The central region of spiral galaxies as seen by Herschel. M 81, M 99, and M 100

Sauvage, M.; Sacchi, N.; Bendo, G. J.; Boselli, A.; Pohlen, M.; Wilson, C. D.; Auld, R.; Baes, M.; Barlow, M. J.; Bock, J. J.; Bradford, M.; Buat, V.; Castro-Rodríguez, N.; Chanial, P.; Charlot, S.; Ciesla, L.; Clements, D. L.; Cooray, A.; Cormier, D.; Cortese, L.; Davies, J. I.; Dwek, E.; Eales, S. A.; Elbaz, D.; Galametz, M.; Galliano, F.; Gear, W. K.; Glenn, J.; Gomez, H. L.; Griffin, M.; Hony, S.; Isaak, K. G.; Levenson, L. R.; Lu, N.; Madden, S. C.; O'Halloran, B.; Okumura, K.; Oliver, S.; Page, M. J.; Panuzzo, P.; Papageorgiou, A.; Parkin, T. J.; Pérez-Fournon, I.; Rangwala, N.; Rigby, E. E.; Roussel, H.; Rykala, A.; Schulz, B.; Schirm, M. R. P.; Smith, M. W. L.; Spinoglio, L.; Stevens, J. A.; Srinivasan, S.; Symeonidis, M.; Trichas, M.; Vaccari, M.; Vigroux, L.; Wozniak, H.; Wright, G. S.; Zeilinger, W. W.
Referencia bibliográfica

Astronomy and Astrophysics, Volume 518, id.L64

Fecha de publicación:
7
2010
Número de autores
60
Número de autores del IAC
2
Número de citas
15
Número de citas referidas
13
Descripción
With appropriate spatial resolution, images of spiral galaxies in thermal infrared (~10 μm and beyond) often reveal a bright central component, distinct from the stellar bulge, superimposed on a disk with prominent spiral arms. ISO and Spitzer studies have shown that much of the scatter in the mid-infrared colors of spiral galaxies is related to changes in the relative importance of these two components, rather than to other modifications, such as the morphological type or star formation rate, that affect the properties of the galaxy as a whole. With the Herschel imaging capability from 70 to 500 μm, we revisit this two-component approach at longer wavelengths, to see if it still provides a working description of the brightness distribution of galaxies, and to determine its implications on the interpretation of global far-infrared properties of galaxies. We quantify the luminosity of the central component by both a decomposition of the radial surface brightness profile and a direct extraction in 2D. We find the central component contribution is variable within the three galaxies in our sample, possibly connected more directly to the presence of a bar than to the morphological type. The central component's relative contribution is at its maximum in the mid-infrared range and drops around 160 μm to reach a constant value beyond 200 μm. The central component contains a greater fraction of hot dust than the disk component, and while the colors of the central components are scattered, colors of the disk components are more homogenous from one galaxy to the next. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with significant participation from NASA.
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Formación y Evolución de Galaxias: Observaciones Infrarrojas y en otras Longitudes de Onda
Este grupo desarrolla varios proyectos extragalácticos en diferentes rangos del espectro electromagnético utilizando satélites y telescopios en tierra para estudiar la evolución cosmológica de las galaxias y el origen de la actividad nuclear en galaxias activas. En el aspecto instrumental, el grupo forma parte del consorcio internacional que ha
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Pérez Fournon