TY - JOUR A1 - Zabl, Johannes A1 - Bouche, Nicolas F. A1 - Schroetter, Ilane A1 - Wendt, Martin A1 - Finley, Hayley A1 - Schaye, Joop A1 - Conseil, Simon A1 - Contini, Thierry A1 - Marino, Raffaella Anna A1 - Mitchell, Peter A1 - Muzahid, Sowgat A1 - Pezzulli, Gabriele A1 - Wisotzki, Lutz T1 - MusE GAs FLOw and Wind (MEGAFLOW) BT - II. A study of gas accretion around z approximate to 1 star-forming galaxies with background quasars JF - Monthly notices of the Royal Astronomical Society N2 - We use the MusE GAs FLOw and Wind (MEGAFLOW) survey to study the kinematics of extended disc-like structures of cold gas around z approximate to 1 star-forming galaxies. The combination of VLT/MUSE and VLT/UVES observations allows us to connect the kinematics of the gas measured through MgII quasar absorption spectroscopy to the kinematics and orientation of the associated galaxies constrained through integral field spectroscopy. Confirming previous results, we find that the galaxy-absorber pairs of the MEGAFLOW survey follow a strong bimodal distribution, consistent with a picture of MgII absorption being predominantly present in outflow cones and extended disc-like structures. This allows us to select a bona-fide sample of galaxy-absorber pairs probing these discs for impact paramometers of 10-70 kpc. We test the hypothesis that the disc-like gas is co-rotating with the galaxy discs, and find that for seven out of nine pairs the absorption velocity shares the sign of the disc velocity, disfavouring random orbits. We further show that the data are roughly consistent with inflow velocities and angular momenta predicted by simulations, and that the corresponding mass accretion rates are sufficient to balance the star formation rates. KW - galaxies: evolution KW - galaxies: formation KW - galaxies: haloes KW - galaxies: kinematics and dynamics KW - quasars: absorption lines Y1 - 2019 U6 - https://doi.org/10.1093/mnras/stz392 SN - 0035-8711 SN - 1365-2966 VL - 485 IS - 2 SP - 1961 EP - 1980 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Wucknitz, Olaf A1 - Wisotzki, Lutz A1 - Lopez, S. A1 - Gregg, M. D. T1 - Disentangling microlensing and differential extinction in the double QSO HE 0512-3329 N2 - We present the first separate spectra of both components of the small-separation double QSO HE 0512-3329 obtained with HST/STIS in the optical and near UV. The similarities especially of the emission line profiles and redshifts strongly suggest that this system really consists of two lensed images of one and the same source. The emission line flux ratios are assumed to be unaffected by microlensing and are used to study the differential extinction effects caused by the lensing galaxy. Fits of empirical laws show that the extinction properties seem to be different on both lines of sight. With our new results, HE 0512-3329 becomes one of the few extragalactic systems which show the 2175 Å absorption feature, although the detection is only marginal. We then correct the continuum flux ratio for extinction to obtain the differential microlensing signal. Since this may still be significantly affected by variability and time-delay effects, no detailled analysis of the microlensing is possible at the moment. This is the first time that differential extinction and microlensing could be separated unambiguously. We show that, at least in HE 0512-3329, both effects contribute significantly to the spectral differences and one cannot be analysed without taking into account the other. For lens modelling purposes, the flux ratios can only be used after correcting for both effects. Y1 - 2003 ER - TY - JOUR A1 - Worseck, Gabor A1 - Prochaska, J. Xavier A1 - McQuinn, Matthew A1 - Dall'Aglio, Aldo A1 - Fechner, Cora A1 - Hennawi, Joseph F. A1 - Reimers, Dieter A1 - Richter, Philipp A1 - Wisotzki, Lutz T1 - The end of Helium Reionization at z similar or equal to 2.7 Inferred from cosmic variance in HST/COS He II Ly alpha Absorption spectra JF - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters N2 - We report on the detection of strongly varying intergalactic He II absorption in HST/COS spectra of two z(em) similar or equal to 3 quasars. From our homogeneous analysis of the He II absorption in these and three archival sightlines, we find a marked increase in the mean He II effective optical depth from similar or equal to 1 at z similar or equal to 2.3 to greater than or similar to 5 at z similar or equal to 3.2, but with a large scatter of 2 less than or similar to tau(eff, He II) less than or similar to 5 at 2.7 < z < 3 on scales of similar to 10 proper Mpc. This scatter is primarily due to fluctuations in the He II fraction and the He II-ionizing background, rather than density variations that are probed by the coeval Hi forest. Semianalytic models of He II absorption require a strong decrease in the He II-ionizing background to explain the strong increase of the absorption at z greater than or similar to 2.7, probably indicating He II reionization was incomplete at z(reion) greater than or similar to 2.7. Likewise, recent three-dimensional numerical simulations of He II reionization qualitatively agree with the observed trend only if He II reionization completes at z(reion) similar or equal to 2.7 or even below, as suggested by a large tau(eff, He II) greater than or similar to 3 in two of our five sightlines at z < 2.8. By doubling the sample size at 2.7 less than or similar to z less than or similar to 3, our newly discovered He II sightlines for the first time probe the diversity of the second epoch of reionization when helium became fully ionized. KW - dark ages, reionization, first stars KW - diffuse radiation KW - intergalactic medium KW - quasars: absorption lines KW - quasars: individual (SDSS J092447.36+485242.8, SDSS J110155.74+105302.3) Y1 - 2011 U6 - https://doi.org/10.1088/2041-8205/733/2/L24 SN - 2041-8205 VL - 733 IS - 2 PB - IOP Publ. Ltd. CY - Bristol ER - TY - JOUR A1 - Wolf, C. A1 - Wisotzki, Lutz A1 - Borch, Andrea A1 - Dye, S. A1 - Kleinheinrich, M. A1 - Meisenheimer, Klaus T1 - The evolution of faint AGN between z similar or equal to 1 and z similar or equal to 5 from the COMBO-17 survey N2 - We present a determination of the optical/UV AGN luminosity function and its evolution, based on a large sample of faint (R < 24) QSOs identified in the COMBO-17 survey. Using multi-band photometry in 17 filters within 350 nm <~ lambdaobs <~ 930 nm, we could simultaneously determine photometric redshifts with an accuracy of sigmaz <0.03 and obtain spectral energy distributions. The redshift range covered by the sample is 1.2 < z < 4.8, which implies that even at z =~ 3, the sample reaches below luminosities corresponding to MB = -23, conventionally employed to distinguish between Seyfert galaxies and quasars. We clearly detect a broad plateau-like maximum of quasar activity around z =~ 2 and map out the smooth turnover between z =~ 1 and z =~ 4. The shape of the LF is characterised by some mild curvature, but no sharp ``break'' is present within the range of luminosities covered. Using only the COMBO-17 data, the evolving LF can be adequately described by either a pure density evolution (PDE) or a pure luminosity evolution (PLE) model. However, the absence of a strong L*-like feature in the shape of the LF inhibits a robust distinction between these modes. We present a robust estimate for the integrated UV luminosity generation by AGN as a function of redshift. We find that the LF continues to rise even at the lowest luminosities probed by our survey, but that the slope is sufficiently shallow that the contribution of low-luminosity AGN to the UV luminosity density is negligible. Although our sample reaches much fainter flux levels than previous data sets, our results on space densities and LF slopes are completely consistent with extrapolations from recent major surveys such as SDSS and 2QZ. Y1 - 2003 ER - TY - JOUR A1 - Wolf, C. A1 - Dye, S. A1 - Kleinheinrich, M. A1 - Meisenheimer, Klaus A1 - Rix, Hans-Walter A1 - Wisotzki, Lutz T1 - Deep BVR photometry of the Chandra Deep Field South from the COMBO-17 survey N2 - We report on deep multi-color imaging (R5sigma = 26) of the Chandra Deep Field South, obtained with the Wide Field Imager (WFI) at the MPG/ESO 2.2 m telescope on La Silla as part of the multi-color survey COMBO-17. As a result we present a catalogue of 63 501 objects in a field measuring 31farcm5 x 30arcmin with astrometry and BVR photometry. A sample of 37 variable objects is selected from two-epoch photometry. We try to give interpretations based on color and variation amplitude. Y1 - 2001 ER - TY - JOUR A1 - Wisotzki, Lutz A1 - Schechter, P. L. A1 - Chen, H. W. A1 - Richstone, D. A1 - Jahnke, Knud A1 - Sanchez, Sebastian F. A1 - Reimers, Dieter T1 - HE 0047-1756 : a new gravitationally lensed double QSO N2 - The quasar HE 0047-1756, at z = 1.67, is found to be split into two images 1."144 apart by an intervening galaxy acting as a gravitational lens. The flux ratio for the two components is roughly 3.5:1, depending slightly upon wavelength. The lensing galaxy is seen on images obtained in the i (800 nm) and K-s bands (2.1 mum); there is also a nearby faint object which may be responsible for some shear. The spectra of the two quasar images are nearly identical, but the emission line ratio between the two components scale differently from the continuum. Moreover, the fainter component has a bluer continuum slope than the brighter one. We argue that these small differences are probably due to microlensing. There is evidence for a partial Einstein ring emanating from the brighter image toward the fainter one Y1 - 2004 SN - 0004-6361 ER - TY - JOUR A1 - Wisotzki, Lutz A1 - Schechter, P. L. A1 - Bradt, H. V. A1 - Heinmüller, Janine A1 - Reimers, Dieter T1 - HE 0435-1223 : a wide separation quadruple QSO and gravitational lens N2 - We report the discovery of a new gravitationally lensed QSO, at a redshift z = 1.689, with four QSO components in a cross-shaped arrangement around a bright galaxy. The maximum separation between images is 2farcs 6, enabling a reliable decomposition of the system. Three of the QSO components have g =~ 19.6, while component A is about 0.6 mag brighter. The four components have nearly identical colours, suggesting little if any dust extinction in the foreground galaxy. The lensing galaxy is prominent in the i band, weaker in r and not detected in g. Its spatial profile is that of an elliptical galaxy with a scale length of ~ 12 kpc. Combining the measured colours and a mass model for the lens, we estimate a most likely redshift range of 0.3 < z < 0.4. Predicted time delays between the components are la 10 days. The QSO shows evidence for variability, with total g band magnitudes of 17.89 and 17.71 for two epochs separated by ~ 2 months. However, the relative fluxes of the components did not change, indicating that the variations are intrinsic to the QSO rather than induced by microlensing. Based in part on observations obtained with the Baade 6.5-m telescope of the Magellan Consortium. Also based in part on observations collected at the European Southern Observatory, La Silla, Chile. Y1 - 2002 ER - TY - JOUR A1 - Wisotzki, Lutz A1 - Kuhlbrodt, B. A1 - Jahnke, Knud T1 - The luminosity function of QSO host galaxies Y1 - 2001 SN - 0-306-46662-7 ER - TY - JOUR A1 - Wisotzki, Lutz A1 - Christlieb, N. A1 - Liu, M. C. A1 - Maza, J. A1 - Morgan, N. D. A1 - Schechter, P. L. T1 - Discovery of a New Multiple Gravitationally Lensed QSO Y1 - 2001 SN - 1-583-81074-9 ER - TY - JOUR A1 - Wisotzki, Lutz A1 - Becker, Thomas A1 - Christensen, Lise Bech A1 - Jahnke, Knud A1 - Helms, Andreas A1 - Kelz, A. A1 - Roth, Martin M. A1 - Sanchez, Sebastian F. T1 - Integral field spectrophotometry of gravitationally lensed QSOs with PMAS N2 - We present spatially resolved spectrophotometric observations of multiply imaged QSOs, using the Potsdam Multi- Aperture Spectrophotometer (PMAS), with the intention to search for spectral differences between components indicative of either microlensing or dust extinction. For the quadruple QSO HE 0435-1223 we find that the continuum shapes are indistinguishable, therefore differential extinction is negligible. The equivalent widths of the broad emission lines are however significantly different, and we argue that this is most likely due to microlensing. Contrariwise, the two components of the well-known object UM 673 have virtually identical emission line properties, but the continuum slopes differ significantly and indicate different dust extinction along both lines of sight Y1 - 2004 SN - 0004-6337 ER - TY - JOUR A1 - Wisotzki, Lutz A1 - Becker, Thomas A1 - Christensen, Lise Bech A1 - Helms, Andreas A1 - Jahnke, Knud A1 - Kelz, A. A1 - Roth, Martin M. A1 - Sanchez, Sebastian F. T1 - Integral-field spectrophotometry of the quadruple QSO HE 0435-1223 : Evidence for microlensing N2 - We present the first spatially resolved spectroscopic observations of the recently discovered quadruple QSO and gravitational lens HE 0435-1223. Using the Potsdam Multi-Aperture Spectrophotometer (PMAS), we show that all four QSO components have very similar but not identical spectra. In particular, the spectral slopes of components A, B, and D are indistinguishable, implying that extinction due to dust plays no major role in the lensing galaxy. While also the emission line profiles are identical within the error bars, as expected from lensing, the equivalent widths show significant differences between components. Most likely, microlensing is responsible for this phenomenon. This is also consistent with the fact that component D, which shows the highest relative continuum level, has brightened by 0.07 mag since Dec. 2001. We find that the emission line flux ratios between the components are in better agreement with simple lens models than broad band or continuum measurements, but that the discrepancies between model and data are still unacceptably large. Finally, we present a detection of the lensing galaxy, although this is close to the limits of the data. Comparing with a model galaxy spectrum, we obtain a redshift estimate of zlens=0.44+/- 0.02. Y1 - 2003 ER - TY - JOUR A1 - Wisotzki, Lutz A1 - Bacon, Roland A1 - Blaizot, J. A1 - Brinchmann, Jarle A1 - Herenz, Edmund Christian A1 - Schaye, Joop A1 - Bouche, Nicolas A1 - Cantalupo, Sebastiano A1 - Contini, Thierry A1 - Carollo, C. M. A1 - Caruana, Joseph A1 - Courbot, J. -B. A1 - Emsellem, E. A1 - Kamann, S. A1 - Kerutt, Josephine Victoria A1 - Leclercq, F. A1 - Lilly, S. J. A1 - Patricio, V. A1 - Sandin, C. A1 - Steinmetz, Matthias A1 - Straka, Lorrie A. A1 - Urrutia, Tanya A1 - Verhamme, A. A1 - Weilbacher, Peter Michael A1 - Wendt, Martin T1 - Extended Lyman alpha haloes around individual high-redshift galaxies revealed by MUSE JF - Science N2 - We report the detection of extended Ly alpha emission around individual star-forming galaxies at redshifts z = 3-6 in an ultradeep exposure of the Hubble Deep Field South obtained with MUSE on the ESO-VLT. The data reach a limiting surface brightness (1 sigma) of similar to 1 x 10(-19) erg s(-1) cm(-2) arcsec(-2) in azimuthally averaged radial profiles, an order of magnitude improvement over previous narrowband imaging. Our sample consists of 26 spectroscopically confirmed Ly alpha-emitting, but mostly continuum-faint (m(AB) greater than or similar to 27) galaxies. In most objects the Ly alpha emission is considerably more extended than the UV continuum light. While five of the faintest galaxies in the sample show no significantly detected Ly alpha haloes, the derived upper limits suggest that this is due to insufficient S/N. Ly alpha haloes therefore appear to be ubiquitous even for low-mass (similar to 10(8)-10(9) M-circle dot) star-forming galaxies at z > 3. We decompose the Ly alpha emission of each object into a compact component tracing the UV continuum and an extended halo component, and infer sizes and luminosities of the haloes. The extended Ly alpha emission approximately follows an exponential surface brightness distribution with a scale length of a few kpc. While these haloes are thus quite modest in terms of their absolute sizes, they are larger by a factor of 5-15 than the corresponding rest-frame UV continuum sources as seen by HST. They are also much more extended, by a factor similar to 5, than Ly alpha haloes around low-redshift star-forming galaxies. Between similar to 40% and greater than or similar to 90% of the observed Ly alpha flux comes from the extended halo component, with no obvious correlation of this fraction with either the absolute or the relative size of the Ly alpha halo. Our observations provide direct insights into the spatial distribution of at least partly neutral gas residing in the circumgalactic medium of low to intermediate mass galaxies at z > 3. KW - galaxies: high-redshift KW - galaxies: evolution KW - galaxies: formation KW - cosmology: observations KW - intergalactic medium Y1 - 2016 U6 - https://doi.org/10.1051/0004-6361/201527384 SN - 1432-0746 VL - 587 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Wisotzki, Lutz A1 - Bacon, R. A1 - Brinchmann, J. A1 - Cantalupo, S. A1 - Richter, Philipp A1 - Schaye, J. A1 - Schmidt, Kasper Borello A1 - Urrutia, Tanya A1 - Weilbacher, Peter Michael A1 - Akhlaghi, M. A1 - Bouche, N. A1 - Contini, T. A1 - Guiderdoni, B. A1 - Herenz, E. C. A1 - Inami, H. A1 - Kerutt, Josephine Victoria A1 - Leclercq, F. A1 - Marino, R. A. A1 - Maseda, M. A1 - Monreal-Ibero, A. A1 - Nanayakkara, T. A1 - Richard, J. A1 - Saust, R. A1 - Steinmetz, Matthias A1 - Wendt, Martin T1 - Nearly all the sky is covered by Lyman-alpha emission around high-redshift galaxies JF - Nature : the international weekly journal of science N2 - Galaxies are surrounded by large reservoirs of gas, mostly hydrogen, that are fed by inflows from the intergalactic medium and by outflows from galactic winds. Absorption-line measurements along the lines of sight to bright and rare background quasars indicate that this circumgalactic medium extends far beyond the starlight seen in galaxies, but very little is known about its spatial distribution. The Lyman-alpha transition of atomic hydrogen at a wavelength of 121.6 nanometres is an important tracer of warm (about 104 kelvin) gas in and around galaxies, especially at cosmological redshifts greater than about 1.6 at which the spectral line becomes observable from the ground. Tracing cosmic hydrogen through its Lyman-a emission has been a long-standing goal of observational astrophysics(1-3), but the extremely low surface brightness of the spatially extended emission is a formidable obstacle. A new window into circumgalactic environments was recently opened by the discovery of ubiquitous extended Lyman-alpha emission from hydrogen around high-redshift galaxies(4,5). Such measurements were previously limited to especially favourable systems(6-8) or to the use of massive statistical averaging(9,10) because of the faintness of this emission. Here we report observations of low-surface-brightness Lyman-alpha emission surrounding faint galaxies at redshifts between 3 and 6. We find that the projected sky coverage approaches 100 per cent. The corresponding rate of incidence (the mean number of Lyman-alpha emitters penetrated by any arbitrary line of sight) is well above unity and similar to the incidence rate of high-column-density absorbers frequently detected in the spectra of distant quasars(11-14). This similarity suggests that most circumgalactic atomic hydrogen at these redshifts has now been detected in emission. Y1 - 2018 U6 - https://doi.org/10.1038/s41586-018-0564-6 SN - 0028-0836 SN - 1476-4687 VL - 562 IS - 7726 SP - 229 EP - 232 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Wisotzki, Lutz T1 - The evolution of optically selected QSOs Y1 - 2001 SN - 1-5838-1127-3 ER - TY - JOUR A1 - Wisotzki, Lutz T1 - Luminosity and mass functions of active galactic nuclei Y1 - 2001 SN - 3-540-41581-5 ER - TY - JOUR A1 - Werner, Klaus A1 - Dreizler, S. A1 - Heber, Ulrich A1 - Rauch, Thomas A1 - Wisotzki, Lutz A1 - Hagen, H.-J. T1 - Discovery of two hot DO white dwarfs exhibiting ultrahigh-excitation absorption lines Y1 - 1995 ER - TY - JOUR A1 - Wendt, Martin A1 - Husser, Tim-Oliver A1 - Kamann, Sebastian A1 - Monreal-Ibero, Ana A1 - Richter, Philipp A1 - Brinchmann, Jarle A1 - Dreizler, Stefan A1 - Weilbacher, Peter Michael A1 - Wisotzki, Lutz T1 - Mapping diffuse interstellar bands in the local ISM on small scales via MUSE 3D spectroscopy A pilot study based on globular cluster NGC 6397 JF - Astronomy and astrophysics : an international weekly journal N2 - Context. We map the interstellar medium (ISM) including the diffuse interstellar bands (DIBs) in absorption toward the globular cluster NGC6397 using VLT/MUSE. Assuming the absorbers are located at the rim of the Local Bubble we trace structures on the order of mpc (milliparsec, a few thousand AU). Aims. We aimed to demonstrate the feasibility to map variations of DIBs on small scales with MUSE. The sightlines defined by binned stellar spectra are separated by only a few arcseconds and we probe the absorption within a physically connected region. Methods. This analysis utilized the fitting residuals of individual stellar spectra of NGC6397 member stars and analyzed lines from neutral species and several DIBs in Voronoi-binned composite spectra with high signal-to-noise ratio (S/N). Results. This pilot study demonstrates the power of MUSE for mapping the local ISM on very small scales which provides a new window for ISM observations. We detect small scale variations in Na-I and K-I as well as in several DIBs within few arcseconds, or mpc with regard to the Local Bubble. We verify the suitability of the MUSE 3D spectrograph for such measurements and gain new insights by probing a single physical absorber with multiple sight lines. KW - techniques: imaging spectroscopy KW - globular clusters: individual: NGC 6397 KW - dust, extinction KW - ISM: structure KW - ISM: lines and bands Y1 - 2017 U6 - https://doi.org/10.1051/0004-6361/201629816 SN - 1432-0746 VL - 607 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Weilbacher, Peter Michael A1 - Monreal-Ibero, Ana A1 - Verhamme, Anne A1 - Sandin, Christer A1 - Steinmetz, Matthias A1 - Kollatschny, Wolfram A1 - Krajnovic, Davor A1 - Kamann, Sebastian A1 - Roth, Martin M. A1 - Erroz-Ferrer, Santiago A1 - Marino, Raffaella Anna A1 - Maseda, Michael V. A1 - Wendt, Martin A1 - Bacon, Roland A1 - Dreizler, Stefan A1 - Richard, Johan A1 - Wisotzki, Lutz T1 - Lyman-continuum leakage as dominant source of diffuse ionized gas in the Antennae galaxy JF - Astronomy and astrophysics : an international weekly journal N2 - 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 H II 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 H II regions, showing fainter luminosities. By comparing H II 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 H II 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 H II regions for the diffuse ionized gas in the Antennae. KW - galaxies: interactions KW - galaxies: individual: NGC 4038, NGC 4039 KW - galaxies: ISM KW - ISM: structure KW - H II regions Y1 - 2018 U6 - https://doi.org/10.1051/0004-6361/201731669 SN - 1432-0746 VL - 611 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Weilbacher, Peter Michael A1 - Monreal-Ibero, Ana A1 - Kollatschny, Wolfram A1 - Ginsburg, Adam A1 - McLeod, Anna F. A1 - Kamann, Sebastian A1 - Sandin, Christer A1 - Palsa, Ralf A1 - Wisotzki, Lutz A1 - Bacon, Roland A1 - Selman, Fernando A1 - Brinchmann, Jarle A1 - Caruana, Joseph A1 - Kelz, Andreas A1 - Martinsson, Thomas A1 - Pecontal-Rousset, Arlette A1 - Richard, Johan A1 - Wendt, Martin T1 - A MUSE map of the central Orion Nebula (M 42) JF - Astronomy and astrophysics : an international weekly journal N2 - 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 similar to 5'9 x 4'9 (corresponding to similar to 0.76 x 0.63 pc(2)) and a contiguous wavelength coverage of 4595 ... 9366 angstrom, spatially sampled at 0 ''.2. We provide two versions with a sampling of 1.25 angstrom and 0.85 angstrom 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 T-e) and [S II] and [Cl III] (for the electron density N-e), and show 2D images of the velocity measured from several bright emission lines. KW - H II regions KW - ISM: individual objects: M 42 KW - open clusters and associations: individual: Trapezium cluster Y1 - 2015 U6 - https://doi.org/10.1051/0004-6361/201526529 SN - 1432-0746 VL - 582 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Schroetter, Ilane A1 - Bouche, Nicolas F. A1 - Zabl, Johannes A1 - Contini, Thierry A1 - Wendt, Martin A1 - Schaye, Joop A1 - Mitchell, Peter A1 - Muzahid, Sowgat A1 - Marino, Raffaella Anna A1 - Bacon, Roland A1 - Lilly, Simon J. A1 - Richard, Johan A1 - Wisotzki, Lutz T1 - MusE GAs FLOw andWind (MEGAFLOW) BT - III. Galactic wind properties using background quasars JF - Monthly notices of the Royal Astronomical Society N2 - We present results from our on-going MusE GAs FLOw and Wind (MEGAFLOW) survey, which consists of 22 quasar lines of sight, each observed with the integral field unit MUSE and the UVES spectrograph at the ESO Very Large Telescopes (VLT). The goals of this survey are to study the properties of the circumgalactic medium around z similar to 1 star-forming galaxies. The absorption-line selected survey consists of 79 strong MgII absorbers (with rest-frame equivalent width greater than or similar to 0.3 angstrom) and, currently, 86 associated galaxies within 100 projected kpc of the quasar with stellar masses (M-star) from 109 to 1011 M-circle dot. We find that the cool halo gas traced by MgII is not isotropically distributed around these galaxies from the strong bi-modal distribution in the azimuthal angle of the apparent location of the quasar with respect to the galaxy major axis. This supports a scenario in which outflows are bi-conical in nature and co-exist with a co-planar gaseous structure extending at least up to 60-80 kpc. Assuming that absorbers near the minor axis probe outflows, the current MEGAFLOW sample allowed us to select 26 galaxy-quasar pairs suitable for studying winds. From this sample, using a simple geometrical model, we find that the outflow velocity only exceeds the escape velocity when M-star less than or similar to 4 x 10(9) M-circle dot, implying the cool material is likely to fall back except in the smallest haloes. Finally, we find that the mass loading factor., the ratio between the ejected mass rate and the star formation rate, appears to be roughly constant with respect to the galaxy mass. KW - galaxies: evolution KW - galaxies: formation KW - intergalactic medium KW - quasars: absorption lines Y1 - 2019 U6 - https://doi.org/10.1093/mnras/stz2822 SN - 0035-8711 SN - 1365-2966 VL - 490 IS - 3 SP - 4368 EP - 4381 PB - Oxford Univ. Press CY - Oxford ER -