On the transition rates of the Fe X and Fe XIV coronal lines

Abstract

Abstract. Despite a considerable scatter of the theoretical predictions of the M1/E2 transition rate of the "red iron line" (Fe X) in the solar corona, there is disagreement of all the results with the single measurement that used an electrostatic ion trap. Employing a heavy-ion storage ring for measuring the same transition in isoelectronic ions of Co, Ni, and Cu, the situation has been clarified, and a new, accurate data point for Fe X can be determined by extrapolation. This result agrees with the basic atomic structure prediction for the line strength in combination with the experimental transition energy. For the "green iron line" (Fe XIV), a recent measurement with an electron beam ion trap has resolved similar discrepancies.

Irreducible tensor form of the relativistic corrections to the M1 transition operator

“…A similar experimental setup has been adopted for the measurement of the metastable lifetime of 2s 2 2p 2 1 S 0 in O +2 [38]. The electron beam ion trap technique [39] and/or the heavy-ion storage ring measurements [40,41] have been explored to investigate the E1-forbidden transition probabilities between the fine-structure levels of the ground configuration or to measure the E1-forbidden excited levels decay rates in Be-like [42,43,44], B-like [45,43,44,46,47,48,49], C-like [50,51], N-like [50], F-like [43,44], Al-like [52,53,54,55], Si-like [45,56,57,58,56,55], P-like [58,59,60,55], S-like [61,58,62,60,55], Cl-like [58,63,53,59], Ti-like [23,64] ions. The accuracy achieved in the EBIT measurement of the 1s 2 2s 2 2p 2 P o 3/2 level lifetime in boronlike Argon ...…”

Isoelectronic trends of the E1-forbidden decay rates of Al-, Si-, P-, and S-like ions of Cl, Ti, Mn, Cu, and Ge

“…Similar to work with an electrostatic ion trap [1][2][3] or with an electron beam ion trap (EBIT) [4][5][6][7][8], previous lifetime studies at the Heidelberg heavy-ion storage ring [9][10][11][12][13][14][15][16] have repeatedly targeted Fe (nuclear charge Z = 26) and nearby elements, because in the astrophysical context iron plays a dominant role [17]. (For a general overview of the experimental techniques, see [18][19][20][21][22][23].)…”

Iron Depletion in the Hot Bubbles in Planetary Nebulae

“…All of these objects have been found to contain diffuse X-rays with either the Chandra X-ray Observatory or XMM-Newton. Throughout, we adopt wavelengths of 6374.51 Å and 5302.86 Å for [Fe X]λ6374 and [Fe XIV]λ5303, respectively (Träbert 2004). The observations and reductions are described in Sect.…”