Friday, December 01, 2023 at 12:15 pm

JILA Foothills Room

Thomas Gomez, CU Boulder

"A New Era Of Laboratory Astrophysics"

Abstract:

Atomic spectroscopy is one of the bedrocks of astronomy. However, deficiencies in our atomic physics models may be responsible for certain problems we see in astrophysics. For example, helioseismology disagrees with the standard solar model when abundances were updated, black hole accretion disks seem to have super-solar abundances of iron, and different methods for determining masses of white dwarfs are inconsistent. These problems likely arise due to the difficulty in modeling the behavior of atoms in astrophysical plasmas.

The Z-machine at Sandia National Laboratories—the largest X-ray source in the world—can reproduce the conditions found in these astrophysical objects. This capability allows us to study atomic processes in the sun, white dwarfs, and black holes up close. So far, we have found that solar opacities are higher than previously expected, transitions of iron are stronger than initially thought, and there may be problems with line shapes in absorption. A new project to explore tidally disrupted exoplanets on white dwarf photospheres is currently in development.

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