Absolute UV and vacuum UV oscillator strengths for NiII

被引:52
作者
Fedchak, JA [1 ]
Lawler, JE [1 ]
机构
[1] Univ Wisconsin, Dept Phys, Madison, WI 53706 USA
关键词
atomic data; ISM : abundances; methods : laboratory;
D O I
10.1086/307763
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Radiative lifetimes, measured using time-resolved laser-induced fluorescence, are reported for 18 odd-parity levels of Ni+. The radiative lifetimes are combined with Ni+ emission branching fractions to produce 59 accurate (typically +/-10%) absolute atomic transition probabilities in the ultraviolet (UV) and vacuum ultraviolet (VUV). The UV and VUV branching fractions are determined using a combination of measurements from a Fourier transform spectrometer at the University of Lund and a 3 m focal length vacuum echelle spectrometer system at the University of Wisconsin. Accurate f-values for Ni II resonance lines are important for analysis of spectra on the diffuse interstellar medium (ISM) at low redshift and for studies of the same lines in high-redshift QSO absorption line systems. Resonance lines at vacuum wavelengths of 170.960, 174.155, and 175.191 nn have log gf values of -0.68, -0.60, and -0.80, respectively. Until additional laboratory measurements are completed, we recommend that f-values for other Ni n resonance lines be taken from the relative f-values from Zsargo & Federman with a multiplicative scaling factor of 0.534 (+/-10%). The present measurements indicate that nickel is less depleted in the ISM than previously estimated.
引用
收藏
页码:734 / 738
页数:5
相关论文
共 25 条
[1]   RELATIVE TRANSITION PROBABILITIES FOR PROMINENT NI1 AND NI2 LINES IN NEAR-ULTRAVIOLET [J].
BELL, GD ;
PAQUETTE, DR ;
WIESE, WL .
ASTROPHYSICAL JOURNAL, 1966, 143 (02) :559-&
[2]   RADIATIVE LIFETIMES, BRANCHING RATIOS, AND ABSOLUTE TRANSITION-PROBABILITIES IN CR-II AND ZN-II [J].
BERGESON, SD ;
LAWLER, JE .
ASTROPHYSICAL JOURNAL, 1993, 408 (01) :382-388
[3]   High-sensitivity absorption spectroscopy in Fe II [J].
Bergeson, SD ;
Mullman, KL ;
Lawler, JE .
ASTROPHYSICAL JOURNAL, 1996, 464 (02) :1050-1053
[4]   OSCILLATOR-STRENGTHS OF THE SI-PI 181-NANOMETER RESONANCE MULTIPLET [J].
BERGESON, SD ;
LAWLER, JE .
ASTROPHYSICAL JOURNAL, 1993, 414 (02) :L137-L140
[5]   OSCILLATOR-STRENGTHS FOR FE-II TRANSITIONS AT 224.918 AND 226.008 NANOMETERS [J].
BERGESON, SD ;
MULLMAN, KL ;
LAWLER, JE .
ASTROPHYSICAL JOURNAL, 1994, 435 (02) :L157-L159
[6]   Branching fractions and oscillator strengths for Fe II transitions from the 3d(6)((5)d)4p subconfiguration [J].
Bergeson, SD ;
Mullman, KL ;
Wickliffe, ME ;
Lawler, JE ;
Litzen, U ;
Johansson, S .
ASTROPHYSICAL JOURNAL, 1996, 464 (02) :1044-1049
[7]  
BIEMONT E, 1989, ASTRON ASTROPHYS, V209, P391
[8]  
BIZZARRI A, 1993, ASTRON ASTROPHYS, V273, P707
[9]   VACUUM ULTRAVIOLET RADIOMETRY .3. ARGON MINI-ARC AS A NEW SECONDARY STANDARD OF SPECTRAL RADIANCE [J].
BRIDGES, JM ;
OTT, WR .
APPLIED OPTICS, 1977, 16 (02) :367-376
[10]   DETECTION OF BORON, COBALT, AND OTHER WEAK INTERSTELLAR LINES TOWARD ZETA-OPHIUCHI [J].
FEDERMAN, SR ;
SHEFFER, Y ;
LAMBERT, DL ;
GILLILAND, RL .
ASTROPHYSICAL JOURNAL, 1993, 413 (01) :L51-L54