1. PV Ceph: Young Star Caught Speeding?
Alyssa A. Goodman
Harvard-Smithsonian Center for Astrophysics
Héctor G. Arce
Caltech
Begin by telling the whole story through using just this title slide, with no visuals
We noticed star moving much faster than “normal”
In fact, “speeding”
Piqued our interest
Investigated where it came from
Surprised to learn it came from very far away
“Ejected” from its homeland (of political unrest) managed to find a new life in a new land
It is important to figure out if this happens often--this is the first time it’s been seen
Are we seeing immigration on a cosmic scale?
We need to understand how often this happens in order to properly model star formation in the Universe

2. “Preponderance of the Evidence”
3 light years
“Preponderance of the Evidence”
Geometry of the “HH” knots
Morphology of Molecular Outflow & Star-Forming “Blob”
“Wiggle” of the Jet
Orientation: North is rotated 117 degrees clockwise from the vertical
Goodman & Arce 2004 Figure 1
PV Ceph: The Movie

3. Simulated Formation of a Star Cluster
Christine will get me time scale
Bate, Bonnell & Bromm 2002

4. Ejected!? Optical Image of NGC 7023 Dust Emission Map NGC 7023 PV Ceph
Tom Licha, 2002
Dust Emission Map
Goodman & Arce 2004
NGC 7023
PV Ceph
“Exit wound”
Ejected!?

5. 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 km s-1, Loinard 2002
T-Tau Sb 20 km s-1, Loinard et al. 2003
Deduced from Outflow Morphology
B5 IRS1~10 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
New measurements say no
See Furlan et al. 2003?
*but the possibility of motion was dismissed, or not emphasized!

6. Young Star Caught Speeding Away from Home
gap
Optical Image of NGC 7023
Tom Licha, 2002
First Evidence for a Young Star moving at such High Speed far from a Cluster
NGC 7023
PV Ceph
Dust Emission Map
Young Star Caught Speeding Away from Home
Speed=22 km/s
Age=0.5 million years
Goodman & Arce 2004