How Stars Form

Shantanu Basu

Physics & Astronomy

University of Western Ontario

Preview Western, May 3/4, 2003

Understanding our Origins

The Galaxy

Molecular Clouds

Disorderly

Complex

Nonlinear

Giant Molecular Cloud in Orion

Infrared view

From IRAS satellite

Magnetic Fields and PolarimetryŠ

Background Star emits Unpolarized Continuum

Result: Observed -vector is parallel to plane-of-the-sky component of .

EB

B

ee

Most Likely Orientation

Least Likely Orientation

Polarization of Background Starlight by Magnetically Aligned Grains

E

B

(Partial) Polarization Observed

Courtesy A

. Goodm

an

Taurus Cloud Complex (up to ~ 30 light years across)

Magnetic Fields in Astrophysics

B

Earth Bar magnet

Magnetic Fields near Solar surface

Outflows

MHDWaves

Thermal Motions

MHDTurbulence

InwardMotions

SNeH II Regions

Scenario for a Molecular Cloud B

Canada-France-Hawaii

Telescope (CFHT)

Mauna Kea, Hawaii

Optical and

near-infrared

Tools of the Trade

Observational Astronomy

Tools of the Trade

James Clerk Maxwell

Telescope (JCMT)

Mauna Kea, Hawaii

British-Canadian-Dutch

collaboration

Short-wavelength radio

(submillimeter) waves

Observational Astronomy

Tools of the Trade

Hubble Space Telescope

Optical and near-infrared

Resolution not limited by atmospheric turbulence

Observational Astronomy

21st Century Telescopes

Gemini 8m ALMA 64 x 12m NGST 8m

Star Formation at High Resolution

Motte et al. (1998) HH47 jet seen by HST

Young stellar object and disk - HST

At highest resolution, see disks and jets(!) near forming stars.

Local collapse of dense cores within larger clouds.

Molecular or Dark Clouds

"Cores" and Outflows

Stages of Star Formation

Jets and Disks

Extrasolar System

~fe

w lig

ht y

ears

Tools of the Trade

High-performance computers

Parallel computing

Theoretical Astrophysics

New organization: SHARCNET (Shared Hierarchichal Computing Network) – a consortium of Western, Guelph, and McMaster plus other regional institutions.

Mission: Enable forefront computational research in science, engineering, and business.

www.sharcnet.ca

Numerical Simulation

Takahiro Kudoh (UWO)

Collaborators: R. Matsumoto, K. Shibata

Star + rotating disk + magnetic field (white lines)

Numerical Simulation3-D view

Takahiro Kudoh (UWO)

Collaborators: R. Matsumoto, K. Shibata

Cross-section of disk

Magnetic field lines: inner lines (pink) and outer lines (white)