James Wadsley

My Kids: Fiona and Ian Pictures

Astronomy 101V (Tuesday/Thursday 7-9:20pm class)

CV One Page Research Interests PAPERS Completed Ph.D. 1998 with Dick Bond

Where the baryons are: (20 Mpc Box, Gas simulation with cooling)

I am investigating the high redshift universe, linking observations of Lyman alpha clouds and Large scale structure to theory via SPH cosmological simulations. I have strong interests in Galaxy Formation and MHD. Recently I have been writing parallel hydrodynamics code.

Below is a 1.6 million particle gasdynamical super cluster simulation in a universe with non-negligible vaccuum energy (Lambda). It took 35 days on an SGI Origin single processor. The box shown is 100 Mpc (3x10^21 km) at z=0 and scaled to match the expansion at other redshifts. The colours indicate density going from blue through green and yellow to red at higher densities. There are 4 major clusters and 13 smaller clusters providing the contraints that define this region. In a Lambda dominated universe cluster scale structures are present at z=1.5 (9 billion years ago). The parameters are Omega=0.35, Lambda=0.65 and H0=70 km/s/Mpc. The redshifts shown are z=0, 0.1, 0.2, 0.5, 0.7, 1.0, 1.5, 3.0 and 8.0 corresponding to universe ages 13 (now), 11.8, 10.6, 8.1, 6.9, 5.5, 4.0, 2.0 and 0.6 billion years.

The background is a pseudo-ray traced image of a Lyman alpha simulation. Shown is 5 Mpc box containing a few Lyman Alpha cloud producing filaments and dwarf galaxies at z ~ 3. Higher Brightness and opacity indicate higher density. Colours indicate temperature. Red is 4,000,000K, Blue is 10,000K and purples represent intermediate temperatures. Note that the cores of the knots are cool and thus blue. Through the red hot gas around them they appear purple.

email: wadsley@astro.washington.edu