Multi-Wavelength Study of Stellar and Gas Morphology in the Starburst Galaxy Maffei~2
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Session 23 -- Galaxies I
Oral presentation, Wednesday, January 12, 10:15-11:45, Salon IV Room (Crystal Gateway)

[23.02] Multi-Wavelength Study of Stellar and Gas Morphology in the Starburst Galaxy Maffei~2

R.L.Hurt, J.L.Turner (UCLA)

The galaxy Maffei 2 is notable for its strong nuclear starburst and proximity to the Milky Way. While virtually undetectable in visible light due to its location behind the Galactic plane, longer wavelength studies are less impaired. Its substantial angular extent make it an ideal candidate for studying a starburst at high angular resolutions. We present results from an ongoing multi-wavelength study of this intriguing source.\par

Near infrared imaging has shown Maffei 2 to be a barred galaxy of peculiar morphology. With J, H, and K band images made using KNPO's SQIID, we find the stellar bar is not symmetric about the nucleus and the spiral arms are of unequal extent. These peculiarities argue for a recent interaction driving the nuclear star formation. \par

Large scale CO mapping with NRAO's 12m shows that the molecular component is strongest in the nucleus, coincident with the starburst emission, but extends well into the bar and arms. High resolution imaging with the Owens Valley Millimeter Interferometer shows the molecular morphology on 100 pc scales is linear through the nucleus, suggesting the star formation is triggered by a density wave extending to within 50 pc of the dynamical center of the galaxy. \par

The large-scale HI structure, observed with the VLA, indicates a phase transition from molecular gas in the nucleus to atomic gas in the outer disk. The velocity field, consistent with gas dynamics in barred galaxies, indicates the presence of a kinematic disruption in one of the spiral arms. \par

By correlating the results of these different observations, a picture of the nature of the Maffei 2 system emerges. We conclude that the nuclear starburst is driven by a tidal interaction with a dwarf companion. Seen as a faint extension in the infrared, this companion is likely also responsible for disrupting the spiral density wave kinematics and may ultimately be responsible for driving the bar.

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