IRAC Observations of M81

Abstract

IRAC images of M81 show three distinct morphological constituents: a smooth distribution of evolved stars with bulge, disk, and spiral arm components; a clumpy distribution of dust emission tracing the spiral arms; and a pointlike nuclear source. The bulge stellar colors are consistent with M-type giants, and the disk colors are consistent with a slightly younger population. The dust emission generally follows the blue and ultraviolet emission, but there are large areas that have dust emission without ultraviolet and smaller areas with ultraviolet but little dust emission. The former are presumably caused by extinction, and the latter may be due to cavities in the gas and dust created by supernova explosions. The nucleus appears fainter at 8 um than expected from ground-based 10 um observations made four years ago.

ApJS in press (Spitzer special issue); 15 pages, 3 figures. Changes: unused references removed, numbers and labels in Table 1 changed

References in corpus (4)

• The Infrared Array Camera (IRAC) for the Spitzer Space Telescope
• The Anatomy of Star Formation in NGC 300
• Mid-Infrared Galaxy Morphology Along the Hubble Sequence
• Spatially Resolved Ultraviolet, H-alpha, Infrared, and Radio Star Formation in M81

Cited by in corpus (42)

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• The Herschel Space Observatory view of dust in M81
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• H-alpha Kinematics of the SINGS Nearby Galaxies Survey. I
• Results from an extensive simultaneous broadband campaign on the underluminous active nucleus M81*: further evidence for mass-scaling accretion in black holes
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• Mid-Infrared Galaxy Morphology Along the Hubble Sequence
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• Spatially Resolved Ultraviolet, H-alpha, Infrared, and Radio Star Formation in M81
• The ACS Nearby Galaxy Survey Treasury I. The Star Formation History of the M81 Outer Disk
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• IRAC and MIPS Observations of the Interacting Galaxies IC 2163 and NGC 2207: Clumpy Emission
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• Resolving the Stellar Outskirts of M81: Evidence for a Faint, Extended Structural Component
• Galactic Spiral Shocks with Thermal Instability
• Nature of the Wiggle Instability of Galactic Spiral Shocks
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• Quantifying the Heating Sources for Mid-infrared Dust Emissions in Galaxies: The Case of M 81
• Wiggle Instability of Galactic Spiral Shocks: Effects of Magnetic Fields
• Lack of Interaction between the Dust Grains and the Anomalous Radio Jet in the Nearby Spiral Galaxy NGC 4258
• Lifting the Veil of Dust from NGC 0959: The Importance of a Pixel-Based 2D Extinction Correction
• A Multiwavelength View of Star Formation in Interacting Galaxies in the Pavo Group
• Mapping the Spatial Distribution of Dust Extinction in NGC 959 Using Broadband Visible and mid-IR Filters
• New Globular Cluster Candidates in the M81 group
• Spiral Density Waves in M81. II. Hydrodynamic Simulations for Gas Response to Stellar Spiral Density Waves
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