Young Star Caught Speeding

1
Young Star Caught Speeding

• Alyssa A. Goodman
• Harvard-Smithsonian Center for Astrophysics
• Héctor G. Arce
• Caltech

2
Star Planet Formation
Disk Jet
Star-Forming Globule
3
How fast is 22 km/s?

• 45,000 miles per hour (45 x a speeding bullet)
• 10-20 times faster than most stars move

4
Exiled, but Accepted in New Land
Homeland
Ocean of Emptiness
NGC 7023
PV Ceph
New Land
5
Coming Soon PV Ceph The Movie
Goodman Arce 2004, Figure 1
6
Whats an HH knot?
7
Coming Soon PV Ceph The Movie
Goodman Arce 2004, Figure 1
8
Simulated Formation of a Star Cluster
Bate, Bonnell Bromm 2002
9
Young StarCaughtSpeeding Away from Home
10
Immigration Happens

• This discovery was a surprise.
• Underage stars can run away from home, fast!
• A proper speeding study is needed to understand
  what stars formed where, as a function of time.

11
Young StarCaughtSpeeding Away from Home
Speed22 km/s Age0.5 million years
Goodman Arce 2004
12
Young StarCaughtSpeeding Away from Home
Dust Emission Map
Deceleration of Jets
Speed22 km/s Age0.5 million years
Goodman Arce 2004
13
(No Transcript)
14
Clues

• Geometry of the HH knots
• Morphology of Molecular Outflow
• Morphology of Star-Forming Blob
• Wiggle of the Jet

15
The Most Subtle Evidence for PV Cephs Motion
Each point shows position of emission peak in
high-res molecular line map.
Goodman Arce 2004
16
Deceleration Means Outflows Lie About their Age
Goodman Arce 2004
17
How often does this happen?

• Direct Proper Motion
• RW Aur 16 km s-1, Jones Herbig 1979
• BN object w.r.t. I 50 km s-1, Plambeck et al.
  1995
• IRAS 16293-2422 30 km s-1, Loinard 2002
• T-Tau Sb 20 km s-1, Loinard et al. 2003
• Deduced from Outflow Morphology
• B5 IRS110 km s-1, Bally et al. 1996
• Jets in NGC 1333 Orion clusters 10 km s-1
  (Bally Reipurth 2001)
• PV Ceph 20 km s-1, Goodman Arce 2004

but the possibility of motion was not emphasized!
18
Variability in Gyulbudaghain's Nebula(the fuzz
surrounding PV Ceph)
July 98
Oct/Nov 98
Oct 00
In 1 year, PV Ceph moves about the distance from
the Sun to Jupiter (5 A.U.)