Results 121 to 130 of about 301,064 (245)

Understanding the chemical complexity in Circumstellar Envelopes of C-Rich AGB stars: the case of IRC +10216 [PDF]

, 2007
The circumstellar envelopes of carbon-rich AGB stars show a chemical complexity that is exemplified by the prototypical object IRC +10216, in which about 60 different molecules have been detected to date.
M. Agúndez, J. Cernicharo, J. Pardo, J. P. Fonfría Expósito, M. Guélin, E. Tenenbaum, L. Ziurys, A. Apponi   +7 more
semanticscholar   +1 more source

Gas-phase Molecules in Protoplanetary Nebulae with the 21 μm Emission Feature. II. Carbon Monosulfide

The Astronomical Journal
The carrier of the 21 μ m emission feature discovered in a handful of protoplanetary nebulae (PPNe) is one of the most intriguing enigmas in circumstellar chemistry.
Jian-Jie Qiu, Yong Zhang, Deng-Rong Lu, Zheng-Xue Chang, Jiang-Shui Zhang, Xiao-Hu Li, Xin-Di Tang, Yisheng Qiu, Jun-ichi Nakashima, Lan-Wei Jia   +9 more
doaj   +1 more source

Theoretical study on the reaction mechanism of cyclopropenylidene with cyclic CnH2nO (n = 2, 3) compounds: Ring expansion process

Journal of Saudi Chemical Society, 2016
The ring expansion reaction mechanisms between cyclopropenylidene and cyclic CnH2nO (n = 2, 3) compounds have been systematically investigated employing the second-order Møller-Plesset perturbation theory (MP2) method in order to better understand the ...
Xiaojun Tan, Weihua Wang, Ping Li
doaj   +1 more source

Grown-up stars physics with MATISSE

, 2016
MATISSE represents a great opportunity to image the environment around massive and evolved stars. This will allow one to put constraints on the circumstellar structure, on the mass ejection of dust and its reorganization , and on the dust-nature and ...
Bendjoya, P, Berio, P, Chiavassa, A, Cruzalèbes, P, de Souza, A Domiciano, Hofmann, K. -H, Hron, J, Khorrami, Z, Lanz, T, Lopez, B, Matter, A, Meilland, A, Millour, Florentin, Nardetto, N, Niccolini, G, Paladini, C, Petrov, R, Schertl, D, Soulain, A, Stee, P, Thévenin, F, Vakili, F, Weigelt, G   +22 more
core   +3 more sources

Al-26 and circumstellar envelopes

The Astrophysical Journal, 1995
The effects of the radioactive decay of Al-26 on the circumstellar envelopes of asymptotic giant branch stars are analyzed. The gamma-rays emitted by the product nucleus Mg-26 escape most envelopes, but the beta-decay positrons are stopped and can ionize and heat the gas.
openaire   +1 more source

Outflow-Circumstellar Envelope Interactions in Protostars [PDF]

Symposium - International Astronomical Union, 2004
We present the results of a high angular resolution (< 5″) survey of protostars with outflows, at different evolutionary stages, using the Owens Valley Radio Observatory Millimeter Array. This survey aims to understand the evolution of the interaction between protostellar outflows and the infalling circumstellar envelopes.
openaire   +1 more source

Circumstellar molecular envelopes - Spectroscopy and structure [PDF]

Publications of the Astronomical Society of the Pacific, 1988
The chemical composition and structure of envelopes surrounding cool evolved stars, as determined from microwave spectroscopic observations is reviewed. Emphasis is placed on recent observations with the new large mm-wavelength telescopes and interferometer arrays, and on new theoretical work, especially concerning ion-molecule chemistry in these ...
openaire   +1 more source

Velocity Structure of Circumstellar Environment around Class 0/I Protostars: Uncertainty in the Protostellar Mass Estimation Using Circumstellar Velocities

The Astrophysical Journal
Recent high-resolution observations have enabled detailed investigations of the circumstellar environments around Class 0/I protostars. Several studies have reported that the infall velocity of the envelope is a few times smaller than the freefall ...
Shingo Hirano, Yuri Aikawa, Masahiro N. Machida   +2 more
doaj   +1 more source

Long-Term Spectroscopic Monitoring and Surveys of Early-Type Stars with and without Circumstellar Envelopes

Open Astronomy, 2017
Ongoing studies of different groups of stars result in improving our knowledge of their fundamental parameters and evolutionary status. Also, they result in finding new phases of stellar evolution, which require theoretical explanation. At the same time,
Miroshnichenko Anatoly S., Danford Steven, Zharikov Sergei V., Manset Nadine, Levato Hugo, Grosso Monica, Korčáková Daniela, Kusakin Anatoly V., Khokhlov Serik A., Prendergast Peter   +9 more
doaj   +1 more source

Filaments as Possible Signatures of Magnetic Field Structure in Planetary Nebulae

, 2005
We draw attention to the extreme filamentary structures seen in high-resolution optical images of certain planetary nebulae. We determine the physical properties of the filaments in the nebulae IC 418, NGC 3132, and NGC 6537, and based on their large ...
Corradi R. L. M., Gathier R., Gussie G. T., Huggins P. J., Mauron N., P. J. Huggins, Pascoli G., Pottasch S. R., Pottasch S. R., Preite-Martinez A., S. P. Manley   +10 more
core   +2 more sources