Aims.
Two-dimensional spectroscopic data for the whole extent of the NGC 3132 planetary nebula have been obtained. We deliver a reduced data-cube and high-quality maps on a spaxel-by-spaxel basis for ...the many emission lines falling within the Multi-Unit Spectroscopic Explorer (MUSE) spectral coverage over a range in surface brightness >1000. Physical diagnostics derived from the emission line images, opening up a variety of scientific applications, are discussed.
Methods.
Data were obtained during MUSE commissioning on the European Southern Observatory (ESO) Very Large Telescope and reduced with the standard ESO pipeline. Emission lines were fitted by Gaussian profiles. The dust extinction, electron densities, and temperatures of the ionised gas and abundances were determined using Python and
PyNeb
routines.
Results.
The delivered datacube has a spatial size of ~63′′× 123′′, corresponding to ~0.26 × 0.51 pc
2
for the adopted distance, and a contiguous wavelength coverage of 4750–9300 Å at a spectral sampling of 1.25 Å pix
−1
. The nebula presents a complex reddening structure with high values (
c
(H
β
) ~ 0.4) at the rim. Density maps are compatible with an inner high-ionisation plasma at moderate high density (~1000 cm
−3
), while the low-ionisation plasma presents a structure in density peaking at the rim with values ~700 cm
−3
. Median
T
e
, using different diagnostics, decreases according to the sequence N
II
, S
II
→S
III
→ O
I
→ He
I
→ Paschen Jump. Likewise, the range of temperatures covered by recombination lines is much larger than those obtained from collisionally excited lines (CELs), with large spatial variations within the nebula. If these differences were due to the existence of high density clumps, as previously suggested, these spatial variations would suggest changes in the properties and/or distribution of the clumps within the nebula. We determined a median helium abundance He/H = 0.124, with slightly higher values at the rim and outer shell. The range of measured ionic abundances for light elements are compatible with literature values. Our kinematic analysis nicely illustrates the power of 2D kinematic information in many emission lines, which sheds light on the intrinsic structure of the nebula. Specifically, our derived velocity maps support a geometry for the nebula that is similar to the diabolo-like model previously proposed, but oriented with its major axis roughly at PA ~ −22°. We identified two low-surface brightness arc-like structures towards the northern and southern tips of the nebula, with high extinction, high helium abundance, and strong low-ionisation emission lines. They are spatially coincident with some extended low-surface brightness mid-infrared emission. The characteristics of the features suggest that they could be the consequence of precessing jets caused by the binary star system. A simple 1D Cloudy model is able to reproduce the strong lines in the integrated spectrum of the whole nebula with an accuracy of ~15%.
Conclusions.
Together with similar work with MUSE on NGC 7009, the present study illustrates the enormous potential of wide field integral field spectrographs for the study of Galactic planetary nebulae.
Abstract
We study the physical properties of the ionized gas in local discs using the sample of 38 nearby ∼108.5–11.2 M⊙ Star-Forming Main-Sequence (SFMS) galaxies observed so far as part of the MUSE ...Atlas of Disks (MAD). Specifically, we use all strong emission lines in the MUSE wavelength range 4650–9300 Å to investigate the resolved ionized gas properties on ∼100 pc scales. This spatial resolution enables us to disentangle H ii regions from the diffuse ionized gas (DIG) in the computation of gas metallicities and star formation rates (SFRs) of star-forming regions. The gas metallicities generally decrease with radius. The metallicity of the H ii regions is on average ∼0.1 dex higher than that of the DIG, but the metallicity radial gradient in both components is similar. The mean metallicities within the inner galaxy cores correlate with the total stellar mass of the galaxies. On our < 100 pc scales, we find two correlations previously reported at kpc scales: a spatially resolved mass–metallicity relation (RMZR) and a spatially resolved SFMS (RSFMS). We find no secondary dependence of the RMZR with the SFR density. We find that both resolved relations have a local origin, as they do not depend on the total stellar mass. The observational results of this paper are consistent with the inside-out scenario for the growth of galactic disks.
Spectroscopic mapping of planetary nebulae (PNe) is particularly useful to capture the richness in terms of physical and chemical properties that exist in these objects. The advent of the multi-unit ...spectroscopic explorer (MUSE), a large integral field unit mounted on the ESO Very Large Telescope, allow us to obtain this information over the whole face of galactic PNe in a reasonable amount of time. This in turn reveals a wealth of information that can bring insight into this structural complexity. Here we discuss new results from commissioning data for the physical properties of IC 418 and succinctly review recently published results on two additional targets (NGC 3132 and NGC 7009). For the newly-analysed PN, electron densities are high with ne(S ii) displaying a completely different structure than ne(Cl iii). The electron temperature was relatively uniform, but somewhat higher at the rim as measured by two of the three used diagnostics (S iii 6312/9069, and Ar iii 5192/7136). The joint results for the three PNe amply illustrate the potential of MUSE for the study of galactic PNe.
The Antennae galaxy (NGC 4038/39) is the closest major interacting galaxy system and is therefore often studied as a merger prototype. We present the first comprehensive integral field spectroscopic ...dataset of this system, observed with the MUSE instrument at the ESO VLT. We cover the two regions in this system which exhibit recent star formation: the central galaxy interaction and a region near the tip of the southern tidal tail. In these fields, we detect HII regions and diffuse ionized gas to unprecedented depth. About 15% of the ionized gas was undetected by previous observing campaigns. This newly detected faint ionized gas is visible everywhere around the central merger, and shows filamentary structure. We estimate diffuse gas fractions of about 60% in the central field and 10% in the southern region. We are able to show that the southern region contains a significantly different population of HII regions, showing fainter luminosities. By comparing HII region luminosities with the HST catalog of young star clusters in the central field, we estimate that there is enough Lyman-continuum leakage in the merger to explain the amount of diffuse ionized gas that we detect. We compare the Lyman-continuum escape fraction of each HII region against emission line ratios that are sensitive to the ionization parameter. While we find no systematic trend between these properties, the most extreme line ratios seem to be strong indicators of density bounded ionization. Extrapolating the Lyman-continuum escape fractions to the southern region, we conclude that simply from the comparison of the young stellar populations to the ionized gas there is no need to invoke other ionization mechanisms than Lyman-continuum leaking HII regions for the diffuse ionized gas in the Antennae.
A MUSE map of the central Orion Nebula (M 42) Weilbacher, Peter M.; Monreal-Ibero, Ana; Kollatschny, Wolfram ...
Astronomy and astrophysics (Berlin),
10/2015, Letnik:
582
Journal Article
Recenzirano
Odprti dostop
We present a new integral field spectroscopic dataset of the central part of the Orion Nebula (M 42), observed with the MUSE instrument at the ESO VLT. We reduced the data with the public MUSE ...pipeline. The output products are two FITS cubes with a spatial size of ~5.́9×4.́9 (corresponding to ~0.76 × 0.63 pc2) and a contiguous wavelength coverage of 4595...9366 Å, spatially sampled at 0.́2. We provide two versions with a sampling of 1.25 Å and 0.85 Å in dispersion direction. Together with variance cubes these files have a size of 75 and 110 GiB on disk. They are the largest integral field mosaics to date in terms of information content. We make them available for use in the community. To validate this dataset, we compare world coordinates, reconstructed magnitudes, velocities, and absolute and relative emission line fluxes to the literature values and find excellent agreement. We derive a 2D map of extinction and present de-reddened flux maps of several individual emission lines and of diagnostic line ratios. We estimate physical properties of the Orion Nebula, using the emission line ratios N ii and S iii (for the electron temperature Te) and S ii and Cl iii (for the electron density Ne), and show 2D images of the velocity measured from several bright emission lines.
The Multi-Unit Spectroscopic Explorer (MUSE) is a large integral field unit mounted on the ESO Very Large Telescope. Its spatial (60 arcsecond field) and wavelength (4800–9300Å) coverage is well ...suited to detailed imaging spectroscopy of extended planetary nebulae, such as in the Galaxy. An overview of the capabilities of MUSE applied to Planetary Nebulae (PNe) is provided together with the specific advantages and disadvantages. Some examples of archival MUSE observations of PNe are provided. MUSE datacubes for two targets (NGC 3132 and NGC 7009) are analyzed in detail, and they are used to show the advances achievable for planetary nebula studies. Prospects for further MUSE observations of PNe and a broader analysis of existing datasets are outlined.
Until now, spatially resolved Raman Spectroscopy has required to scan a sample under investigation in a time-consuming step-by-step procedure. Here, we present a technique that allows the capture of ...an entire Raman image with only one single exposure. The Raman scattering arising from the sample was collected with a fiber-coupled high-performance astronomy spectrograph. The probe head consisting of an array of 20 × 20 multimode fibers was linked to the camera port of a microscope. To demonstrate the high potential of this new concept, Raman images of reference samples were recorded. Entire chemical maps were received without the need for a scanning procedure.
Aims. As a new approach to the study of resolved stellar populations in nearby galaxies, our goal is to demonstrate with a pilot study in NGC 300 that integral field spectroscopy with high spatial ...resolution and excellent seeing conditions reaches an unprecedented depth in severely crowded fields. Methods. Observations by MUSE with seven pointings in NGC 300 have resulted in data cubes that are analyzed in four ways: (1) Point spread function-fitting 3D spectroscopy with PampelMUSE, as already successfully pioneered in globular clusters, yields de-blended spectra of individually distinguishable stars, thus providing a complete inventory of blue and red supergiants, and asymptotic giant branch (AGB) stars of type M and C. The technique is also applicable to emission line point sources and provides samples of planetary nebulae (PNe) that are complete down to m5007 = 28. (2) Pseudo-monochromatic images, created at the wavelengths of the most important emission lines and corrected for continuum light with the P3D visualization tool, provide maps of H II regions, supernova remnants (SNR), and the diffuse interstellar medium (ISM) at a high level of sensitivity, where also faint point sources stand out and allow for the discovery of PNe, Wolf–Rayet (WR) stars, etc. (3) The use of the P3D line-fitting tool yields emission line fluxes, surface brightness, and kinematic information for gaseous objects, corrected for absorption line profiles of the underlying stellar population in the case of Hα. (4) Visual inspection of the data cubes by browsing through the row-stacked spectra image in P3D is demonstrated to be efficient for data mining and the discovery of background galaxies and unusual objects. Results. We present a catalog of luminous stars, rare stars such as WR, and other emission line stars, carbon stars, symbiotic star candidates, PNe, H II regions, SNR, giant shells, peculiar diffuse and filamentary emission line objects, and background galaxies, along with their spectra. Conclusions. The technique of crowded-field 3D spectroscopy, using the PampelMUSE code, is capable of deblending individual bright stars, the unresolved background of faint stars, gaseous nebulae, and the diffuse component of the ISM, resulting in unprecedented legacy value for observations of nearby galaxies with MUSE.
We present results of integral field optical spectroscopy of five luminous blue compact dwarf galaxies. The data were obtained using the fiber system INTEGRAL attached to the William Herschel ...Telescope. The galaxies Mrk 370, Mrk 35, Mrk 297, Mrk 314, and III Zw 102 were observed. The central image regions of the galaxies were mapped with a spatial resolution of 2.7 super(image ) spaxelimage, except for Mrk 314, in which we observed the central image region with a resolution of 0.9 super(image ) spaxelimage. We use high-resolution optical images to isolate the star-forming knots in the objects; line ratios, electron densities, and oxygen abundances in each of these regions are computed. We build continuum and emission-line intensity maps, as well as maps of the most relevant line ratios: O iii image /image, N ii image /image, and image /image, which allow us to obtain spatial information on the ionization structure and mechanisms. We also derive the gas velocity field from the image and O iii image emission lines. We find that all five galaxies are in the high end of the metallicity range of blue compact dwarfs with oxygen abundances varying from image to 1.5 Z sub(image). The objects show H ii-like ionization in the whole field of view, except the outer regions of III Zw 102, whose large N ii image /image values suggest the presence of shocks. The five galaxies display inhomogeneous extinction patterns, and three of them have high image /image ratios, indicative of a large dust content; all of the galaxies display complex, irregular velocity fields in their inner regions.
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