Optical Integral Field Spectroscopy of NGC 5850

Abstract

Abstract. Here we present the preliminary results of the analysis of VIMOS observations of the central 4.5 kpc of the double-barred galaxy NGC 5850. We use optical diagnostic diagrams to study the main ionization mechanism across the field of view confirming the LINER nature in the continuum peak location. Also a star-forming (SF) region is found close to it (0.46kpc), a second SF region is located east of the center (1.6kpc). Further the data reveals complex nuclear gas kinematics which is likely to be dominated by the secondary bar.

Distinct stellar populations in the inner bars of double-barred galaxies

“…The position of the Hβ emission peak in NGC 5850 corresponds with a small potential star-forming region, as indicated by the [OIII]/Hβ ratio map also shown in Figure 5. This result is confirmed by Bremer et al (2012) in a study of optical diagnostic diagrams using VIMOS integral-field spectroscopy. In addition they found a faint, second star-forming region 1.6 kpc (i.e., ∼11.4 arcsec) East of the centre, which is not observed in our data.…”

“…In our analysis, we do not find differences between the galaxies hosting or not an AGN, so we are not able to shed light on the role of inner bars in fueling the AGNs. As indicated in Section 2, NGC 3941 and NGC 4725 are Seyfert 2 galaxies (Véron-Cetty & Véron 2006), NGC 5850 hosts a LINER (Bremer et al 2012), and NGC 2859 shows no signs of nuclear activity. More double-barred galaxies are needed to do a proper statistical analysis and to draw conclusions on this matter.…”

“…In particular, the galaxies were selected to have almost no dust, although it is worth noting here that our stellar population analysis is based on the measurement of the line indices which are little affected by dust (see MacArthur 2005). Finally, NGC 3941 and NGC 4725 are classified as Seyfert 2 galaxies (Véron-Cetty & Véron 2006), whereas NGC 2859 presents no signs of nuclear activity and NGC 5850 is considered a LINER (Low Ionisation Nuclear Emission Region, see Section 5.2.2 for further details on the LINER classification of this galaxy; Bremer et al 2012). The bar lengths, ellipticities, position angles (hereafter PA), and other relevant properties for the sample galaxies are summarized in Table 1.…”