Identification of Three New Protoplanetary Nebulae Exhibiting the Unidentified Feature at 21 μm

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Circumstellar Matter, Infrared: Stars, Stars: Agb And Post-Agb

Scientific paper

Among its great findings, the Infrared Astronomical Satellite mission showed the existence of an unidentified mid-IR feature around 21 μm. Since its discovery, this feature has been detected in all C-rich protoplanetary nebulae (PPNe) of intermediate spectral type (F-G) and—weakly—in a few PNe and asymptotic giant branch (AGB) stars, but the nature of its carriers remains unknown. In this paper, we show the detection of this feature in the spectra of three new stars transiting from the AGB to the PN stage obtained with the Spitzer Space Telescope. Following a recent suggestion, we try to model the spectral energy distributions of our targets with amorphous carbon and FeO, which might be responsible for the unidentified feature. The fit thus obtained is not completely satisfactory, since the shape of the feature is not well matched. In an attempt to relate the unidentified feature to other dust features, we retrieved mid-IR spectra of all 21 μm sources currently known from Infrared Space Observatory and Spitzer online archives and noticed a correlation between the flux emitted in the 21 μm feature and that emitted at 7 and 11 μm (polycyclic aromatic hydrocarbon bands and hydrogenated amorphous carbon broad emission). Such a correlation may point to a common nature of the carriers.

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

Identification of Three New Protoplanetary Nebulae Exhibiting the Unidentified Feature at 21 μm 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 Identification of Three New Protoplanetary Nebulae Exhibiting the Unidentified Feature at 21 μm, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Identification of Three New Protoplanetary Nebulae Exhibiting the Unidentified Feature at 21 μm will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1079998

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