:
Bibliographic Details
Published in:Monthly notices of the Royal Astronomical Society. Letters 2016-07, Vol.460 (1), p.L89-L93
Main Authors: Kasparova, Anastasia V., Katkov, Ivan Yu, Chilingarian, Igor V., Silchenko, Olga K., Moiseev, Alexey V., Borisov, Svyatoslav B.
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Request full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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 6-m telescope BTA we collected deep spectra of thick discs in three edge-on S0-a disc galaxies located in different environments: NGC 4111 in a dense group, NGC 4710 in the Virgo cluster, and NGC 5422 in a sparse group. We see intermediate age (4–5 Gyr) metal rich ([Fe/H] ∼− 0.2…0.0 dex) stellar populations in NGC 4111 and NGC 4710. On the other hand, NGC 5422 does not harbour young stars, its disc is thick and old (10 Gyr), without evidence for a second component, and its α-element abundance suggests a 1.5–2 Gyr long formation epoch implying its formation at high redshift. Our results suggest the diversity of thick disc formation scenarios.
ISSN:1745-3925
1745-3933
DOI:10.1093/mnrasl/slw083