We report an analysis of the interstellar gamma-ray emission from nearby molecular clouds Chamaeleon, R Coronae Australis (R CrA), and Cepheus and Polaris flare regions with the {it Fermi} Large Area Telescope (LAT). They are among the nearest molecu
lar cloud complexes, within $sim$ 300 pc from the solar system. The gamma-ray emission produced by interactions of cosmic-rays (CRs) and interstellar gas in those molecular clouds is useful to study the CR densities and distributions of molecular gas close to the solar system. The obtained gamma-ray emissivities from 250 MeV to 10 GeV for the three regions are about (6--10) $times$ 10$^{-27}$ photons s$^{-1}$ sr$^{-1}$ H-atom$^{-1}$, indicating a variation of the CR density by $sim$ 20% even if we consider the systematic uncertainties. The molecular mass calibration ratio, $X_{rm CO} = N{rm (H_2)}/W_{rm CO}$, is found to be about (0.6--1.0) $times$ 10$^{20}$ H$_2$-molecule cm$^{-2}$ (K km s$^{-1}$)$^{-1}$ among the three regions, suggesting a variation of $X_{rm CO}$ in the vicinity of the solar system. From the obtained values of $X_{rm CO}$, we calculated masses of molecular gas traced by Wco in these molecular clouds. In addition, similar amounts of dark gas at the interface between the atomic and molecular gas are inferred.
Dwarf spheroidal galaxies have a large mass to light ratio and low astrophysical background, and are therefore considered one of the most promising targets for dark matter searches in the gamma-ray band. By applying a joint likelihood analysis, the p
ower of resultant limits in case of no detection can be enhanced and robust constraints on the dark matter parameter space can be obtained. We present results from a combined analysis of 10 dwarf spheroidal galaxies using Fermi-LAT data. Different annihilation channels have been analyzed and uncertainties from astrophysical properties have been taken into account.
