An exploration of O and Be stars properties with state-of-the-art modeling techniques

• Grant number: 11/17930-5
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: April 01, 2012
• End date: March 31, 2015
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Stellar Astrophysics
• Principal Investigator: Alex Cavaliéri Carciofi
• Grantee: Cyril Escolano
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

This project has the goal of bringing Dr. Cyril Escolano for a collaboration with Prof. Alex C. Carciofi and the interferometry group of IAG.This project has the goal of bringing Dr. Cyril Escolano for a collaboration with Prof. Alex C. Carciofi and the interferometry group of IAG. It is divided in two research lines, building on the experience of the applicant in (i) modeling thecomplex physics of massive stars, and (ii) drawing physical interpretations from the confrontation between observed and theoretical spectra at different wavelengths.The first and most ambitious project will represent the core of the applicant's work. It consists in generating a very large grid of models of Be stars. From these models, synthetic photometric, spectroscopic, polarimetric, and interferometric data will be created, allowing for a direct comparison to observations. This catalog of simulated observables will provide a fast and accurate analysis tool for already existing and future observations of Be stars. A systematic study of the grid will allow to draw a clear picture of which observations are needed to uniquely probe each part of the disk structure, and which uncertainties remain with which observations. In addition, the catalog will be made available for the community using the tools of the Virtual Observatory.The second part of the project will be dedicated to the study of O stars, in particular the structure of their winds and their mass loss rates. It will take advantage of the complementarity of two codes: CMFGEN (in which the applicant has an extensive knowledge), which computes 1D models with a very realistic chemical composition (lots of species included, very thin treatment of the line-blanketing through the super--level formalism), and HDUST (developed by the supervisor), at the moment less complete in terms of chemical species, but capable of performing the radiative transfer in three-dimensional configurations.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ESCOLANO, C.; CARCIOFI, A. C.; OKAZAKI, A. T.; RIVINIUS, T.; BAADE, D.; STEFL, S.. 2.5D global-disk oscillation models of the Be shell star zeta Tauri I. Spectroscopic and polarimetric analysis. Astronomy & Astrophysics, v. 576, APR 2015. (09/54006-4, 11/17930-5)

ESCOLANO, C.; CARCIOFI, A. C.; OKAZAKI, A. T.; RIVINIUS, T.; BAADE, D.; STEFL, S.; SIGUT, TAA; JONES, CE. 2.5D Global Disk Oscillation Models Applied to the Be Shell Star zeta Tauri. BRIGHT EMISSARIES: BE STARS AS MESSENGERS OF STAR-DISK PHYSICS, v. 506, p. 6-pg., 2016-01-01. (11/17930-5, 09/54006-4)

SILAJ, J.; JONES, C. E.; CARCIOFI, A. C.; ESCOLANO, C.; TYCNER, C.; SIGUT, TAA; JONES, CE. Probing the Density Structure of 48 Librae's Circumstellar Disk. BRIGHT EMISSARIES: BE STARS AS MESSENGERS OF STAR-DISK PHYSICS, v. 506, p. 4-pg., 2016-01-01. (11/17930-5, 09/54006-4)