Seminario: "Population synthesis in galaxies with Spitzer data at 3.6 and 4.5 micron"

Día: 10 de Noviembre
Hora: 12:00
Lugar: Seminario del Departamento de Física Teórica y del Cosmos (Edificio Mecenas).
Organiza: Sala de Conferencias FISYMAT (planta baja del edificio de matemáticas de la Facultad de Ciencias)
Ponente: Prof. Reynier Peletier (Kapteyn Astronomical Institute, Groningen).
Resumen del seminario:
I discuss the [3.6] – [4.5] Spitzer-IRAC colour in early-type galaxies of the SAURON survey, a representative sample of 48 nearby ellipticals and lenticulars. For such galaxies, the light in these 2 bands mostly comes from the photospheres of old stars. I will discuss how this colour, which is unaffected by dust extinction, can be used to constrain the stellar populations in these galaxies. In this talk I will talk about scaling relations (colour-mass, colour-line strength etc.), and how these can be used to study the formation and evolution of early-type galaxies. The relation between [3.6]-[4.5] colour and velocity dispersion is found to be inverted, i.e. more metal rich and younger stellar populations are redder. This is caused by a strong CO absorption band, whose line strength increases strongly with decreasing temperature and which covers a considerable fraction of the 4.5 micron filter. I will also discuss radial [3.6] – [4.5] gradients in galaxies and their dependence on mass and environment, and conclude with some implications for future use of this colour.

Seminario: «Population synthesis in galaxies with Spitzer data at 3.6 and 4.5 micron»