Volume 468, Number 3, June IV 2007Extended baselines for the IRAM Plateau de Bure interferometer: First results
|Page(s)||885 - 901|
|Published online||26 March 2007|
Multi-wavelength study of the gravitational lens system RXS J1131-1231*
III. Long slit spectroscopy: micro-lensing probes the QSO structure
Laboratoire d'Astrophysique, École Polytechnique Fédérale de Lausanne (EPFL) Observatoire, 1290 Sauverny, Switzerland e-mail: email@example.com
2 Institut d'Astrophysique et de Géophysique, Université de Liège, Allée du 6 Août 17, B5C, 4000 Sart Tilman, Belgium
Accepted: 26 February 2007
Aims.We discuss and characterize micro-lensing among the 3 brightest lensed images (A-B-C) of the gravitational lens system RXS J1131-1231 (a quadruply imaged AGN) by means of long slit optical and NIR spectroscopy. Qualitative constraints on the size of different emission regions are derived. We also perform a spectroscopic study of two field galaxies located within 1.6 arcmin radius from the lens.
Methods. We decompose the spectra into their individual emission components using a multi-component fitting approach. A complementary decomposition of the spectra enables us to isolate the macro-lensed fraction of the spectra independently of any spectral modelling.
Results.1. The data support micro-lensing de-amplification of images A and C. Not only is the continuum emission microlensed in those images but also a fraction of the Broad Line emitting Region (BLR). 2. Micro-lensing of a very broad component of Mg ii emission line suggests that the corresponding emission occurs in a region more compact than the other components of the emission line. 3. We find evidence that a large fraction of the Fe ii emission arises in the outer parts of the BLR. We also find a very compact emitting region in the ranges 3080–3540 Å and 4630–4800 Å that is likely associated with Fe ii. 4. The [O iii] narrow emission line regions are partly spatially resolved. This enables us to put a lower limit of ~ pc on their intrinsic size. 5. Analysis of Mg ii absorption found in the spectra indicates that the absorbing medium is intrinsic to the quasar, has a covering factor of 20%, and is constituted of small clouds homogeneously distributed in front of the continuum and BLRs. 6. Two neighbour galaxies are detected at redshifts and . These galaxies are possible members of galaxy groups reported at those redshifts.
Key words: gravitational lensing / galaxies: Seyfert
© ESO, 2007
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.