Bibcode
Lipari, S.; Sanchez, S. F.; Bergmann, M.; Terlevich, R.; Garcia-Lorenzo, B.; Punsly, B.; Mediavilla, E.; Taniguchi, Y.; Ajiki, M.; Zheng, W.; Acosta, J.; Jahnke, K.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 392, Issue 4, pp. 1295-1338.
Advertised on:
2
2009
Citations
44
Refereed citations
41
Description
In this paper we present the first results of a study of BAL QSOs (at
low and high redshift), based on very deep Gemini GMOS integral field
spectroscopy. In particular, the results obtained for the nearest BAL
IR-QSO Mrk 231 are presented.
For the nuclear region of Mrk 231, the QSO and host galaxy components
were modelled, using a new technique of decoupling 3D spectra. From this
study, the following main results were found: (i) in the pure host
galaxy spectrum an extreme nuclear starburst component was clearly
observed, as a very strong increase in the flux, at the blue
wavelengths; (ii) the BAL system I is observed in the spectrum of the
host galaxy; (iii) in the clean/pure QSO emission spectrum, only broad
lines were detected. 3D GMOS individual spectra (specially in the
near-infrared CaII triplet) and maps confirm the presence of an extreme
and young nuclear starburst (8 < age < 15 Myr), which was detected
in a ring or toroid with a radius r = 0.3arcsec ~ 200 pc, around the
core of the nucleus. The extreme continuum blue component was detected
only to the south of the core of the nucleus. This area is coincident
with the region where we previously suggested that the galactic wind is
cleaning the nuclear dust.
Very deep 3D spectra and maps clearly show that the BAL systems I and II
- in the strong `absorption lines' NaIDλ5889-95 and CaII
Kλ3933 - are extended (reaching ~1.4-1.6 arcsec ~ 1.2-1.3 kpc,
from the nucleus) and clearly elongated at the position angle (PA) close
to the radio jet PA, which suggest that the BAL systems I and II are
`both' associated with the radio jet.
The physical properties of the four expanding nuclear bubbles were
analysed, using the GMOS 3D spectra and maps. In particular, we found
strong multiple LINER/OF emission-line systems and Wolf-Rayet features
in the main knots of the more external super bubble S1 (r = 3.0 kpc).
The kinematics of these knots - and the internal bubbles - suggest that
they are associated with an area of rupture of the shell S1 (at the
south-west). In addition, in the more internal superbubble S4 and close
to the core of the nucleus (for r < 0.7arcsec ~ 0.6 kpc), two similar
narrow emission-line systems were detected, with strong [SII] and [OI]
emission and ΔV ~ -200 km s-1. These results suggest
that an important part of the nuclear NLR is generated by the OF process
and the associated low-velocity ionizing shocks.
Finally, the nature of the composite BAL systems and very extended OF
process - of 50 kpc - in Mrk 231 (and similar QSOs) are discussed. In
addition, the `composite hyperwind scenario' (already proposed for BALs)
is suggested for the origin of giant Lyα blobs. The importance of
study the end phases of Mrk 231, and similar evolving elliptical
galaxies and QSOs (i.e. galaxy remnants) is discussed.