Multi-Longslit Spectroscopy for Kinematic Studies

Jiehae Choi

I present a two-dimensional spectroscopy method developed for the ARC 3.5m telescope and results from data for the Owl Nebula, and two spiral galaxies, NGC 891 and M33, using the technique. I discuss how accurate our measured velocities are across the detector by measuring the velocities across the Owl Nebula. To do so, we offset the telescope in different positions so that a certain part of the nebula can be taken in different parts of the detector. The velocity comparison shows good agreement in general, except near the edges of the detector, especially towards the bottom. The velocities fields of an edge-on galaxy, NGC 891, shows that the halo gas rotates slower than the gas in the disk. Deeper observation of more edge-on galaxies can help us build a model of thick diffuse gas halo above the disk. Lagging features did not appear in all slits, but only in some. The central region of M33 was studied, and the velocities of major axis and minor axis with our setup were compared to those from single long slit method (Corbelli & Walterbos 2007).