Cool gas in brightest cluster galaxies
Oonk, J.B.R.
Citation
Oonk, J. B. R. (2011, October 6). Cool gas in brightest cluster galaxies. Retrieved from https://hdl.handle.net/1887/17900
Version: Corrected Publisher’s Version
License: Licence agreement concerning inclusion of doctoral thesis in the Institutional Repository of the University of Leiden
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Cool Gas in Brightest Cluster Galaxies
Cool Gas in Brightest Cluster Galaxies
Proefschrift
ter verkrijging van
de graad van Doctor aan de Universiteit Leiden,
op gezag van de Rector Magnificus prof. mr. P.F. van der Heijden, volgens besluit van het College voor Promoties
te verdedigen op donderdag 6 oktober 2011 klokke 11.15 uur
door
Johannes Bernardus Raymond Oonk
geboren te Hengelo in 1981
Promotiecommissie
Promotor: Prof. dr. W. Jaffe Overige leden: Dr. J. Brinchmann
Prof. dr. A. C. Fabian (University of Cambridge) Prof. dr. F. P. Israel
Prof. dr. K. Kuijken
ISBN: 978-94-6191-031-8
Contents vii
Contents
Page
Chapter1. Introduction 1
1.1 Galaxy Clusters. . . 1
1.2 Cool-core Clusters . . . 1
1.3 The hot gas at T>107K . . . 2
1.4 The cool gas at T<104K . . . 2
1.5 This Thesis . . . 3
1.6 Outlook . . . 5
Chapter2. Warm Molecular Gas in Abell 2597 and Sersic 159-03 7 2.1 Introduction . . . 8
2.1.1 This project . . . 10
2.2 Observations and reduction . . . 10
2.2.1 Near Infrared Data . . . 10
2.2.2 X-ray Data . . . 13
2.2.3 Radio Data . . . 14
2.3 Abell 2597 – Gas Distribution . . . 14
2.3.1 Molecular gas . . . 15
2.3.2 Ionised gas . . . 16
2.4 Abell 2597 – Gas Kinematics . . . 16
2.4.1 Molecular gas . . . 17
2.4.2 Ionised gas . . . 18
2.4.3 Filaments . . . 18
2.5 Sersic 159-03 – Gas Distribution. . . 19
2.5.1 Molecular gas . . . 20
2.5.2 Ionised gas . . . 20
2.6 Sersic 159-03 – Gas Kinematics . . . 21
2.6.1 Molecular gas . . . 21
2.6.2 Ionised gas . . . 22
2.6.3 Filaments . . . 22
2.7 Physical Conditions in the Warm Molecular Gas . . . 22
2.7.1 A2597: Selected regions . . . 23
2.7.2 S159: Selected regions . . . 24
2.7.3 Thermal excitation of the molecular gas . . . 24
2.7.4 Luminosity of the Warm Molecular Gas . . . 26
2.7.5 Mass of the Warm Molecular Gas . . . 27
2.7.6 Mass of the Ionised Gas . . . 27
2.7.7 Stability of the Filaments . . . 28
2.8 X-ray and Radio Emission . . . 29
viii Contents
2.8.1 X-ray emission . . . 29
2.8.2 Radio emission . . . 30
2.9 Summary . . . 32
2.10 Conclusions . . . 35
A.1 . . . 58
A.2 . . . 58
A.3 . . . 58
Chapter3. FUV emission in Abell 2597 and Abell 2204 67 3.1 Introduction . . . 68
3.1.1 This project . . . 69
3.2 . . . 70
3.2.1 HST ACS-SBC imaging . . . 70
3.2.2 Optical data . . . 71
3.2.3 Radio data. . . 71
3.2.4 X-ray data . . . 72
3.3 . . . 72
3.3.1 FUV: A2597 and A2204. . . 72
3.3.2 Optical: A2597 and A2204 . . . 73
3.3.3 Radio and X-ray emission . . . 73
3.3.4 Surface brightness profiles . . . 75
3.4 Total FUV/U emission . . . 76
3.4.1 Bruzual & Charlot 2003 SSP models. . . 76
3.5 Excess FUV/U: Stellar Origin ? . . . 77
3.5.1 Contamination by line emission . . . 77
3.5.2 Removing the old stellar population . . . 79
3.5.3 The FUVν,exc/Uν,excexcess ratio . . . 80
3.5.4 Nebular continuum emission . . . 81
3.5.5 Dust intrinsic to the BCG . . . 82
3.6 Star formation . . . 83
3.6.1 The Hα nebula . . . 83
3.6.2 FUV and Hα star formation rates. . . 84
3.6.3 Dust and gas mass estimates from AV . . . 85
3.7 Excess FUV/U: Non-stellar Origin ? . . . 86
3.7.1 Active Galactic Nuclei . . . 86
3.7.2 Non-thermal processes . . . 86
3.8 . . . 86
3.8.1 Crawford & Fabian 1993 . . . 86
3.8.2 Hicks et al. 2010 . . . 88
3.8.3 The extinction law in BCGs . . . 88
3.8.4 A2597 versus A2204 . . . 90
3.9 . . . 91
B.1 . . . 116
B.2 . . . 119
B.3 . . . 121
Contents ix Chapter4. Herschel photometry of brightest cluster galaxies in cooling flow clusters123
4.1 Introduction . . . 124
4.2 Observations . . . 124
4.2.1 PACS Data . . . 125
4.2.2 SPIRE Data . . . 125
4.3 Results . . . 126
4.4 Discussion and conclusions . . . 128
4.5 Acknowledgements. . . 129
Chapter5. Herschel observations of FIR emission lines in brightest cluster galaxies 135 5.1 Introduction . . . 136
5.2 Observations . . . 137
5.3 Results . . . 138
5.4 Discussion . . . 140
5.5 Conclusions . . . 141
5.6 Acknowledgements. . . 141
Chapter6. Optical Line Emission in BCGs 143 6.1 Introduction . . . 144
6.1.1 This Project . . . 144
6.1.2 Targets . . . 145
6.2 . . . 145
6.3 . . . 146
6.3.1 Spatially integrated spectra . . . 147
6.3.2 Variations along the Slit . . . 148
6.4 Diagnostic diagrams . . . 149
6.5 . . . 150
6.5.1 Dust . . . 150
6.5.2 Temperature. . . 151
6.5.3 Density . . . 151
6.5.4 Metallicity . . . 152
6.5.5 Ionisation Parameter . . . 152
6.6 MAPPINGS III line modelling . . . 153
6.6.1 Stars. . . 154
6.6.2 AGN . . . 155
6.6.3 Bremsstrahlung . . . 156
6.7 Combining Stars and Bremsstrahlung . . . 157
6.7.1 The combined model grid . . . 157
6.7.2 Exploring the best-fit combined models . . . 158
6.7.3 Gas heating in A2597. . . 161
6.8 . . . 165
6.8.1 Warm, low-ionisation gas in BCGs . . . 165
6.8.2 Comparison with previous studies . . . 167
6.9 . . . 169
C.1 . . . 196
x Contents C.1.1 Photon spectra A2597 . . . 196 C.1.2 Ionisation fractions A2597 . . . 203
Nederlandse samenvatting 205
Curriculum Vitae 213
Nawoord 215
