A star formation study of the ATLAS3D early-type galaxies with the AKARI all-sky survey

Abstract

The star formation properties of early-type galaxies (ETGs) are currently the subject of considerable interest, particularly whether they differ from those of gas-rich spirals. We perform a systematic study of star formation in a large sample of local ETGs using polycyclic aromatic hydrocarbon (PAH) and dust emission, focusing on the galaxies' star formation rates (SFRs) and star formation efficiencies (SFEs). Our sample is composed of the 260 ETGs from the ATLAS3D survey, from which we use the cold gas measurements (HI and CO). The SFRs are estimated from stellar, PAH and dust fits to spectral energy distributions created from new AKARI measurements and literature data from WISE and 2MASS. The mid-infrared luminosities of non-CO-detected galaxies are well correlated with their stellar luminosities, showing that they trace (circum)stellar dust emission. CO-detected galaxies show an excess above these correlations, uncorrelated with their stellar luminosities, indicating that they likely contain PAHs and dust of interstellar origin. PAH and dust luminosities of CO-detected galaxies show tight correlations with their molecular gas masses, and the derived current SFRs are typically 0.01-1 Msun/yr. These SFRs systematically decrease with stellar age at fixed stellar mass, while they correlate nearly linearly with stellar mass at fixed age. The majority of local ETGs follow the same star-formation law as local star-forming galaxies, and their current SFEs do not depend on either stellar mass or age. Our results clearly indicate that molecular gas is fueling current star formation in local ETGs, that appear to acquire this gas via mechanisms regulated primarily by stellar mass. The current SFEs of local ETGs are similar to those of local star-forming galaxies, indicating that their low SFRs are likely due to smaller cold gas fractions rather than a suppression of star formation.

30 pages, 12 figures, 4 tables, accepted for publication in A&A

References in corpus (21)

• Infrared Emission from Interstellar Dust. IV. The Silicate-Graphite-PAH Model in the Post-Spitzer Era
• HyperLEDA. III. The catalogue of extragalactic distances
• A systematic variation of the stellar initial mass function in early-type galaxies
• COLD GASS, an IRAM legacy survey of molecular gas in massive galaxies: I. Relations between H2, HI, stellar content and structural properties
• The Atlas3D Project - XXX. Star formation histories and stellar population scaling relations of early-type galaxies
• Molecular and atomic gas along and across the main sequence of star-forming galaxies
• Molecular Gas and Star Formation in the SAURON Early-type Galaxies
• The ATLAS3D Project - XXVIII. Dynamically-driven star formation suppression in early-type galaxies
• Suppression of star formation in early-type galaxies by feedback from supermassive black holes
• The distribution of the ISM in the Milky Way A three-dimensional large-scale model
• Suppression of Star Formation in NGC 1266
• The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies. III. The Reddest Extended Sources in WISE
• SPITZER IRS spectra of Virgo early type galaxies: detection of stellar silicate emission
• Properties of polycyclic aromatic hydrocarbons in local elliptical galaxies revealed by the Infrared Spectrograph on Spitzer
• The $AKARI$ Far-Infrared All-Sky Survey Maps
• Structure and Kinematics of Molecular Disks in Fast-Rotator Early-Type Galaxies
• Exceptional AGN-driven turbulence inhibits star formation in the 3C 326N radio-galaxy
• Connection between dynamically derived IMF normalisation and stellar population parameters
• Calibration of the AKARI Far-infrared All Sky Survey Maps
• Star Formation in Nearby Early-Type Galaxies: The Radio Continuum Perspective
• An extremely low gas-to-dust ratio in the dust-lane lenticular galaxy NGC 5485

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