Figuring Out Gas & Galaxies In Enzo

HI projection at z=0.95

In our first generation of FOGGIE simulations, we have improved the circumgalactic resolution to be 549 comoving parsecs within ~100 kiloparsecs of the main halo, a Milky Way-like galaxy at z=0. Above: a projection of the neutral hydrogen (HI) column density at z=0.95 (6.1 billion years after the Big Bang) in one of our simulations; the colored material is optically thick to the Lyman Limit (NHI ≳ 1017.2cm-2). The width of this projection is about 100 kiloparsecs, and small dense cloudlets can clearly be seen far from the main galaxy disk.

The movie below shows the evolution in projected density, temperature, and metallicity over ~1.5 billion years in our new simulation (top) and a simulation with more traditional circumgalactic resolution (bottom). The spatial scale is 200/h comoving kiloparsecs across (about 100 physical kiloparsecs at the end of the movie).

Below: the stellar light as would be seen by Hubble and JWST for the same galaxy as evolved with a "normally" resolved (left) and with our improved (right) circumgalactic resolution at z=2 (3.3 billion years after the Big Bang). We find that with no changes to the interstellar resolution or star formation feedback physics, the morphology, kinematics, and and size of the galaxy changes dramatically.

starlight at z=2
Funding sources: NSF AST-1517908 HST AR #15012 NASA 17-ATP17-0169
Core team: Molly Peeples Lauren Corlies Jason Tumlinson Brian O'Shea Gregory Snyder