EDP Sciences
Free Access
Volume 493, Number 3, January III 2009
Page(s) 1061 - 1065
Section Interstellar and circumstellar matter
DOI https://doi.org/10.1051/0004-6361:200810690
Published online 22 December 2008

A&A 493, 1061-1065 (2009)
DOI: 10.1051/0004-6361:200810690

Research Note

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

E. Sonbas1, 2, A. Akyuz1, and S. Balman3

1  University of Cukurova, Department of Physics, 01330 Adana, Turkey
    e-mail: edasonbas@yahoo.com
2  Special Astrophysical Observatory of R.A.S., Karachai-Cherkessia, Nihnij Arkhyz 369167, Russia
3  Dept. of Physics, Middle East Technical University, 06531 Ankara, Turkey

Received 28 July 2008 / Accepted 11 December 2008

Aims. 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 $\times$ 10-15 to 1.7 $\times$ 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.

Key words: ISM: supernova remnants -- galaxies: spiral -- galaxies: individual: NGC 2903

© ESO 2009