The feeding and feedback of massive protostars

Michael D Smith et al. CAPS

University of Kent

September 2012

● 2

Talk outline

The Model: Scenarios, Mechanisms and Stages ● Scheme construction● Feeding: clump to envelope to disc to

star+jets● Evolutionary Model (abrupt, gradual,

episodal, eruptive)● Feedback predictions● Global predictions

The Revolution● Rapid conception - turbulence ephemeral clouds

● The Birth: abrupt Class 0 high accretion

● Powerful jets: strong extraction

● Form in clusters in giant clouds spatial distribution

● Brown dwarfs and planets mass distribution

● Starbursts global evolution

● Primordial stars: early re-ionisation z=20 stars

Turbulence, Gravity, Feedback, Regulation, Interaction, Triggering: COMPLEX SYSTEM

● Michael D. Smith - Accretion Discs

● 4

Star & Planet Building

● Discs evolve: massive to light● Accretion rate determined by envelope● No single development (numerical +

observed)● MSN is irrelevant: far exceeded in Class 0/I

stages● Star and planets form out of the same disc

● Turbulence, Gravity, Feedback, Regulation, Interaction, Triggering:

COMPLEX SYSTEM

Red X Radio sources (VLA)

Blue <> millimetre cores

Yellow + sub-millimetre cores

Green Optical HH shocks

Light blue Infrared sources

Contours H2 molecules

Image H(alpha) / S[II]

● The Confusion

Motivation

• Dedication to massive stars

How? How do the observable phenomena/components correlate? Is there a systematic evolution? Tracks?

• Why? What processes and physics are implied?

Specific Motivations

• Where does the angular momentum end up?

• Are jets a necessity?

• Why don’t clusters overheat?

• When can jets occur along with HII regions?

• Is the accretion hot/cold/outbursting?

● mass conservation

● prescribed accretion rate

● bifurcation coefficient

● jet speed ~ escape speed

The Unification Scheme: Construction● Clump Envelope Accretion Disc Protostars

● Bipolar Outflow Jets ● Evolution:

● systematic and simultaneous

• Protostar L(Bolometric)

• Jet L(Shock)

• Outflow Momentum (Thrust)

• Clump/Envelope Mass

• Class Temperature

• Disk Infrared excess

The Unification Scheme: Construction

● Clump Envelope Accretion Disc Protostar

● Bipolar Outflow Jets

● Lyman Flux

● thermal radio jets

● H2 shocks

● 10

The protostar

rigin ofStellar radius as mass accumulates: hot

● 11

The protostar

rigin ofStellar radius as mass accumulates: cold

● 12

The protostar

Origin Luminosity as mass accumulates

Origin Luminosity as clump mass declines

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The clump mass

Origin Luminosity as clump mass declines

● 14

The clump mass

Orig Accelerated accretion Power Law deceleration

Origin Herschel cores + model temperture

● 15

The clump mass

Origin Distance

● 16

The Jet Speed: hot

Orig

Origin Distance

● 17

The Jet Speed: cold

Orig

Origin Distance Distance-immune evolution

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The Lyman Flux

Orig Accelerated accretion

Origin Distance Distance-immune evolution

● 19

The Lyman Flux

Orig Power Law deceleration

20% Discount Code F1ASTROJET

● X-Axia: Luminosity

● Y-Axis: Jet Power

● Tracks/Arrows: the scheme

● Diagonal line:

● Class 0/I border

● Data: ISO FIR + NIR (Stanke)

● Above: Class 0

● Under: Class 1

Protostellar Tracks

● Michael D. Smith - Accretion Discs

● 22

Disc evolution

● Column density as function of radius and time: (r,t)

● Assume accretion rate from envelope

● Assume entire star (+ jets) is supplied through disc

● Angular momentum transport:

● - turbulent viscosity: `alpha’ prescription

● - tidal torques: Toomre Q parameterisation

● Class 0 stage: very abrupt evolution?? Test……

● …to create a One Solar Mass star

● Michael D. Smith - Accretion Discs

● 23

The envelope-disc connection; slow inflow

● Peak accretion at 100,000 yr● Acc rate 3.5 x 10-6 Msun/yr● Viscosity alpha = 0.1

● 50,000 yr: blue

● 500,000 yr: green

● 2,000,000 yr: red

● Michael D. Smith - Accretion Discs

● 24

The envelope-disc connection; slow inflow; low alpha

● Peak accretion at 200,000 yr● Acc rate 3.5 x 10-6 Msun/yr● Viscosity alpha = 0.01

● 50,000 yr: blue● 500,000 yr: green

● 2,000,000 yr: red