New Infrared Seyfert Galaxies

Abstract

We present optical spectra for new infrared Seyfert galaxies obtained with the 2.16m telescope at Beijing Astronomical Observatory (BAO). After wavelength and flux calibration, they are classified by the degree of nuclear activity: nine Seyfert 2 and three Seyfert 3 galaxies. In addition, by using the data from de Grijp et al.(1992), we find that (1) there exists a tight correlation between luminosities of far-infrared ($L_{FIR}$) and \Ha ($L_{Hα}$) for both Seyfert and HII-like (starburst) galaxies; (2) the median value of \Ha luminosities of Seyfert 1s is one magnitude larger than that of Seyfert 2s and starburst galaxies; (3) the cumulative distributions of FIR luminosities and infrared spectral index $α(100,60)$ for Seyfert 1s and 2s are similar to that of starburst galaxies. We conclude that most of the far-infrared emission from Seyfert 2 galaxies is due to the violent nuclear/circumnuclear starburst, rather than the nonthermal activity in the nucleus, this may also be the case for many Seyfert 1s as well.