J/A+A/591/A143 NGC 3115 MUSE images (Guerou+, 2016)
Exploring the mass assembly of the early-type disc galaxy NGC 3115 with MUSE.
Guerou A., Emsellem E., Krajnovic D., Mcdermid R.M., Contini T.,
Weilbacher P.M.
<Astron. Astrophys., 591, A143 (2016)>
=2016A&A...591A.143G 2016A&A...591A.143G (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Spectroscopy
Keywords: galaxies: elliptical and lenticular, cD - galaxies: evolution -
galaxies: formation - galaxies: kinematics and dynamics -
galaxies: stellar content - galaxies: structure
Abstract:
We present MUSE integral field spectroscopic data of the S0 galaxy NGC
3115 obtained during the instrument commissioning at the ESO Very
Large Telescope (VLT). We analyse the galaxy stellar kinematics and
stellar populations and present two-dimensional maps of their
associated quantities. We thus illustrate the capacity of MUSE to map
extra-galactic sources to large radii in an efficient manner, i.e.
∼4Re, and provide relevant constraints on its mass assembly. We
probe the well-known set of substructures of NGC 3115 (nuclear disc,
stellar rings, outer kpc-scale stellar disc, and spheroid) and show
their individual associated signatures in the MUSE stellar kinematics
and stellar populations maps. In particular, we confirm that NGC 3115
has a thin fast-rotating stellar disc embedded in a fast-rotating
spheroid, and that these two structures show clear differences in
their stellar age and metallicity properties. We emphasise an observed
correlation between the radial stellar velocity, V, and the
Gauss-Hermite moment, h3, which creates a butterfly shape in the
central 15" of the h3 map. We further detect the previously
reported weak spiral- and ring-like structures, and find evidence that
these features can be associated with regions of younger mean stellar
ages. We provide tentative evidence for the presence of a bar,
although the V-h3 correlation can be reproduced by a simple
axisymmetric dynamical model. Finally, we present a reconstruction of
the two-dimensional star formation history of NGC 3115 and find that
most of its current stellar mass was formed at early epochs (>12Gyr
ago), while star formation continued in the outer (kpc-scale) stellar
disc until recently. Since z∼2 and within ∼4Re, we suggest that NGC
3115 has been mainly shaped by secular processes.
Description:
NGC 3115 was observed during the night of 8 February 2014 using MUSE
nominal mode (WFM-N) that allows a continuous wavelength coverage from
4750-9300Å with a varying resolution of R=2000-4000.
These data were designed as a first test of the mosaicing abilities of
MUSE using an extended (bright) target that showed substructures and
had ample published imaging and spectroscopic data for comparison.
Five exposures of only 10 minutes each were obtained, each exposure
overlapping its neighbours over a quarter of the field of view
(i.e. 30"x30"), with the central exposure centred on the galaxy
nucleus. The data obtained cover ∼4Re (Re∼35", Arnold et al.
2014ApJ...791...80A 2014ApJ...791...80A) along the NGC 3115 major axis.
File images.fits contains multiple extensions to allow users to
reproduce the figures 3 and 5 of the paper, and so most of the other
figures.
Objects:
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RA (2000) DE Designation(s)
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10 05 13.98 -07 43 06.9 NGC 3115 = UGCA 199
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 91 9 Information on fits images
images.fits 2880 20691 Multi-image fits file
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 8 F8.4 deg RAdeg Right Ascension of center (J2000)
9- 15 F7.4 deg DEdeg Declination of center (J2000)
17- 19 I3 --- Nx Number of pixels along X-axis
21- 23 I3 --- Ny Number of pixels along Y-axis
25 I1 --- Index Index number in the multi-image FITS file
27- 30 I4 Kibyte size Size of FITS file
32- 42 A11 --- FileName Name of FITS file
44- 91 A48 --- Title Title of the FITS image
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Acknowledgements:
Adrien Guerou, aguerou(at)eso.org
(End) Patricia Vannier [CDS] 20-Jul-2016