Kinematics and Modeling of the Inner Region of M83

• Grant number: 09/00706-5
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: March 01, 2009
• End date: August 31, 2009
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Extragalactic Astrophysics
• Principal Investigator: Irapuan Rodrigues de Oliveira Filho
• Grantee: Irapuan Rodrigues de Oliveira Filho
• Host Institution: Instituto de Pesquisa e Desenvolvimento (IP&D). Universidade do Vale do Paraíba (UNIVAP). São José dos Campos , SP, Brazil

Abstract

2-D kinematics of the central region of M83 (NGC5236) were obtained through 3-D NIR spectroscopy with Gemini South telescope. The spatial region covered by the integral field unit (~500×1300 arcsec or ~90×240 pc), was centered approximately at the center of the bulge isophotes and oriented SE-NW. The Pa-beta emission at half arcsecond resolution clearly reveals spider-like diagrams around three centers, indicating the presence of extended masses, which we describe in terms of Satoh distributions. One of the mass concentrations is identified as the optical nucleus (ON), another as the center of the bulge isophotes, similar to the CO kinematical center (KC), and the third as a condensation hidden at optical wavelengths (HN), coincident with the largest lobe in 10 ¼m emission. We run numerical simulations that take into account ON, KC and HN and four more clusters, representing the star forming arc at the SW of the optical nucleus. We show that ON, KC and HN suffer strong evaporation and merge in 10-50 Myr. The star-forming arc is scattered in less than one orbital period, also falling intothe center. Simulations also show that tidal-striping boosts the external shell of the condensations to their escape velocity. This fact might lead to an overestimation of the mass of the condensations in kinematical observations with spatial resolution smaller than the condensations' apparent sizes. Additionally the existence of two ILR resonances embracing the chain of HII regions, claimed by different authors, might not exist due to the similarity of the masses of the different components and the fast dynamical evolution of M83 central 300 pc. (AU)