Small Line Shifts Research Articles

Spectral variations of Lyman $\alpha$ emission within strongly lensed sources observed with MUSE

ABSTRACT We present an analysis of ${\rm H\,\rm{\small {I}}}$ Lyman $\alpha$ emission in deep VLT/MUSE observations of two highly magnified and extended galaxies at $z=3.5$ and 4.03, including a newly discovered, almost complete Einstein ring. While these Lyman $\alpha$ haloes are intrinsically similar to the ones typically seen in other MUSE deep fields, the benefits of gravitational lensing allow us to construct exceptionally detailed maps of Lyman $\alpha$ line properties at sub-kpc scales. By combining all multiple images, we are able to observe complex structures in the Lyman $\alpha$ emission and uncover small ($\sim120$ km s−1 in Lyman $\alpha$ peak shift), but significant at $ \gt $4 $\sigma$, systematic variations in the shape of the Lyman $\alpha$ line profile within each halo. Indeed, we observe a global trend for the line peak shift to become redder at large radii, together with a strong correlation between the peak wavelength and line width. This systematic intrahalo variation is markedly similar to the object-to-object variations obtained from the integrated properties of recent large samples. Regions of high surface brightness correspond to relatively small line shifts, which could indicate that Lyman $\alpha$ emission escapes preferentially from regions where the line profile has been less severely affected by scattering of Lyman $\alpha$ photons.

Multi-contact switch using double-dressing regularity of probe, fluorescence, and six-wave mixing in a Rydberg atom.

In this paper, we study the realization of a multi-contact switch using the double-dressing regularity of probe, fluorescence, and six-wave mixing signals in a five-level 85Rb atomic system. For the first time, we compare the dressing regularity of Rydberg states by observing electromagnetically induced transparency and signals. With the scanning probe and dressing fields, both large and small line shifts in signals are observed. The small line shifts are induced by double-dressed line shifts. Also, the big line shifts result from the Rydberg dressing. In addition, with an increase in the principal quantum number n of the Rydberg state, all the signals become weaker, while the line shifts of the signals become enhanced. Using the regularity in line shifts of the signals and an acoustic optical modulator to modulate the frequency detuning, we can realize a multi-contact switch action and fast conversion between different contacts.

Alkali-metal electron spin density shift induced by a helium nanodroplet

Helium (He) nanodroplets provide a cold and virtually unperturbing environment for the study of weakly bound molecules and van der Waals aggregates. High resolution microwave spectroscopy and the detection of electron spin transitions in doped He droplets have recently become possible. Measurements of hyperfine-resolved electron spin resonance in potassium (39K) and rubidium (85Rb) atoms on the surface of He droplets show small line shifts relative to the bare atoms. These shifts were recorded for all 2I + 1 components (I is the nuclear spin) of a transition at high accuracy for He droplets ranging in size from 1000 to 15,000 He atoms. Evaluation of the spectra yields the influence of the He environment on the electron spin density at the alkali-metal nucleus. A semi-empirical model is presented that shows good qualitative agreement with the measured droplet size dependent increase of Fermi contact interaction at the nuclei of dopant K and Rb.

Topochemical Speciation of Intercalated Palladium in Graphite by Valence Band X-ray Spectrometry in the Electron Microprobe

The binding state of palladium was studied within the frame of an investigation on the mechanism of analyte fixation during the pyrolysis step in graphite furnace atomic spectrometry. One approach was the determination of the palladium intercalated in the pyrolytic coating of the graphite tube. Due to the low concentrations of intercalated palladium in the pyrolytic coating, precise determination of the shift of certain X-ray lines was chosen. From several investigated valence state sensitive X-ray transitions, the Pd Lbeta2/15 (L3-N4,5) line shift was the one best determinable. The measured line shifts are in the range of -0.14 to 0.71 eV at line widths of 13 eV (fwhm) and a line energy of 3.1729 keV. These very small line shifts were determined by electron probe microanalysis. The detection of the small line shifts was performed with a new method-by evaluation of the change of the intensity in the flanks of the X-ray line. The measurements yielded the following results: inside the pyrolytic graphite, the palladium is distributed inhomogeneously in the form of clusters or islands and in the form of particles on the surface of the pyrolytic graphite. The differentiation between particles and clusters is a very practical one: as long as a particle can be seen in the SEM we talk of particles. Often, however, Pd is detected in an area on the tube or platform surface without detection of a particle. Hence, it can be assumed that the Pd is present in the form of clusters which might even be intercalated in the uppermost graphite layers. The valence state inside these clusters does not appear to be uniform. It can be interpreted as a mixture of Pd with PdO in the center of the clusters or particles (positive peak shift) and of Pd bound to the graphite (strong negative peak shift). On the basis of these observations, a way is proposed to determine how activated Pd atoms in intercalated Pd domains are forming strong covalent bonds to analytes. These bonds are responsible for the analyte fixation of even very volatile analytes.

Two- and three-photon spectroscopy of ZnO under uniaxial stress

Resonances on the polariton branches of the A, B and C 1S excitons of ZnO are studied under uniaxial stress by nonlinear spectroscopy. Due to the small line width, shifts and splittings are clearly resolved and the crystal-field splitting, the analytical exchange, the spin—orbit parameters and all six deformation potentials are determined with high accuracy.

Determination of ion charge state distributions in krypton and cobalt electron cyclotron resonance plasmas by wavelength dispersive x-ray spectroscopy

Wavelength dispersive x-ray measurements on cobalt and krypton ions were presented to determine the ion charge state distribution (CSD) inside the electron cyclotron resonance (ECR) plasma of the 14.5 GHz ECR ion source of the TU Dresden. For clearly from the parent diagram lines separating x-ray satellites a comparison between calculated wavelength shifts and measured ones allows it to deduce the ion CSD of the analyzed ions. In the case of small line shifts (lower ionization states) a comparison with x-ray spectra derived from plasma modeling is done. By approximating the modeled spectra to the measured ones a most probable ion CSD was derived.

Measurements of the pressure shift of water vapor absorption lines by simultaneous photoacoustic spectroscopy

Simultaneous photoacoustic spectroscopy is introduced as a convenient and accurate method for the measurement of small absorption line shifts due to the pressure of the surrounding atmosphere. Results are presented for fourteen water vapor lines in the 725-nm spectral region. Rather large pressure shift coefficients of up to −0.040 cm−1/atm are observed, which have to be taken into consideration in remote sensing applications in which the exact positioning on the line center is critical, e.g., differential absorption lidar.

Statistical evaluation and measuring strategy for extremely small line shifts

For a measuring situation limited by counting statistics, but where the level of precision is such that possible systematic errors are a major concern, it is proposed to determine the position of a spectral line from a measured line segment by applying a bias correction to the centre of gravity of the segment. This procedure is statistically highly efficient and not sensitive to small errors in assumptions about the line shape. The counting strategy for an instrument that takes data point by point is also considered. It is shown that an optimum (“two-point”) strategy exists; a scan of the central part of the line is 68% efficient by this standard.

Evidence for dynamical screening of projectile ions passing through solids

X-ray energies of multiplet transitions in helium-like sulphur projectiles passing through thin foils have been measured with high resolution. Small lineshifts have been found which can be attributed to the effect of dynamical screening of the projectiles by the target electron gas.

A method for the measurement of lineshifts using a comparator gated system

A new method for the measurement of rotation vibration absorption lineshifts of polar molecules is described. With the help of a 'comparator gated system' the authors obtain the perturbed and they reference lines on the same record. In particular the have measured the small lineshifts of H35Cl( nu 1 from 0) perturbed by argon and xenon.

Mesure des largeurs et des deplacements des raies de la bande 0 → 2 de CO autoperturbe et perturbe par N 2, O 2, H 2, HCl, NO et CO 2

Linewidths of CO pressure-broadened by itself and by foreign gases have been measured in the 0 → 2 band. An experimental slit correction was used. The very small lineshifts of compressed CO have also been estimated using two different methods of measurement. An order-of-magnitude estimate is given for lineshifts due to foreign gases.

Anthracene fluorescence at low temperatures. II. Doped single crystals

By the addition of dopants to single crystal anthraoene it is shown that many of the fluorescence bands additional to exciton emission are due to traces of 2-methylanthracene. Other impurity bands, apparently arising from locally disorientated host molecules, appear on doping with most of the following, the effects increasing in the order given: carbazole, biphenyl, p-terphenyl, anthraquinone, naphthalene, naphthacene, phenanthrene, pyrene, chrysene. The host vibronic bands were virtually unaffected by dopants, except for small line shifts in the presence of 2-methylanthracene.

Improved Duochromator for Measurement of Small Spectral Line Shifts

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text U. Kogelschatz, D. R. Brooks, and J. M. Hoell, "Improved Duochromator for Measurement of Small Spectral Line Shifts," Appl. Opt. 9, 494-495 (1970) Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article

Absorption Spectra of Cuprous Oxide Quenched

Quenching experiments are performed with pure impure crystals of Cu 2 O, the latter of which contained small quantities of Zn, Ni and Ag. As regards the impure crystal quenched from 950°C to room temperature, all absorption lines appearing in the yellow and the green region of its spectrum taken at 77°K shift to red. The Ag-mingled crystal shows that it is much larger in line-shift than the others, whereas it reveals very small line-shifts when slowly cooled within the above limits of temperature. The large shift is inferred to be due to numerous “complexes” which consist of Ag + -ions and Cu + -ion vacancies. As to the pure crystal rapidly cooled, its absorption spectra display slight line-shifts, sharp lines about the yellow region when observed at 4.2°K and disturbed lines of absorption in the green series, while normal lines in the yellow, their interpretations being examined.

Recording Fabry-Perot Interferometer

A recording interferometer is described in which a direct plot of spectral intensity against wavenumber is obtained without the use of a time base. When used as a double recorder, the instrument records two spectral profiles simultaneously. In this form, the recorder is particularly suited to the comparison of spectral profiles and the measurement of small line shifts.