1. Intrinsic Absorption of Mrk 279
The Variable UV
Intrinsic Absorption of Mrk 279
Jennifer E. Scott NRC/NASA/GSFC
N. Arav, J. Gabel (CASA/CU) G. Kriss, J. Kim Quijano (STScI)

2. Mrk 279 Observations Summary
Date
Instrument
ksec
1999 Dec
FUSE 61
2000 Jan 30
2002 Jan 37
2002 May 47
STIS/E140M 13
CXO/HETGS
114
2003 May 91 41
CXO/LETGS
340
Two sets of coordinated observations
How do changes in emission components impact absorption profiles?
Photoionization
Effective Covering fraction
(lines vs .continuum, or ILR vs. BLR )

3. Continuum Variability
Dec. 1999
Flux
May 2003
Jan. 2000
Jan., May 2002
Spectral index

4. Mrk 279
Seyfert 1 galaxy z=0.0305
Five velocity components of UV absorption
Most likely intrinsic absorption -300 < vout< -200 km/s
Scott et al. 2004, Gabel et al. 2005

5. Absorption Profile with Multiple Emission Sources
Each source i (continuum, BLR, etc.) contributes Ri to total flux at pixel j
Effective covering fraction is a weighted sum of individual covering fractions
Gabel et al. 2005, Scott et al. 2004

6. Change in Lyman alpha absorption profile can be explained by change in relative contribution of continuum and BLR
No change in covering fraction or column density necessary
Gabel et al. 2005

7. Global CNO Fits to 2003 Spectra
Gabel et al. 2005

8. Relative contribution of emission lines is larger in 2002 low flux state

9. Can changes in O VI, N V, and C IV be explained in a similar way?
Use well-constrained 2003 covering fractions, column densities
Try to reproduce 2002 profiles by:
Allowing the covering fraction of the intermediate line region (ILR) to be different from that of the BLR. (See emission profiles below)
(2) Vary the column densities according to changes in the ionizing flux (photoionization models)

10. Relative contributions of ILR and BLR change with continuum level

11. Relative contributions of ILR and BLR change with continuum level

12. Relative contributions of ILR and BLR change with continuum level

13. Photoionization Models: Spectral Energy Distributions

14. Photoionization Models: 2002/2003 Column Density Ratios

15. O VI: Compare 2002 profiles to variations on 2003 Cc, CBLR, N solutions

16. N V: Compare 2002 profiles to variations on 2003 Cc, CBLR, N solutions

17. C IV : Compare 2002 profiles to variations on 2003 Cc, CBLR, N solutions

18. For -300 < vout < -200 km/s absorption
2002 (low state) vs (high state):
O VI: CILR = 0, saturation -> N(O VI) unconstrained
N V
CILR = 0.5 CBLR, same N(N V) -or-
0 < CILR < 0.5 CBLR, larger N(N V) in 2002 vs. 2003
C IV
C ILR= C BLR, same N(C IV) -or-
0.5 CBLR< C ILR < C BLR, larger N(C IV) in 2002 vs. 2003
Problem with C III?

19. Expect the column density to vary by a factor of up to ~1000 for observed changes in ionizing flux. However, profile changes little, particularly over -300 < vout < -200 km/s