H alpha measurements using DEFPOS/RTT150 Telescope: Instrumentation and observations

To investigate the physical properties of HII regions and some PNe about 4' in size, a DEFPOS Fabry-Perot spectrometer has been redesigned and set up at the coude exit of the 150cm RT7150 telescope (f/48) at TUBITAK National Observatory (Antalya/Bakirhtepe, Turkey). The spectrometer has a 4' circular field of view and a velocity resolution of 27.27 km s(-1) (a spectral resolving power of 11 000) over a 200 km s(-1) spectral window near H alpha. This work presents the details of the newly redesigned instrument for coude observations, the data reduction techniques and finally presents some physical results of our new H alpha observations selected from the Reynolds et al. (2005) and Fich et al. (1990) papers. The DEFPOS system has been fully tested and the first observations of HII regions and PNe in the Galaxy are used to illustrate the power of the instrument. We feel that our first Fabry-Perot observations can provide a powerful tool for the study of objects with small angular size. In the future, we are planning to prepare a catalog including some physical properties such as radial velocity, line width, and intensity of some PNe and HII regions close to the 4' field of view.