J/A+A/620/A169 NGC 7009 MUSE imaging spectroscopic survey (Walsh+, 2018)
An imaging spectroscopic survey of the planetary nebula NGC 7009 with MUSE.
Walsh J.R., Monreal-Ibero A., Barlow M.J., Ueta T., Wesson R.,
Zijlstra A.A., Kimeswenger S., Leal-Ferreira M.L., Otsuka M.
<Astron. Astrophys. 620, A169 (2018)>
=2018A&A...620A.169W 2018A&A...620A.169W (SIMBAD/NED BibCode)
ADC_Keywords: Planetary nebulae ; Spectroscopy ; Optical ; Abundances
Keywords: planetary nebulae: individual: NGC 7009 -
stars: AGB and post-AGB - ISM: abundances - dust, extinction -
atomic processes
Abstract:
The spatial structure of the emission lines and continuum over the
50-arcsecond extent of the nearby, O-rich, PN NGC 7009 (Saturn Nebula)
have been observed with the MUSE integral field spectrograph on the
ESO Very Large Telescope. This study concentrates on maps of line
emission and their interpretation in terms of physical conditions.
MUSE Science Verification data, in <0.6-arcsecond seeing, have been
reduced and analysed as maps of emission lines and continuum over the
wavelength range 4750-9350Å. The dust extinction, the electron
densities and temperatures of various phases of the ionized gas,
abundances of species from low to high ionization and some total
abundances are determined using standard techniques.
Emission line maps over the bright shells are presented, from neutral
to the highest ionization available (HeII and [MnV]). For
collisionally excited lines (CELs), maps of electron temperature (Te
from [NII] and [SIII]) and density (Ne from [SII] and [ClIII])
are available and for optical recombination lines (ORLs) temperature
(from the Paschen jump and ratio of HeI lines) and density (from high
Paschen lines). These estimates are compared: for the first time, maps
of the differences in CEL and ORL Te's have been derived, and
correspondingly a map of t2 between a CEL and ORL temperature,
showing considerable detail. Total abundances of only He and O were
formed, the latter using three ionization correction factors. However
the map of He/H is not flat, departing by ∼2% from a constant value,
with remnants corresponding to ionization structures. An integrated
spectrum over an area of 2340-arcseconds squared was also formed and
compared to 1D photoionization models.
The spatial variation of a range of nebular parameters illustrates the
complexity of the ionized media in NGC 7009. These MUSE data are very
rich with detections of hundreds of lines over areas of hundreds of
arcseconds squared and follow-on studies are outlined.
Description:
During the MUSE Science Verification in June and again in August 2014,
NGC 7009 was observed in service mode with the MUSE Wide Field Mode
(WFM-N) spatial setting WFM (0.2"spaxels) with the standard
(blue filter) wavelength range (4750-9300Å, 1.25Å per pixel).
FITS files are named according to whether they correspond to the value
or the statistical error. Names ending in "s.fit" denote result (e.g.,
flux, ratio, electron density, temperature, etc); file names ending in
"e.fit" denote statistical error, where available.
Objects:
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RA (2000) DE Designation(s)
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21 04 10.82 -11 21 48.6 NGC 7009 = PN G037.7-34.5
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 283 90 List of fits maps
fits/* . 90 Individual fits maps
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See also:
J/MNRAS/409/881 : Spectrosocpy of NGC 7009 (Phillips+, 2010)
J/MNRAS/415/181 : Deep spectroscopy of NGC 7009 (Fang+, 2011)
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 [0.2] Scale of the image
24- 26 I3 --- Nx [310] Number of pixels along X-axis
28- 30 I3 --- Ny [250] Number of pixels along Y-axis
32- 41 A10 "date" Obs.Date Observation date (2014-06-24)
43- 45 I3 Kibyte size Size of FITS file
47- 60 A14 --- FileName Name of FITS file, in subdirectory fits
62- 68 A7 --- Fig Figure number in the paper
70-283 A214 --- Title Title of the FITS file
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Acknowledgements:
Jeremy R. Walsh, jwalsh(at)eso.org
(End) Patricia Vannier [CDS] 17-Oct-2018