IAU Symposium Abstract S186-031P

Dwarf galaxy NGC3782 at 21 cm

B. Peng1, W. Yuan1, T. A. Th. Spoelstra2
1 Beijing Astronomical Observatory < PB@bao01.bao.ac.cn >
2 The Netherlands Foundation for Research in Astronomy < spoelstra@nfra.nl >

The classification of the dwarf galaxy NGC3782 is somewhat ambiguous from Sb to Irr. Its optical CCD image taken by Yunnan Observatory shows a disturbed morphology with several bright blue spots embedded on it, whose luminosities are comparable with that of the nucleus. It is also an IRAS source. The far-infrared emission is thought to originate from the star-forming regions which are probably associated with the bright blue spots. In this paper, we present HI line images of NGC3782 observed with the Westerbork Synthesis Radio Telescope (WSRT). The HI is observed to break up into small condensations at ~ 13" resolution, there is some asymmetry in the HI distribution which extends to about twice the optical diameter. The fitted rotation curve of NGC3782 confirms that somewhat solid body rotation exists within 40 arcsec from the dynamic center of the galaxy, the systemic velocity is determined to be 764 km/s. The warped structure is manifest in the velocity field.