1 Introduction

The relationship between an active galactic nucleus (AGN) and its host galaxy is one of the key issues in the study of nuclear activity. One would expect that certain properties of active galaxies such as mass, luminosity, bulge to disk ratio and colors could influence nuclear activity or vice versa. In fact, the unified model for an AGN requires gas accretion, most probably from the host galaxy, onto a massive and compact object (Malkan 1983). Similarly, the nuclear burst scenario (Terlevich et al. 1992) requires gas fueling together with an efficient way to concentrate that gas into a small region of space, in a relatively short time-scale. Besides this, gas fueling seems to be connected to the presence of a bar, which is needed to get the non-axisymmetric potential that arises in from the theoretical works (Barnes & Hernquist 1991). However, recent observational studies based on optical data show that barred galaxies are not a specific signature of nuclear activity (Ho et al. 1997; Hunt et al. 1999). In this sense, Regan & Mulchaey (1999), based on the analysis of 12 Seyferts galaxies imaged with the HST, proposed central spiral dust lanes as an alternative mechanism to drive the gas to the central regions.

Another important question to consider is the role played by the environment as a trigger of nuclear activity. De Robertis et al. (1998) have found that AGNs are not more likely to be associated with interactions than normal galaxies. However, Pastoriza et al. (1999), studying a sample of interacting galaxies, found that almost 40% of the galaxies may host a low luminosity AGN.

It is also worth noting that most of the studies on the topics mentioned above are focused on the galaxy nuclei and some of them on the circumnuclear regions, but only a few works have paid attention to the properties of the stellar populations of the hosts galaxies. As an example, González-Delgado et al. (1997)(hereafter GD97), presented H$\alpha$ images of a sample of 55 active galaxies and Sánchez-Portal et al. (2000) gave results of broad band VRI and narrow band H$\alpha$ photometry for a sample of 24 nearby active galaxies. Also, Hunt et al. (1997) and Márquez et al. (2000) presented near infrared broad band images of a sample of 26 and 18 active galaxies respectively.

Our goal in this paper is to present a new valuable set of photometric data for a sample of 10 Seyfert 1 galaxies and to describe the main properties of both the stellar component and the gas of the hosts galaxies. The paper is organized as follows: In Sect. 2 we describe the sample selection. In Sect. 3 we summarize the observations and data reduction. Section 4 discusses the photometric results and Sect. 5 describes the particular properties of each galaxy of the sample. Finally, in Sect. 6 we provide our conclusions.