Pierre Augusto Ré Martho

Formação complementar

Idiomas

Áreas de atuação

Participação em eventos

Projetos de pesquisa

• 2022 - Atual

  Search and Characterization of Satellite Galaxies and Stellar Streams, Descrição: Multi-band surveys such as the Southern photometric Local Universe survey (Mendes de Oliveira et al. 2019) have a key advantage: the narrow band that covers the magnesium triplet (filter J0515) is sensitive to the surface gravity of stars, which allows the selection of distant giant stars (e.g. Majewski et al., 2000). Cleaning the sample of nearby dwarf stars is crucial, as they can correspond to more than 90% of the stars in the magnitude range observed. This filtering process allows us to highlight distant overdensities, even though this survey does not reach magnitudes as faint as others (e.g. DES, SDSS). In previous studies, we have developed a method to highlight stars of a given stellar population in the SDSS survey (which has been used to successfully find a stellar stream in the Pegasus region; Perottoni et al., 2019). As part of another undergrad research project, this method was adapted to the SPLUS survey and is now ready to be applied in large scale surveys. This capacity to highlight distant populations of giant stars will be used to search for new stellar overdensities in the form of satellite galaxies, as well as to map the structure of known stellar streams, and select candidate stars for spectroscopic follow-ups to study their chemical abundances, which is important for us to better understand their origins and the role that they play in the chemodynamical evolution of the Milky Way Galaxy.. , Situação: Em andamento; Natureza: Pesquisa. , Alunos envolvidos: Graduação: (1) . , Integrantes: Pierre Augusto Ré Martho - Integrante / Felipe de Almeida Fernandes - Integrante / Helio Dotto Perottoni - Integrante / Claudia Lucia Mendes de Oliveira - Coordenador., Financiador(es): Fundação de Amparo à Pesquisa do Estado de São Paulo - Bolsa.

• 2021 - 2022

  Busca e Caracterização de galáxias satélites e Correntes Estelares da Via Láctea no levantamento S-PLUS, Descrição: We present a methodology to search for new overdensities in the Milky Way with the isochronal filter technique. The overdensities, which in general are satellite galaxies accreted by the Milky Way, open the possibility of the study for a better understanding of the origin and evolution of our galaxy. Observing the various mergers that occurred until reaching the structure we see today, it is still predicted that new overdensities will still be found. Data from the S-PLUS survey will be used, which makes observations in 12 photometric filters. The use of more photometric bands brings new findings, as we can separate data from nearby dwarf stars and distant giant stars, due to narrow filters, that are sensitive to the surface gravity. In addition, the new areas to be explored in the southern hemisphere sky, are promising within the search. Thus, we apply to the data a technique already used in other works, which consists of using evolutionary isochrones to select the stars belonging to a certain population. However, with a differential, including probabilities of belonging to these populations. The calculated probabilities are considered in the construction of density maps to assign greater weight to the stars in the population.. , Situação: Concluído; Natureza: Pesquisa. , Alunos envolvidos: Graduação: (1) . , Integrantes: Pierre Augusto Ré Martho - Integrante / Felipe de Almeida Fernandes - Integrante / Helio Dotto Perottoni - Integrante / Claudia Lucia Mendes de Oliveira - Coordenador., Financiador(es): Programa Unificado de Bolsas - Bolsa.

• 2020 - 2021

  Busca por novas sobredensidades na Galáxia através de filtros de população estelar aplicados ao levantamento S-PLUS, Descrição: Trabalhando com os dados do S-PLUS, um mapeamento que vem obtendo imagens de objetos astronômicos em 12 filtros fotométricos, será aplicada uma técnica com isócronas evolutivas para encontrar novas sobredensidades na Via Láctea. Também iremos verificar tanto a eficácia da técnica em regiões já conhecidas, quanto a sua aplicação em novos dados.. , Situação: Concluído; Natureza: Pesquisa. , Alunos envolvidos: Graduação: (1) . , Integrantes: Pierre Augusto Ré Martho - Integrante / Felipe de Almeida Fernandes - Integrante / Helio Dotto Perottoni - Integrante / Claudia Lucia Mendes de Oliveira - Coordenador., Financiador(es): Programa Institucional de Bolsas de Iniciação Científica - Bolsa.