Late-type galaxies observed with SAURON: two-dimensional stellar and emission-line kinematics of 18 spirals |
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| Authors: | Katia Ganda Jesús Falcón-Barroso Reynier F Peletier Michele Cappellari Eric Emsellem Richard M McDermid P Tim de Zeeuw C Marcella Carollo |
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| Institution: | Kapteyn Astronomical Institute, Postbus 800, 9700 AV Groningen, the Netherlands;Leiden Observatory, Postbus 9513, 2300 RA Leiden, the Netherlands;Centre de Recherche Astrophysique de Lyon –Observatoire, 9 Avenue Charles André, 69230 Saint Genis Laval, France;Eidgenössische Technische Hochschule Zurich, Hönggerberg HPF G4.3, CH-8092 Zurich, Switzerland |
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| Abstract: | We present the stellar and gas kinematics of a sample of 18 nearby late-type spiral galaxies (Hubble types ranging from Sb to Sd), observed with the integral-field spectrograph SAURON at the 4.2-m William Herschel Telescope. SAURON covers the spectral range 4800–5380 Å, allowing us to measure the Hβ, Fe, Mg b absorption features and the emission in the Hβ line and the O iii ]λλ4959, 5007 Å and N i ]λλ5198, 5200 Å doublets over a 33 × 41-arcsec2 field of view. The maps cover the nuclear region of these late-type galaxies and in all cases include the entire bulge. In many cases the stellar kinematics suggests the presence of a cold inner region, as visible from a central drop in the stellar velocity dispersion. The ionized gas is almost ubiquitous and behaves in a complicated fashion: the gas velocity fields often display more features than the stellar ones, including wiggles in the zero-velocity lines, irregular distributions, ring-like structures. The line ratio O iii ]/Hβ often takes on low values over most of the field, probably indicating a wide-spread star formation. |
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| Keywords: | galaxies: bulges galaxies: evolution galaxies: formation galaxies: kinematics and dynamics galaxies: spiral |
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