The Fundamental Plane of Quasars

1. The Fundamental Plane of Quasars …Putting the “fun” back in “Fundamental Plane”! Timothy Scott Hamilton NASA/GSFC, National Research Council

2. QSO Fundamental Plane Abstract The “Fundamental Plane” for quasars relates the nuclear luminosity to the size and surface brightness of the host galaxy. Quasars lie on a thin plane within this phase space. Comparisons with the elliptical galaxy fundamental plane could tell us about the formation history of quasars. The “tilt” of the plane might be a characteristic of the type of active galaxy.

3. Full Sample • 70 low-z QSOs from Hubble Space Telescope archives • MV < -23 • redshifts 0.06 < z < 0.46 • WFPC2 broad-band filters

4. Restricted Sample • Require: • Host: Elliptical or elliptical bulges of spirals • Effective radius (re )and effective magnitude (me ) • Nuclear x-ray luminosity (Lx ) • Literature data from ROSAT (mostly) and other missions. • Eliminated 4 outliers Restricted sample has 38 QSOs.

5. Image Analysis • Standard HST pipeline and cosmic-ray removal. • Fit PSF structure to core—color, focus, centering. • Fit 2-D PSF+host models simultaneously. • Subtract PSF model to reveal host.

6. Image Analysis: PG 0052+251 Cosmic-ray cleaned, before PSF removal

7. Image Analysis: PG 0052+251 PSF model

8. Image Analysis: PG 0052+251 PSF + host models

9. Image Analysis: PG 0052+251 PSF-subtracted host

10. PG 0052+251 Bulge Before After

11. Physical Parameters • Obtain MV(nuc) from fitted PSF scaling. • re directly from host model. • MV(host) from PSF-subtracted image, with model used only to fill in missing data and extrapolate to infinite radius. • Bulge and disk fitted separately. • X-ray luminosity & black hole masses from literature.

12. Varieties of Hosts SB S MS 0801.9+2129 PG 0052+251 E S? Q 2215-037 PG 1309+355

13. Host vs. Nuclear Luminosity

14. Look for multiple correlations MV(host) vs. MV(nuc) shows a weak correlation. Look for host—nuclear correlations among several parameters at once. Principal Components Analysis

15. Principal Components Analysis(PCA) • Looks for correlations in multi-dimensional data. • Rotates coordinate axes to align with directions of greatest variance—finds the eigenvectors. • If there are strong correlations, the dataset might be described by smaller number of parameters.

16. First-Run PCA • Used MV(nuc), MV(bulge), & log re • First two eigenvectors account for 89% of variance. • QSOs lie roughly in a thick plane defined by first 2 eigenvectors. • Third eigenvector (11%) accounts for thickness of plane.

17. Improved PCA • Use MV(nuc), me , & log re • 96% of variance explained by 2 eigenvectors. • Plane is thinner. • Only 4% variance in third eigenvector. •  The “Fundamental Plane” of quasars.

18. X-ray PCA • Perform PCA using x-ray nuclear luminosities: log LX, me , & log re • First two eigenvectors explain 95% of variance.

19. Subsample PCA results

20. QSO FP • QSO optical fundamental plane: MV(nuc) = 3.1 me - 13 log re - 76 • QSO x-ray fundamental plane: log LX = -1.9 me + 7.9 log re + 78

21. Accuracy of QSO FP Optical fundamental plane vs. data X-ray fundamental plane vs. data

22. Derivation from Normal FP? • Normal galaxy FP (Scodeggio et al. 1998): log re = 1.35 sc + 0.35 me + Constant • Use MBH ~ sc relation to get black hole masses. • Obtain MV(nuc) from MBH? • No! • …and why not? 

23. Black Hole vs. Nucleus

24. QSO Fundamental Plane:Comparison with Derivation • QSO FP derived from normal galaxy fundamental plane: log re = -0.41 MV(nuc) + 0.35 me + Constant • QSO FP (correct form, from PCA): log re = -0.074 MV(nuc) + 0.23 me + Constant  This argues that we do not have the complete story.

25. Edge-on views of plane Complete sample Radio-louds in ellipticals

26. Size—Surface Magnitude

27. Size—Surface Magnitude • Indicator of galaxy merger history? • Equal-sized mergers shallow slope • Big swallows small  steep slope • Group by RL/RQ • Inconclusive. • …Dead-end for interpretation?

28. Size—Surface Magnitude

29. FP Tilt • Quasar FP is composed of different overlapping, tilted planes for different subsamples. • Subsamples have same re ~ me slopes but different tilts relative to MV(nuc) . • So host behavior is ~same, but it is connected to the nucleus in different ways. •  Is slope characteristic of accretion mechanism?

30. Testing Meaning of QSO FP • Analyze lower-luminosity AGN: • Seyferts, radio galaxies, blazars, Low-Luminosity AGN, etc. • Do other AGN classes have fundamental planes? • How do those planes compare with the QSO FP?

31. Possible Outcomes • Plane is parallel to QSO FP but shifted. • Host type has little effect on AGN type. What creates the difference? • Plane is tilted to QSO FP. • FP slope is characteristic of AGN type. Slope directly tied to accretion mechanism? • They share the QSO FP. • AGN power scales directly with the galaxy properties! Even across types. • Argument for unification. • No trend whatsoever. • QSOs have special property not shared by other AGN. High-powered objects more closely connected with their host properties. • ?!?

32. Status of Project • LLAGN (sample of Ho et al. 2001) show evidence of a fundamental plane (90% of variance). • Strong encouragement for additional work! • Proposals for Chandra observations. • Hubble and Chandra archival data next.