Star formation towards the Galactic center

PERREN, GABRIEL; VÁZQUEZ, RUBEN; CARRARO, GIOVANNI

La Plata

Workshop; IV La Plata International School on Astronomy and astrophysics (LAPIS) - ?Millimeter/submillimeter astronomy with LLAMA?; 2012

Facultad de Ciencias Astronómicas y Geofísicas, UNLP

The spiral structure of the Milky Way inside the solar ring is still poorly known because of the high density of the material and high extinction towards the Galactic center. We present results of the first extensive and deep CCD photometric survey carried out in the field of the open cluster Trumpler 27, an object immersed in a region of extremely high visual absorption in the constellation of Sagittarius. We look for young stars clumps that might plausibly be associated with spiral structure. Wide-field UBVI photometry allows us to reconstruct the distribution in reddening and distance of young stars in the field using the Color-Color and Color-Magnitude Diagrams We found that Trumpler 27 is a superposition of early type stars seen along the line of sight which extends over several kiloparsecs beyond even the center of the galaxy. Our analysis indicates that what was considered an open cluster characterized by a significant age spread is, indeed, a stellar continuum that reaches its maximum number of stars at approximately 3.5 kpc from the Sun. %At the same Some of these stellar groups may be linked, within the distance errors, with the inner spiral arms of our galaxy, including the Near 3 kpc arm.