(Proposal ID) S16A-096

(PI) Okamoto, Sakurako

(Proposal Title)
M81; Near field cosmology beyond the Local Group 4

(Abstract)
We wish to take 1 pointing in g- and i-band and 2 pointings in NB656 and 
r-band of the M81 halo by Hyper Suprime-Cam (HSC).  Recent photometric surveys,
 such as SDSS and PAndAS, led to discover many substructures, satellites, and 
to refine characterization of halo properties of the Milky Way and M31, which 
make a progress on solving the missing satellite problem, together with 
subsequent improvements of simulations. Nearby M81 is the best target to 
investigate the hierarchal structural formation on galactic scales beyond the 
Local Group, and the HSC is the only instrument which enable us to do this. 
We ask for 1 night to complete the g and i mapping together with the previous 
and scheduled observations and to augment our initial aims with a search for 
sites of massive star formation in the central regions of the M81 Group with 
the use of new NB656 filter.  Our primary goals will be to [1] Map the history 
of star formation in the center of M81 Group, [2] Establish the stellar 
population content of large-scale structures, [3] Understand the true nature 
of the extended envelope, [4] Search for new  satellites and tidal streams in 
the central regions of the M81 Group, and [5] Search for globular clusters in 
entire region of M81 and around.