The molecular H2 emission and the stellar kinematics in the nuclear region of the Sombrero galaxy

Abstract

We analyze the molecular H${}_2$ emission and the stellar kinematics in a data cube of the nuclear region of M104, the Sombrero galaxy, obtained with NIFS on the Gemini-north telescope. After a careful subtraction of the stellar continuum, the only emission line we detected in the data cube was H${}_2\lambda 21218$. An analysis of this emission revealed the existence of a rotating molecular torus/disk, aproximately co-planar with a dusty structure detected by us in a previous work. We interpret these two structures as being associated with the same obscuring torus/disk. The kinematic maps provided by the Penalized Pixel Fitting method revealed that the stellar kinematics in the nuclear region of M104 appears to be the result of the superposition of a "cold" rotating disk and a "hot" bulge. Using a model of a thin eccentric disk, we reproduced the main properties of the maps of the stellar radial velocity and of the stellar velocity dispersion, specially within a distance of 0.2" from the kinematic axis (in regions at larger distances, the limitations of a model of a thin rotating disk become more visible). The general behavior of the $h_3$ map, which is significantly noisier than the other maps, was also reproduced by our model (although the discrepancies, in this case, are considerably higher). With our model, we obtained a mass of (9.0 +/- 2.0) x 10^8 Mo for the supermassive black hole of M104, which is compatible, at $1\sigma$ or $2\sigma$ levels, with the values obtained by previous studies.

11 pages, 5 figures, 1 table, published online in ApJ

References in corpus (6)

• Measuring the inclination and mass-to-light ratio of axisymmetric galaxies via anisotropic Jeans models of stellar kinematics
• PCA Tomography: how to extract information from datacubes
• 2D kinematic signatures of boxy/peanut bulges
• A treatment procedure for Gemini North/NIFS data cubes: application to NGC 4151
• A treatment procedure for VLT/SINFONI data cubes: application to NGC 5643
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Cited by in corpus (6)

• Forming circumnuclear disks and rings in galactic nuclei: a competition between supermassive black hole and nuclear star cluster
• The molecular H2 and stellar discs in the nuclear region of NGC 4258
• Digging process in NGC 6951: the molecular disc bumped by the jet
• The DIVING${}^{3D}$ Survey -- Deep IFS View of Nuclei of Galaxies -- I. Definition and Sample Presentation
• Multifrequency Very Long Baseline Interferometry Imaging of the Subparsec-scale Jet in the Sombrero Galaxy (M104)
• Evaluating the efficacy of a data cube treatment procedure for kinematic analyses: application to NGC 3115 and NGC 4699