Molecules, grains, and shocks - A comparison of CO, H I, and IRAS data

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

82

Carbon Monoxide, H I Regions, Infrared Astronomy, Interstellar Matter, Molecular Clouds, Particle Size Distribution, Radio Emission, Shock Waves, Brightness, Infrared Astronomy Satellite, Interstellar Gas, Interstellar Radiation, Normal Density Functions

Scientific paper

The authors have compared the IR and H I properties, and CO content, of a set of 26 isolated, degree-sized interstellar clouds. The comparisons offer some conclusions concerning the effects of kinematics on molecular content and grain size distribution. The departure of S100/NHI, where S100 is the 100 μm surface brightness, from the theoretically predicted value is a measure of the H2 content of clouds. Even clouds with low column density, ≡2.4×1020H-nuclei cm-2 or less, may contain more H2 than H I, in contrast to results obtained from UV absorption line studies. The dependence of S60/S100 on velocity implies that fast shocks preferentially destroy large grains or produce small grains, or both. The data imply that very small grains (VSGs) are formed in shocks in the 10 - 20 km s-1 velocity range, and destroyed at slightly higher velocities. Nearly all clouds, independently of kinematics, appear to contain VSGs. Some clouds must have very large fractions of their total carbon in the form of polycyclic aromatic hydrocarbons (PAHs), if VSGs are exclusively PAHs.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Molecules, grains, and shocks - A comparison of CO, H I, and IRAS data does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Molecules, grains, and shocks - A comparison of CO, H I, and IRAS data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Molecules, grains, and shocks - A comparison of CO, H I, and IRAS data will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-909411

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.