6533b882fe1ef96bd12db5b2

RESEARCH PRODUCT

Infrated photometry of NGC 1893

subject

description

The independence of the star formation processes with respect to the environmental conditions is controversial. In particular it is not clear whether star formation in the outer Galaxy, where the environmental conditions are, theoretically, less conducive, occurs in the same way as in the inner Galaxy. We investigate the population of NGC 1893, a young cluster (~3-4Myr) in the outer part of the Galaxy (galactic radius >11kpc) in order to explore the effects of environmental conditions on star forming regions. We present the infrared observations obtained with the IRAC camera on board of the Spitzer Space Telescope and analyze the color-color diagrams to establish the membership of stars with excesses. We also merge this information with that obtained from Chandra ACIS-I observations, in order to identify the Class III population. We find that the cluster is very rich, with 242 PMS Classical T-Tauri stars and 7 Class 0/I stars. Moreover we identify 110 Class III candidate cluster members in the ACIS-I field of view. We estimate a disk fraction for NGC 1893 of about 67%, similar to fraction calculated for nearby star forming regions of the same age. Although the environmental conditions are not favorable, star formation can clearly be very successful in the outer Galaxy, allowing creation of a very rich cluster like NGC 1893. Cone search capability for table J/A+A/488/211/table1 (Coordinates and magnitudes of sources in our catalog)