Berkeley-Illinois-Maryland Assoc. (BIMA) Array

CO J=1-0 Survey

M. Meixner (STScI)

Collaborators: Fong, Justtanont,Sutton, Welch, Zalucha

Background/motivationObservationsModelsSummary

Conclusions

• Observed features: expanding shells, protrusions, collimated outflows, rotation

• Kinematic trichotomy: -simple expansion with protrusions

found in elliptical (SOLE) PPN -expansion + collimated outflows found in bipolar (DUPLEX) PPN -expansion + rotation (new class)

• Mass loss histories

Motivations for CO J=1-0

• Best tracer of molecular gas mass

• AGB mass loss is predominantly molecular

• Kinematics in proto-planetary nebulae (0.5 km/s)

• Toughest molecule w.r.t. photodissociation => probes outer regions

CO

VexpVexp

V0

V0-Vexp

V0+Vexp

V0 Jy

V0V0-Vexp

V0+Vexp

Vexp

Vexp

Observations

• Millimeter interferometry with the BIMA array

• Combined with single dish maps from the NRAO 12 m

• Full synthesis maps provide– Spectral resolution 1 km/s, coverage 128 km/s– 0.5" to 200" scale sizes

Three kinematic signatures

I. Simple expansion: IRC+10216 (Fong), IRAS 22272+5435, HD179821, HD 161796, HD 56126, IRAS 21282+5050

II. Expansion + collimated outflows: AFGL 2688, NGC 7027, AFGL 618

III. Expansion + rotation: Mira, 89 Her, Red Rectangle (Doering)

IRAS 22272+5435

IRAS 22272+5435

IRAS 22272+5435

HD 179821

HD 179821

HD 179821

HD 161796

HD 161796

HD 161796

Simple expansion:PPN show protrusions but no

outflows to create them.

How did they form?

Egg Nebula / AFGL 2688

Egg Nebula / AFGL 2688

Egg Nebula / AFGL 2688

Egg Nebula / AFGL 2688

NGC 7027

NGC 7027

NGC 7027

NGC 7027

Expansion + collimated outflows

• Velocity of collimated outflow is faster than the expansion velocity of the envelope (AFGL 2688 and NGC 7027)

• Collimated outflows or bullets?

Mira

Mira

89 Her

89 Her

Expansion + rotation

• Rotation? Or low velocity bipolar outflow?

• Expansion velocity of the envelope is greater than the rotation/bipolar velocity (Mira, 89 Her)

• In either case, they are kinematically distinct from expansion + collimated outflow

HD 56126

HD 56126

HD 56126: Models & Observ.

Parameter Value

D 2.4 kpc

Rin 3.6×1016 cm

Rout 2.5×1017 cm

RSW 1.3×1017 cm

Vexp 11 km s-1

CO/H2 1.1×10-3

dMAGB/dt 5×10-6 MO yr-1

dMSW/dt 3×10-5 MO yr-1

Mgas/Mdust 800

Conclusions

• Observed features: expanding shells, protrusions, collimated outflows, rotation

• Kinematic trichotomy: -simple expansion with protrusions

found in elliptical (SOLE) PPN -expansion + collimated outflows found in bipolar (DUPLEX) PPN -expansion + rotation (new class)

• Mass loss histories

Vexp-Vexp

V0

V0-Vexp

V0+Vexp

V0 Jy

V0V0-Vexp

V0+Vexp