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.
NGC 4636, an X-ray bright elliptical galaxy, was observed for 70 ks with Suzaku. The low background and good energy resolution of the XIS enable us to estimate the foreground Galactic emission accurately and hence measure, for the first time, the O,
Mg, Si and Fe abundances out to a radius of ~28 arcmin ($simeq$ 140 kpc). These metal abundances are as high as $>$1 solar within the central 4 and decrease by ~50% towards the outer regions. Further, the O to Fe abundance ratio is about 0.60--1.0 solar in all regions analyzed, indicating that the products of both SNe II and SNe Ia have mixed and diffused to the outer regions of the galaxy. The O and Fe metal mass-to-light-ratios (MLR) of NGC 4636 are 2--3 times larger than those of NGC 1399 implying that metal distributions in NGC 4636 are less extended than those in NGC 1399, possibly due to environmental factors, such as frequency of galaxy interaction. We also found that the MLRs of NGC 4636 at 0.1 $r_{180}$ are $sim$5 times smaller than those of clusters of galaxies, possibly consistent with the correlation between temperature and MLR of other spherically symmetric groups of galaxies. We also confirmed a resonant scattering signature in the Fe$_{XV II}}$ line in the central region, as previously reported using the XMM-Newton RGS.
