Transcript Shock Waves and Motions in Stellar Jets

Department of Physics
and Astronomy
Rice University
Patrick Hartigan
Stromfest
April 4, 2008
Evolving Ideas About HH Objects
History
•
•
The Reflection Nebula Hypothesis
Subsequent Development of Field
New Stuff
•
•
Conditions near the Star
MHD far from the star
DISCOVERY!
Herbig 1951, ApJ 113 697
Emission lines… Photoionized… but where is the blue star?
Haro 1952, ApJ 115 572
Ambarzumian, 1954 Comm. Burakan Obs No 13
Argues these are related to young stars – coins term HH object
What Causes the Emission Lines?
1956 ApJ 123 379
High ionization, low temperature:
“The most obvious means of explaining the ionization is to
assume a strong radiation field in the far-ultraviolet”
HH Objects as Reflection Nebulae
ApJ 191, 111, 1974
They are polarized!
ApJ 191, L93, 1974
But Wait, Emission Lines Unpolarized
ApJ 234, L191, 1979
What went wrong?
Examples can be
more complex:
Hartigan et al 1999
What went right?
•
There are reflection nebulae in these objects
•
HH Objects are displaced from host stars
•
HH Objects are usually not photoionized nebulae
•
Motivated future work
•
Model made TESTABLE PREDICTIONS
(i.e. it could be proved wrong)
Spectra, Supersonic Velocities Imply Shocks Schwartz 1975
Large Linewidths Imply Bow Shocks
Schwartz 1978
Proper Motions Imply “Bullets”
Herbig and Jones 1981
UV Spectra Confirm Shocks
Bohm et al 1981
Ortolani and D’Odorico 1980
Bow Shock Models
Hartmann & Raymond 1984
Raga & Bohm 1985
Hartigan etal 1987
Jet Connection
Bow Shock/Mach Disk
Mundt & Fried 1983
Hartigan 1989
Reipurth & Heathcote 1992
Physical Conditions in Jets
HST Proper Motions
Brugel, Bohm Mannery 1981
Hartigan et al 1994
Bacciotti & Eisloffel 1998
Nisini 2005
Reipurth, Bally, Hartigan etc. 1996-2007
ApJS 62, 39, 1986
Tilting Filter Images
Close to the source: Slit Mapping, Image Slicers
Lavalley et al 1997, A&A 327, 671
Jet is fastest along the axis
Coffey et al 2004, ApJ 604, 758
… and may even be rotating
Bacciotti et al 2000, ApJ 537, L49
…and gets denser close to the star
NEW RESULTS
1. Near the Source
2. Far From the Source
Physical Conditions Throughout the Jet
Jet Collimation
RW AUR
Keck, NIRSPAO [Fe II] 1.64 Slit=0.068” (9.6 AU)
Linewidths
Spectroastrometry
NEW RESULTS
1. Near the Source
2. Far From the Source
Scaled Laser Experiments
Brugel, Bohm and Mannery 1981
No single density or temperature describes HH objects
Filling factor is low