Tracing the Cosmic Web with Star-forming Galaxies in the Distant Universe
A research group led by Hiroshima University has revealed a picture of the increasing fraction of massive star-forming galaxies in the distant universe. Massive star-forming galaxies in the distant universe, about 5 billion years ago, trace large-scale structure in the universe. In the nearby universe, about 3 billion years ago, massive star-forming galaxies are not apparent. This change in the way star-forming galaxies trace the matter distribution is consistent with the picture of galaxy evolution established by other independent studies.
The research team provides a new window on galaxy evolution by comparing the three-dimensional galaxy distribution mapped with a redshift survey including star-forming galaxies to a weak lensing map based on Subaru imaging.
“It turns out that the contribution of star-forming galaxies as tracers of the mass distribution in the distant universe is not negligible,” said Dr. Utsumi. “The HSC weak lensing map should contain signals from more distant galaxies in the 8 billion-year-old universe. Deeper redshift surveys combined with similar weak lensing maps should reveal an even greater contribution of star-forming galaxies as tracers of the matter distribution in this higher redshift range. Using the next generation spectrograph for the Subaru Telescope, Prime Focus Spectrograph (PFS), we hope to extend our maps to the interesting era.”
This research is published in the Astrophysical Journal in its December 14, 2016 on-line version and December 20, 2016 in the printed version, Volume 833, Number 2. The title of the paper is “A weak lensing view of the downsizing of star-forming galaxies” by Y. Utsumi et al.