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Modeling Intrinsic Flux of Star Forming Regions in NGC 6822

POSTER

Abstract

NGC 6822 is a nearby irregular dwarf galaxy located in the Local Group and is currently undergoing significant star formation. Newly formed stars (OB type) emit UV radiation that excites the surrounding interstellar medium (ISM) which then fluoresces. The problem comes from large amounts of gas and dust occupying the ISM, affecting how we observe light in these regions (extinction). The most ubiquitous emission from the ISM comes from hydrogen which will be heavily scattered and absorbed by colder gas. The observed ISM emission is thus an underestimate of the intrinsic emission. In order to correct the spectrum of a source for extinction we used the Cardelli extinction law and measured the Hα/Hβ ratio to generate an absorption spectrum. I have implemented this procedure with a python code and applied it to a data cube of NGC 6822 obtained with the SITELLE instrument at the Canada-France-Hawaii Telescope. The SITELLE instrument is an optical imaging Fourier transform spectrometer capable of providing medium resolution spectroscopic data across the entire galaxy. I applied my corrected data to generate a new set of intrinsic flux data. With an extinction-corrected spectrum of NGC 6822 we will calculate star formation rates across the galaxy.

Presenters

  • Edward Ward

Authors

  • Edward Ward

  • Marianne Takamiya

    Professor, University of Hawaii at Hilo

  • Laurie Rousseau-Nepton

    Resident Astronomer

  • Aidan Walk

    Team Member

  • Franccesca Scheckel

    Team Member, University of Hawaii at Hilo

  • Jonathan Loomis

    Team Member