Estudo espectroscópico das regiões HII da Galáxia NGC 1232

• Ano de defesa: 2019
• Autor(a) principal: Costa , Fabiana Lima
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Cruzeiro do Sul; Brasil; Mestrado em Astrofísica e Física Computacional; Cruzeiro do Sul
• Palavras-chave em Português: Regiões HII; Formação estelar; NGC 1232; CNPQ::CIENCIAS EXATAS E DA TERRA::ASTRONOMIA::ASTROFISICA ESTELAR
• Link de acesso: https://repositorio.cruzeirodosul.edu.br/handle/123456789/280

NGC 1232 is a face-on spiral galaxy, and an excellent laboratory for the study of star formation due to its proximity. Recent studies reveal interesting features about this galaxy: X-ray observations suggest that it recently collided with a dwarf galaxy - of which there is no apparent remnant. We got spectra of this galaxy in the optical using a long slit in two different positions and the Goodman spectrograph at the SOAR telescope. We detected 18 HII regions in the north-south direction and 22 HII regions in the east-west direction. A background galaxy called NGC 1232B was also detected. In the north-south direction, 11 regions have intense emission lines besides H . In the east-west direction, we identified lines other than the H in all HII regions. Through the emission lines we calculate the extinction coefficients for these regions, which indicate that extinctions are generally low. Correcting the fluxes of the lines by extinction, we obtained electron density and chemical abundances through the indices N2 and O3N2, through the bright lines method for both the HII regions and the background galaxy. It was possible to measure the [OIII] 5007 line, required to measure the index O3N2, for some HII regions only, which makes constructing a gradient uncertain. However, the few points suggest an abundance gradient typical of spiral galaxies. For the background galaxy NGC 1232B, its redshift was measured for the fist time in this work, and through BPT diagrams we characterize this galaxy as a starburst.