Spatially Resolved Imaging at 350um of Cold Dust in Nearby Elliptical Galaxies

Abstract

Continuum observations at 350um are presented of seven nearby elliptical galaxies, for which CO-gas disks have recently been resolved with interferometry mapping. These SHARCII mapping results provide the first clearly resolved far-infrared(FIR) to submillimeter(submm) continuum emission from cold dust (with temperatures 32K > T > 22K) of any elliptical galaxy at a distance >40Mpc. The measured FIR excess shows that the most likely and dominant heating source of this dust is not dilute stellar radiation or cooling flows, but rather star-formation, that could have been triggered by an accretion or merger event and fueled by dust-rich material that has settled in a dense region co-spatial with the central CO-gas disks. The dust is detected even in two cluster ellipticals that are deficient in HI, showing that, unlike the HI, cold dust and CO in ellipticals can survive in the presence of hot X-ray gas, even in galaxy clusters. No dust cooler than 20K, either distributed outside the CO disks, or co-spatial with and heated by the entire dilute stellar optical galaxy (or very extended HI), is currently evident.

arXiv commentAccepted for publication in The Astrophysical Journal (ApJ) and tentatively scheduled for the ApJ April 10, 2008, v677 n1 issue

References in corpus (19)

• Star Formation in Galaxies Along the Hubble Sequence
• Interstellar Dust Grains
• The SCUBA Local Universe Galaxy Survey I: First Measurements of the Submillimetre Luminosity and Dust Mass Functions
• Formation of gas disks in merging galaxies
• Dust in the Cores of Early-Type Galaxies
• Dusty Nuclear Disks and Filaments in Early Type Galaxies
• Mid-IR Observations of Mass Loss in Elliptical Galaxies
• Cold Dust in Early-Type Galaxies. I. Observations
• Molecular Gas in Elliptical Galaxies: Distribution and Kinematics
• The Central Gas Systems of Early-Type Galaxies Traced by Dust Feature: Based on the HST WFPC2 Archival Images
• Spitzer observations of the dusty warped disk of Centaurus A
• Rapid Cooling of Dusty Gas in Elliptical Galaxies
• Molecular Disks in the Elliptical Galaxies NGC 83 and NGC 2320
• Observations of Cold Dust in Nearby Elliptical Galaxies
• A Survey of Merger Remnants III: Are Merger Remnants Supported by Rotation or Anisotropy
• Deep Submillimeter Imaging of Dust Structures in Centaurus A
• HI in the shell elliptical NGC 3656
• Two tails in NGC 3656, and the major merger origin of shell and minor axis dust lane ellipticals
• Ram Pressure Stripping in the Low Luminosity Virgo Cluster Elliptical Galaxy NGC 4476

Cited by in corpus (12)

• Inclination- and dust-corrected galaxy parameters: Bulge-to-disc ratios and size-luminosity relations
• H-ATLAS/GAMA: Dusty early-type galaxies and passive spirals
• The unexpectedly large dust and gas content of quiescent galaxies at z>1.4
• Mid- to Far-IR Emission and Star Formation in Early-Type Galaxies
• The dust morphology of the elliptical Galaxy M86 with SPIRE
• The gas-to-dust mass ratio of Centaurus A as seen by Herschel
• GAMA/H-ATLAS: Linking the Properties of Sub-mm Detected and Undetected Early-Type Galaxies: I. z$\le$0.06 Sample
• The SAMI Galaxy Survey: Kinematics of Dusty Early-Type Galaxies
• Dust and Ionized Gas Association in E/S0 Galaxies with Dust Lanes: Clues to their Origin
• An extremely low gas-to-dust ratio in the dust-lane lenticular galaxy NGC 5485
• Cold dust but warm gas in the unusual elliptical galaxy NGC 4125
• Using GAMA and H-ATLAS Data to Explore the Cold Dust Properties of Early-Type Galaxies