Study of a bright-rimmed cloud at the border of the infrared dust bubble CN20

M.E. ORTEGA; E. GIACANI; S. PARON; M. RUBIO

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016 vol. 458

0035-8711

We characterize an uncatalogued bright-rimmed cloud located at theborder of the infrared dust bubble CN20 with the aim of investigatingtriggered star formation. In order to do this, we carried out radiocontinuum observations at 8.9 GHz using the Jansky Very Large Array(JVLA) interferometer with a synthesized beam size of 13 arcsec x5 arcsec, and molecular observations using the Atacama SubmillimeterTelescope Experiment (ASTE) at the 13CO J=3-2 and CS J=7-6 transitions. An analysis of the molecular observations and ofHerschel public data revealed the presence of a warm and dense clumpwith Tdust ? 25 K and n(H2) ~ 3 x 10^5 cm^-3. The high angular resolution andsensitivity of the new radio continuum data revealed an arc-like radiofilament in excellent correspondence with the illuminated border of thebright-rimmed cloud. This ionized boundary layer has an electron densityof 176 cm^-3. The spatial distribution of the young stellarobject candidates probably related to the bright-rimmed cloud does notshow clear evidence of a triggered origin. Finally, based on theevaluation of the pressure balance between the ionized and moleculargas, we conclude that the ionization front has stalled at the surface ofthe clump.