J/A+A/625/A76 NGC1052-DF2 VLT/MUSE datacubes (Emsellem+, 2019)
The ultra-diffuse galaxy NGC 1052-DF2 with MUSE.
I. Kinematics of the stellar body.
Emsellem E., van der Burg R.F.J., Fensch J., Jerabkova T., Zanella A.,
Agnello A., Hilker M., Mueller O., Rejkuba M., Duc P-A., Durrell P.,
Habas R., Lelli F., Lim S., Marleau F., Peng E., Sanchez-Janssen R.
<Astron. Astrophys. 625, A76 (2019)>
=2019A&A...625A..76E 2019A&A...625A..76E (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Radial velocities
Keywords: galaxies: dwarf - galaxies: kinematics and dynamics -
galaxies: individual: NGC 1052-DF2 - galaxies: stellar content
Abstract:
The so-called ultra-diffuse galaxy NGC 1052-DF2 was announced to be a
galaxy lacking dark matter based on a spectroscopic study of its
constituent globular clusters. Here we present the first spectroscopic
analysis of the stellar body of this galaxy using the MUSE
integral-field spectrograph at the (ESO) Very Large Telescope. The
MUSE datacube simultaneously provides DF2's stellar velocity field and
systemic velocities for seven globular clusters (GCs). We further
discovered three planetary nebulae (PNe) that are likely part of this
galaxy. While five of the clusters had velocities measured in the
literature, we were able to confirm the membership of two more
candidates through precise radial velocity measurements, which
increases the measured specific frequency of GCs in DF2. The mean
velocity of the diffuse stellar body, 1792.9-1.8+1.4km/s, is
consistent with the mean globular cluster velocity.We detect a weak
but significant velocity gradient within the stellar body, with a
kinematic axis close to the photometric major axis, making it a
prolate-like rotator. We estimate a velocity dispersion from the
clusters and PNe of σint= 10.6+3.9-2.3km/s. The velocity
dispersion DF2?(Re) for the stellar body within one effective radius
is 10.8-4.0+3.2km/s. Considering various sources of systemic
uncertainties, this central value varies between 5 and 13km/s, and we
conservatively report a 95% confidence upper limit to the dispersion
within one Re of 21km/s. We provide updated mass estimates based on
these dispersions corresponding to the different distances to NGC
1052-DF2 that have been reported in the recent literature.
Description:
We provide here the various MUSE/VLT datacubes produced during the
course of the MUSE-DF2 study.
The originally combined MUSE datacube includes 28 individual MUSE
exposures each rotated by 90 degrees. The total exposure time is about
5.1h. The combined datacubes for NGC1052-DF2 are given as Linear and
Log rebinning versions. The rebinning itself is done during the
combination phase which minimises the resampling steps (to 1). We then
provide one sky subtracted (Zapped) version for each version with a
window of 50 pixels, as mentioned in the paper.
The datacube used in the paper for the full analysis is the Log
version with a window of 50 pixels.
We also provide a sky subtraction (Zapped) version of the Log version
with a window of 300 pixels, thus minimising the residual wiggles in
the continuum (visible in Figure 2 of the paper). This Log_300
datacube is very similar to the Log_50 version, and results extracted
from that version are fully consistent with results presented in the
A&A paper. We recommend the users to download the Log version with sky
or with the sky subtracted using the 300 pixels window.
MUSE at the VLT, used in NOAO and Wide Field mode.
The data has been reduced with a python wrapper around the official
MUSE DRS end of 2018.
Objects:
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RA (2000) DE Designation(s)
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02 41 46.5 -08 24 08 NGC1052-DF2 = [CVD2018] NGC1052-DF2
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 199 5 List of fits datacubes
fits/* . 5 Individual fits datacubes
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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 slices
37- 59 A23 "datime" Obs.date Observation date
61- 67 F7.2 0.1nm blambda Lower value of wavelength interval
69- 75 F7.2 0.1nm Blambda Upper value of wavelength interval
77- 84 F8.6 0.1nm dlambda Wavelenght resolution
86- 92 I7 Kibyte size Size of FITS file
94-137 A44 --- FileName Name of FITS file, in subdirectory fits
139-199 A61 --- Title Title of the FITS file
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Acknowledgements:
Eric Emsellem, eric.emsellem(at)eso.org
(End) Patricia Vannier [CDS] 09-May-2019