Bibcode
Lípari, S.; Terlevich, R.; Zheng, W.; Garcia-Lorenzo, B.; Sanchez, S. F.; Bergmann, M.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 360, Issue 4, pp. 416-446.
Advertised on:
6
2005
Citations
30
Refereed citations
28
Description
We present a study of outflow (OF) and broad absorption line (BAL)
systems in Mrk 231, and in similar infrared (IR) quasi-stellar objects
(QSOs). This study is based mainly on one-dimensional and
two-dimensional spectroscopy (obtained at La Palma/William Herschel
Telescope, Hubble Space Telescope, International Ultraviolet Explorer,
European Southern Observatory/New Technology Telescope, Kitt Peak
National Observatory, Apache Point Observatory and Complejo Astronomico
El Leoncito observatories) plus Hubble Space Telescope images. For Mrk
231, we report evidence that the extreme nuclear OF process has at least
three main components on different scales, which are probably associated
with: (i) the radio jet, at parsec scale; (ii) the extreme starburst at
parsec and kiloparsec scale. This OF has generated at least four
concentric expanding superbubbles and the BAL systems.
Specifically, inside and very close to the nucleus the two-dimensional
spectra show the presence of an OF emission bump in the blend
Hα+[NII], with a peak at the same velocity of the main BAL-I
system (VEjectionBAL-I~-4700 km s-1). This bump
was more clearly detected in the area located at 0.6-1.5 arcsec
(490-1220 pc), to the south-west of the nucleus core, showing a strong
and broad peak. In addition, in the same direction [at position angle
(PA) ~-120°, i.e. close to the PA of the small-scale radio jet] at
1.7-2.5 arcsec, we also detected multiple narrow emission-line
components, with `greatly' enhanced [NII]/Hα ratio (very similar
to the spectra of jets bow shocks). These results suggest that the BAL-I
system is generated in OF clouds associated with the parsec-scale jet.
The Hubble Space Telescope images show four (or possibly five) nuclear
superbubbles or shells with radii r~ 2.9, 1.5, 1.0, 0.6 and 0.2 kpc. For
these bubbles, the two-dimensional Hα velocity field map and
two-dimensional spectra show the following. (i) At the border of the
more extended bubble (S1), a clear expansion of the shell with
blueshifted velocities (with circular shape and at a radius r~ 5.0
arcsec). This bubble shows a rupture arc - to the south - suggesting
that the bubble is in the blowout phase. The axis of this rupture or
ejection (at PA ~ 00°) is coincident with the axis of the
intermediate and large-scale structures detected at radio wavelengths.
(ii) In addition, in the three more external bubbles (S1, S2, S3), the
two-dimensional William Herschel Telescope spectra show multiple
emission-line components with OF velocities, of
S1, S2 and S3 =[-(650 - 420) +/- 30], [-500
+/- 30] and [-230 +/- 30] km s-1. (iii) In the whole
circumnuclear region (1.8 < r < 5 arcsec), the [NII]/Hα and
[SII]/Hα narrow emission-line ratios show high values (>0.8),
which are consistent with low-ionization nuclear emission-line region/OF
processes associated with fast velocity shocks. Therefore, we suggest
that these giant bubbles are associated with the large-scale nuclear OF
component, which is generated - at least in part - by the extreme
nuclear starburst: giant supernova/hypernova explosions.
The variability of the short-lived BAL-III NaI D system was studied,
covering almost all the period in which this system appeared (between
~1984 and 2004). We have found that the BAL-III light curve is clearly
asymmetric with a steep increase, a clear maximum and an exponential
fall (similar to the shape of a supernova light curve). The origin of
this BAL-III system is discussed, mainly in the framework of an extreme
explosive event, probably associated with giant supernova/hypernova
explosions.
Finally, the IR colour diagram and the ultraviolet BAL systems of IR +
GW/OF + FeII QSOs are analysed. This study shows two new BAL IR QSOs and
suggests/confirms that these objects could be nearby young BAL QSOs,
similar to those detected recently at z~ 6.0. We propose that the phase
of young QSOs is associated with accretion of a large amount of gas (by
the supermassive black hole) + extreme starbursts + extreme composite
OFs/BALs.