High Resolution Mid-High Resolution Mid-Infrared Imaging of Dusty Infrared Imaging of Dusty Circumstellar Structure Circumstellar Structure

around Evolved Stars with around Evolved Stars with the MMT Adaptive Optics the MMT Adaptive Optics

SystemSystemB.A. Biller, L.M. Close, A. Li, J.H. B.A. Biller, L.M. Close, A. Li, J.H. Bieging, W.F. Hoffmann, P.M. Hinz, D. Bieging, W.F. Hoffmann, P.M. Hinz, D. Potter, D. Miller, G. Brusa, M. Lloyd-Potter, D. Miller, G. Brusa, M. Lloyd-

Hart, F. Wildi, and B.D. Oppenheimer,Hart, F. Wildi, and B.D. Oppenheimer, Steward ObservatorySteward Observatory

High Resolution Adaptive High Resolution Adaptive Optics Imaging in the Mid-Optics Imaging in the Mid-

InfraredInfrared MMT adaptive secondary MMT adaptive secondary

removes ~8 warm optical removes ~8 warm optical elements compared to elements compared to standard AOstandard AO

Background 3x lower than Background 3x lower than standard AO opens up standard AO opens up Mid-IR wavelengths to AOMid-IR wavelengths to AO

Can achieve Strehls of Can achieve Strehls of ~100% at Mid-IR ~100% at Mid-IR wavelengths and wavelengths and resolution down to the resolution down to the diffraction limit.diffraction limit.

Lifecycle of Evolved Lifecycle of Evolved StarsStars

AGB (Asymptotic Giant Branch)AGB (Asymptotic Giant Branch)• Significant ISM enrichment through Slow WindSignificant ISM enrichment through Slow Wind• In some cases, dense toroidal structure can form In some cases, dense toroidal structure can form

Post-AGB / Proto-Planetary NebulaPost-AGB / Proto-Planetary Nebula

• Mass loss ceasesMass loss ceases• Circumstellar material observable primarily in IRCircumstellar material observable primarily in IR

White Dwarf / Planetary NebulaWhite Dwarf / Planetary Nebula• Hard photons from white dwarf ionize and light up Hard photons from white dwarf ionize and light up circumstellar material.circumstellar material.

Planetary Nebulae Planetary Nebulae ShapesShapes

Collimation due to: Magnetic Fields Dense Toroidal Structure Binary Interaction Not Well Understood

Balick and Frank (2002)

RV Boo and CH CygRV Boo and CH Cyg

RV Boo – AGB star with possible Keplerian RV Boo – AGB star with possible Keplerian diskdisk

CH Cyg -- Only known symbiotic triple star – CH Cyg -- Only known symbiotic triple star – consists of:consists of: inner red giant/white dwarf pair inner red giant/white dwarf pair

(period~800 days, Hinkle et al. 1993)(period~800 days, Hinkle et al. 1993) outer red giant (period ~ 14.5 years, outer red giant (period ~ 14.5 years,

Skopal et al. 1996)Skopal et al. 1996) system viewed nearly edge onsystem viewed nearly edge on

A Keplerian Disk around A Keplerian Disk around RV Boo?RV Boo?

Bergman et al. (2000)

RV Boo – Raw DataRV Boo – Raw Data Observations @ 9.8 m SR ~ 100%! 145 Jy RV Boo total flux 5% eccentricity

Super-Resolution through Super-Resolution through DeconvolutionDeconvolution

0.16” (60 AU @ 390 pc) FWHM disk,Position Angle of 120o comparable to that of CO disk.

0.1”

Parallactic Angle vs. Parallactic Angle vs. Position AnglePosition Angle

ModelingModeling Emission modeled using A. Li’s dust thermal emission models. Grain size distribution modeled as a power law. Minimum grain size: 0.01 m Maximum grain size: 1000 m Dust spatial distribution modeled as a modified power law. Star modeled using Kurucz 3000 K M6IIIe star model. Fit SED to our 9.8 m point and IRAS/ISO fluxes and spectra. Best fit model had disk inclination of 30oo to 40o from edge on and a mid-IR disk mass of 1.6 x 10-6 Msun

Model ComparisonModel Comparison

CH Cyg CH Cyg

Only known symbiotic triple star – consists Only known symbiotic triple star – consists of:of: inner red giant/white dwarf pair inner red giant/white dwarf pair

(period~800 days, Hinkle et al. 1993)(period~800 days, Hinkle et al. 1993) outer red giant (period ~ 14.5 years, outer red giant (period ~ 14.5 years,

Skopal et al. 1996)Skopal et al. 1996)system viewed nearly edge onsystem viewed nearly edge onMultiple outbursting phases since Multiple outbursting phases since

19631963

CH Cyg – Raw ImagesCH Cyg – Raw Images

CH Cyg – Cut PlotsCH Cyg – Cut Plots9.8 m horizontal 9.8 m vertical

11.7 m horizontal 11.7 m vertical

e vs. FWHMe vs. FWHM

9.8 m

11.7 m

Deconvolution – Deconvolution – Highlighting the Highlighting the

Spherically Symmetric Spherically Symmetric StructureStructure

CH Cyg – Modeling CH Cyg – Modeling The Symmetric StructureThe Symmetric Structure

CH Cyg – Residual “Jets”CH Cyg – Residual “Jets”

Crocker et al. 2001

ConclusionsConclusions RV Boo (Biller et al. 2005) -- 0.16” disk (60 AU RV Boo (Biller et al. 2005) -- 0.16” disk (60 AU

at 390 pc) with PA of 120at 390 pc) with PA of 120oo and inclined 30-45 and inclined 30-45oo from edge on.from edge on.

CH Cyg (Biller et al. 2006) – Nearly spherically CH Cyg (Biller et al. 2006) – Nearly spherically symmetric extension after deconvolutionsymmetric extension after deconvolution FWHM(9.8 FWHM(9.8 m) of 0.15m) of 0.15++0.01” (40.50.01” (40.5++2.7 AU at 270 2.7 AU at 270

pc.)pc.) FWHM(11.7 FWHM(11.7 m) of 0.17m) of 0.17++0.01” (45.90.01” (45.9++2.7 AU at 270 2.7 AU at 270

pc.)pc.) Fainter, ~0.7” asymmetric extension stretching Fainter, ~0.7” asymmetric extension stretching

north to south, with similar direction/size to the north to south, with similar direction/size to the radio/optical jets imaged by Crocker et al. 2001.radio/optical jets imaged by Crocker et al. 2001.

X Her and RS CncX Her and RS Cnc

Followup ObservationsFollowup Observations