Deep Submillimeter Images of NGC 891—Cold Dust at Larger Galactic Radii

We present images in the 450 and 850 μm continuum of the edge-on galaxy NGC 891. These measurements, carried out with the recently commissioned Submillimeter Common-User Bolometer Array, provide the deepest images yet of a nearby galaxy in the submillimeter wave band. We detect dust emission from 2/3 of the optical disk and confirm the presence of dust chimneys escaping from the main absorption layer up to z-heights of nearly 2 kpc. A comparison between the submillimeter surface brightness along the major axis with that corresponding to the IRAS 60 and 100 μm filters implies that large amounts of cold dust (~15 K) are present in the disk (in fact, an order of magnitude more grain material than the warm dust detected by IRAS). These cold grains predominate at larger galactic radii.

[1]  S. Bianchi,et al.  SCUBA imaging of the NGC 7331 dust ring , 1998, astro-ph/9806370.

[2]  J. Davies,et al.  The distribution of far‐infrared emission from edge‐on galaxies , 1998 .

[3]  R. Rand.  A Very Deep Spectrum of the Diffuse Ionized Gas in NGC 891 , 1999 .

[4]  J. Davies,et al.  A model of the far-infrared emission from the Galaxy , 1997 .

[5]  Steve Rawlings,et al.  High-redshift radio galaxies and quasars at submillimetre wavelengths: assessing their evolutionary status , 1997, astro-ph/9705094.

[6]  B. Savage,et al.  WIYN Imaging of Extraplanar Dust in the Edge-On Spiral NGC 891 , 1997, astro-ph/9709197.

[7]  M. Rowan-Robinson,et al.  Multiwavelength energy distributions of ultraluminous IRAS galaxies - I. Submillimetre and X-ray observations , 1996 .

[8]  J. M. van der Hulst,et al.  The H I Halo of NGC 891 , 1997, astro-ph/9707150.

[9]  A. Boscaleri,et al.  ARGO 1993 Observations of Interstellar Dust Emission , 1995 .

[10]  Jr.,et al.  Far-Infrared Spectral Observations of the Galaxy by COBE , 1995, astro-ph/9504056.

[11]  J. Shull,et al.  Photoionization of the Diffuse Interstellar Medium and Galactic Halo by OB Associations , 1994 .

[12]  D. Clements,et al.  Submillimetre observations of galaxies – I. First results , 1993 .

[13]  J. Carlstrom,et al.  The Scale Height and Radial Distribution of Molecular Gas in NGC 891 , 1993 .

[14]  G. Engargiola,et al.  The Structure of NGC 4565 at 100, 160, and 200 Microns: Continuum Dust Emission in a Quiescent SB Galaxy , 1992 .

[15]  R. Allen,et al.  Polarized radio emission from the edge-on spiral galaxies NGC 891 and NGC 4565 , 1991 .

[16]  F. Ferrini,et al.  Evolution of Dust Grains through a Hot Gaseous Halo , 1991 .

[17]  G. Engargiola.  Origins of the 12-200 micron flux in NGC 6946 - Starlight and continuum dust emission from AN Sc galaxy , 1991 .

[18]  M. Rupen.  Neutral Hydrogen Observations of NGC 4565 and NGC 891 , 1991 .

[19]  S. Casey.  Emission from dust in visual reflection nebulae at infrared and submillimeter wavelengths , 1991 .

[20]  M. Rowan-Robinson,et al.  Interstellar dust galaxies , 1992 .

[21]  N. Devereux,et al.  THE GAS DUST RATIO IN SPIRAL GALAXIES , 1990 .

[22]  C. Wynn-Williams,et al.  Cold Dust in Galaxies , 1989 .

[23]  E. Salpeter,et al.  Galactic fountains and extended H I disks , 1988 .

[24]  H. M. Lee,et al.  Optical properties of interstellar graphite and silicate grains , 1984 .

[25]  J. Smith.  The far-infrared disk of M51 , 1982 .