"Tomography" is defined as the imaging by sections or sectioning. It is now widely used in the 3D mapping of our body to remote sensing of volcanic activity. In astrophysics, it had been predicted that we can reconstruct the filamentary structure of the Universe by using the Lyman alpha Forest. With modern technologies and deep observations by large telescopes, it is now becoming a reality that tomography of the Intergalactic Medium (IGM) will open up a new frontier. We can map out the neutral hydrogen from spectroscopic observations and infer the underlying dark matter distribution. On top of that, we can place galaxies along such large-scale structures using deep narrow-band imaging and probe galactic-scale structures (Circum-Galactic Medium; CGM).
The "SuMiRe" (Subaru Measurement of Images and Redshifts) project is composed of Imaging by Hyper-Suprime Cam (HSC) and Spectroscopy by Prime Focus Spectrograph (PFS). The HSC team is now carrying out 300 dark nights of a Subaru Strategic Program (SSP) over 5 years and getting superb 5-broad-band and a few narrow band images. PFS is a next-generation fiber multi-object spectrograph with 2400 fibers at a spectral resolution of 3000.PFS is an instrument, operational on a relatively short timescale, that enables us to investigate the tomography of the Universe on a large scale. We are now preparing the SSP for PFS. With experts from all around the world, we would like to discuss and optimize the survey strategy for PFS. Any new or wild ideas are welcome to discuss at this workshop.
The current plan of the PFS-SSP galaxy survey, with ~500,000 galaxy spectra out to z ~ 4 over 25 deg2, will allow us to directly link galaxy properties to the evolving cosmic web (IGM/CGM). Simulations will play a critical role to optimize the observations. The goal of this workshop is to identify the best possible simulations for IGM tomography and maximize the science outcome by optimizing the PFS SSP program. Synergy with other large programs such as DESI, LSST, WFIRST are also welcome to be discussed.
This workshop is supported by WPI (World Premier Institute) program by MEXT
Nao Suzuki, John Silverman (Kavli IPMU),
Masami Ouchi (ICRR)
E-mail: IGM-tomography-2016_at_googlegroups.com (change "_at_" to "＠")