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  - 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  - 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  -