There may be far fewer galaxies further out in the Universe then might be expected, suggests a new study based on simulations conducted using the Blue Waters supercomputer at the National Center for Supercomputing Applications, with resulting data transferred to SDSC Cloud at the San Diego Supercomputer Center at the University of California, San Diego, for future analysis.
The study, published this week in the Astrophysical Journal Letters, shows the first results from the Renaissance Simulations, a suite of extremely high-resolution adaptive mesh refinement (AMR) calculations of high redshift galaxy formation.
Moreover, these simulations show hundreds of well-resolved galaxies, allowing researchers to make several novel and verifiable predictions ahead of the October 2018 launch of the James Webb Space Telescope (JWST), a new space observatory that succeeds the Hubble Space Telescope.
There may be far fewer galaxies further out in the Universe then might be expected, suggests a new study based on simulations conducted using the Blue Waters supercomputer at the National Center for Supercomputing Applications, with resulting data transferred to SDSC Cloud at the San Diego Supercomputer Center at the University of California, San Diego, for future analysis.
The study, published this week in the Astrophysical Journal Letters, shows the first results from the Renaissance Simulations, a suite of extremely high-resolution adaptive mesh refinement (AMR) calculations of high redshift galaxy formation.
Moreover, these simulations show hundreds of well-resolved galaxies, allowing researchers to make several novel and verifiable predictions ahead of the October 2018 launch of the James Webb Space Telescope (JWST), a new space observatory that succeeds the Hubble Space Telescope.
"Most critically, we show that the ultraviolet luminosity function of our simulated galaxies is consistent with observations of redshift galaxy populations at the bright end of the luminosity function, but at lower luminosities is essentially flat rather than rising steeply," wrote researchers in their paper, called 'Probing the Ultraviolet Luminosity Function of the Earliest Galaxies with the Renaissance Simulations.'
"Our work suggests that there are far fewer faint galaxies than one could previously infer," said principal investigator and lead author Brian W. O'Shea, an associate professor at Michigan State University with a joint appointment in the Department of Computational Mathematics, Science and Engineering; the Department of Physics and Astronomy; and the National Superconducting Cyclotron Laboratory. "Observations of high redshift galaxies provide poor constraints on the low-luminosity end of the galaxy luminosity function, and thus makes it challenging to accurately account for the full budget of ionizing photons during that epoch."
"The Hubble Space Telescope can only see the what we might call the tip of the iceberg when it comes to taking inventory of the most distant galaxies," said SDSC Director Michael Norman, who was part of the research team for this study. "A key question is how many galaxies are too faint to see. By analyzing these new ultra-detailed simulations, we find that there are 10 to 100 times fewer galaxies than a simple extrapolation would predict."
Space photo via Shutterstock.
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