IRAS surface brightness maps of visible reflection nebulae: Evidence for non-equilibrium infrared emission

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Brightness Distribution, Emission Spectra, Hydrocarbons, Infrared Astronomy, Mapping, Reflection Nebulae, Black Body Radiation, Dust, Energy Distribution, Infrared Astronomy Satellite, Pleiades Cluster, Spatial Resolution

Scientific paper

Surface brightness maps at 12, 25, 60, and 100 microns of 16 visible reflection nebulae were extracted from the Infrared Astronomy Satellite (IRAS) database. The maps were produced by coadding IRAS survey scans over areas centered on the illuminating stars, and have spatial resolutions of 0.9' x 4' at 12 and 25 microns, 1.8' x 4.5' at 60 microns, and 3.6' x 5' at 100 microns. Extended emission in the four IRAS bandpasses was detected in fourteen of the reflection nebulae. The IRAS data were used to measure the flux of the infrared emission associated with each source. The energy distributions show that the 12 micron flux is greater than the 25 micron flux in 11 of the nebulae, and the peak flux occurs in the 60 or 100 micron bandpass in all 16 nebular. The 60 and 100 micron flux can be approximated by blackbodies with temperatures between 30 and 50 K, consistent with temperatures expected from extrapolation of greybody fits to the 60 and 100 micron data. The excess 12 and 25 micron emission is attributed to a nonequilibrium process such as emission from thermal fluctuations of very small grains excited by single ultraviolet photons, or emission from polycyclic aromatic hydrocarbons (PAHs) excited by ultraviolet radiation. The common features of the energy distributions of the 16 reflection nebulae, also seen in the reflection nebulae associated with the Pleiades, suggest that PAHs or very small grains may be found in most reflection nebulae.

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

IRAS surface brightness maps of visible reflection nebulae: Evidence for non-equilibrium infrared emission 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 IRAS surface brightness maps of visible reflection nebulae: Evidence for non-equilibrium infrared emission, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and IRAS surface brightness maps of visible reflection nebulae: Evidence for non-equilibrium infrared emission will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1738052

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