A team leaded by Kartik Sheth has been recently awarded 637 hours of Spitzer observing time to carry out an extensive infrared survey of nearby galaxies. The team comprises researches of several institutions, including GUAIX members Armando Gil de Paz and Juan Carlos Muñoz Mateos. The so-called Spitzer Survey of Stellar Structure in Galaxies (S4G) will map more than 1700 galaxies closer than 40 Mpc using the IRAC camera at 3.6 and 4.5 microns, the only channels that will work at full sensitivity once Spitzer runs out of coolant. These observations will shed light on crucial issues regarding the structure of galaxies: bars, rings, spiral arms, truncations in the light profiles... Below you can see three nearby galaxies imaged at 3.6 micron by the SINGS survey, showing the kind of data S4G will provide.

The S4G builds on previous Spitzer Legacy surveys of nearby galaxies: SINGS (75 galaxies within 30 Mpc) and LVL (258 galaxies within 11 Mpc). Together with these already existing data-sets, S4G will increase the number of objects to more than 2300 galaxies, thus constituting an unbiased inventory of the stellar mass and galactic structure in the local universe. Moreover, when combined with existing and requested data from other facilities such as GALEX, we should be able to reconstruct the star formation history of galaxy disks. Below we overplot our sample (red circles) over the large scale structure at z<0.01 from the 2MASS XSC (purple). The LVL (cyan) and other archival galaxies (yellow) are also shown.