A two-component power law covering nearly four orders of magnitude in the power spectrum of spitzer far-infrared emission from the large magellanic cloud

Power spectra of Large Magellanic Cloud (LMC) emission at 24, 70 and 160 μm observed with the Spitzer Space Telescope have a two-component power-law structure with a shallow slope of −1.6 at low wavenumber, , and a steep slope of −2.9 at high . The break occurs at ⁻¹~100− 200 pc, which is interprete...

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Detalles Bibliográficos
Autor: Ivanio Puerari
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2010
País:México
Institución:Instituto Nacional de Astrofísica, Óptica y Electrónica
Repositorio:Repositorio Institucional del INAOE
Idioma:inglés
OAI Identifier:oai:inaoe.repositorioinstitucional.mx:1009/1559
Acceso en línea:http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/1559
Access Level:acceso abierto
Palabra clave:info:eu-repo/classification/Inspec/ISM: structure
info:eu-repo/classification/Inspec/Galaxies: ISM
info:eu-repo/classification/Inspec/Magellanic Clouds
info:eu-repo/classification/Inspec/Infrared: ISM
info:eu-repo/classification/cti/1
info:eu-repo/classification/cti/21
Descripción
Sumario:Power spectra of Large Magellanic Cloud (LMC) emission at 24, 70 and 160 μm observed with the Spitzer Space Telescope have a two-component power-law structure with a shallow slope of −1.6 at low wavenumber, , and a steep slope of −2.9 at high . The break occurs at ⁻¹~100− 200 pc, which is interpreted as the line-of-sight thickness of the LMC disk. The slopes are slightly steeper for longer wavelengths, suggesting the cooler dust emission is smoother than the hot emission. The power spectrum covers ~ 3.5 orders of magnitude and the break in the slope is in the middle of this range on a logarithmic scale. Large-scale driving from galactic and extragalactic processes, including disk self-gravity, spiral waves and bars, presumably cause the low- structure in what is effectively a two-dimensional geometry. Small-scale driving from stellar processes and shocks cause the high-k structure in a 3D geometry. This transition in dimensionality corresponds to the observed change in power spectrum slope. A companion paper models the observed power-law with a self-gravitating hydrodynamics simulation of a galaxy like the LMC.