We observed the nearby galaxy M31 in the 〔C II〕158 μm emission line. An extended component was detected over the central 1 5 kpc region with a line-to-continuum ratio of 〔C II〕/〔40-120μm〕6×10 -3 . This ...We observed the nearby galaxy M31 in the 〔C II〕158 μm emission line. An extended component was detected over the central 1 5 kpc region with a line-to-continuum ratio of 〔C II〕/〔40-120μm〕6×10 -3 . This ratio is 3 times larger than that of the Galactic counterpart and is comparable to that in the general Galactic Plane. We expect that the difference between the two central regions are due to different gas densities; the self-shielding of CO molecules decreases the C + abundance at the higher density in the Galactic case.展开更多
文摘We observed the nearby galaxy M31 in the 〔C II〕158 μm emission line. An extended component was detected over the central 1 5 kpc region with a line-to-continuum ratio of 〔C II〕/〔40-120μm〕6×10 -3 . This ratio is 3 times larger than that of the Galactic counterpart and is comparable to that in the general Galactic Plane. We expect that the difference between the two central regions are due to different gas densities; the self-shielding of CO molecules decreases the C + abundance at the higher density in the Galactic case.