Fornax 3D project: a two-dimensional view of the stellar initial mass function in the massive lenticular galaxy FCC 167

Martín-Navarro, I.; Lyubenova, M.; van de Ven, G.; Falcón-Barroso, J.; Coccato, L.; Corsini, E. M.; Gadotti, D. A.; Iodice, E.; La Barbera, F.; McDermid, R. M.; Pinna, F.; Sarzi, M.; Viaene, S.; de Zeeuw, P. T.; Zhu, L.
Bibliographical reference

Astronomy and Astrophysics, Volume 626, id.A124, 12 pp.

Advertised on:
6
2019
Number of authors
15
IAC number of authors
2
Citations
38
Refereed citations
35
Description
The stellar initial mass function (IMF) regulates the baryonic cycle within galaxies, and is a key ingredient for translating observations into physical quantities. Although it was assumed to be universal for decades, there is now growing observational evidence showing that the center of massive early-type galaxies hosts a larger population of low-mass stars than is expected based on observations from the Milky Way. Moreover, these variations in the IMF have been found to be related to radial metallicity variations in massive galaxies. We present here a two-dimensional stellar population analysis of the massive lenticular galaxy FCC 167 (NGC 1380) as part of the Fornax3D project. Using a newly developed stellar population fitting scheme, we derive a full two-dimensional IMF map of an early-type galaxy. This two-dimensional analysis allows us go further than a radial analysis, showing how the metallicity changes along a disk-like structure while the IMF follows a distinct, less disky distribution. Thus, our findings indicate that metallicity cannot be the sole driver of the observed radial IMF variations. In addition, a comparison with the orbital decomposition shows suggestive evidence of a coupling between stellar population properties and the internal dynamical structure of FCC 167, where metallicity and IMF maps seem to track the distribution of cold and warm orbits, respectively.
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Group members
Traces of Galaxy Formation: Stellar populations, Dynamics and Morphology
We are a large, diverse, and very active research group aiming to provide a comprehensive picture for the formation of galaxies in the Universe. Rooted in detailed stellar population analysis, we are constantly exploring and developing new tools and ideas to understand how galaxies came to be what we now observe.
Ignacio
Martín Navarro