Astronomy and Astrophysics – Astrophysics
Scientific paper
1999-03-31
Astronomy and Astrophysics
Astrophysics
33 pages, 19 Postscript figures comprising Figures 1-11 in the text, to be published in Astrophysical Journal
Scientific paper
10.1086/307237
We present new groundbased 3 $\mu$m spectra of 14 young stellar objects with H_2O ice absorption bands. The broad absorption feature at 3.47 $\mu$m was detected toward all objects and its optical depth is correlated with the optical depth of H_2O ice, strengthening an earlier finding. The broad absorption feature at 3.25 $\mu$m was detected toward two more sources and an upper limit is given for a third source. The optical depths of the 3.25 $\mu$m feature obtained to date are better correlated with the optical depth of the refractory silicate dust than with that of H_2O ice. If this trend is confirmed, this would support our proposed identification of the feature as the C--H stretch of aromatic hydrocarbons at low temperature. An absorption feature at 3.53 $\mu$m due to solid methanol was detected for the first time toward MonR2/IRS2, as well as toward W33A and GL 2136. The wavelengths of the CH_3OH features toward W33A, GL 2136, and NGC7538/IRS9 can be fit by CH_3OH-rich ices, while the wavelength of the feature toward MonR2/IRS2 suggests an H_2O-rich ice environment. Solid methanol abundances toward GL 2136, NGC7538/IRS9, and MonR2/IRS2 are 3-5 % relative to H_2O ice. There is an additional narrow absorption feature near 3.47 $\mu$m toward W33A. For the object W51/IRS2, spatially resolved spectra from 2 to 4 $\mu$m indicate that the H_2O ice is located predominantly in front of the eastern component and that the H_2O ice extinction is much deeper than previously estimated. For the object RNO 91, spectra from 2 to 4 $\mu$m reveal stellar (or circumstellar) CO gas absorption and deeper H_2O ice extinction than previously estimated.
Brooke Timothy Young
Geballe Thomas Ronald
Sellgren Kris
No associations
LandOfFree
New Three Micron Spectra of Young Stellar Objects with H_2O Ice Bands 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 New Three Micron Spectra of Young Stellar Objects with H_2O Ice Bands, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and New Three Micron Spectra of Young Stellar Objects with H_2O Ice Bands will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-479339