Refining the Radius–Luminosity Relationship

for Active Galactic Nuclei

Misty BentzThe Ohio State University

October 19, 2006

Collaborators: Brad Peterson, Kelly Denney, Rick Pogge, Marianne Vestergaard

Talk Outline

• Review of Radius—Luminosity Relationship

• Host-galaxy starlight images

• New BLR radii from reverberation-mapping

• Summary and future plans

Radius—Luminosity Relationship

Kaspi, S. et al. 2000 ApJ, 533, 631

Long lags, some not well constrained

Bright, nearby galaxies with faint AGNs and substantial starlight

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

Goal – Measure host galaxy contribution to luminosity

Examples: Aperture Geometry

Examples: Galfit 2-D Image Decompositionsfit

sresiduals

Image Decompositions, cont…fit

sresiduals

PSF Subtractions

Bentz, M. C., et al. 2006, ApJ, 644, 133

Revised Radius—Luminosity Relationship

Excluded Points:

NGC 3516, NGC 7469,IC 4329A: awaiting HST imaging

NGC 4051, NGC 3227: significant nuclear structure & reddening

PG 2130+099: suspicious lag

NGC 4151

NGC 4151τcent = 6.6 +/- 0.9 d σline = 2680 +/- 64 km s-1

MBH = 4.57 +/- 0.52 x 107 M☼

(Bentz, M. C., et al. 2006, ApJ, in press)

NGC 4593 τcent = 3.76 +/- 0.76 days σline = 1547 +/- 53 km s-1

MBH = 9.6 +/- 2.0 x 106 M☼

(Denney, K. D., et al. 2006, ApJ, in press)

New Reverberation Mapping ProgramSpring ’05 Program – Remeasure Hβ Lag Time

6 targets: 2 varied substantially, 1 marginally

See poster by Kelly Denney

HST Imaging Program #2

Cycle 14 GO Program

• 4 Seyferts:NGC3516, NGC4593,

NGC7469, and IC4329A

• Same observational setup as before

• Same techniques employed

New monitoring program Fall ‘06

HST Cycle 15 Program: ACS HRC imaging of last 17 objects

HST imagingJuly ‘06

New monitoring program Spring ‘07

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