“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