Production rates of molecular hydrogen obtained via low energy (E < 1 GeV) cosmic rays interaction with interstellar dust mantles are obtained and compared with those deduced considering recombination of absorbed H atoms on amorphous grain surfaces at the edge (depth A(v) < 2 mag) of a dense cloud. The grain model used is that of Greenberg, which has an organic refractory layer rich in hydrogen between the core and the icy mantle. The result of the Monte Carlo simulation performed by us is that recombination is dominant over the sputter production of molecular hydrogen only in a restricted range of depths. In particular this second mechanism is more efficient at the external edge of the cloud.
SYNTHESIS OF H2 AT THE EDGE OF DENSE COLD CLOUDS BY COSMIC-RAY BOMBARDMENT OF GRAIN MANTLES
PIRRONELLO, Valerio
1991-01-01
Abstract
Production rates of molecular hydrogen obtained via low energy (E < 1 GeV) cosmic rays interaction with interstellar dust mantles are obtained and compared with those deduced considering recombination of absorbed H atoms on amorphous grain surfaces at the edge (depth A(v) < 2 mag) of a dense cloud. The grain model used is that of Greenberg, which has an organic refractory layer rich in hydrogen between the core and the icy mantle. The result of the Monte Carlo simulation performed by us is that recombination is dominant over the sputter production of molecular hydrogen only in a restricted range of depths. In particular this second mechanism is more efficient at the external edge of the cloud.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
