TY  - JOUR
A1  - Richter, Philipp
A1  - Nuza, S. E.
A1  - Fox, Andrew J.
A1  - Wakker, Bart P.
A1  - Lehner, N.
A1  - Ben Bekhti, Nadya
A1  - Fechner, Cora
A1  - Wendt, Martin
A1  - Howk, J. Christopher
A1  - Muzahid, S.
A1  - Ganguly, R.
A1  - Charlton, Jane C.
T1  - An HST/COS legacy survey of high-velocity ultraviolet absorption in the
JF  - Astronomy and astrophysics : an international weekly journal
N2  - Context. The Milky Way is surrounded by large amounts of diffuse gaseous matter that connects the stellar body of our Galaxy with its large-scale Local Group (LG) environment. Aims. To characterize the absorption properties of this circumgalactic medium (CGM) and its relation to the LG we present the so-far largest survey of metal absorption in Galactic high-velocity clouds (HVCs) using archival ultraviolet (UV) spectra of extragalactic background sources. The UV data are obtained with the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope (HST) and are supplemented by 21 cm radio observations of neutral hydrogen. Methods. Along 270 sightlines we measure metal absorption in the lines of Si II, Si III, C II, and C IV and associated H I 21 cm emission in HVCs in the velocity range vertical bar v(LSR)vertical bar = 100-500 km s(-1). With this unprecedented large HVC sample we were able to improve the statistics on HVC covering fractions, ionization conditions, small-scale structure, CGM mass, and inflow rate. For the first time, we determine robustly the angular two point correlation function of the high-velocity absorbers, systematically analyze antipodal sightlines on the celestial sphere, and compare the HVC absorption characteristics with that of damped Lyman alpha absorbers (DLAs) and constrained cosmological simulations of the LG (CLUES project).
KW  - Galaxy: halo
KW  - Galaxy: structure
KW  - Galaxy: evolution
KW  - ISM: kinematics and dynamics
KW  - techniques: spectroscopic
KW  - ultraviolet: ISM
Y1  - 2017
U6  - https://doi.org/10.1051/0004-6361/201630081
SN  - 1432-0746
VL  - 607
PB  - EDP Sciences
CY  - Les Ulis
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  - Turner, Monica L.
A1  - Schaye, Joop
A1  - Crain, Robert A.
A1  - Theuns, Tom
A1  - Wendt, Martin
T1  - Observations of metals in the z approximate to 3.5 intergalactic medium and comparison to the EAGLE simulations
JF  - Monthly notices of the Royal Astronomical Society
N2  - We study the z approximate to 3.5 intergalactic medium (IGM) by comparing new, high-quality absorption spectra of eight QSOs with < z(QSO)> = 3.75, to virtual observations of the Evolution and Assembly of Galaxies and their Environments (EAGLE) cosmological hydrodynamical simulations. We employ the pixel optical depth method and uncover strong correlations between various combinations of H I, C III, C IV, Si III, Si IV, and O VI. We find good agreement between many of the simulated and observed correlations, including tau(O) (VI) (tau(H) (I)). However, the observed median optical depths for the tau(C) (IV) (tau(H) (I)) and tau(Si) (IV) (tau(H) (I)) relations are higher than those measured from the mock spectra. The discrepancy increases from up to approximate to 0.1 dex at tau(H) (I) = 1 to approximate to 1 dex at tau(H) (I) = 10(2), where we are likely probing dense regions at small galactocentric distances. As possible solutions, we invoke (a) models of ionizing radiation softened above 4 Ryd to account for delayed completion of He II reionization; (b) simulations run at higher resolution; (c) the inclusion of additional line broadening due to unresolved turbulence; and (d) increased elemental abundances; however, none of these factors can fully explain the observed differences. Enhanced photoionization of H I by local sources, which was not modelled, could offer a solution. However, the much better agreement with the observed O VI(H I) relation, which we find probes a hot and likely collisionally ionized gas phase, indicates that the simulations are not in tension with the hot phase of the IGM, and suggests that the simulated outflows may entrain insufficient cool gas.
KW  - galaxies: formation
KW  - intergalactic medium
KW  - quasars: absorption lines
Y1  - 2016
U6  - https://doi.org/10.1093/mnras/stw1816
SN  - 0035-8711
SN  - 1365-2966
VL  - 462
SP  - 2440
EP  - 2464
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Bouche, Nicolas
A1  - Finley, H.
A1  - Schroetter, I.
A1  - Murphy, M. T.
A1  - Richter, Philipp
A1  - Bacon, Roland
A1  - Contini, Thierry
A1  - Richard, J.
A1  - Wendt, Martin
A1  - Kamann, S.
A1  - Epinat, Benoit
A1  - Cantalupo, Sebastiano
A1  - Straka, Lorrie A.
A1  - Schaye, Joop
A1  - Martin, C. L.
A1  - Peroux, C.
A1  - Wisotzki, Lutz
A1  - Soto, K.
A1  - Lilly, S.
A1  - Carollo, C. M.
A1  - Brinchmann, Jarle
A1  - Kollatschny, W.
T1  - POSSIBLE SIGNATURES OF A COLD-FLOW DISK FROM MUSE USING A z similar to 1
GALAXY-QUASAR PAIR TOWARD SDSS J1422-0001
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We use a background quasar to detect the presence of circumgalactic gas around a z = 0.91 low-mass star-forming galaxy. Data from the new Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope show that the galaxy has a dust-corrected star formation rate (SFR) of 4.7 +/- 2.0. M-circle dot yr(-1), with no companion down to 0.22 M-circle dot yr(-1) (5 sigma) within 240 h(-1) kpc ("30"). Using a high-resolution spectrum of the background quasar, which is fortuitously aligned with the galaxy major axis (with an azimuth angle alpha of only 15 degrees), we find, in the gas kinematics traced by low-ionization lines, distinct signatures consistent with those expected for a "cold-flow disk" extending at least 12 kpc (3 x R-1/2). We estimate the mass accretion rate M-in to be at least two to three times larger than the SFR, using the geometric constraints from the IFU data and the H (I) column density of log N-H (I)/cm(-2) similar or equal to 20.4 obtained from a Hubble Space Telescope/COS near-UV spectrum. From a detailed analysis of the low-ionization lines (e.g., Zn II, Cr II, Ti II, MnII, Si II), the accreting material appears to be enriched to about 0.4 Z(circle dot) (albeit with large uncertainties: log Z/Z(circle dot) = -0.4 +/- 0.4), which is comparable to the galaxy metallicity (12 + log O/H = 8.7 +/- 0.2), implying a large recycling fraction from past outflows. Blueshifted Mg II and Fe II absorptions in the galaxy spectrum from the MUSE data reveal the presence of an outflow. The Mg II and Fe II absorption line ratios indicate emission infilling due to scattering processes, but the MUSE data do not show any signs of fluorescent Fe II* emission.
KW  - galaxies: evolution
KW  - galaxies: formation
KW  - intergalactic medium
KW  - quasars: individual (SDSS J142253.31-000149)
Y1  - 2016
U6  - https://doi.org/10.3847/0004-637X/820/2/121
SN  - 0004-637X
SN  - 1538-4357
VL  - 820
SP  - 1872
EP  - 1882
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Husser, Tim-Oliver
A1  - Kamann, Sebastian
A1  - Dreizler, Stefan
A1  - Wendt, Martin
A1  - Wulff, Nina
A1  - Bacon, Roland
A1  - Wisotzki, Lutz
A1  - Brinchmann, Jarle
A1  - Weilbacher, Peter Michael
A1  - Roth, Martin M.
A1  - Monreal-Ibero, Ana
T1  - MUSE crowded field 3D spectroscopy of over 12 000 stars in the globular cluster NGC 6397 I. The first comprehensive HRD of a globular cluster
JF  - Nucleic acids research
N2  - Aims. We demonstrate the high multiplex advantage of crowded field 3D spectroscopy with the new integral field spectrograph MUSE by means of a spectroscopic analysis of more than 12 000 individual stars in the globular cluster NGC 6397. Methods. The stars are deblended with a point spread function fitting technique, using a photometric reference catalogue from HST as prior, including relative positions and brightnesses. This catalogue is also used for a first analysis of the extracted spectra, followed by an automatic in-depth analysis via a full-spectrum fitting method based on a large grid of PHOENIX spectra. Results. We analysed the largest sample so far available for a single globular cluster of 18 932 spectra from 12 307 stars in NGC 6397. We derived a mean radial velocity of v(rad) = 17.84 +/- 0.07 km s(-1) and a mean metallicity of [Fe/H] = -2.120 +/- 0.002, with the latter seemingly varying with temperature for stars on the red giant branch (RGB). We determine Teff and [Fe/H] from the spectra, and log g from HST photometry. This is the first very comprehensive Hertzsprung-Russell diagram (HRD) for a globular cluster based on the analysis of several thousands of stellar spectra, ranging from the main sequence to the tip of the RGB. Furthermore, two interesting objects were identified; one is a post-AGB star and the other is a possible millisecond-pulsar companion.
KW  - methods: data analysis
KW  - techniques: imaging spectroscopy
KW  - planets and satellites: fundamental parameters
KW  - stars: atmospheres
KW  - pulsars: general
KW  - globular clusters: individual: NGC 6397
Y1  - 2016
U6  - https://doi.org/10.1051/0004-6361/201526949
SN  - 1432-0746
VL  - 588
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Kamann, S.
A1  - Husser, T. -O.
A1  - Brinchmann, Jarle
A1  - Emsellem, E.
A1  - Weilbacher, Peter Michael
A1  - Wisotzki, Lutz
A1  - Wendt, Martin
A1  - Krajnovic, D.
A1  - Roth, M. M.
A1  - Bacon, Roland
A1  - Dreizler, S.
T1  - MUSE crowded field 3D spectroscopy of over 12 000 stars in the globular cluster NGC 6397
JF  - Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth
N2  - We present a detailed analysis of the kinematics of the Galactic globular cluster NGC 6397 based on more than similar to 18 000 spectra obtained with the novel integral field spectrograph MUSE. While NGC 6397 is often considered a core collapse cluster, our analysis suggests a flattening of the surface brightness profile at the smallest radii. Although it is among the nearest globular clusters, the low velocity dispersion of NGC 6397 of < 5 km s(-1) imposes heavy demands on the quality of the kinematical data. We show that despite its limited spectral resolution, MUSE reaches an accuracy of 1 km s(-1) in the analysis of stellar spectra. We find slight evidence for a rotational component in the cluster and the velocity dispersion profile that we obtain shows a mild central cusp. To investigate the nature of this feature, we calculate spherical Jeans models and compare these models to our kinematical data. This comparison shows that if a constant mass-to-light ratio is assumed, the addition of an intermediate-mass black hole with a mass of 600 M-circle dot brings the model predictions into agreement with our data, and therefore could be at the origin of the velocity dispersion profile. We further investigate cases with varying mass-to-light ratios and find that a compact dark stellar component can also explain our observations. However, such a component would closely resemble the black hole from the constant mass-to-light ratio models as this component must be confined to the central similar to 5 ' of the cluster and must have a similar mass. Independent constraints on the distribution of stellar remnants in the cluster or kinematic measurements at the highest possible spatial resolution should be able to distinguish the two alternatives.
KW  - globular clusters: individual: NGC 6397
KW  - stars: kinematics and dynamics
KW  - techniques: radial velocities
KW  - techniques: imaging spectroscopy
KW  - black hole physics
Y1  - 2016
U6  - https://doi.org/10.1051/0004-6361/201527065
SN  - 1432-0746
VL  - 588
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Schroetter, I.
A1  - Bouche, Nicolas
A1  - Wendt, Martin
A1  - Contini, Thierry
A1  - Finley, H.
A1  - Pello, R.
A1  - Bacon, Roland
A1  - Cantalupo, Sebastiano
A1  - Marino, Raffaella Anna
A1  - Richard, J.
A1  - Lilly, S. J.
A1  - Schaye, Joop
A1  - Soto, K.
A1  - Steinmetz, Matthias
A1  - Straka, Lorrie A.
A1  - Wisotzki, Lutz
T1  - MUSE GAS FLOW AND WIND (MEGAFLOW). I. FIRST MUSE RESULTS ON BACKGROUND QUASARS
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - The physical properties of galactic winds are one of the keys to understand galaxy formation and evolution. These properties can be constrained thanks to background quasar lines of sight (LOS) passing near star-forming galaxies (SFGs). We present the first results of the MusE GAs FLOw and Wind survey obtained from two quasar fields, which have eight Mg II absorbers of which three have rest equivalent width greater than 0.8 angstrom. With the new Multi Unit Spectroscopic Explorer (MUSE) spectrograph on the Very Large Telescope (VLT), we detect six (75%) Mg II host galaxy candidates within a radius of 30. from the quasar LOS. Out of these six galaxy-quasar pairs, from geometrical argument, one is likely probing galactic outflows, where two are classified as "ambiguous,"two are likely probing extended gaseous disks and one pair seems to be a merger. We focus on the wind-pair and constrain the outflow using a high-resolution quasar spectra from the Ultraviolet and Visual Echelle Spectrograph. Assuming the metal absorption to be due to ga;s flowing out of the detected galaxy through a cone along the minor axis, we find outflow velocities in the order of approximate to 150 km s(-1) (i.e., smaller than the escape velocity) with a loading factor, eta = M-out/SFR, of approximate to 0.7. We see evidence for an open conical flow, with a low-density inner core. In the future, MUSE will provide us with about 80 multiple galaxy-quasar pairs in two dozen fields.
KW  - galaxies: evolution
KW  - galaxies: formation
KW  - intergalactic medium
KW  - quasars: individual (SDSS J213748+001220, SDSS J215200+062516)
Y1  - 2016
U6  - https://doi.org/10.3847/1538-4357/833/1/39
SN  - 0004-637X
SN  - 1538-4357
VL  - 833
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Monreal-Ibero, Ana
A1  - Weilbacher, Peter Michael
A1  - Wendt, Martin
A1  - Selman, Fernando
A1  - Lallement, Rosine
A1  - Brinchmann, Jarle
A1  - Kamann, Sebastian
A1  - Sandin, Christer
T1  - Towards DIB mapping in galaxies beyond 100 Mpc A radial profile of the lambda 5780.5 diffuse interstellar band in AM1353-272 B
JF  - Astronomy and astrophysics : an international weekly journal
N2  - Context. Diffuse interstellar bands (DIBs) are non-stellar weak absorption features of unknown origin found in the spectra of stars viewed through one or several clouds of the interstellar medium (ISM). Research of DIBs outside the Milky Way is currently very limited. In particular, spatially resolved investigations of DIBs outside of the Local Group are, to our knowledge, inexistent.
 Aims. In this contribution, we explore the capability of the high-sensitivity integral field spectrograph, MUSE, as a tool for mapping diffuse interstellar bands at distances larger than 100 Mpc.
 Methods. We used MUSE commissioning data for AM1353-272 B, the member with the highest extinction of the Dentist's Chair, an interacting system of two spiral galaxies. High signal-to-noise spectra were created by co-adding the signal of many spatial elements distributed in a geometry of concentric elliptical half-rings.
 Results. We derived decreasing radial profiles for the equivalent width of the lambda 5780.5 DIB both in the receding and approaching side of the companion galaxy up to distances of similar to 4.6 kpc from the centre of the galaxy. The interstellar extinction as derived from the Ha/H beta line ratio displays a similar trend, with decreasing values towards the external parts. This translates into an intrinsic correlation between the strength of the DIB and the extinction within AM1353-272 B, consistent with the currently existing global trend between these quantities when using measurements for Galactic and extragalactic sightlines.
 Conclusions. It seems feasible to map the DIB strength in the Local Universe, which has up to now only been performed for the Milky Way. This offers a new approach to studying the relationship between DIBs and other characteristics and species of the ISM in addition to using galaxies in the Local Group or sightlines towards very bright targets outside the Local Group.
KW  - dust, extinction
KW  - ISM: lines and bands
KW  - galaxies: ISM
KW  - galaxies: individual: AM1353-272 B
Y1  - 2015
U6  - https://doi.org/10.1051/0004-6361/201525854
SN  - 0004-6361
SN  - 1432-0746
VL  - 576
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  - Evans, T. M.
A1  - Murphy, M. T.
A1  - Whitmore, J. B.
A1  - Misawa, T.
A1  - Centurion, Martin
A1  - Lopez, S.
A1  - Martins, C. J. A. P.
A1  - Molaro, P.
A1  - Petitjean, P.
A1  - Rahmani, H.
A1  - Srianand, R.
A1  - Wendt, Martin
T1  - The UVES Large Program for testing fundamental physics - III. Constraints on the fine-structure constant from three telescopes
JF  - Monthly notices of the Royal Astronomical Society
KW  - intergalactic medium
KW  - quasars: absorption lines
KW  - quasars: individual: HS 1549+1919
KW  - cosmology: miscellaneous
KW  - cosmology: observations
Y1  - 2014
U6  - https://doi.org/10.1093/mnras/stu1754
SN  - 0035-8711
SN  - 1365-2966
VL  - 445
IS  - 1
SP  - 128
EP  - 150
PB  - Oxford Univ. Press
CY  - Oxford
ER  -