Paper detail

Panoramic Spectroscopy of Galaxies with Star-formation Regions. A Study of SBS 1202+583

The methods of panoramic (3D) spectroscopy are used in a detailed study of galaxies with ongoing star formation chosen from among objects in seven selected fields of the Second Byurakan Survey (SBS). This article deals with the irregular galaxy SBS 1202+583, which our classification scheme identifies as being in a continuous phase of starformation. Observations were made with the panoramic spectrographs MPFS at the 6-m telescope of the Special Astrophysical Observatory (SAO) of the Russian Academy of Sciences and VAGR at the 2.6-m telescope of the Byurakan Astrophysical Observatory (BAO) in Armenia. The data are used to construct charts of the radiative fluxes in the continuum and various emission lines. Special attention is devoted to analyzing the emission in the Hα hydrogen recombination line and in the forbidden low-ionization doublets of nitrogen [NII]λλ6548, 6583 and sulfur [SII]λλ 6716,6731, and the ratios of the intensities of the forbidden lines to Hα. The observable characteristics (sizes, Hα fluxes, etc.) of nine HII regions are studied. The estimated current rates of starformation in the individual HII regions based on the Hα fluxes lie within the range of 0.3-1.2 Msun/year. The dependence of the ratio of the intensities of the emission in these two forbidden doublets on the rate of star formation in the HII regions is found.