Resolved Inner Disks around Herbig Ae/Be Stars:

Near-IR Interferometry with PTIJosh Eisner

Collaborators: Ben Lane, Lynne Hillenbrand, Rachel Akeson, and Anneila Sargent

• Eisner et al. 2003, ApJ, 598, 1341• Eisner et al. 2004, ApJ, submitted

Ringberg Castle, 2004

Circumstellar Disks

• Disks linked to star and planet-formation

• Accretion mechanism: IMF, stellar rotation, magnetic properties, outflows

• Disk properties (e.g., temperature, density, geometry) dictate planetary properties

• Relation to proto-solar nebula

Artist’s conception of TW Hya Disk

• Herbig Ae/Be stars:– Higher-mass analog of T Tauris: 2-10 M

– Emission lines,variability, excess IR and mm emission

• SED models: thin accretion disks (Hillenbrand et al. 1992), flared disks (Chiang & Goldreich 1997), puffed up inner disk walls (Dullemond et al. 2001)

• Forbidden emission lines (Corcoran & Ray 1997)• H spectropolarimetry (Vink et al. 2002)• Resolved mm emission: flattened structures on

100 AU scales with Keplerian rotation• Strong evidence from new near-IR interferometry

(Corcoran & Ray 1997)

• Herbig Ae/Be stars:– Higher-mass analog of T Tauris: 2-10 M

– Emission lines,variability, excess IR and mm emission

• SED models: thin accretion disks (Hillenbrand et al. 1992), flared disks (Chiang & Goldreich 1997), puffed up inner disk walls (Dullemond et al. 2001)

• Forbidden emission lines (Corcoran & Ray 1997)• H spectropolarimetry (Vink et al. 2002)• Resolved mm emission: flattened structures on

100 AU scales with Keplerian rotation• Strong evidence from new near-IR interferometry

(Dullemond, Dominik, & Natta 2001)

• Herbig Ae/Be stars:– Higher-mass analog of T Tauris: 2-10 M

– Emission lines,variability, excess IR and mm emission

• SED models: thin accretion disks (Hillenbrand et al. 1992), flared disks (Chiang & Goldreich 1997), puffed up inner disk walls (Dullemond et al. 2001)

• Forbidden emission lines (Corcoran & Ray 1997)• H spectropolarimetry (Vink et al. 2002)• Resolved mm emission: flattened structures on

100 AU scales with Keplerian rotation• Strong evidence from new near-IR interferometry

Disks Around HAEBEs

(Vink et al. 2002)

• Herbig Ae/Be stars:– Higher-mass analog of T Tauris: 2-10 M

– Emission lines,variability, excess IR and mm emission

• SED models: thin accretion disks (Hillenbrand et al. 1992), flared disks (Chiang & Goldreich 1997), puffed up inner disk walls (Dullemond et al. 2001)

• Forbidden emission lines (Corcoran & Ray 1997)• H spectropolarimetry (Vink et al. 2002)• Resolved mm emission: flattened structures on

100 AU scales with Keplerian rotation• Strong evidence from new near-IR interferometry

(Mannings & Sargent 1997)

• Herbig Ae/Be stars:– Higher-mass analog of T Tauris: 2-10 M

– Emission lines,variability, excess IR and mm emission

• SED models: thin accretion disks (Hillenbrand et al. 1992), flared disks (Chiang & Goldreich 1997), puffed up inner disk walls (Dullemond et al. 2001)

• Forbidden emission lines (Corcoran & Ray 1997)• H spectropolarimetry (Vink et al. 2002)• Resolved mm emission: flattened structures on

100 AU scales with Keplerian rotation• Strong evidence from new near-IR interferometry

< 0.1-1 AU

• Herbig Ae/Be stars:– Higher-mass analog of T Tauris: 2-10 M

– Emission lines,variability, excess IR and mm emission

• SED models: thin accretion disks (Hillenbrand et al. 1992), flared disks (Chiang & Goldreich 1997), puffed up inner disk walls (Dullemond et al. 2001)

• Forbidden emission lines (Corcoran & Ray 1997)• H spectropolarimetry (Vink et al. 2002)• Resolved mm emission: flattened structures on

100 AU scales with Keplerian rotation• Strong evidence from new near-IR interferometry

…

Palomar Testbed Interferometer

(PTI)

• PTI observations allow large sample, good uv coverage

• longer baselines facilitate detection of asymmetry

• PTI components: – 3 telescopes each 0.4 m

• 110 m NS oriented 20º E of N (4 mas)• 85 m NW oriented 81º E of N (5 mas)• 87 m SW baseline recently operational!

– two apertures (A1,A2), delay lines (DL), beam combiner (BC), single-mode fiber (SMF), detector

B

s

DLDetector

BCSMF

A1A2

DL

delay

ampl

itude s

Fringe Measurement: V2 • I1 ~ e-ik d1 e-it ; I2 ~ e-k d2 e-iks•B e-it; IC = I1 + I2

• P = <IC*IC> = 2+2cos(k [s•B+d1-d2])

• Fringe Spacing: s = /B (~5 mas for PTI)• Visibilities: V(u,v) = ∫ dx dy A(x,y) F(x,y) e-2i(ux+vy)

– u = Bx/ ; v = By/– V is the FT of brightness distribution (van Cittert-Zernike

theorem)– IFT: F(x,y) A(x,y) = ∫ du dv V(u,v) e2i(ux+vy)

• PTI measures normalized V2

Sky U-V

delay

ampl

itude

s

System visibility from unresolved calibrators

PTI Observations of HAEBEs• 2.2 m observations of 14 HAEBEs

SpTyp ~ O9-F0; d~100-1000 pc• Fit models to PTI visibilities: uniform

disk, Gaussian, ring, accretion disk with hole, flared disk with puffed-up inner wall (+star)

• All but 2 sources (HD141569, HD158352) resolved; angular sizes ~1-6 mas.

• Inclinations: – MWC 480, MWC 758, CQ Tau, VV

Ser, V1685Cyg, AS 442, MWC 1080 inclined

– AB Aur nearly face-on– V1295 Aql, T Ori, MWC 297

unknown• Puffed-up inner disk inconsistent

for earliest spectral types: MWC 297, V1685 Cyg, MWC 1080

uv sky

PTI+IOTA Data

• Some of our sample also observed by IOTA (Millan-Gabet, Schloerb, & Traub 2001)– K-band: AB Aur, MWC 1080– H-band: AB Aur, T Ori, MWC 297,

V1295 Aql, V1686 Cyg, MWC 1080• Shorter baselines than PTI (20-40m vs.

85-110m)additional constraints on geometry

• Larger FOV than PTI (3˝ vs 1˝) constrains incoherent emission from extended dust

SEDs• Inner radius, inclination from PTI data; provide inputs for

SED modeling. Can probe large range of disk radii, constrain parameters including temperature, overall geometry, mass)

• SEDs compiled from new JHK PALAO data and the literature (stellar params from published spec type & BVRI photometry)

• 2 models: –geometrically thin accretion disks w/ inner holes –flared 2-layer disks w/ puffed-up inner walls

T(R) R-3/4

Parameters: Rin,i, Tin (Rout)

Trim, Tint, Tsurf

Parameters: Rin, i, Tin,Rout,

Geometrically Flat Accretion Disks

Flared Passive Disks with Puffed-Up Inner Walls

Inner Disk Vertical Structure• For later-type

HAEBEs, puffed-up inner disk models better

• Early-types are fit well by flat disk models; not at all by puffed-up inner walls

• Different accretion mechanism?

Puffed-Up Inner DisksFlat Inner Disks

Inner vs. Outer Disks: Warping? PTI near-IR: i ≈ 10-20

Millimeter: i ≈ 76

Mannings & Sargent 1997

(Lack of) Disk Warping

Source PTI i mm i mm ref.

AB Aur 10-15˚ ~76˚; <30˚ Mannings & Sargent 1997; Natta et al. 2001; Corder et al. in prep.

MWC 480 24-32˚ ~30˚ Mannings et al. 1997

MWC 758 33-37˚ ~46˚ Mannings & Sargent 1997

CQ Tau 48˚ ~70˚; ~45˚ Testi et al. 2003; Corder et al. in prep.

Summary

• PTI observations of 14 HAEBEs: 12 resolved (1-6 mas), ≥7 significantly inclined

• No significant mis-alignment of inner and outer disks

• Different vertical disk structure for early and late spectral types– Flat accretion disks better for early-types– Flared disks w/ puffed-up inner walls for later types– Magnetospheric accretion in HAes vs. Equatorial

accretion in HBes?

The End.