Bibcode
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.
Bibliographical reference
Astronomy and Astrophysics, Volume 518, id.L64
Advertised on:
7
2010
Journal
Citations
15
Refereed citations
13
Description
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.
Related projects
Formation and Evolution of Galaxies: Observations in Infrared and other Wavelengths
This IAC research group carries out several extragalactic projects in different spectral ranges, using space as well as ground-based telescopes, to study the cosmological evolution of galaxies and the origin of nuclear activity in active galaxies. The group is a member of the international consortium which built the SPIRE instrument for the
Ismael
Pérez Fournon