Aravind G

The stability of FeC- against dissociation in an astrophysical environment was probed by the collisional excitation of FeC-. Two anion resonances yielding Fe- and C- fragments were observed and studied through measurement of the kinetic energy released during fragmentation. The yield of Fe- was found to be nearly 5.5 times more than that of C- indicating the C- fragment to be in the loosely bound (2D) state. The possibility of avoided crossing leading to the observed fragment ion yield is also discussed. The dissociation of FeCn(n = 2 to 4, 6) cluster anions predominantly resulted in the cleavage of Fe-C bond yielding only fragments with similar energy release. The yield of Cn is discussed in the light of the observed abundances of HCn in IRC+10216. The importance of rotational transitions pertaining to both the ground and excited-electronic states of these cluster anions is discussed.

Depletion of FeO in the interstellar medium through resonance states of FeO- was studied through collision-induced dissociation of FeO-. Collisional excitation of FeO- lead to the yield of Fe- and O-, with a higher yield for Fe-. The ground electronic state of FeO- was identified to be 6Δ state and the results are compared with previous theoretical and experimental results. The kinetic energy distributions of the fragments revealed two FeO- anion resonances accessed upon excitation and their potential energy curves were evaluated. The role of the observed resonances in the depletion of FeO and the viable presence of Fe- and O- in Sagittarius B2 are discussed.