CO observations of the central region of the galaxy NGC 4258.
Abstract
The central region of the spiral galaxy NGC 4258,, known for its anomalous radio arms, has been observed in the C-12O (J = 1-0) line. A massive concentration of molecular hydrogen gas was found in the center. This molecular clump is situated at the minimum of H I emission of the central H I bar and is elongated in the direction of the bar. No significant CO line was detected on the northern, denser H I bar. The high-density gas concentration and the asymmetric distribution of the H I-to-H2 mass ratio with respect to the galaxy center may be related to the dynamical state of the gas near the nucleus. The CO rotation curve is flat even in the central few hundred parsecs. No particular association of the CO emission with the anomalous radio arms was found.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- 1989
- Bibcode:
- 1989PASJ...41..113S
- Keywords:
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- Active Galaxies;
- Carbon Monoxide;
- Emission Spectra;
- Galactic Nuclei;
- Molecular Clouds;
- Spiral Galaxies;
- Hydrogen;
- Molecular Gases;
- Astrophysics