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The Size of Absorption Line Systems
Cloud (inhomogeneities) – Object – Large scale correlation
Patrick PetitjeanInstitut d’Astrophysique de Paris
B. Aracil R. Srianand C. Ledoux F. Stoehr C. Pichon
J. Bergeron E. Rollinde M. Longhetti F. Coppolani E. Scannapieco
Damped Lyman-alpha Systems
1. System as a whole Broad-band imaging of the field : HST - z < 1 Le Brun et al. (1997, A&A, 321, 733), Chen et al., Rao et al. -> 10 kpc - z = 1.892 LBQS 1210+1731; Kulkarni et al. (2000, ApJ 536, 36) -> 2 kpc Lenses: - z = 0.93 ; HE0512-3329; 5 kpc ; Lopez et al. 2005, astro-ph/0503026 Lyman- emission : - z > 1.9; Moeller et al. (2004, A&A, 422, L33) => Small sizes -> a few kpc : 2 (high z) to 10 (low z) kpc Additional argument ? : Homogeneity of the gas for abundance ratios Prochaska (2003, ApJ, 583, 49); Rodriguez et al. (submitted)
SiII/SII or FeII/SII are fairly constant through the profile
2. Clouds Physical conditions in the gas: nH = 1 to 100 cm-3 (Srianand et al. 2005;
Ledoux et al. 2003, MNRAS, 346, 209) => 1 (H2) to 100 (diffuse) pc Lenses: < 25 pc (Churchill et al., 2003, ApJ, 593, 203)
MgII systems
1. Systems (z ~ 1) * Broad band imaging and spectroscopic follow-up -> 35 kpc Bergeron & Boissé (1991, A&A 243, 344); Steidel (1993) * Weak MgII systems ? Churchill et al. (2000) -> larger ?
2. Clouds * The case APM08279+5255
Inhomogeneities over 1kpc
Ellison et al. (2004, A&A, 414, 79)
-> photometric redshifts ?
MgII z = 0.73
100 kpc
CIV sytems
1. Clouds - Lenses : Rauch et al. (2001, ApJ, 554, 823)Featureless on scales < 300 pc
2. SystemsMuch larger cross-sectionEspecially for weak systems
=> Correlation functions
Longhetti & Petitjean in prep
CIV z = 1.339
150 kpc
MgII z = 0.58
200 kpc
Overall Picture
• The IGM
• Where are the metals ?
• Physical state ?
• Expelled from the center of Halos -> Winds
• Along filaments
• What about the Voids ?
•Correlations
Along the los -> Big Sample
Transverse -> Pairs or groups
CIV longitudinal correlation function
Large Programme ESO – 643 CIV systems
Column density distribution
SPH Simulation : -Bubbles (radius Rbubble) around haloes of mass Mhalo
- Ionized by the UV background - Los analized the same way as data
Fitting the CIV longitudinal correlation function
Fitting the column density distribution and the correlation function => Mhalo = 5x1011 Msun and Rbubble = 2.5 Mpc
Scannapieco et al., 2005, astro-ph/0503001
for Z/20
Correlation in the Lyman-alpha forest
Longitudinal : Large Programme ESO : 20 LOS UVES R=45000 S/N=40-100
Transverse : 32 pairs 1-3 arcmin observed with FORS
Simulated correlation functions
- Hydro simulations in a 100 Mpc simulation box- Effect of thermal broadening and peculiar velocities on longitudinal and transverse correlation functions
Longitudinal
Transverse
Longitudinal correlation function
UVES
FORS
z=2
z=3
Observed versus Simulated correlation functions
see poster Aghaee
Transverse correlation functionAlcock & Paczynski test
Sample should be increased to derive
Very good prospect for further investigation
Groups of QSOs
Conclusion
Small scales : One to one association
Impact parameters of metal line systems : bigger sample
Completeness ?
Star-formation vs physical state of the gas
Large Scales
Where are the metals ? How are they expelled from the site of
star-formation ?
Spatial distribution of the gas and galaxies; Topology and kinematics (see poster Caucci)