NGC 1266: CHARACTERIZATION OF THE NUCLEAR MOLECULAR GAS IN AN UNUSUAL SB0 GALAXY

作者：Glenn J^*; Rangwala N; Maloney P R; Kamenetzky J R

来源：Astrophysical Journal, 2015, 800(2): 105.

DOI：10.1088/0004-637X/800/2/105

• galaxies: active
• galaxies: individual (NGC 1266)
• galaxies: ISM
• galaxies: jets
• ISM: molecules
• submillimeter: galaxies

With a substantial nuclear molecular gas reservoir and broad, high-velocity CO molecular line wings previously interpreted as an outflow, NGC 1266 is a rare SB0 galaxy. Previous analyses of interferometry, spectrally resolved low-JCO emission lines, and unresolved high-J emission lines have established basic properties of the molecular gas and the likely presence of an active galactic nucleus. Here, new spectrally resolved COJ = 5-4 to J = 8-7 lines from Herschel Space Observatory HIFI observations are combined with ground-based observations and high-J Herschel SPIRE observations to decompose the nuclear and putative outflow velocity components and to model the molecular gas to quantify its properties. Details of the modeling and results are described, with comparisons to previous results and exploration of the implications for the gas excitation mechanisms. Among the findings, like for other galaxies, the nuclear and putative outflow molecular gas are well represented by components that are cool (T-nuclear = 6(-2)(+10) K and T-outflow similar to 30 K), comprising bulk of the mass (log M-nuclear/M-circle dot = 8.3(-0.4)(+0.5) and log M-outflow/M-circle dot = 7.6(-0.3)(+0.3)), and the minority of the luminosity (log L-nuclear/L-circle dot = 5.44(-0.18)(+0.22) and log L-outflow/L-circle dot similar to 6.5) and warm (T-nuclear = 74(-26)(+130) K and T-outflow > 100 K), comprising a minority of the mass (log M-nuclear/M-circle dot = 7.3(-0.5)(+0.5) and log M-outflow/M-circle dot similar to 6.3) but the majority of the luminosity (log L-nuclear/L-circle dot = 6.90(-0.16)(+0.16) and log L-outflow/L-circle dot similar to 7.2). The outflow has an anomalously high L-CO/L-FIR of 1.7x10(-3) and is almost certainly shock excited.

• 出版日期2015-2-20