The following document lists the file abstract/KMOCHIZU_M31.abs
from catalogue VI/111.
A plain copy of the file
(without headers/trailers) may be downloaded.
The large scale observation of our Galactic plane with a balloon telescope in the [C II] 158 mm line shows that our Galactic center has lower [C II]/FIR continuum intensity ratio than that in general Galactic plane region. The line/continuum ratio has rather flat distribution over wide area of the general Galactic plane. Thus, this large scale (500pc) defect of [C II] line intensity is not local effect, but is important for Galactic structure. We have proposed two possible sources of the [C II] defect: 1) molecular self-shielding in dense molecular clouds in the Galactic center region; 2) added heating of grains by late-type stars in the bulge. These two decrease formation of C+ ions, which emit [C II] line, and/or excitation of the ions to upper level of the transition. We propose observation of [C II] intensity along the major axis of M31, whose center has larger bulge and lesser molecular gas than the Galactic center. The center with different physical conditions from our Galactic Center should give answer for this problem.