Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-07-24
Astrophys.J.652:426-441,2006; Erratum-ibid.656:629,2007
Astronomy and Astrophysics
Astrophysics
24 pages, 19 figures, accepted for publication in the Astrophysical Journal. A version of the paper with higher resolution ima
Scientific paper
10.1086/507944
We have mapped the Helix (NGC 7293) planetary nebula (PN) with the IRAC instrument on the Spitzer Space Telescope. The Helix is one of the closest bright PN, and therefore provides an opportunity to resolve the small-scale structure in the nebula. The emission from this PN in the 5.8 and 8 micron IRAC bands is dominated by the pure rotational lines of molecular hydrogen, with a smaller contribution from forbidden line emission such as [Ar III] in the ionized region. The IRAC images resolve the "cometary knots" which have been previously studied in this PN. The "tails" of the knots and the radial rays extending into the outer regions of the PN are seen in emission in the IRAC bands. IRS spectra on the main ring and the emission in the IRAC bands are consistent with shock-excited H2 models, with a small (~10%) component from photodissociation regions. In the Northeast Arc, the H2 emission is located in a shell outside of the H alpha emission.
Hora Joseph L.
Latter William B.
Marengo Massimo
Smith Howard A.
No associations
LandOfFree
Infrared Observations of The Helix Planetary Nebula 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 Infrared Observations of The Helix Planetary Nebula, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Infrared Observations of The Helix Planetary Nebula will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-586059