TY  - JOUR
A1  - Göttgens, Fabian
A1  - Weilbacher, Peter Michael
A1  - Roth, Martin M.
A1  - Dreizler, Stefan
A1  - Giesers, Benjamin
A1  - Husser, Tim-Oliver
A1  - Kamann, Sebastian
A1  - Brinchmann, Jarle
A1  - Kollatschny, Wolfram
A1  - Monreal-Ibero, Ana
A1  - Schmidt, Kasper Borello
A1  - Wendt, Martin
A1  - Wisotzki, Lutz
A1  - Bacon, Roland
T1  - Discovery of an old nova remnant in the Galactic globular cluster M 22
JF  - Astronomy and astrophysics : an international weekly journal
N2  - A nova is a cataclysmic event on the surface of a white dwarf in a binary system that increases the overall brightness by several orders of magnitude. Although binary systems with a white dwarf are expected to be overabundant in globular clusters compared with in the Galaxy, only two novae from Galactic globular clusters have been observed. We present the discovery of an emission nebula in the Galactic globular cluster M 22 (NGC 6656) in observations made with the integral-field spectrograph MUSE. We extracted the spectrum of the nebula and used the radial velocity determined from the emission lines to confirm that the nebula is part of NGC 6656. Emission-line ratios were used to determine the electron temperature and density. It is estimated to have a mass of 1-17 x 10(-5) M-circle dot. This mass and the emission-line ratios indicate that the nebula is a nova remnant. Its position coincides with the reported location of a "guest star", an ancient Chinese term for transients, observed in May 48 BCE. With this discovery, this nova may be one of the oldest confirmed extra-solar events recorded in human history.
KW  - globular clusters: individual: NGC 6656
KW  - novae, cataclysmic variables
KW  - techniques: imaging spectroscopy
Y1  - 2019
U6  - https://doi.org/10.1051/0004-6361/201935221
SN  - 1432-0746
VL  - 626
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Kamann, Sebastian
A1  - Husser, T. -O.
A1  - Dreizler, S.
A1  - Emsellem, E.
A1  - Weilbacher, Peter Michael
A1  - Martens, S.
A1  - Bacon, R.
A1  - den Brok, M.
A1  - Giesers, B.
A1  - Krajnovic, Davor
A1  - Roth, Martin M.
A1  - Wendt, Martin
A1  - Wisotzki, Lutz
T1  - A stellar census in globular clusters with MUSE
BT  - the contribution of rotation to cluster dynamics studied with 200 000 stars
JF  - Monthly notices of the Royal Astronomical Society
N2  - This is the first of a series of papers presenting the results from our survey of 25 Galactic globular clusters with the MUSE integral-field spectrograph. In combination with our dedicated algorithm for source deblending, MUSE provides unique multiplex capabilities in crowded stellar fields and allows us to acquire samples of up to 20 000 stars within the half-light radius of each cluster. The present paper focuses on the analysis of the internal dynamics of 22 out of the 25 clusters, using about 500 000 spectra of 200 000 individual stars. Thanks to the large stellar samples per cluster, we are able to perform a detailed analysis of the central rotation and dispersion fields using both radial profiles and two-dimensional maps. The velocity dispersion profiles we derive show a good general agreement with existing radial velocity studies but typically reach closer to the cluster centres. By comparison with proper motion data, we derive or update the dynamical distance estimates to 14 clusters. Compared to previous dynamical distance estimates for 47 Tuc, our value is in much better agreement with other methods. We further find significant (>3 sigma) rotation in the majority (13/22) of our clusters. Our analysis seems to confirm earlier findings of a link between rotation and the ellipticities of globular clusters. In addition, we find a correlation between the strengths of internal rotation and the relaxation times of the clusters, suggesting that the central rotation fields are relics of the cluster formation that are gradually dissipated via two-body relaxation.
KW  - techniques: imaging spectroscopy
KW  - stars: kinematics and dynamics
KW  - globular clusters: general
Y1  - 2017
U6  - https://doi.org/10.1093/mnras/stx2719
SN  - 0035-8711
SN  - 1365-2966
VL  - 473
IS  - 4
SP  - 5591
EP  - 5616
PB  - Oxford Univ. Press
CY  - Oxford
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  - 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  - 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  - 
TY  - JOUR
A1  - Christensen, Lise Bech
A1  - Schulte-Ladbeck, R. E.
A1  - Sanchez, Sebastian F.
A1  - Becker, Thomas
A1  - Jahnke, Knud
A1  - Kelz, A.
A1  - Roth, Martin M.
A1  - Wisotzki, Lutz
T1  - Abundances and kinematics of a candidate sub-damped Lymana galaxy toward PHL 1226
N2  - The spectrum of the quasar PHL 1226 is known to have a strong Mg II and sub-damped Lymanalpha (sub-DLA) absorption line system with N(H I) = (5 +/- 2) x 10(19) cm(-2) at z = 0.1602. Using integral field spectra from the Potsdam Multi Aperture Spectrophotometer (PMAS) we investigate a galaxy at an impact parameter of 6".4 which is most probably responsible for the absorption lines. A fainter galaxy at a similar redshift and a slightly larger distance from the QSO is known to exist, but we assume that the absorption is caused by the more nearby galaxy. From optical Balmer lines we estimate an intrinsic reddening consistent with 0, and a moderate star formation rate of 0.5 M-circle dot yr(-1) is inferred from the Ha luminosity. Using nebular emission line ratios we find a solar oxygen abundance 12 + log (O/H) = 8.7 +/- 0.1 and a solar nitrogen to oxygen abundance ratio log (N/O) = -1.0 +/- 0.2. This abundance is larger than those of all known sub-DLA systems derived from analyses of metal absorption lines in quasar spectra. On the other hand, the properties are compatible with the most metal rich galaxies responsible for strong Mg II absorption systems. These two categories can be reconciled if we assume an abundance gradient similar to local galaxies. Under that assumption we predict abundances 12 + log (O/H) = 7.1 and log (N/O) = -1.9 for the sub-DLA cloud, which is similar to high redshift DLA and sub-DLA systems. We find evidence for a rotational velocity of similar to200 km s(-1) over a length of similar to7 kpc. From the geometry and kinematics of the galaxy we estimate that the absorbing cloud does not belong to a rotating disk, but could originate in a rotating halo
Y1  - 2005
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  - Christensen, Lise Bech
A1  - Sanchez, Sebastian F.
A1  - Jahnke, Knud
A1  - Becker, Thomas
A1  - Wisotzki, Lutz
A1  - Kelz, A.
A1  - Popovic, L. C.
A1  - Roth, Martin M.
T1  - Integral field spectroscopy of extended Ly alpha emission from the DLA galaxy in Q2233+131
N2  - This paper presents observations of an extended Lyman-alpha emission nebula surrounding the galaxy responsible for the Damped Lyman-alpha Absorption (DLA) line in the spectrum of the quasar Q2233+131. With the Potsdam Multi Aperture Spectrophotometer (PMAS) we measure the properties of the extended Lyalpha emission in an area of 3" x 5" having a total line flux of (2.8 +/- 0.3) x 10(-16) erg cm(-2) s(-1), which at redshift z = 3.15 corresponds to a luminosity of (2.4(-0.2)(+0.3)) x 10(43) erg s(-1) and a size of 23 x 38 kpc. The location of the emission is spatially coincident with the previously detected DLA galaxy, but extends significantly beyond its limb. We argue that the Lya emission is likely to be caused by an outflow from the DLA galaxy, presumably powered by star formation. In the case of negligible dust extinction, the Lya luminosity indicates a star-formation rate of 19 +/- 10 M-. yr(-1) consistent with that derived from the UV continuum flux from the parent galaxy. The wind velocity indicated by the integral field spectra is of the order of several hundred km s(-1). We find no indication of emission originating in a rotating disk
Y1  - 2004
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  - Christensen, Lise Bech
A1  - Sanchez, Sebastian F.
A1  - Jahnke, Knud
A1  - Becker, Thomas
A1  - Kelz, A.
A1  - Wisotzki, Lutz
A1  - Roth, Martin M.
T1  - Integral field observations of damped Lyman-alpha galaxies
N2  - We report preliminary results from a targeted investigation on quasars containing damped Lyman-alpha absorption (DLA) lines as well strong metal absorption lines, carried out with the Potsdam Multi Aperture Spectrophotometer (PMAS). We search for line-emitting objects at the same redshift as the absorption lines and close to the line of sight of the QSOs. We have observed and detected the already confirmed absorbing galaxies in Q2233+131 (Z(abs) = 3.15) and Q0151+045 (Z(abs),= 0.168), while failing to find spectral signatures for the z = 0.091 absorber in Q0738+313. From the Q2233+131 DLA galaxy, we have detected extended Lyalpha emission from an area of 3" x 5"
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Jahnke, Knud
A1  - Wisotzki, Lutz
A1  - Sanchez, Sebastian F.
A1  - Christensen, Lise Bech
A1  - Becker, Thomas
A1  - Kelz, A.
A1  - Roth, Martin M.
T1  - Integral field spectroscopy of QSO host galaxies
N2  - We describe a project to study the state of the ISM in similar to20 low redshift (z < 0.3) QSO host galaxies observed with the PMAS integral field spectrograph. We describe the development of the method to access the stellar and gas components of the spectrum without the strong nuclear emission, in order to access the host galaxy properties in the central region. It shows that integral field spectroscopy promises to be very efficient in studying the gas distribution and its velocity field, and also the spatially resolved stellar population in the host galaxies of luminous AGN
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Christensen, Lise Bech
A1  - Becker, Thomas
A1  - Jahnke, Knud
A1  - Kelz, A.
A1  - Roth, Martin M.
A1  - Sanchez, S. S.
A1  - Wisotzki, Lutz
T1  - Integral field spectroscopy of SN 2002er with PMAS
N2  - sent observations of the Type Ia supernova SN 2002er during the brightening phase. The observations were performed with the Potsdam Multi Aperture Spectrophotometer (PMAS) integral field instrument. Due to the 8arcsecx8 arcsec field of view of the spectrograph an accurate background subtraction was possible. Results from analyses of the evolution of absorption features in comparisons with other SNe show that SN 2002er is a fairly bright Type Ia supernova with a peak brightness of MB=-19.6+/-0.1.
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Marino, Raffaella Anna
A1  - Cantalupo, Sebastiano
A1  - Lilly, Simon J.
A1  - Gallego, Sofia G.
A1  - Straka, Lorrie A.
A1  - Borisova, Elena
A1  - Pezzulli, Gabriele
A1  - Bacon, Roland
A1  - Brinchmann, Jarle
A1  - Carollo, C. Marcella
A1  - Caruana, Joseph
A1  - Conseil, Simon
A1  - Contini, Thierry
A1  - Diener, Catrina
A1  - Finley, Hayley
A1  - Inami, Hanae
A1  - Leclercq, Floriane
A1  - Muzahid, Sowgat
A1  - Richard, Johan
A1  - Schaye, Joop
A1  - Wendt, Martin
A1  - Wisotzki, Lutz
T1  - Dark Galaxy Candidates at Redshift similar to 3.5 Detected with MUSE
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - Recent theoretical models suggest that the early phase of galaxy formation could involve an epoch when galaxies are gas rich but inefficient at forming stars: a "dark galaxy" phase. Here, we report the results of our Multi-Unit Spectroscopic Explorer (MUSE) survey for dark galaxies fluorescently illuminated by quasars at z > 3. Compared to previous studies which are based on deep narrowband (NB) imaging, our integral field survey provides a nearly uniform sensitivity coverage over a large volume in redshift space around the quasars as well as full spectral information at each location. Thanks to these unique features, we are able to build control samples at large redshift distances from the quasars using the same data taken under the same conditions. By comparing the rest-frame equivalent width (EW0) distributions of the Ly alpha sources detected in proximity to the quasars and in control samples, we detect a clear correlation between the locations of high-EW0 objects and the quasars. This correlation is not seen in other properties, such as Ly alpha luminosities or volume overdensities, suggesting the possible fluorescent nature of at least some of these objects. Among these, we find six sources without continuum counterparts and EW0 limits larger than 240 angstrom that are the best candidates for dark galaxies in our survey at z > 3.5. The volume densities and properties, including inferred gas masses and star formation efficiencies, of these dark galaxy candidates are similar to those of previously detected candidates at z approximate to 2.4 in NB surveys. Moreover, if the most distant of these are fluorescently illuminated by the quasar, our results also provide a lower limit of t - 60 Myr on the quasar lifetime.
KW  - galaxies: formation
KW  - galaxies: high-redshift
KW  - galaxies: star formation
KW  - intergalactic medium
KW  - quasars: emission lines
KW  - quasars: general
Y1  - 2018
U6  - https://doi.org/10.3847/1538-4357/aab6aa
SN  - 0004-637X
SN  - 1538-4357
VL  - 859
IS  - 1
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Paalvast, M.
A1  - Verhamme, A.
A1  - Straka, L. A.
A1  - Brinchmann, J.
A1  - Herenz, Edmund Christian
A1  - Carton, D.
A1  - Gunawardhana, M. L. P.
A1  - Boogaard, L. A.
A1  - Cantalupo, S.
A1  - Contini, T.
A1  - Epinat, Benoit
A1  - Inami, H.
A1  - Marino, R. A.
A1  - Maseda, M. V.
A1  - Michel-Dansac, L.
A1  - Muzahid, S.
A1  - Nanayakkara, T.
A1  - Pezzulli, Gabriele
A1  - Richard, J.
A1  - Schaye, Joop
A1  - Segers, M. C.
A1  - Urrutia, Tanya
A1  - Wendt, Martin
A1  - Wisotzki, Lutz
T1  - Properties and redshift evolution of star-forming galaxies with high [0 III]/[O II] ratios with MUSE at 0.28 < z < 0.85
JF  - Astronomy and astrophysics : an international weekly journal
N2  - We present a study of the [O III]/[O II] ratios of star-forming galaxies drawn from Multi-Unit Spectroscopic Explorer (MUSE) data spanning a redshift range 0.28 < z < 0.85. Recently discovered Lyman continuum (LyC) emitters have extremely high oxygen line ratios: [O III]lambda 5007/[O II]lambda lambda 3726, 3729 > 4. Here we aim to understand the properties and the occurrences of galaxies with such high line ratios. Combining data from several MUSE Guaranteed Time Observing (GTO) programmes, we select a population of star-forming galaxies with bright emission lines, from which we draw 406 galaxies for our analysis based on their position in the z-dependent star formation rate (SFR) stellar mass (M*) plane. Out of this sample 15 are identified as extreme oxygen emitters based on their [O III]/[O II] ratios (3.7%) and 104 galaxies have [O III]/[O II] > 1 (26%). Our analysis shows no significant correlation between M*, SFR, and the distance from the SFR M, relation with [O III]/[O II]. We find a decrease in the fraction of galaxies with [O III]/[O II] > 1 with increasing M*, however, this is most likely a result of the relationship between [O III]/[O II] and metallicity, rather than between [O III]/[O II] and M. We draw a comparison sample of local analogues with < z > 0.03 from the Sloan Digital Sky Survey, and find similar incidence rates for this sample. In order to investigate the evolution in the fraction of high [O III]/[O II] emitters with redshift, we bin the sample into three redshift subsamples of equal number, but find no evidence for a dependence on redshift. Furthermore, we compare the observed line ratios with those predicted by nebular models with no LyC escape and find that most of the extreme oxygen emitters can be reproduced by low metallicity models. The remaining galaxies are likely LyC emitter candidates.
KW  - galaxies: evolution
KW  - galaxies: ISM
KW  - galaxies: abundances
KW  - ISM: structure
KW  - ISM: kinematics and dynamics
KW  - dark ages, reionization, first stars
Y1  - 2018
U6  - https://doi.org/10.1051/0004-6361/201832866
SN  - 0004-6361
SN  - 1432-0746
VL  - 618
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Johnson, Sean D.
A1  - Chen, Hsiao-Wen
A1  - Straka, Lorrie
A1  - Schaye, Joop
A1  - Cantalupo, Sebastiano
A1  - Wendt, Martin
A1  - Muzahid, Sowgat
A1  - Bouché, Nicolas
A1  - Herenz, Edmund Christian
A1  - Kollatschny, Wolfram
A1  - Mulchaey, John S.
A1  - Marino, Raffaella A.
A1  - Maseda, Michael
A1  - Wisotzki, Lutz
T1  - Galaxy and quasar fueling caught in the act from the intragroup to the interstellar medium
JF  - The astrophysical journal : Part 2, Letters
N2  - We report the discovery of six spatially extended (10-100 kpc) line-emitting nebulae in the z approximate to 0.57 galaxy group hosting PKS 0405-123, one of the most luminous quasars at z < 1. The discovery is enabled by the Multi Unit Spectroscopic Explorer and provides tantalizing evidence connecting large-scale gas streams with nuclear activity on scales of <10 proper kpc (pkpc). One of the nebulae exhibits a narrow, filamentary morphology extending over 50 pkpc toward the quasar with narrow internal velocity dispersion (50 km s(-1)) and is not associated with any detected galaxies, consistent with a cool intragroup medium filament. Two of the nebulae are 10 pkpc north and south of the quasar with tidal-arm-like morphologies. These two nebulae, along with a continuum-emitting arm extending 60 pkpc from the quasar, are signatures of interactions that are expected to redistribute angular momentum in the host interstellar medium (ISM) to facilitate star formation and quasar fueling in the nucleus. The three remaining nebulae are among the largest and most luminous [O III] emitting "blobs" known (1400-2400 pkpc(2)) and correspond both kinematically and morphologically to interacting galaxy pairs in the quasar host group, consistent with arising from stripped ISM rather than large-scale quasar outflows. The presence of these large- and small-scale nebulae in the vicinity of a luminous quasar bears significantly on the effect of large-scale environment on galaxy and black hole fueling, providing a natural explanation for the previously known correlation between quasar luminosity and cool circumgalactic medium.
KW  - galaxies: interactions
KW  - intergalactic medium
KW  - quasars: general
KW  - quasars: individual (PKS 0405-123)
Y1  - 2018
U6  - https://doi.org/10.3847/2041-8213/aaf1cf
SN  - 2041-8205
SN  - 2041-8213
VL  - 869
IS  - 1
PB  - IOP Publishing Ltd. (Bristol)
CY  - Bristol
ER  - 
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  - 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  - 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  - 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  - 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  - Finley, Hayley
A1  - Bouche, Nicolas
A1  - Contini, Thierry
A1  - Epinat, Benoit
A1  - Bacon, Roland
A1  - Brinchmann, Jarle
A1  - Cantalupo, Sebastiano
A1  - Erroz-Ferrer, Santiago
A1  - Marino, Aella Anna
A1  - Maseda, Michael
A1  - Richard, Johan
A1  - Schroetter, Ilane
A1  - Verhamme, Anne
A1  - Weilbacher, Peter Michael
A1  - Wendt, Martin
A1  - Wisotzki, Lutz
T1  - Galactic winds with MUSE: A direct detection of Fe II* emission from a z=1.29 galaxy
JF  - Astronomy and astrophysics : an international weekly journal
N2  - Emission signatures from galactic winds provide an opportunity to directly map the outflowing gas, but this is traditionally challenging because of the low surface brightness. Using very deep observations (27 h) of the Hubble Deep Field South with the Multi Unit Spectroscopic Explorer (MUSE) instrument, we identify signatures of an outflow in both emission and absorption from a spatially resolved galaxy at z = 1.29 with a stellar mass M-star = 8 x 10(9) M-circle dot, star formation rate SFR = 77(-25)(+40) M-circle dot yr(-1), and star formation rate surface brightness Sigma(SFR) = 1.6 M-circle dot kpc(-2) within the [OII] lambda lambda 3727, 3729 half-light radius R-1/2, ([OII]) = 2.76 +/- 0.17 kpc. From a component of the strong resonant Mg II and Fe II absorptions at -350 km s(-1), we infer a mass outflow rate that is comparable to the star formation rate. We detect non-resonant Fe II* emission, at lambda 2365, lambda 2396, lambda 2612, and lambda 2626, at 1.2-2.4-1.5-2.7 x 10-(18) erg s(-1) cm(-2) respectively. The flux ratios are consistent with the expectations for optically thick gas. By combining the four non-resonant Fe II* emission lines, we spatially map the Fe II* emission from an individual galaxy for the first time. The Fe II* emission has an elliptical morphology that is roughly aligned with the galaxy minor kinematic axis, and its integrated half-light radius, R-1/2, (Fe II*) = 4.1 +/- 0.4 kpc, is 70% larger than the stellar continuum (R-1/2,(star) similar or equal to 2.34 +/- 0.17) or the [O II] nebular line. Moreover, the Fe II* emission shows a blue wing extending up to -400 km s(-1), which is more pronounced along the galaxy minor kinematic axis and reveals a C-shaped pattern in a p - v diagram along that axis. These features are consistent with a bi-conical outflow.
KW  - galaxies: evolution
KW  - galaxies: formation
KW  - galaxies: starburst
KW  - galaxies: ISM
KW  - ISM: jets and outflows
KW  - ultraviolet: ISM
Y1  - 2017
U6  - https://doi.org/10.1051/0004-6361/201730428
SN  - 1432-0746
VL  - 605
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  - 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  -