J/MNRAS/390/733 FTS reference UV wavelengths of CrIII (Smillie+, 2008) ================================================================================ Reference ultraviolet wavelengths of Cr III measured by Fourier transform spectrometry. Smillie D.G., Pickering J.C., Smith P.L. =2008MNRAS.390..733S ================================================================================ ADC_Keywords: Atomic physics Keywords: atomic data - line: identification - methods: laboratory Abstract: We report CrIII ultraviolet (UV) transition wavelengths measured using a high-resolution Fourier transform spectrometer (FTS), for the first time, available for use as wavelength standards. The doubly ionized iron group element spectra dominate the observed opacity of hot B stars in the UV, and improved, accurate, wavelengths are required for the analysis of astronomical spectra. The spectrum was excited using a chromium-neon Penning discharge lamp and measured with the Imperial College vacuum ultraviolet FTS. 140 classified 3d^3^4s-3d^3^4p CrIII transition lines, in the spectral range 38000 to 49000cm^-1^ (2632 to 2041{AA}), the strongest having wavelength uncertainties less than one part in 10^7^, are presented. Description: The Cr III spectrum was acquired in the wavenumber range 31596 to 63192cm^-1^, using the Imperial College (IC) VUV FTS, and a PDL as light source. The spectral resolution used, 0.12cm^-1^, was sufficient to fully resolve the Doppler broadened transition line profiles, for which the average unblended full-width at half maximum (FWHM) was just under 0.3cm^-1^. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 88 140 The classified Cr III transition linelist observed by FTS -------------------------------------------------------------------------------- Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 F4.2 [-] logInt Logarithm (to the base ten) of the integrated intensity (in arbitrary units) 6- 10 F5.3 cm-1 FWHM Line full-width at half maximum 12- 14 I3 --- SNR Signal-to-noise ratio 16- 24 F9.4 0.1nm lam.air Air wavelength 26- 34 F9.4 0.1nm lam.vac Vacuum wavelength 36- 44 F9.3 cm-1 sigma Line wavenumber 46- 51 F6.3 cm-1 Dsigma Wavenumber difference (sigma_obs_-sigma_Ritz_) (1) 53- 57 F5.3 cm-1 e_sigma rms uncertainty on sigma 60- 84 A25 --- Trans Transition (Lower - Upper) 86- 88 A3 --- Note Note (2) -------------------------------------------------------------------------------- Note (1): Wavenumber difference between the FTS observed wavCobs) and the Ritz wavenumber from Ekberg (1997, Phys. Scr., 56, 141) Note (2): Note provides additional information about the line, as follows: II = blended or doubly identified with a Cr II line III = blended or doubly identified with a Cr III line G = centre-of-gravity (COG) line fit (otherwise least-squares fit to Voigt profile) -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Patricia Vannier [CDS] 27-Mar-2009