Structure of the interstellar medium around Cas A

Abstract

We present a three-year series of observations at 24 microns with the Spitzer Space Telescope of the interstellar material in a 200 x 200 arcmin square area centered on Cassiopeia A. Interstellar dust heated by the outward light pulse from the supernova explosion emits in the form of compact, moving features. Their sequential outward movements allow us to study the complicated three-dimensional structure of the interstellar medium (ISM) behind and near Cassiopeia A. The ISM consists of sheets and filaments, with many structures on a scale of a parsec or less. The spatial power spectrum of the ISM appears to be similar to that of fractals with a spectral index of 3.5. The filling factor for the small structures above the spatial wavenumber k ~ 0.5 cycles/pc is only ~ 0.4%.

29 pages including 10 figures; accepted by The Astrophysical Journal

References in corpus (19)

• Interstellar Dust Grains
• Infrared Emission from Interstellar Dust. II. The Diffuse Interstellar Medium
• The Mid-Infrared Spectrum of Star-Forming Galaxies: Global Properties of PAH Emission
• Molecular Cloud Evolution II. From cloud formation to the early stages of star formation in decaying conditions
• Reduction Algorithms for the Multiband Imaging Photometer for Spitzer
• Helical Fields and Filamentary Molecular Clouds
• The Expansion Center and Dynamical Age of the Galactic Supernova Remnant Cassiopeia A
• Constraints on the Progenitor of Cassiopeia A
• Magnetically Dominated Strands of Cold Hydrogen in the Riegel-Crutcher Cloud
• No cold dust within the supernova remnant Cassiopeia A
• Infrared Echoes near the Supernova Remnant Cassiopeia A
• Reflections on Reflexions: I. Light Echoes in Type Ia Supernovae
• Attenuation caused by a distant Isothermal Turbulent Screen
• Attenuation law of normal disc galaxies with clumpy distributions of stars and dust
• 3-D Models of Embedded High-Mass Stars: Effects of a Clumpy Circumstellar Medium
• Estimating the Porosity of the Interstellar Medium from Three-Dimensional Photoionization Modeling of H II Regions
• Tiny HI Clouds in the Local ISM
• Mapping and Mass Measurement of the Cold Dust in NGC 205 with Spitzer
• Structure and Colors of Diffuse Emission in the Spitzer Galactic First Look Survey

Cited by in corpus (21)

• The strongest cosmic magnets: Soft Gamma-ray Repeaters and Anomalous X-ray Pulsars
• The warm ionized medium in spiral galaxies
• Dust and the type II-plateau supernova 2004et
• The Youngest Galactic Supernova Remnant: G1.9+0.3
• First search for gravitational waves from the youngest known neutron star
• Molecular Rings and the Thickness of Star-Forming Clouds
• Central Compact Objects in Supernova Remnants
• New constraints on the cooling of the Central Compact Object in Cas A
• Discovery of a 112 ms X-ray Pulsar in Puppis A: Further Evidence of Neutron Stars Weakly Magnetized at Birth
• Dust and the type II-Plateau supernova 2004dj
• Spitzer Spectral Mapping of Supernova Remnant Cassiopeia A
• Supernova Feedback and the Hot Gas Filling Fraction of the Interstellar Medium
• A dedicated Chandra ACIS observation of the central compact object in the Cassiopeia A supernova remnant
• A JWST Survey of the Supernova Remnant Cassiopeia A
• Ejecta Knot Flickering, Mass Ablation, and Fragmentation in Cassiopeia A
• Infrared Echoes Reveal the Shock Breakout of the Cas A Supernova
• Asymmetry in the Outburst of SN 1987A Detected Using Light Echo Spectroscopy
• Supernova Remnant Kes 17: Efficient Cosmic Ray Accelerator inside a Molecular Cloud
• The Infrared Properties of Super Star Clusters: Predictions from Three-Dimensional Radiative Transfer Models
• Probing Interstellar Dust with Infrared Echoes from the Cas A Supernova
• An Exploration of X-ray Supernova Remnants in the Milky Way and Nearby Galaxies