“Magnets in Space” Alyssa A. Goodman Harvard-Smithsonian Center for Astrophysics
Dec 19, 2015
“Magnets in Space”
Alyssa A. GoodmanHarvard-Smithsonian Center for
Astrophysics
Magnetic Field Lines
Our Sun
Magnetic Fields Dancing on the Sun
Images from NASA’s “TRACE” Satellite
http://vestige.lmsal.com/TRACE/
Earthlings Saved by Magnetic Fields!*
*but not the poor (surface) Martians, or Venusians!
Earthlings Saved by Magnetic Fields!*
Aurora Borealis
A Star-Forming Region
The Old(er),
The Young &
the Unborn
Molecular or Dark Clouds
"Cores" and Outflows
Star and Planet Formation
Jets and Disks
Solar System Formation
1 p
c = 3
lyr
Outflows
MagnetohydrodynamicWaves
Thermal Motions
MHDTurbulence
Infall
SNe/GRBH II Regions
What magnetic fields have to do with this whole picture?
Magnetic Fields in Star Forming Gas
Stone, Gammie & Ostriker 1999 •Driven Turbulence; M K; no gravity•Colors: log density•Computational volume: 2563
•Dark blue lines: B-field•Red : isosurface of passive contaminant after saturation
=0.01 =1
T / 10 K
nH 2 / 100 cm-3 B / 1.4 G 2
Star Formation the Easy Way (that doesn’t work)
Global Instability (e.g. Jeans) Fragments Cloud
(hierarchically)
time~106 yearsHoyle 1953
Fragments Collapse UnderGravity into “Protostars”
time~105 years
Ta-Da
A Group of Young“Zero-Age Main Sequence”
Stars is Born
The History of the Universe