Tracking the Evolutionary Stage of Protostars through the Abundances of Astrophysical Ices

Autor(es)

Rocha, W. R. M. ^{[1, 2, 3]} ; Pilling, S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Vale Paraiba, Inst Pesquisa & Desenvolvimento, Ave Shishima Hifumi 2911, BR-12244000 Sao Jose Dos Campos, SP - Brazil

^[2] Univ Copenhagen, Niels Bohr Inst, Oster Voldgade 5-7, DK-1350 Copenhagen K - Denmark

^[3] Univ Copenhagen, Ctr Star & Planet Format, Oster Voldgade 5-7, DK-1350 Copenhagen K - Denmark

• Tipo de documento: Artigo Científico
• Fonte: ASTROPHYSICAL JOURNAL; v. 896, n. 1 JUN 2020.
• Citações Web of Science: 0

Resumo

The physical evolution of young stellar objects (YSOs) is accompanied by an enrichment of the molecular complexity, mainly triggered by the heating and energetic processing of astrophysical ices. In this paper, a study of how the ice column density varies across the protostellar evolution has been performed. Tabulated data of H2O, CO2, CH3OH, and HCOOH observed by ground- and space-based telescopes toward 27 early-stage YSOs were taken from the literature. The observational data show that ice column density and spectral index (alpha), used to classify the evolutionary stage, are well correlated. A 2D continuum radiative transfer simulation containing bare and ice-covered grains at different levels of cosmic-ray processing were used to calculate the spectral energy distributions in different angle inclinations between face-on and edge-on configurations. The H2O:CO(2)ice mixture was used to address the H2O and CO(2)column density variation, whereas CH3OH and HCOOH are by-products of the virgin ice after energetic processing. The simulated spectra were used to calculate the ice column densities of YSOs in an evolutionary sequence. As a result, the models show that the ice column density variation of HCOOH with alpha can be justified by envelope dissipation and energetic processing of ice. On the other hand, the ice column densities are mostly overestimated in the cases of H2O, CO(2)and CH3OH, even though the physical and cosmic-ray processing effects are taken into account. (AU)

• Processo FAPESP: 15/10492-3 - Estudo da evolução química de gelos astrofísicos na vizinhança de objetos estelares jovens empregando dados experimentais no infravermelho e modelagem computacional
• Beneficiário: Will Robson Monteiro Rocha
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 16/22018-7 - Produção de moléculas orgânicas complexas em luas congeladas do sistema solar induzidos por íons rápidos (raios cósmicos simulados).
• Beneficiário: Sergio Pilling Guapyassu de Oliveira
• Modalidade de apoio: Bolsas no Exterior - Pesquisa
• Processo FAPESP: 16/23054-7 - Formação de moléculas complexas de gelos astrofísicos em regiões de formação estelar por UV e raios-X empregando o código ProDiMo e dados de laboratório
• Beneficiário: Will Robson Monteiro Rocha
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado