The AGN-host galaxy connection : new insights from the extended ionised gas [Elektronische Ressource] / Bernd Husemann. Betreuer: Lutz Wisotzki
142 pages
English

The AGN-host galaxy connection : new insights from the extended ionised gas [Elektronische Ressource] / Bernd Husemann. Betreuer: Lutz Wisotzki

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142 pages
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Publié le 01 janvier 2011
Nombre de lectures 28
Langue English
Poids de l'ouvrage 14 Mo

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The AGN-host galaxy connection:
New insights from the extended ionised gas
Bernd Husemann
Astrophysikalisches Institut Potsdam
Dissertation
zur Erlangung des akademischen Grades
doctor rerum naturalium (Dr. rer. nat.)
in der Wissenschaftsdisziplin Astrophysik
Eingereicht an der Mathematisch-Naturwissenschaftlichen Fakultat¨
der Universitat¨ Potsdam
31 Marz¨ 2011This work is licensed under a Creative Commons License:
Attribution - Noncommercial - Share Alike 3.0 Germany
To view a copy of this license visit
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Published online at the
Institutional Repository of the University of Potsdam:
URL http://opus.kobv.de/ubp/volltexte/2011/5555/
URN urn:nbn:de:kobv:517-opus-55556
http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-55556 Contents
Abstract 5
Zusammenfassung 7
1 Introduction 9
1.1 Active Galactic Nuclei . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.2 AGN host galaxies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.3 Tracing the AGN host interplay via ionised gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
1.4 Goals and outline of this work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2 Mapping the ionised gas around the luminous QSO HE 1029 1401: Evidence for minor merger events? 21
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.2 Morphology of the host galaxy of HE 1029 1401 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.3 IFU Observations and Data Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.4 IFU decomposition of host and QSO emission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.5 Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.6 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.7 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.8 Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3 The properties of extended emission-line regions around low-redshift QSOs and the lack of high-velocity AGN out-
flows 35
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.2 The QSO sample and characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.3 Spatially resolved spectroscopy of QSOs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
3.4 AGN parameters from the QSO spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.5 Emission line diagnostics of EELRs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
3.6 Kinematics of the EELRs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3.7 The extended narrow-line region . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
3.8 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
4 Integral field spectroscopy of nearby QSOs:
Emission-line diagnostics, resolved gas-phase metallicities & the NLR size-luminosity relation 67
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
4.2 The QSO sample . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
4.3 Observations and data reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
4.4 Spectral QSO-host deblending in 3D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
4.5 Emission-line measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
4.6 diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
4.7 Gas-phase metallicities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
4.8 NLR scaling relations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
4.9 Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
5 The low-metallicity QSO HE 2158 0107: A phase of galaxy and BH growth due to cold gas accretion? 93
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
5.2 Observations and data reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
5.3 Black hole mass and NLR metallicity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
5.4 The multi-colour SED of HE 21584 0107 and its bulge mass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
5.5 Discussion and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
6 Conclusions and Outlook 105
6.1 Summary of results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
6.2 Future Prospects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
3DA Deblending of AGN and hosts emission in IFU data:QDeblend 109
A.1. Description of the algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
3DA.2. The Graphical User Interface of QDeblend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111B Analysis of QSOs spectra 113
B.1. Modelling of the broad-line AGN spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
B.2. BH masses and Eddington ratios from single-epoch AGN spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
B.3. Uncertainty of measurements and possible observational systematics . . . . . . . . . . . . . . . . . . . . . . . . . 117
B.4. Bolometric correction based on emission lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
C Results of the spectral QSO-host deblending for the QSOs observed with VIMOS 123
D Gas and stellar kinematics of QSO hosts in the VIMOS sample 127
D.1. Kinematic maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
D.2. Comments on individual objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
E Kinematics of the nuclear [O iii]5007 line 133
E.1. Blueshifted [O iii] line in QSO spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
E.2. Systemic redshift from gas and stellar kinematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
E.3. Testing the use of the [O iii] line width as a proxy for . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
F Systematic eects and detection limits recovered with simulations 139
F.1. Systematics of the QSO-host decomposition for HE 2158 0107 . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
F.2. Estimation of the [N ii] detection limit in the spectra of HE 2158 0107 . . . . . . . . . . . . . . . . . . . . . . . . 140
Acknowledgements 141Abstract
Active Galactic Nuclei (AGN) are powered by gas accretion onto supermassive Black Holes (BH), that are sus-
pected to reside at the centre of all galaxies with a bulge component. The luminosity of AGN can exceed the
integrated luminosity of their host g by orders of magnitude, which are then classified as Quasi-Stellar
Objects (QSOs). Some mechanisms are needed to trigger the nuclear activity in galaxies and to feed the nuclei
with gas. Among several possibilities, such as gravitational interactions, bar instabilities, and smooth gas accretion
from the environment, the dominant process has yet to be identified. Feedback from AGN may be important for
the evolution of galaxies, since the BH mass is correlated with several bulge properties and the fraction of AGN
among galaxies is the highest for host galaxies with intermediate colours between blue star forming and red quies-
cent galaxies. Theoretical studies showed that the local galaxy population can be better reproduced assuming that
a fraction of the AGN luminosity is transferred onto the host galaxies to suppress star formation or even to expel a
large fraction of the gas. However, the details of this coupling between AGN and their host galaxies remain unclear.
In this work we aim to inve

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