Abundance ratios and IMF slopes in the dwarf elliptical galaxy NGC 1396 with MUSE
View/ Open
Date
2016Author
Mentz, J.J.
Loubser, S.I.
La Barbera, F.
Peletier, R.F.
Falcón-Barroso, J.
Metadata
Show full item recordAbstract
Deep observations of the dwarf elliptical (dE) galaxy NGC 1396 (MV = −16.60, Mass ∼4 × 108 M⊙), located in the Fornax cluster, have been performed with the Very Large Telescope/Multi Unit Spectroscopic Explorer spectrograph in the wavelength region from 4750 to 9350 Å. In this paper, we present a stellar population analysis studying chemical abundances, the star formation history (SFH) and the stellar initial mass function (IMF) as a function of galactocentric distance. Different, independent ways to analyse the stellar populations result in a luminosity-weighted age of ∼6 Gyr and a metallicity [Fe/H]∼ −0.4, similar to other dEs of similar mass. We find unusually overabundant values of [Ca/Fe] ∼+ 0.1, and underabundant Sodium, with [Na/Fe] values around −0.1, while [Mg/Fe] is overabundant at all radii, increasing from ∼+ 0.1 in the centre to ∼+ 0.2 dex. We notice a significant metallicity and age gradient within this dwarf galaxy. To constrain the stellar IMF of NGC 1396, we find that the IMF of NGC 1396 is consistent with either a Kroupa-like or a top-heavy distribution, while a bottom-heavy IMF is firmly ruled out. An analysis of the abundance ratios, and a comparison with galaxies in the Local Group, shows that the chemical enrichment history of NGC 1396 is similar to the Galactic disc, with an extended SFH. This would be the case if the galaxy originated from a Large Magellanic Cloud-sized dwarf galaxy progenitor, which would lose its gas while falling into the Fornax cluster
URI
http://hdl.handle.net/10394/21294https://doi.org/10.1093/mnras/stw2129
https://academic.oup.com/mnras/article-pdf/463/3/2819/8284660/stw2129.pdf
Collections
Related items
Showing items related by title, author, creator and subject.
-
Stellar populations in central cluster galaxies: the influence of cooling flows
Loubser, S.I. (Oxford Univ Press, 2014)We present detailed, high spatial and spectral resolution, long-slit observations of four central cluster galaxies (CCGs; Abell 0085, 0133, 0644 and Ophiuchus) recently obtained on the Southern African Large Telescope. ... -
The detailed nature of active central cluster galaxies
Loubser, S.I.; Soechting, I.K. (Oxford Univ Press, 2013)We present detailed integral field unit observations of the central few kiloparsecs of the ionized nebulae surrounding four active central cluster galaxies (CCGs) in cooling flow clusters (Abell 0496, 0780, 1644 and ... -
Investigating the star formation histories of the brightest cluster galaxies
Groenewald, D.N.; Loubser, S.I. (Oxford Univ Press, 2014)This article is devoted to the study of the central stellar populations of the brightest cluster galaxies (BCGs). High signal-to-noise ratio, long-slit spectra for a sample of 39 galaxies were fitted against two stellar ...