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- ItemMUSE crowded field 3D spectroscopy in NGC 300: III. Characterizing extremely faint HII regions and diffuse ionized gas(Les Ulis : EDP Sciences, 2022) Micheva, Genoveva; Roth, Martin M.; Weilbacher, Peter M.; Morisset, Christophe; Castro, Norberto; Monreal Ibero, Ana; Soemitro, Azlizan A.; Maseda, Michael V.; Steinmetz, Matthias; Brinchmann, JarleContext. There are known differences between the physical properties of H II and diffuse ionized gas (DIG). However, most of the studied regions in the literature are relatively bright, with log10 L(Hα)[erg s-1] ≳37. Aims. We compiled an extremely faint sample of 390 H II regions with a median Hα luminosity of 34.7 in the flocculent spiral galaxy NGC 300, derived their physical properties in terms of metallicity, density, extinction, and kinematics, and performed a comparative analysis of the properties of the DIG. Methods. We used MUSE data of nine fields in NGC 300, covering a galactocentric distance of zero to ~450 arcsec (~4 projected kpc), including spiral arm and inter-arm regions. We binned the data in dendrogram leaves and extracted all strong nebular emission lines. We identified H II and DIG regions and compared their electron densities, metallicity, extinction, and kinematic properties. We also tested the effectiveness of unsupervised machine-learning algorithms in distinguishing between the H II and DIG regions. Results. The gas density in the H II and DIG regions is close to the low-density limit in all fields. The average velocity dispersion in the DIG is higher than in the H II regions, which can be explained by the DIG being 1.8 kK hotter than H II gas. The DIG manifests a lower ionization parameter than H II gas, and the DIG fractions vary between 15-77%, with strong evidence of a contribution by hot low-mass evolved stars and shocks to the DIG ionization. Most of the DIG is consistent with no extinction and an oxygen metallicity that is indistinguishable from that of the H II gas. We observe a flat metallicity profile in the central region of NGC 300, without a sign of a gradient. Conclusions. The differences between extremely faint H II and DIG regions follow the same trends and correlations as their much brighter cousins. Both types of objects are so heterogeneous, however, that the differences within each class are larger than the differences between the two classes.
- ItemMUSE crowded field 3D spectroscopy in NGC 300 : I. First results from central fields(Les Ulis : EDP Sciences, 2018) Roth, Martin M.; Sandin, Christer; Kamann, Sebastian; Husser, Tim-Oliver; Weilbacher, Peter M.; Monreal-Ibero, Ana; Bacon, Roland; den Brok, Mark; Dreizler, Stefan; Kelz, Andreas; Marino, Raffaella Anna; Steinmetz, MatthiasAims. 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 HâII 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, HâII 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.
- ItemAn atlas of MUSE observations towards twelve massive lensing clusters(Les Ulis : EDP Sciences, 2021) Richard, Johan; Claeyssens, Adélaïde; Lagattuta, David; Guaita, Lucia; Bauer, Franz Erik; Pello, Roser; Carton, David; Bacon, Roland; Soucail, Geneviève; Lyon, Gonzalo Prieto; Kneib, Jean-Paul; Mahler, Guillaume; Clément, Benjamin; Mercier, Wilfried; Variu, Andrei; Tamone, Amélie; Ebeling, Harald; Schmidt, Kasper B.; Nanayakkara, Themiya; Maseda, Michael; Weilbacher, Peter M.; Bouché, Nicolas; Bouwens, Rychard J.; Wisotzki, Lutz; de la Vieuville, Geoffroy; Martinez, Johany; Patrício, VeraContext. Spectroscopic surveys of massive galaxy clusters reveal the properties of faint background galaxies thanks to the magnification provided by strong gravitational lensing. Aims. We present a systematic analysis of integral-field-spectroscopy observations of 12 massive clusters, conducted with the Multi Unit Spectroscopic Explorer (MUSE). All data were taken under very good seeing conditions (~0".6) in effective exposure times between two and 15 h per pointing, for a total of 125 h. Our observations cover a total solid angle of ~23 arcmin2 in the direction of clusters, many of which were previously studied by the MAssive Clusters Survey, Frontier Fields (FFs), Grism Lens-Amplified Survey from Space and Cluster Lensing And Supernova survey with Hubble programmes. The achieved emission line detection limit at 5? for a point source varies between (0.77-1.5) × 10-18 erg s-1 cm-2 at 7000 Å. Methods. We present our developed strategy to reduce these observational data, detect continuum sources and line emitters in the datacubes, and determine their redshifts. We constructed robust mass models for each cluster to further confirm our redshift measurements using strong-lensing constraints, and identified a total of 312 strongly lensed sources producing 939 multiple images. Results. The final redshift catalogues contain more than 3300 robust redshifts, of which 40% are for cluster members and ∼30% are for lensed Lyman-α emitters. Fourteen percent of all sources are line emitters that are not seen in the available HST images, even at the depth of the FFs (∼29 AB). We find that the magnification distribution of the lensed sources in the high-magnification regime (μ = 2–25) follows the theoretical expectation of N(z) ∝ μ−2. The quality of this dataset, number of lensed sources, and number of strong-lensing constraints enables detailed studies of the physical properties of both the lensing cluster and the background galaxies. The full data products from this work, including the datacubes, catalogues, extracted spectra, ancillary images, and mass models, are made available to the community.
- ItemThe MUSE Extremely Deep Field: The cosmic web in emission at high redshift(Les Ulis : EDP Sciences, 2021) Bacon, Roland; Mary, David; Garel, Thibault; Blaizot, Jeremy; Maseda, Michael; Schaye, Joop; Wisotzki, Lutz; Conseil, Simon; Brinchmann, Jarle; Leclercq, Floriane; Abril-Melgarejo, Valentina; Boogaard, Leindert; Bouché, Nicolas; Contini, Thierry; Feltre, Anna; Guiderdoni, Bruno; Herenz, Christian; Kollatschny, Wolfram; Kusakabe, Haruka; Matthee, Jorryt; Michel-Dansac, Léo; Nanayakkara, Themiya; Richard, Johan; Roth, Martin; Schmidt, Kasper B.; Steinmetz, Matthias; Tresse, Laurence; Urrutia, Tanya; Verhamme, Anne; Weilbacher, Peter M.; Zabl, Johannes; Zoutendijk, Sebastiaan L.We report the discovery of diffuse extended Lyα emission from redshift 3.1 to 4.5, tracing cosmic web filaments on scales of 2.5-4 cMpc. These structures have been observed in overdensities of Lyα emitters in the MUSE Extremely Deep Field, a 140 h deep MUSE observation located in the Hubble Ultra-Deep Field. Among the 22 overdense regions identified, five are likely to harbor very extended Lyα emission at high significance with an average surface brightness of 5 × 10-20 erg s-1 cm-2 arcsec-2. Remarkably, 70% of the total Lyα luminosity from these filaments comes from beyond the circumgalactic medium of any identified Lyα emitter. Fluorescent Lyα emission powered by the cosmic UV background can only account for less than 34% of this emission at z ≈ 3 and for not more than 10% at higher redshift. We find that the bulk of this diffuse emission can be reproduced by the unresolved Lyα emission of a large population of ultra low-luminosity Lyα emitters (< 1040 erg s-1), provided that the faint end of the Lyα luminosity function is steep (α ⪅ -1.8), it extends down to luminosities lower than 1038 - 1037 erg s-1, and the clustering of these Lyα emitters is significant (filling factor < 1/6). If these Lyα emitters are powered by star formation, then this implies their luminosity function needs to extend down to star formation rates < 10-4M yr-1. These observations provide the first detection of the cosmic web in Lyα emission in typical filamentary environments and the first observational clue indicating the existence of a large population of ultra low-luminosity Lyα emitters at high redshift. © R. Bacon et al. 2021.
- ItemThe MUSE Hubble Ultra Deep Field surveys: Data release II(Les Ulis : EDP Sciences, 2023) Bacon, Roland; Brinchmann, Jarle; Conseil, Simon; Maseda, Michael; Nanayakkara, Themiya; Wendt, Martin; Bacher, Raphael; Mary, David; Weilbacher, Peter M.; Krajnović, Davor; Boogaard, Leindert; Bouché, Nicolas; Contini, Thierry; Epinat, Benoît; Feltre, Anna; Guo, Yucheng; Herenz, Christian; Kollatschny, Wolfram; Kusakabe, Haruka; Leclercq, Floriane; Michel-Dansac, Léo; Pello, Roser; Richard, Johan; Roth, Martin; Salvignol, Gregory; Schaye, Joop; Steinmetz, Matthias; Tresse, Laurence; Urrutia, Tanya; Verhamme, Anne; Vitte, Eloise; Wisotzki, Lutz; Zoutendijk, Sebastiaan L.We present the second data release of the MUSE Hubble Ultra-Deep Field surveys, which includes the deepest spectroscopic survey ever performed. The MUSE data, with their 3D content, amazing depth, wide spectral range, and excellent spatial and medium spectral resolution, are rich in information. Their location in the Hubble ultra-deep field area, which benefits from an exquisite collection of ancillary panchromatic information, is a major asset. This update of the first release incorporates a new 141-h adaptive-optics-assisted MUSE eXtremely Deep Field (MXDF; 1 arcmin diameter field of view) in addition to the reprocessed 10-h mosaic (3 × 3 arcmin2) and the single 31-h deep field (1 × 1 arcmin2). All three data sets were processed and analyzed homogeneously using advanced data reduction and analysis methods. The 3σ point-source flux limit of an unresolved emission line reaches 3.1 × 10-19 and 6.3 × 10-20 erg s-1 cm-2 at 10-and 141-h depths, respectively. We have securely identified and measured the redshift of 2221 sources, an increase of 41% compared to the first release. With the exception of eight stars, the collected sample consists of 25 nearby galaxies (z < 0.25), 677 [O II] emitters (z = 0.25-1.5), 201 galaxies in the MUSE redshift desert range (z = 1.5-2.8), and 1308 Lyα emitters (z = 2.8-6.7). This represents an order of magnitude more redshifts than the collection of all spectroscopic redshifts obtained before MUSE in the Hubble ultra-deep field area (i.e., 2221 versus 292). At high redshift (z > 3), the difference is even more striking, with a factor of 65 increase (1308 versus 20). We compared the measured redshifts against three published photometric redshift catalogs and find the photo-z accuracy to be lower than the constraints provided by photo-z fitting codes. Eighty percent of the galaxies in our final catalog have an HST counterpart. These galaxies are on average faint, with a median AB F775W magnitude of 25.7 and 28.7 for the [O II] and Lyα emitters, respectively. Fits of their spectral energy distribution show that these galaxies tend to be low-mass star-forming galaxies, with a median stellar mass of 6.2 × 108 M· and a median star-formation rate of 0.4 M· yr-1. We measured the completeness of our catalog with respect to HST and found that, in the deepest 141-h area, 50% completeness is achieved for an AB magnitude of 27.6 and 28.7 (F775W) at z = 0.8-1.6 and z = 3.2-4.5, respectively. Twenty percent of our catalog, or 424 galaxies, have no HST counterpart. The vast majority of these new sources are high equivalent-width z > 2.8 Lyα emitters that are detected by MUSE thanks to their bright and asymmetric broad Lyα line. We release advanced data products, specific software, and a web interface to select and download data sets.
- ItemCross-checking SMBH mass estimates in NGC 6958-I. Stellar dynamics from adaptive optics-Assisted MUSE observations(Oxford : Oxford Univ. Press, 2021) Thater, Sabine; Krajnović, Davor; Weilbacher, Peter M.; Nguyen, Dieu D.; Bureau, Martin; Cappellari, Michele; Davis, Timothy A.; Iguchi, Satoru; McDermid, Richard; Onishi, Kyoko; Sarzi, Marc; van de Ven, GlennSupermassive black hole masses ( M BH ) can dynamically be estimated with various methods and using different kinematic tracers. Different methods have only been cross-checked for a small number of galaxies and often show discrepancies. To understand these discrepancies, detailed cross-comparisons of additional galaxies are needed. We present the first part of our cross-comparison between stellar-And gas-based M BH estimates in the nearby fast-rotating early-Type galaxy NGC 6958. The measurements presented here are based on ground-layer adaptive optics-Assisted Multi-Unit Spectroscopic Explorer (MUSE) science verification data at around 0 . 6 spatial resolution. The spatial resolution is a key ingredient for the measurement and we provide a Gaussian parametrization of the adaptive optics-Assisted point spread function for various wavelengths. From the MUSE data, we extracted the stellar kinematics and constructed dynamical models. Using an axisymmetric Schwarzschild technique, we measured an M BH of (3 . 6 + 2 . 7-2 . 4 ) × 10 8 M at 3 significance taking kinematical and dynamical systematics (e.g. radially varying mass-To-light ratio) into account. We also added a dark halo, but our data do not allow us to constrain the dark matter fraction. Adding dark matter with an abundance matching prior results in a 25 per cent more massive black hole. Jeans anisotropic models return M BH of (4 . 6 + 2 . 5-2 . 7 ) × 10 8 and (8 . 6 + 0 . 8-0 . 8 ) × 10 8 M at 3 confidence for spherical and cylindrical alignments of the velocity ellipsoid, respectively. In a follow-up study, we will compare the stellar-based M BH with those from cold and warm gas tracers, which will provide additional constraints for the M BH for NGC 6958, and insights into assumptions that lead to potential systematic uncertainty.
- ItemResolving stellar populations with integral field spectroscopy(Berlin : Wiley-VCH Verl., 2019) Roth, Martin M.; Weilbacher, Peter M.; Castro, NorbertoHigh-performance instruments at large ground-based telescopes have made integral field spectroscopy (IFS) a powerful tool for the study of extended objects such as galaxies, nebulae, or even larger survey fields on the sky. Here, we discuss the capabilities of IFS for the study of resolved stellar populations, using the newmethod of point-spread-function-fitting crowded field IFS, analogous to the well-established technique of crowded field photometry with image sensors.We review early pioneering work with first-generation integral field spectrographs, the breakthrough achieved with the multiunit spectral explorer (MUSE) instrument at the European Organisation for Astronomical Research in the Southern Hemisphere (ESO)Very Large Telescope, the remarkable progress accomplished with MUSE in the study of globular clusters, and first results on nearby galaxies. We discuss the synergy of integral field spectrographs at 8–10 mclass telescopes with future facilities such as the extremely large telescope (ELT).
- ItemLatitudinal variation in the abundance of methane (CH4) above the clouds in Neptune's atmosphere from VLT/MUSE Narrow Field Mode Observations(Orlando, Fla. : Academ. Press, 2019) Irwin, Patrick G.J.; Toledo, Daniel; Braude, Ashwin S.; Bacon, Roland; Weilbacher, Peter M.; Teanby, Nicholas A.; Fletcher, Leigh N.; Orton, Glenn S.Observations of Neptune, made in 2018 using the new Narrow Field Adaptive Optics mode of the Multi Unit Spectroscopic Explorer (MUSE) instrument at the Very Large Telescope (VLT) from 0.48 to 0.93 μm, are analysed here to determine the latitudinal and vertical distribution of cloud opacity and methane abundance in Neptune's observable troposphere (0.1–∼ 3bar). Previous observations at these wavelengths in 2003 by HST/STIS (Karkoschka and Tomasko 2011, Icarus 205, 674–694) found that the mole fraction of methane above the cloud tops (at ∼ 2 bar) varied from ∼ 4% at equatorial latitudes to ∼ 2% at southern polar latitudes, by comparing the observed reflectivity at wavelengths near 825 nm controlled primarily by either methane absorption or H2–H2/H2–He collision-induced absorption. We find a similar variation in cloud-top methane abundance in 2018, which suggests that this depletion of methane towards Neptune's pole is potentially a long-lived feature, indicative of long-term upwelling at mid-equatorial latitudes and subsidence near the poles. By analysing these MUSE observations along the central meridian with a retrieval model, we demonstrate that a broad boundary between the nominal and depleted methane abundances occurs at between 20 and 40°S. We also find a small depletion of methane near the equator, perhaps indicating subsidence there, and a local enhancement near 60–70°S, which we suggest may be associated with South Polar Features (SPFs) seen in Neptune's atmosphere at these latitudes. Finally, by the use of both a reflectivity analysis and a principal component analysis, we demonstrate that this depletion of methane towards the pole is apparent at all locations on Neptune's disc, and not just along its central meridian.