Andreas Kelz

Integral-field spectrophotometry of the quadruple QSO HE 0435 1223: Evidence for microlensing

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 di erences 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.

An integral field spectroscopic survey for high redshift damped Lyman-α galaxies

We search for galaxy counterparts to damped Lyman-alpha absorbers (DLAs) at z>2 towards nine quasars, which have 14 DLAs and 8 sub-DLAs in their spectra. We use integral field spectroscopy to search for Ly-alpha emission line objects at the redshifts of the absorption systems. Besides recovering two previously confirmed objects, we find six statistically significant candidate Ly-alpha emission line objects. The candidates are identified as having wavelengths close to the DLA line where the background quasar emission is absorbed. In comparison with the six currently known Ly-alpha emitting DLA galaxies the candidates have similar line fluxes and line widths, while velocity offsets between the emission lines and systemic DLA redshifts are larger. The impact parameters are larger than 10 kpc, and lower column density systems are found at larger impact parameters. Assuming that a single gas cloud extends from the QSO line of sight to the location of the candidate emission line, we find that the average candidate DLA galaxy is surrounded by neutral gas with an exponential scale length of ~5 kpc.

Integral field spectroscopy of extended Ly

This paper presents observations of an extended Lyman- α emission nebula surrounding the galaxy responsible for the Damped Lyman- α 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 Ly α emission in an area of

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3arcsec

Integral field spectroscopy of QSO host galaxies

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The merging/AGN connection - II. Ionization of the circumnuclear regions

5arcsec

E3D, the Euro3D visualization tool II: Mosaics, VIMOS data and large IFUs of the future

having a total line flux of (2.8 ± 0.3)

Integral field spectroscopy of SN 2002er with PMAS

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