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Paper: |
Imaging Cold Gas to 1 kpc Scales in High-Redshift Galaxies with the ngVLA |
Monograph: |
7, Science with a Next Generation Very Large Array |
Page: |
629 |
Authors: |
Casey, C. M.; Narayanan, D.; Carilli, C.; Champagne, J.; Hung, C.; Davé, R.; Decarli, R.; Murphy, E. J.; Popping, G.; Riechers, D.; Somerville, R. S.; Walter, F. |
Abstract: |
The next generation Very Large Array (ngVLA) will revolutionize our
understanding of the distant Universe via the detection of cold
molecular gas in the first galaxies. Its impact on studies of galaxy
characterization via detailed gas dynamics will provide crucial
insight on dominant physical drivers for star-formation in high
redshift galaxies, including the exchange of gas from scales of the
circumgalactic medium down to resolved clouds on mass scales of
∼105 M☉. In this study, we employ a series of
high-resolution, cosmological, hydrodynamic zoom simulations from the MUFASA simulation suite and a CASA simulator to generate mock ngVLA observations of a z ∼ 4.5 gas-rich star-forming galaxy. Using the DESPOTIC radiative transfer code that encompasses
simultaneous thermal, chemical, and statistical equilibrium in
calculating the molecular and atomic level populations, we generate
parallel mock observations of low-J to high-J transitions of CO from
ALMA for comparison. We find that observations of CO(1-0) are
especially important for tracing the systemic redshift of the galaxy
and the total mass of the well-shielded molecular gas reservoir, while
even CO(2-1) can predominantly trace denser gas regions distinct from
CO(1-0). The factor of 100 times improvement in mapping speed for the
ngVLA beyond the Jansky VLA and the proposed ALMA Band 1 will make
these detailed, high-resolution imaging and kinematic studies of
CO(1-0) routine at z ∼ 2–5. |
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