The Warped Gas and Dust Lane in NGC 3718

Abstract

We present the first observations of molecular line emission in N GC 3718 with the IRAM 30m and the Plateau de Bure Interferometer. This galaxy is an impressive example for a strongly warped gas disk harboring an active galactic nucleus (AGN). An impressive dust lane is crossing the nucleus and a warp is developing into a polar ring. The molecular gas content is found to be typical of an elliptical galaxy with a relatively low molecular gas mass content (∼ 4 × 10 8 M⊙). The molecular gas distribution is found to warp from the inner disk together with the HI distribution. The CO data were also used to improve the kinematic modeling in the inner part of the galaxy, based on the so-called tilted ring-model. The nature of N GC 3718 is compared with its northern sky "twin" Centaurus A and the possible recent swallowing of a small-size gas-rich spiral is discussed.

Molecular gas in NUclei of GAlaxies (NUGA)

“…These sample the molecular gas emission along the dust lane with ∼12 kpc extent that was previously mapped with the IRAM 30 m by Pott et al (2004) (Fig. 2; see also Hartwich et al 2002 andKrips et al 2003). The central field of the mosaic was set to the same position specified in Sect.…”

Dust and ionized gas association in E/S0 galaxies with dust lanes: clues to their origin

“…A significant fraction of these galaxies exhibit morphological disturbances, such as shells and tidal features, indicative of recent mergers or accretion events (van Dokkum 2005; Tal et al 2009; Kaviraj et al 2011). In fact, when a single stellar population evolves the ejected material is expected to spread evenly throughout the galaxy, whereas the spatial distribution and orientation of the optical dust features are frequently misaligned with those of the stars (van Dokkum & Franx 1995; Tran et al 2001; Krips et al 2003; Martel et al 2004; Quillen et al 2006; Finkelman et al 2010a). Furthermore, the dust content of these galaxies, estimated by measuring total optical extinction, is usually found to be several times larger than expected to be supplied by internal processes, such as stellar mass loss (Patil et al 2007).…”