Signatures of long-lived spiral patterns.
Azimuthal age/color gradients across spiral arms are a signature of long-lived spirals. From a sample of 19 normal (or weakly barred) spirals where we have previously found azimuthal age/color gradient candidates, 13 objects were further selected if a two-armed grand-design pattern survived in a sur...
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2013 |
| País: | México |
| Institución: | Instituto Nacional de Astrofísica, Óptica y Electrónica |
| Repositorio: | Repositorio Institucional del INAOE |
| Idioma: | inglés |
| OAI Identifier: | oai:inaoe.repositorioinstitucional.mx:1009/2248 |
| Acceso en línea: | http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/2248 |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/Inspec/Galaxies: kinematics and dynamics info:eu-repo/classification/Inspec/Galaxies: photometry info:eu-repo/classification/Inspec/Galaxies: spiral info:eu-repo/classification/Inspec/Galaxies: stellar content info:eu-repo/classification/Inspec/Galaxies: structure info:eu-repo/classification/cti/1 info:eu-repo/classification/cti/21 |
| Sumario: | Azimuthal age/color gradients across spiral arms are a signature of long-lived spirals. From a sample of 19 normal (or weakly barred) spirals where we have previously found azimuthal age/color gradient candidates, 13 objects were further selected if a two-armed grand-design pattern survived in a surface density stellar mass map. Mass maps were obtained from optical and near-infrared imaging, by comparing with a Monte Carlo library of stellar population synthesis models that allowed us to obtain the mass-to-light ratio in the J-band, (M=L)J , as a function of (g - i) versus (i - J) color. The selected spirals were analyzed with Fourier methods in search for other signatures of long-lived modes related to the gradients, such as the gradient divergence toward corotation, and the behavior of the phase angle of the two-armed spiral in different wavebands, as expected from theory. The results show additional signatures of long-lived spirals in at least 50% of the objects. |
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