Determination of hyperfine-induced transition rates from observations of a planetary nebula

Tomas Brage; Philip G Judge; Charles R Proffitt

doi:10.1103/PhysRevLett.89.281101

Determination of hyperfine-induced transition rates from observations of a planetary nebula

Phys Rev Lett. 2002 Dec 31;89(28 Pt 1):281101. doi: 10.1103/PhysRevLett.89.281101. Epub 2002 Dec 26.

Authors

Tomas Brage¹, Philip G Judge, Charles R Proffitt

Affiliation

¹ Department of Physics, Lund University, Box 118, S-221 00 Lund, Sweden.

PMID: 12513129
DOI: 10.1103/PhysRevLett.89.281101

Abstract

Observations of the planetary nebula NGC3918 made with the STIS instrument on the Hubble Space Telescope reveal the first unambiguous detection of a hyperfine-induced transition 2s2p 3P(o)(0)-->2s2 1S0 in the berylliumlike emission line spectrum of N IV at 1487.89 A. A nebular model allows us to confirm a transition rate of 4x10(-4) sec(-1)+/-33% for this line. The measurement represents the first independent confirmation of the transition rate of hyperfine-induced lines in low ionization stages, and it provides support for the techniques used to compute these transitions for the determination of very low densities and isotope ratios.