J/A+A/640/A106 MUSE MATLAS-2019 spectral datacube (Mueller+, 2020)
Spectroscopic study of MATLAS-2019 with MUSE:
an ultra-diffuse galaxy with an excess of old globular clusters.
Mueller O., Marleau F.R., Duc P.-A., Habas R., Fensch J., Emsellem E.,
Poulain M., Lim S., Agnello A., Durrell P., Paudel S.,
Sanchez-Janssen R., van der Burg R.F.J.
<Astron. Astrophys. 640, A106 (2020)>
=2020A&A...640A.106M 2020A&A...640A.106M (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, spectra
Keywords: galaxy: kinematics and dynamics - galaxy: stellar content -
galaxies: dwarf
Abstract:
The MATLAS deep imaging survey has uncovered a plethora of dwarf
galaxies in the low density environment it has mapped. A fraction of
them are unusually extended and have a low-surface brightness. Among
these so-called ultra-diffuse galaxies, a few seem to host an excess
of globular clusters. With the integral-field unit spectrograph MUSE
we have observed one of these galaxies - MATLAS J15052031+0148447
(MATLAS-2019) - located towards the nearby group NGC 5846 and measured
its systemic velocity,age, and metallicity, and that of its globular
clusters candidates. For the stellar body of MATLAS-2019 we derive a
metallicity of -1.33+0.19-0.01dex and an age of
11.2+1.8-0.8Gyr. For some of the individual GCs and the stacked GC
population, we derive consistent ages and metallicities. From the 11
confirmed globular clusters and using a Markov Chain Monte Carlo
approach we derived a dynamical mass-to-light ratio of
4.2+8.6-3.4M/L. This is at the lower end of the luminosity-mass
scaling relation defined by the Local Group dwarf galaxies.
Furthermore, we couldn't confirm nor reject the possibility of a
rotational component of the GC system. If present, this would further
modify the inferred mass. Follow-up observations of the globular
cluster population and of the stellar body of the galaxy are needed to
assess whether this galaxy is lacking dark matter like it was
suggested for the pair of dwarf galaxies in the field of NGC 1052, or
if this is a miss-interpretation arising from systematic uncertainties
of the method commonly used for these systems and the large
uncertainties of the individual globular cluster velocities.
Description:
The reduced, combined and ZAP-ed data cube as 3D fits file.
Objects:
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RA (2000) DE Designation(s)
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15 05 20.31 +01 48 44. 7 MATLAS-2019 = MATLAS J15052031+0148447
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 139 1 Information of spectral datacube
fits/* . 1 Spectral datacube
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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- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 22 F3.1 arcsec/pix scale Scale of the image
24- 26 I3 --- Nx Number of pixels along X-axis
28- 30 I3 --- Ny Number of pixels along Y-axis
32- 35 I4 --- Nz Number of pixels along Z-axis
37- 43 F7.2 0.1nm blambda Lower value of wavelength interval
45- 51 F7.2 0.1nm Blambda Upper value of wavelength interval
53- 56 F4.2 0.1nm dlambda Wavelength resolution
58- 64 I7 Kibyte size Size of FITS file
66- 85 A20 --- FileName Name of FITS file, in subdirectory fits
87-139 A53 --- Title Title of the FITS file
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Acknowledgements:
Oliver Mueller, oliver.muller(at)astro.unistra.fr
(End) Oliver Mueller [Strasbourg Obs.], Patricia Vannier [CDS] 10-Jun-2020