* Astronomy

Title: Photometric and Spectroscopic Study of Abell 0671
Authors: Zhizheng Pan, Qirong Yuan, Xu Kong, Dongxin Fan, Xu Zhou, Xuanbin Lin

In this paper we present a photometric and spectroscopic study of the nearby galaxy cluster Abell 0671 (A671) with 15 intermediate-band filters in the Beijing-Arizona-Taiwan-Connecticut (BATC) system and the Sloan Digital Sky Survey (SDSS) data. The photometric redshift technique is applied to the galaxy sample for further membership determination. After the colour-magnitude relation is taken into account, 97 galaxies brighter than h_batc=19.5 mag are selected as new member galaxies. Based on the enlarged sample of cluster galaxies, spatial distribution, dynamics of A671 are investigated. The substructures of A671 are well shown by the sample of bright members, but it appears less significant based on the enlarged sample, which is mainly due to larger uncertainties in the light-of-sight velocities of the newly-selected faint members. The SDSS r-band luminosity function of A671 is flat at faint magnitudes, with the faint end slope parameter alpha=-1.12. The SDSS spectra allow us to investigate the star formation history of bright cluster galaxies, and the galaxies in the core region are found to be older than those in the outskirts. No environmental effect is found for metallicities of the early-type galaxies (ETGs). The positive correlation between age and stellar mass supports the downsizing scenario. By comparing ETG absorption-line indices with the state-of-art stellar population models, we derive the relevant parameters of simple stellar population (such as age, [Fe/H], [Mg/Fe], [C/Fe], [N/Fe], and [Ca/Fe]). The ETGs at cluster center tend to have smaller hb indices, indicating that central ETGs are likely to be older. The distribution of total metallicity indicator, [MgFe]', does not show any environmental effects. The relations between the simple stellar population parameters and velocity dispersion in A671 are in good agreement with previous studies.

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