Variability of the Cosmic-Ray Ionization Rate in Diffuse Molecular Clouds

Details Variability of the Cosmic-Ray Ionization Rate in Diffuse Molecular Clouds Variability of the Cosmic-Ray Ionization Rate in Diffuse Molecular Clouds

Jun 2009

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009mss..confewi09i&link_type=abstract

"International Symposium On Molecular Spectroscopy, 64th Meeting, Held 22-26 June, 2009 at Ohio State University. http://molspec

Other

Astronomical Species And Processes

Scientific paper

The energy spectrum of cosmic-rays - a product of particle acceleration and subsequent diffusion - is generally assumed to be uniform throughout the Galaxy. As a result, the cosmic-ray ionization rate inferred in similar environments (e.g. in several diffuse clouds) should also be relatively constant. However, current estimates of the ionization rate in diffuse molecular clouds vary over the range (1-8)×10^{-16} s^{-1}. In addition, there are a few sight lines with 3σ upper limits of ζ_2<1×10^{-16} s^{-1}, suggesting even lower ionization rates in some clouds. This roughly order of magnitude difference in the cosmic-ray ionization rate between sight lines contradicts the concept of a spatially uniform cosmic-ray flux.
We present cosmic-ray ionization rates derived from several published and unpublished spectroscopic observations of H_3^+ in diffuse cloud sight lines. These ionization rates are then compared with various other parameters (Galactic latitude, Galactic longitude, hydrogen column density) in a search for correlations. Also, sight lines in close proximity are compared to each other to determine the variability of the ionization rate on small spatial scales.
Webber, W. R. 1998, ApJ, 506, 329
Indriolo, N., Geballe, T. R., Oka, T., & McCall, B. J. 2007, ApJ, 671, 1736
McCall B. J., et al. 2002, ApJ, 567, 391

Affiliated with

Also associated with

No associations

Rating

Variability of the Cosmic-Ray Ionization Rate in Diffuse Molecular Clouds 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 Variability of the Cosmic-Ray Ionization Rate in Diffuse Molecular Clouds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Variability of the Cosmic-Ray Ionization Rate in Diffuse Molecular Clouds will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1643075