Accurate laboratory ultraviolet wavelengths for quasar absorption-line constraints on varying fundamental constants

Abstract

The most precise method of investigating possible space-time variations of the fine-structure constant, using high-redshift quasar absorption lines, is the many-multiplet (MM) method. For reliable results this method requires very accurate relative laboratory wavelengths for a number of UV resonance transitions from several different ionic species. For this purpose laboratory wavelengths and wavenumbers of 23 UV lines from MgI, MgII, TiII, CrII, MnII, FeII and ZnII have been measured using high-resolution Fourier Transform (FT) spectrometry. The spectra of the different ions (except for one FeII line, one MgI line and the TiII lines) are all measured simultaneously in the same FT spectrometry recording by using a composite hollow cathode as a light source. This decreases the relative uncertainties of all the wavelengths. In addition to any measurement uncertainty, the wavelength uncertainty is determined by that of the ArII calibration lines, by possible pressure shifts and by illumination effects. The absolute wavenumbers have uncertainties of typically 0.001 to 0.002 cm^(-1) (0.06 to 0.1 mAA at 2500 AA), while the relative wavenumbers for strong, symmetric lines in the same spectral recording have uncertainties of 0.0005 cm^(-1) (0.03 mAA at 2500 AA) or better, depending mostly on uncertainties in the line fitting procedure. This high relative precision greatly reduces the potential for systematic effects in the MM method, while the new TiII measurements now allow these transitions to be used in MM analyses.

arXiv commentAccepted for publication in MNRAS, 10 pages, 9 figures

References in corpus (15)

• Further Evidence for Cosmological Evolution of the Fine Structure Constant
• A Search for Time Variation of the Fine Structure Constant
• Further evidence for a variable fine-structure constant from Keck/HIRES QSO absorption spectra
• Possible evidence for a variable fine structure constant from QSO absorption lines: motivations, analysis and results
• Limits on the time variation of the electromagnetic fine-structure constant in the low energy limit from absorption lines in the spectra of distant quasars
• Space-Time Variation of Physical Constants and Relativistic Corrections in Atoms
• Calculations of the Relativistic Effects in Many-Electron Atoms and Space-Time Variation of Fundamental Constants
• Probing the cosmological variation of the fine-structure constant: Results based on VLT-UVES sample
• Probing the variability of the fine-structure constant with the VLT/UVES
• Astrophysical Limits on the Evolution of Dimensionless Physical Constants over Cosmological Time
• Possible evidence for a variable fine structure constant from QSO absorption lines: systematic errors
• Further constraints on variation of the fine structure constant from alkali doublet QSO absorption lines
• On the variation of the fine-structure constant: Very high resolution spectrum of QSO HE 0515-4414
• The elemental abundance pattern in a galaxy at z=2.626
• VLT/UVES constraints on the cosmological variability of the fine-structure constant

Cited by in corpus (16)

• Spatial variation in the fine-structure constant -- new results from VLT/UVES
• A new measure of Delta alpha/alpha at redshift z = 1.84 from very high resolution spectra of Q1101-264
• Bounds on the fine structure constant variability from FeII absorption lines in QSO spectra
• The spectrum of Fe II
• Frequency Metrology on single trapped ions in the weak binding limit: The 3s1/2-3p3/2 transition in 24-Mg+
• Precision spectroscopy of the 3s-3p fine structure doublet in Mg+
• Laboratory atomic transition data for precise optical quasar absorption spectroscopy
• Experimental Mg I oscillator strengths and radiative lifetimes for astrophysical applications on metal-poor stars - New data for the Mg I b triplet
• Isotope shift calculations in Ti II
• Wavelengths of the 3d6(5D)4s a6D - 3d6(5D)4p y6P Multiplet of Fe II (UV 8)
• Initial Results from the USNO Dispersed Fourier Transform Spectrograph
• Atomic transition frequencies, isotope shifts, and sensitivity to variation of the fine structure constant for studies of quasar absorption spectra
• Accurate Ritz wavelengths of parity-forbidden [Fe II], [Ti II] and [Cr II] infrared lines of astrophysical interest
• Transition frequencies, isotope shifts, and hyperfine structure in $4s\to 4p$ transitions of Ti${}^{+}$ ions
• High-resolution saturation spectroscopy of singly-ionized iron with a pulsed uv laser
• Precision laboratory UV and IR wavelengths for cosmological and astrophysical applications