Papers by Thayse Adineia Pacheco
The Astrophysical Journal Supplement Series, 2021
A new grid of detailed atmosphere model spectra for hot and moderately cool subdwarf stars is pre... more A new grid of detailed atmosphere model spectra for hot and moderately cool subdwarf stars is presented. High-resolution spectra and synthetic photometry are calculated in the range from 1000Å to 10,000Å using Non-LTE fully line-blanketed atmosphere structures. Our grid covers eight temperatures within 10,000 ≤ T eff [K] ≤ 65,000, three surface gravities in the range 4.5 ≤ log g [cgs] ≤ 6.5, two helium abundances matching two extreme helium-rich and helium-poor scenarios, and two limiting metallicity boundaries regarding both solar ([Fe/H] = 0) and Galactic halo ([Fe/H] =-1.5 and [α/Fe] = +0.4). Besides its application in the determination of fundamental parameters of subdwarfs in isolation and in binaries, the resulting database is also of interest for population synthesis procedures in a wide variety of stellar systems.
The Astrophysical Journal Supplement Series, 2021
A new grid of detailed atmosphere model spectra for hot and moderately cool subdwarf stars is pre... more A new grid of detailed atmosphere model spectra for hot and moderately cool subdwarf stars is presented. High-resolution spectra and synthetic photometry are calculated in the range from 1000–10,000 Å using non-LTE fully line-blanketed atmosphere structures. Our grid covers eight temperatures within 10,000 ≤ T eff [K] ≤ 65,000, three surface gravities in the range 4.5 ≤ log g [cgs] ≤ 6.5, two helium abundances matching two extreme helium-rich and helium-poor scenarios, and two limiting metallicity boundaries regarding both solar ([Fe/H] = 0) and Galactic halos ([Fe/H] = −1.5 and [α/Fe] = +0.4). Besides its application in the determination of fundamental parameters of subdwarfs in isolation and in binaries, the resulting database is also of interest for population synthesis procedures in a wide variety of stellar systems.
Para estes cálculos foram adotados os códigos LPCODE e MESA, que modelam a evolução completa de e... more Para estes cálculos foram adotados os códigos LPCODE e MESA, que modelam a evolução completa de estrelas, desde a sequência principal e pré sequência principal, respectivamente, passando por todas as etapas na vida estelar, inclusive após a cristalização do carbono e oxigênio na curva de esfriamento das anãs brancas. Nos cálculos com o MESA utilizou-se das equações de perda de massa Vink e Van Loon e no LPCODE são programadas as equações de Reimers e Vasiliadis & Wood respectivamente nas etapas do ramo de gigantes vermelhas e ramo assintótico das gigantes. Com esta configuração foram ajustados diferentes fatores multiplicativos de perda de massa, além de difusão e overshooting.
Research Notes of the AAS
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Papers by Thayse Adineia Pacheco