An optical search for supernova remnants in the nearby spiral galaxy NGC 2903

WOS: 000262641100025Aims. We present the results of an optical search for supernova remnants (SNRs) in the nearby spiral galaxy NGC 2903. Methods. Interference filter images and spectral data were taken in March 2005 with the f/7.7 1.5 m Russian Turkish Telescope (RTT150) at TUBITAK National Observatory (TUG). Spectral data were obtained with the 6 m BTA (Bolshoi Azimuthal Telescope, Russia). We used the SNR identification criterion that consists of constructing the continuum-subtracted H alpha and continuum-subtracted [SII]lambda lambda 6716, 6731 images and their ratios. Results. Five SNR candidates were identified in NGC 2903 with [SII]/H alpha ratios ranging from 0.41-0.74 and H alpha intensities ranging from 9.4 x 10(-15) to 1.7 x 10(-14) erg cm(-2) s(-1). This work represents the first identification of SNRs by an optical survey in NGC 2903. We present the spectrum of one of the bright candidates and derive an [SII]/H alpha emission line ratio of 0.42 for this source. In addition, the weak [OIII]lambda 5007/H beta emission line ratio in the spectrum of this SNR indicates an old oxygen-deficient remnant with a low propagation velocity