Chandra Observations of the Luminous, O-Rich SNR in the Irregular Galaxy NGC 4449
Abstract
An analysis of a 29 ksec Chandra ACIS-S observation of the young, Cassiopeia-A like supernova remnant in the irregular galaxy NGC 4449 is presented. The observed 0.5-2.1 keV spectrum reveals the likely presence of several emission lines including O VIII at 0.65 keV and 0.77 keV, Ne X at 1.05 keV, Mg XI at 1.5 keV, and Si XIII at 1.85 keV. From the observed spectrum, we derive an NH = 1021 cm-2 and an X-ray temperature of T = 9 * 106 K. A non-equilibrium ionization fit to the spectrum suggests an overabundance of oxygen around 20 times solar, consistent with the remnant's UV and optical emission-line properties. We discuss tht remnant's approximate X-ray derived elemental abundances and compare its X-ray spectrum and luminosity to other oxygen-rich remnants.
Turn this paper into a full lesson
ArcXiv compiles a staged curriculum from this paper: 8-12 lessons across beginner → advanced, synthesised section guides, visuals, flashcards, a quiz, exercises, and on-demand deep dives per section. Grounded in the abstract, never invented.