Oxygen and nitrogen abundances in Virgo and field spirals

¹ Main Astronomical Observatory of National Academy of Sciences of Ukraine, 27 Zabolotnogo Str., 03680 Kiev, Ukraine
² Departamento de Física Teórica, Universidad Autónoma de Madrid, 28049 Cantoblanco, Spain e-mail: mercedes@pollux.ft.uam.es
³ Department of Physics, Section of Astronomy, University of Pisa, Piazza Torricelli 2, 56100 Pisa, Italy
⁴ INTAS, 58 avenue des Arts, 1000 Bruxelles, Belgium e-mail: ferrini@intas.be
⁵ Instituto de Astrofísica de Andalucía, Apdo. 3004, 18080 Granada, Spain e-mail: jvm@iaa.es

Corresponding author: L. S. Pilyugin, pilyugin@mao.kiev.ua

Received: 20 September 2001
Accepted: 6 November 2001

Abstract

The oxygen and nitrogen abundances in the H ii regions of the nine Virgo spirals of the sample from Skillman et al. (1996) and in nine field spiral galaxies are re-determined with the recently suggested P–method. We confirm that there is an abundance segregation in the sample of Virgo spirals in the sense that the H i deficient Virgo spirals near the core of the cluster have higher oxygen abundances in comparison to the spirals at the periphery of the Virgo cluster. At the same time both the Virgo periphery and core spirals have counterparts among field spirals. Some field spirals have H i to optical radius ratios, similar to that in H i deficient Virgo core spirals. We conclude that if there is a difference in the abundance properties of the Virgo and field spirals, this difference appears to be small and masked by the observational errors.