The new Scopus CiteScore formula and the Journal Impact Factor: a look at top ranking journals and middle ranking journals in the Scopus categories of General Physics and Astronomy, Materials Science, General Medicine and Social Sciences.

In June 2020 Elsevier announced that the CiteScore metric of journals underwent a change. This work examines the effect of these changes for 40 journals, chosen from the top five and middle five (ranked by CiteScore) journals in the subject areas of General Physics and Astronomy, Materials Science, Medicine, Social Sciences) and compares to the Journal Impact Factor. It is shown that in the data studied here, the new methodology is less susceptible to influence of the proportion of editorial material in a journal, but tends to favour journals in research fields that publish articles which get cited more quickly.

Small telescopes: detectability and the evaluation of replication results.

This article introduces a new approach for evaluating replication results. It combines effect-size estimation with hypothesis testing, assessing the extent to which the replication results are consistent with an effect size big enough to have been detectable in the original study. The approach is demonstrated by examining replications of three well-known findings. Its benefits include the following: (a) differentiating "unsuccessful" replication attempts (i.e., studies yielding p > .05) that are too noisy from those that actively indicate the effect is undetectably different from zero, (b) "protecting" true findings from underpowered replications, and (c) arriving at intuitively compelling inferences in general and for the revisited replications in particular.

Verification of polarising optics for the LISA optical bench.

The Laser Interferometer Space Antenna (LISA) is a space-based interferometric gravitational wave detector. In the current baseline design for the optical bench, the use of polarising optics is foreseen to separate optical beams. Therefore it is important to investigate the influence of polarising components on the interferometer sensitivity and validate that the required picometre stability in the low-frequency band (1 mHz - 1 Hz) is achievable. This paper discusses the design of the experiment and the implemented stabilisation loops. A displacement readout fulfilling the requirement in the whole frequency band is presented. Alternatively, we demonstrate improvement of the noise performance by implementing various algorithms in data post-processing, which leads to an additional robustness for the LISA mission.

Demonstration of on-sky calibration of astronomical spectra using a 25 GHz near-IR laser frequency comb.

We describe and characterize a 25 GHz laser frequency comb based on a cavity-filtered erbium fiber mode-locked laser. The comb provides a uniform array of optical frequencies spanning 1450 nm to 1700 nm, and is stabilized by use of a global positioning system referenced atomic clock. This comb was deployed at the 9.2 m Hobby-Eberly telescope at the McDonald Observatory where it was used as a radial velocity calibration source for the fiber-fed Pathfinder near-infrared spectrograph. Stellar targets were observed in three echelle orders over four nights, and radial velocity precision of ∼10 m/s (∼6 MHz) was achieved from the comb-calibrated spectra.

Optical frequency combs generated by four-wave mixing in optical fibers for astrophysical spectrometer calibration and metrology.

Optical frequency combs generated by multiple four-wave mixing in short and highly nonlinear optical fibers are proposed for use as high precision frequency markers, calibration of astrophysical spectrometers, broadband spectroscopy and metrology. Implementations can involve two optical frequency standards as input lasers, or one standard and a second laser phase-locked to it using a stable microwave reference oscillator. Energy and momentum conservation required by the parametric generation assures phase coherence among comb frequencies, while fibers with short lengths can avoid linewidth broadening and stimulated Brillouin scattering. In contrast to combs from mode-locked lasers or microcavities, the absence of a resonator allows large tuning of the frequency spacing from tens of gigahertz to beyond teraHertz.