Neutral hydrogen in nearby elliptical and lenticular galaxies: the continuing formation of early-type galaxies

By R. Morganti, P. de Zeeuw, T. Oosterloo, R. McDermid, D. Krajnovi'c, M. Cappellari, F. Kenn, A. Weijmans, M. Sarzi. 2006

177 citations recorded by the source corpus.

We present the results of deep Westerbork Synthesis Radio Telescope observations of neutral hydrogen in 12 nearby elliptical and lenticular galaxi es. The selected objects come from a representative sample of nearby galaxies earlier studied at optical wavelengths with the integral-field spectrograph SAURON. They are field galaxies, or (in two cases) located in poor group environments. We detect H I - both in regular discs as well as in clouds and tails offset from the host galaxy - in 70% of the galaxies. This detection rate is much higher than in previous, shallower single-dish surveys, and is similar to that for the ionised gas. The results suggest that at faint detection levels the presence of H I is a relatively common characteristic of field early-type galaxies, confirming what was suggested t wenty years ago by Jura based on IRAS observations. The observed total H I masses range between a few times 10 6 M⊙ to just over 10 9 M⊙. The presence of regular disc-like structures is a situatio n as common as H I in offset clouds and tails around early-type galaxies. All g alaxies where H I isdetected also contain ionised gas, whereas no H I is found around galaxies without ionised gas. Galaxies with regular H I discs tend to have strong emission from ionised gas. In these cases, the similar kinematics of the neutral hydrogen and ionised gas suggest that they form one structure. The kinematical axis of the stellar component is nearly always misaligned with respect to that of the gas. We do not find a clear trend between the presence of H I and the global age of the stellar population or the global dynamical characteristics of t he galaxies. More specifically, H I detections are uniformly spread through the (V/σ, ǫ) diagram. If fast and slow rotators - galaxies with high and low specific angular momentum - represent th e relics of different formation paths, this does not appear in the presence and characterist ics of the H I. Our observations support the idea that gas accretion is common and does not happen exclusively in peculiar early-type galaxies. The links observed between the large-scale gas and the characteristics on the nuclear scale (e.g., the presence of kinematically de coupled cores, radio continuum emission etc.), suggest that for the majority of the cases th e gas is acquired through merging, but the lack of correlation with the stellar population age s uggests that smooth, cold accretion could be an alternative scenario, at least in some galaxies. In either cases, the data suggest that early-type galaxies continue to build their mass up to the pr esent.

Subfields: Astronomy and Astrophysics, Instrumentation

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In Astronomy and Astrophysics

1. M. Cappellari
2. P. Hopkins
3. C. Conroy
4. T. Naab
5. L. Hernquist
6. M. Sarzi
7. Roger Davies
8. P. V. van Dokkum

In Instrumentation

1. M. Cappellari
2. C. Conroy
3. T. Naab
4. P. Hopkins
5. M. Sarzi
6. L. Hernquist
7. Eric Emsellem
8. Roger Davies

Citations in the corpus

• The ATLAS3D project - VII. A new look at the morphology of nearby galaxies: the kinematic morphology-density relation (2011, background): “…(Böhringer et al. 1994) starts ram-pressure stripping spiral galaxies of their gas (Giovanelli & Haynes1985; di Serego Alighieri et al. 2007; Morganti et al. 2006) and prevents further cold accretion (Oosterloo et al. 2010), thus rapidly transforming the spiral galaxies into red and…”
• The ATLAS3D project – IV. The molecular gas content of early-type galaxies (2011, background): “The gas is detected in dusty silhouette discs (e.g. Goudfrooij et al. 1994), H I emission (e.g. Wardle & Knapp 1986; Huchtmeier, Sage & Henkel 1995; Morganti et al. 2006; Oosterloo et al. 2010) and CO emission (Lees et al. 1991; Wiklind, Combes & Henkel 1995; Combes, Young & Bureau 2007; Welch,…”
• The GALEX Arecibo SDSS Survey I: gas fraction scaling relations of massive galaxies and first data release (2009, background): “A number of past studies have investigated the Hi content of elliptical and early-type galaxies (e.g., Morganti et al. 2006; Oosterloo et al. 2007), but these samples are selected by morphology and hence may not be representative of the full population of massive galaxies.”
• Physical properties and environments of nearby galaxies (2009, background): “Morganti et al. (2006) surveyed a representative subset of the SAURON galaxies and detected H i emission in 70% of the sample, with gas masses ranging from 106 to 109 M⊙.”
• The ATLAS3D project – I. A volume-limited sample of 260 nearby early-type galaxies: science goals and selection criteria (2010, methodology): “Some of the galaxies were observed with the WSRT as part of previous studies (Morganti et al. 2006; Józsa et al. 2009; Oosterloo et al. 2010).”
• The ATLAS3D project - X. On the origin of the molecular and ionized gas in early-type galaxies (2011, background): “Observations are describ d in detail in Morganti et al. (2006); Oosterloo et al. (2010) andSerra et al., in prep (see Serra et al. 2009, for a summary).”
• Fourteen months of observations of the possible super-Chandrasekhar mass Type Ia Supernova 2009dc (2010, background): “However, recent deep H I surveys of S0 galaxies have shown that the majority of non-cluster early-type galaxies contain substantial reservoirs (106–109 M ) of neutral gas that extend to large galactocentric radii (Morganti et al. 2006), whose morphology and kinematics suggest external origins.”
• The ATLAS3D Project – XXVIII. Dynamically driven star formation suppression in early-type galaxies (2014, background): “Atomic gas is present in≈32% of early-type galaxies (ETGs; Bottinelli & Gouguenheim 1977; Knapp, Turner & Cunniffe 1985; Morganti et al. 2006; di Serego Alighieri et al. 2007; Grossiet al. 2009; Oosterloo et al. 2010; Serra et al. 2012), dust in≈60% (Colbert, Mulchaey & Zabludoff 2001; Smith et al.…”
• Molecular gas and star formation in the SAURON early-type galaxies (2007, unknown): “Over the last twenty years, growing evidence has accumulated that early-type galaxies (E/S0s) have detectable amounts of cold gas, sometimes settled in a disc, and recent star formation (e.g. Bregman, Hogg & Roberts 1991; Hogg, Roberts & Sandage 1993; Ferrari et al. 1999; Morganti et al. 2006).”
• The ATLAS3D project - XIV. The extent and kinematics of the molecular gas in early-type galaxies (2012, methodology): “Some ETGs do, however, have molecular (and atomic; see Morganti et al. 2006; Oosterloo et al. 2010; Serra et al. 2011; Paper XIII) gas reservoirs.”
• Environment and self-regulation in galaxy formation (2009, background): “This implies that the majority of the rejuvenated galaxies (84 per cent) are actively forming stars, which is well consistent with the detection of significant amounts of neutral hydrogen in low-mass ellipticals (Morganti et al. 2006).”
• The SAURON project - XVI. On the sources of ionization for the gas in elliptical and lenticular galaxies (2009, methodology): “These range from GALEX ultraviolet images (Jeong et al. 2009), Spitzer infrared data (Shapiro et al. 2009) to mm- and cm- radio observations of the molecular and neutral gas (Combes, Young, & Bureau 2007; Morganti et al. 2006).”
• The ATLAS3D project - II. Morphologies, kinemetric features and alignment between photometric and kinematic axes of early-type galaxies (2011, background): “Observations of the molecular, atomic and ionized gas (Oosterloo et al. 2002; Morganti et al. 2006; Sarzi et al. 2006; Serra et al. 2008; Young, Bureau & Cappellari 2008; Crocker et al. 2009; Oosterloo et al. 2010) suggest that the evolution of early-type galaxies is significantly influenced by gas…”
• Galaxy Masses: A Review (2013, background): “However, many ETGs have a significant amount of gas, either ionised (e.g. Bertola et al. 1984; Fisher 1997; Sarzi et al. 2006), sometimes molecular (e.g. Sage et al. 2007; Young et al. 2011) or even neutral (Knapp et al. 1985; Morganti et al. 2006; di Serego Alighieri et al. 2007).”
• Observational evidence for AGN feedback in early-type galaxies (2007, background): “…lenticular galaxies has shown that many of them have (often extended) emission lines and signs of recent star formation as well as CO emissions from molecular gas and atomic hydrogen indicating sometimes substantial reservoirs of gas (Sarzi et al. 2006; Morganti et al. 2006; Combes et al. 2007).”