This is the second part of an Hα kinematics follow‐up survey of the Spitzer Infrared Nearby Galaxies Survey (SINGS) sample. The aim of this paper is to shed new light on the role of baryons and their kinematics and on the dark/luminous matter relation in the star‐forming regions of galaxies, in relation with studies at other wavelengths. The data for 37 galaxies are presented. The observations were made using Fabry–Perot interferometry with the photon‐counting camera FaNTOmM on four different telescopes, namely the Canada–France–Hawaii 3.6‐m, the ESO La Silla 3.6‐m, the William Herschel 4.2‐m and the Observatoire du mont Mégantic 1.6‐m telescopes. The velocity fields are computed using custom idl routines designed for an optimal use of the data. The kinematical parameters and rotation curves are derived using the gipsy software. It is shown that non‐circular motions associated with galactic bars affect the kinematical parameters fitting and the velocity gradient of the rotation curves. This leads to incorrect determinations of the baryonic and dark matter distributions in the mass models derived from those rotation curves.

Deep Hα observations of the Sculptor Group galaxy NGC 7793 were obtained on the ESO 3.60 m and the Marseille 36 cm telescopes at La Silla, Chile. Hα emission is detected all the way to the edge of the H i disk, making the H ii disk of NGC 7793 one of the largest ever observed in a quiet non-active galactic nucleus (AGN) late-type system. Even in the very outer parts, the H ii ionizing sources are probably mainly internal (massive stars in the disk) with an unlikely contribution from the extragalactic ionizing background. The Hα kinematics confirms what had already been seen with the H i observations: NGC 7793 has a truly declining rotation curve. However, the decline is not Keplerian and a dark halo is still needed to explain the rotation velocities in the outer parts.

Significance: Raman spectroscopy has been developed for surgical guidance applications interrogating live tissue during tumor resection procedures to detect molecular contrast consistent with cancer pathophysiological changes. To date, the vibrational spectroscopy systems developed for medical applications include single-point measurement probes and intraoperative microscopes. There is a need to develop systems with larger fields of view (FOVs) for rapid intraoperative cancer margin detection during surgery. Aim: We design a handheld macroscopic Raman imaging system for in vivo tissue margin characterization and test its performance in a model system. Approach: The system is made of a sterilizable line scanner employing a coherent fiber bundle for relaying excitation light from a 785-nm laser to the tissue. A second coherent fiber bundle is used for hyperspectral detection of the fingerprint Raman signal over an area of 1 cm 2. Machine learning classifiers were trained and validated on porcine adipose and muscle tissue. Results: Porcine adipose versus muscle margin detection was validated ex vivo with an accuracy of 99% over the FOV of 95 mm 2 in ∼3 min using a support vector machine. Conclusions: This system is the first large FOV Raman imaging system designed to be integrated in the workflow of surgical cancer resection. It will be further improved with the aim of discriminating brain cancer in a clinically acceptable timeframe during glioma surgery.

We present useful expressions predicting the filling time of gaseous species inside photonic crystal fibers. Based on the theory of diffusion, this gas-filling model can be applied to any given fiber geometry or length by calculating diffusion coefficients. This was experimentally validated by monitoring the filling process of acetylene gas in several fiber samples of various geometries and lengths. The measured filling times agree well, within AE15%, with the predicted values for all fiber samples. In addition, the pressure dependence of the diffusion coefficient was experimentally verified by filling a given fiber sample with acetylene gas at various pressures. Finally, optimized conditions for gas-light interaction are determined by considering the gas flow dynamics in the design of microstructured fibers for gas detection and all-fiber gas cell applications.

A proof-of-concept of space-borne laser filamentation for atmospheric remote sensing is presented. The remote generation of laser filaments from an Earth-orbiting satellite is shown by numerical simulations to be theoretically possible for a large range of laser parameters. The model includes a realistic representation of the stratified atmosphere and accounts for multi-species ionization and the dependence of air density upon the molecule type and altitude profile. The remote generation of a white light continuum extending from 350 nm to 1.1 μm within the filament is demonstrated, and hereby proposed as an atmospheric in-situ light source for monitoring greenhouse gases and pollutants on a global scale by light detection and ranging (lidar) techniques. Scaling laws are also derived for estimating the filament altitude as a function of peak pulse power (3 GW-3 TW), beam radii (10-200 cm) and for three different curvatures (300, 390, 500 km) for femtosecond infrared (800 nm) pulses. We find that operating conditions for remote supercontinuum generation are already available with current ground-based mobile laser technology and within reach of future space laser systems.