Molecular gas and nuclear activity in early-type galaxies: any link with radio-loudness?

Abstract

Aims. We want to study the amount of molecular gas in a sample of nearby early-type galaxies (ETGs) which host low-luminosity Active Galactic Nuclei (AGN). We look for possible differences between the radio-loud (RL) and radio-quiet (RQ) AGN. Methods. We observed the CO(1-0) and CO(2-1) spectral lines with the IRAM 30m and NRO 45m telescopes for eight galaxies. They belong to a large sample of 37 local ETGs which host both RQ and RL AGN. We gather data from the literature for the entire sample. Results. We report the new detection of CO(1-0) emission in four galaxies (UGC0968, UGC5617, UGC6946, and UGC8355) and CO(2-1) emission in two of them (UGC0968 and UGC5617). The CO(2-1)/CO(1-0) ratio in these sources is $\sim 0.7\pm 0.2$. Considering both the new observations and the literature, the detection rate of CO in our sample is 55 $\pm$ 9%, with no statistically significant difference between the hosts of RL and RQ AGNs. For all the detected galaxies we converted the CO luminosities into the molecular masses, $M_{H_2}$, that range from 10${}^{6.5}$ to 10${}^{8.5}$ M${}_{\odot }$, without any statistically significant differences between RL and RQ galaxies. This suggests that the amount of molecular gas does not likely set the radio-loudness of the AGN. Furthermore, despite the low statistical significance, the presence of a weak trend between the H${}_2$ mass with various tracers of nuclear activity (mainly [O III] emission line nuclear power) cannot be excluded.

arXiv commentAccepted for publication on A&A, 9 pages, 5 figures

References in corpus (35)

• The Centers of Early-Type Galaxies with HST. IV. Central Parameter Relations
• The Resolved Properties of Extragalactic Giant Molecular Clouds
• The relation between accretion rate and jet power in X-ray luminous elliptical galaxies
• The Atlas3D project -- IV: the molecular gas content of early-type galaxies
• The Difference between Radio-Loud and Radio-Quiet Active Galaxies
• On the Relationship Between Molecular Hydrogen and Carbon Monoxide Abundances in Molecular Clouds
• The Atlas3D project - XIV. The extent and kinematics of molecular gas in early-type galaxies
• Global Relationships Among the Physical Properties of Stellar Systems
• Molecular gas in late-type galaxies
• Molecular Gas and Star Formation in the SAURON Early-type Galaxies
• Jet-Powered Molecular Hydrogen Emission from Radio Galaxies
• The ATLAS3D project - XVIII. CARMA CO imaging survey of early-type galaxies
• The origin of cold gas in giant elliptical galaxies and its role in fueling radio-mode AGN feedback
• Energetics of the molecular gas in the H_2 luminous radio galaxy 3C 326: Evidence for negative AGN feedback
• The accretion mechanism in low-power radio galaxies
• Molecular gas and star formation in early-type galaxies
• The Chandra view of the 3C/FRI sample of low luminosity radio-galaxies
• The Cool ISM in S0 Galaxies. I. A Survey of Molecular Gas
• The host galaxy/AGN connection in nearby early-type galaxies. Is there a miniature radio-galaxy in every "core" galaxy?
• Molecular Gas in Elliptical Galaxies: Distribution and Kinematics
• TANGO I: ISM in nearby radio galaxies. Molecular gas
• The Cool ISM in Elliptical Galaxies. I. A Survey of Molecular Gas
• The host galaxy/AGN connection in nearby early-type galaxies. A new view of the origin of the radio-quiet/radio-loud dichotomy?
• The Herschel Virgo Cluster Survey. IX. Dust-to-gas mass ratio and metallicity gradients in four Virgo spiral galaxies
• A new catalogue of ISM content of normal galaxies
• Radio and spectroscopic properties of miniature radio galaxies: revealing the bulk of the radio-loud AGN population
• The host galaxy/AGN connection in nearby early-type galaxies. Sample selection and hosts brightness profiles
• Cold gas in group-dominant elliptical galaxies
• Molecular gas in the central regions of the latest-type spiral galaxies
• Molecular Disks in the Elliptical Galaxies NGC 83 and NGC 2320
• Molecular gas and dust in Arp 94: The formation of a recycled galaxy in an interacting system
• Molecular clouds in the center of M81
• The host galaxy/AGN connection. Brightness profiles of early-type galaxies hosting Seyfert nuclei
• Molecular Gas Distribution in Barred and Non-Barred Galaxies along the Hubble Sequence
• Examining the Radio-Loud/Radio-Quiet dichotomy with new Chandra and VLA observations of 13 UGC galaxies

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• A rare example of low surface-brightness radio lobes in a gas-rich early-type galaxy: the story of NGC 3998
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