1. Refining the Radius–Luminosity Relationship for Active Galactic Nuclei
Misty Bentz
The Ohio State University
October 19, 2006
Collaborators: Brad Peterson, Kelly Denney, Rick Pogge, Marianne Vestergaard

2. Talk Outline • Review of Radius—Luminosity Relationship
• Host-galaxy starlight images
• New BLR radii from reverberation-mapping
• Summary and future plans

3. Radius—Luminosity Relationship
Bright, nearby galaxies with faint AGNs and substantial starlight
Long lags, some not well constrained
- Addition of 17 PG objects allowed real study of relationship by extending L range
- Peterson 2004: self-consistent analysis of all monitoring data, cleaned up plot, but still issues
Kaspi, S. et al ApJ, 533, 631

4. HST Imaging Program Cycle 12 SNAP Program • 14 objects (12 Seyferts,
2 PG quasars)
• ACS HRC camera,
F550M filter
• set of 3 exposures
(120s, 300s, 600s) for
each object
- F550M – narrow band filter that doesn’t allow emission lines from broad or narrow line region, just continuum flux
- Graduated exposures allow correction of saturated nuclear pixels as well as good S/N in outlying galaxy
Goal – Measure host galaxy contribution to luminosity

5. Examples: Aperture Geometry

6. Examples: Galfit 2-D Image Decompositions
fits
residuals

7. Image Decompositions, cont…
fits
residuals

8. PSF Subtractions

9. Revised Radius—Luminosity Relationship
Excluded Points:
NGC 3516, NGC 7469,
IC 4329A:
awaiting HST imaging
NGC 4051, NGC 3227:
significant nuclear
structure & reddening
PG :
suspicious lag
- PG2130 lag suspicious because it’s an outlier in everything and from unpublished collaborator’s proprietary data
- slope of 0.5 consistent with simple photoionization arguments
NGC 4151
Bentz, M. C., et al , ApJ, 644, 133

10. New Reverberation Mapping Program
Spring ’05 Program – Remeasure Hβ Lag Time
6 targets: 2 varied substantially, 1 marginally
NGC 4151
τcent = 6.6 +/- 0.9 d
σline = /- 64 km s-1
MBH = / x 107 M☼
(Bentz, M. C., et al , ApJ, in press)
NGC 4593
τcent = / days
σline = /- 53 km s-1
MBH = 9.6 +/- 2.0 x 106 M☼
(Denney, K. D., et al , ApJ, in press)
See poster by Kelly Denney

11. HST Imaging Program #2 Cycle 14 GO Program • 4 Seyferts:
NGC3516, NGC4593, NGC7469, and IC4329A
• Same observational setup as before
• Same techniques employed

12. New monitoring program Fall ‘06
HST imaging
July ‘06
New monitoring program Spring ‘07
HST Cycle 15 Program:
ACS HRC
imaging of last 17 objects

13. Implications • R-L relationship holds for 5 orders of magnitude
• low luminosity objects have masses ~3x previous estimates
• significant outliers can be expected to have physical differences that separate them from the typical population
R-L relationship now diagnostic tool