HH 24: Multiplicity and Jet Formation Bo Reipurth Institute for - - PowerPoint PPT Presentation

HH 24: Multiplicity and Jet Formation

Bo Reipurth Institute for Astronomy University of Hawaii

Notwithstanding, in this talk I will argue that if we do not understand binary formation we do not understand star formation.

The multiplicity frequency declines through the protostellar and pre-main sequence phases due to breakup of small multiple systems

Larson’s conjecture: all stars are formed in unstable systems that break up, forming the field star population

• Non-hierarchical systems are unstable

and oscillate between two phases: interplay and close triple approach, and the latter can lead to ejection.

Reipurth 2000

Disintegration of Multiple Systems

Numerical Simulations

• Code developed by Seppo Mikkola in Turku
• Newborn triple system inside cloud core
• Stars gain mass through Bondi-Hoyle accretion
• Cloud core loses mass from accretion to stars and

from evaporation

• Extinction of stars calculated continuously

Reipurth et al. 2010

One second of the movie corresponds to 30,000 years Only two stars are seen, because the binary is unresolved

• n this scale

A sample of 100 simulations of three 0.5 Msun stars with initial mean separations of 100 AU emerging from a 3 Msun core

Red: ejections leading to escapes Blue: ejections that remain bound

Numerous stellar seeds escape very early, producing brown dwarfs

A sample of 100 simulations of three 0.5 Msun stars with initial mean separations of 100 AU emerging from a 3 Msun core

Red: ejections leading to escapes Blue: ejections that remain bound

Class 0 Class 1

Prediction: Excess of wide companions at early ages

Do we see an excess of distant companions around embedded young stars?

Samples of near-infrared adaptive optics observations

• f newborn embedded stars

Connelley et al. 2008

The answer is ‘YES’

Binary separation distribution function 2000 AU 5000 AU

Spectral index is a proxy for age

The number of distant companions decreases with age: they are released once the envelopes are dispersed

Orphaned Protostars

An ‘orphan’ is a protostar which has been ejected from deep inside its nascent cloud core. This ejection may be into a loosely bound orbit, which will (briefly) bring it back into the core, or into an escape. By identifying orphans, we are thus able to directly observe a protostar at near-infrared or even at optical wavelengths! T Tauri itself is a prime example of an orphaned protostar

HH 24

L1630

1 hr Ha + 1 hr [SII] with Subaru 8m telescope

C G E X J L

Subaru Ha - [SII]

Six jets

HH 24 with HST

Dominant emission is [FeII] 1.65 micron

STScI

Outflow cavities Destruction of cloud core

The many jets in the HH 24 complex are driven by a non-hierarchical multiple system of at least 6 embedded protostars. This is a situation we would expect should lead to a number of very low mass orphans.

Gemini JHK HST K-band

S

Stellar density 1000 times that in the center of a globular cluster Class 0/I sources

Wide binary Single Spectroscopic binary Single Single Single 5 arcsec AU

Ha1 Ha2 Ha3 Ha4 Ha5

Loosely tethered

• rphaned protostars

and brown dwarfs

Ha1 Ha2 Ha3 Ha4 Ha5

Loosely tethered

• rphaned protostars

and proto brown dwarfs are located far outside the dense cloud core Orphans located far outside the dense cloud core 850 micron

Data from Kirk et al. 2016

Binaries from triple decays have highly eccentric orbits

If a companion moves in an eccentric orbit it can lead to serious disturbance of the disk Disk disturbances lead to sudden increases in accretion onto the star Accretion again leads to mass loss and outflow activity

Courtesy Moeckel & Bally

Courtesy Susanne Pfalzner

The close fly-by of a star induces mass and angular momentum loss in protoplanetary disks. This is shown here for the case of a 1 M⊙ star surrounded by a 100 AU disk encountered by another star with 1 M⊙ and an encounter periastron of 100 AU.

Courtesy Susanne Pfalzner

Only a minor part of the disk reaches escape speed and it soon reassembles Because of such interactions the binary starts to spiral in

Triple disintegration event Binary in-spiral phase First periastron passage

Spectroscopic binary? Merger? FUor eruption?

HH jet structure and binary evolution

Triple disintegration event Binary in-spiral phase First periastron passage

Spectroscopic binary? Merger? FUor eruption?

HH jet structure and binary evolution

Triple disintegration event Binary in-spiral phase First periastron passage

Spectroscopic binary? Merger? FUor eruption?

HH jet structure and binary evolution

5”

Knots are not regularly spaced at each periastron passage because disk needs to reassemble HH 24 jet E HST [FeII] 1.65 micron

ALMA channel maps in H2CO V_hel 8 - 12 km/s Each panel is color coded with velocity Reipurth, Bally et al., in prep.

HH 24

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

12.18 12.35 12.01 km/s

ALMA Field of View

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

12.18 12.35 12.01 km/s

H2CO

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

11.67 11.84 11.51 km/s

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

11.17 11.34 11.00 km/s

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

10.67 10.84 10.50 km/s

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

10.16 10.33 10.00 km/s

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

9.66 9.83 9.49 km/s

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

9.16 9.33 8.99 km/s

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

8.65 8.82 8.49 km/s

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

8.15 8.32 7.98 km/s

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

12.18 12.35 12.01 km/s

ALMA Field of View

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

12.18 12.35 12.01 km/s

H2CO

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

11.67 11.84 11.51 km/s

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

11.17 11.34 11.00 km/s

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

10.67 10.84 10.50 km/s

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

10.16 10.33 10.00 km/s

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

9.66 9.83 9.49 km/s

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

9.16 9.33 8.99 km/s

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

8.65 8.82 8.49 km/s

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

8.15 8.32 7.98 km/s

09.5 5:46:09.0 08.5 08.0 07.5 09:4 45.0 50.0 55.0

• 0:10:00.0

05.0 10.0 15.0

12.18 12.35 12.01 km/s

ALMA Field of View “Hubble” flow: explosion!

Tube caused by explosive event Cavities carved out by jets and wideangle winds

Low mass counterpart to the ‘fingers’ in Orion

Stellar merger?

The Promise of JWST

The JWST Dream

The dream (dream on ….)

The JWST Dream

JWST will provide key information on multiple systems: 1) provide the first meaningful look at a jet engine and jet structure 2) provide jet proper motions to a few km/sec 3) resolve binaries down to <25 AU at 400 pc 4) image major disk disruptions from encounters 5) allow accurate determination of individual SEDs of components in multiple systems

Perhaps something like this?

Scientific biography can be downloaded at

http://www.ifa.hawaii.edu/SP1

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• f the Star Formation Newsletter

appears, just send an email to: reipurth@hawaii.edu