Chemical Abundances in AGN: the Mrk 279 Outflow
Nahum Arav
University of Colorado Boulder
Collaborators:
Jack Gabel, Jelle Kaastra, Gerard A. Kriss, Kirk T. Korista,, Jennifer E. Scott, Daniel Proga,
Katrien C. Steenbrugge, Ehud Behar, Ari Laor, Masao Sako
Using all velocity constraints:
• For Cloudy solar abundances:
C=2.45x10^-4 N=8.5x10^-5 O=4.9x10^-4
• Minimal reduced summed over 15
velocity bins = 4.2 for 44 (75-1-30) dof
2
Using all velocity constraints:
• For Cloudy solar abundances:
C=2.45x10^-4 N=8.5x10^-5 O=4.9x10^-4
• Minimal reduced summed over 15
velocity bins = 4.2 for 44 (75-1-30) dof
• For C=2.2 N=3.5 O=1.6 (times solar)
Minimal reduced summed over 15
velocity bins = 1.2 for 41 (75-1-30-3) dof
2
2
Chemical abundances in Mrk 279
• For solar abundances: C=2.45x10^-4 N=8.5x10^-5 O=4.9x10^-4
C=2.2 N=3.5 O=1.6 times solar
90% Confidence interval
C= 1.5—2.9, N=2.4—4.6, O=0.9—2.4
Summary: Modeling AGN outflows
Analysis Key: Accurate Ionic column densities
Obstacles:- The absorber is not an homogeneous full screen!- Velocity dependent covering factor (separate for continuum and BEL)
Solutions- Data needed: Unblended doublets (CNO) and Lyman series, high S/N- Velocity dependent covering-factor and photoionization models
The Mrk 279 outflow: U~-1 (UV) ~0 (X-ray) NH~10^20
Abundances C=2.2 N=3.5 O=1.6 solar units