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Despite powerful X-ray emission, some active galactic nuclei (AGNs) are known to either lack optical emission lines (so-called 'optically dull' AGNs) or have lines that fall on the star-forming branch of the Baldwin–Phillips–Terlevich (BPT) diagram ('misclassified' AGNs). Aperture effects have been proposed to explain such atypical spectra, especially when based on Sloan Digital Sky Survey (SDSS; 3 arcsec) fibres. We use observations from VLT-MUSE with Adaptive Optics to explore the spatially resolved optical emission line properties of four optically dull and one misclassified X-ray AGN candidates. VLT-MUSE IFU spectra allow us to investigate the extent to which the aperture size affects the emission line measurements. The optically dull AGNs become detectable in deeper VLT-MUSE spectroscopic apertures having the same size (3 arcsec) as SDSS fibres, suggesting no AGN is truly lineless. However, in no case does the line become more detectable as the aperture decreases, as would be expected if dilution by strong continuum was responsible for making the lines appear weak. We also show that the misclassified X-ray AGN retains the same position on the BPT diagram in smaller apertures (down to 0.5 arcsec), demonstrating that its misclassification is not the result of the dilution by H  ii regions. Thus, we conclude that continuum swamping or star formation dilution, i.e. aperture effects, are not responsible for atypical lines. Rather, the AGN lines are intrinsically weak. [ABSTRACT FROM AUTHOR]

The spectroscopic analysis of X-ray magnetic circular dichroism (XMCD), which serves as strong and element-specific magnetic contrast in full-field magnetic transmission soft x-ray microscopy, is shown to provide information on the local distribution of spin (S) and orbital (L) magnetic moments down to a spatial resolution of 25 nm limited by the x-ray optics used in the x-ray microscope. The spatially resolved L/S ratio observed in a multilayered (Co 0.3 nm/Pt 0.5 nm) × 30 thin film exhibiting a strong perpendicular magnetic anisotropy decreases significantly in the vicinity of domain walls, indicating a non-uniform spin configuration in the vertical profile of a domain wall across the thin film. Quantitative XMCD mapping with x-ray spectro-microscopy will become an important characterization tool for systems with topological or engineered magnetization inhomogeneities [ABSTRACT FROM AUTHOR]

We have designed and built a scanning tunneling microscope with a compact inertial-approach mechanism that fits inside the piezoelectric scanner tube. Rigid construction allows the microscope to be operated without the use of external vibration isolators or acoustic enclosures. Thermoelectric cooling and a water-ice bath are used to increase temperature stability when scanning under ambient conditions. [ABSTRACT FROM AUTHOR]

The authors have developed a method of performing scanning tunneling microscopy experiments with a sample that can be controllably heated and quickly cooled. Temperatures in excess of 100 °C are achievable, and the same scanning area can be imaged multiple times before and after repeated heating cycles. This opens up for study any physical process or chemical reaction where the reactants, products, and/or intermediates can be kinetically trapped on a conductive surface at room temperature. As a demonstration of this approach, the authors have investigated desorption from 1-octanethiolate self-assembled monolayers on Au(111). [ABSTRACT FROM AUTHOR]