Extremely Large Telescope

Abstract:

We analyse the ro-vibrational absorption bands of various molecular cations (HCO, HCNH, and NH) and neutral species (HCN, HNC, and HCN) detected in the James Webb Space Telescope/Mid-Infrared Instrument Medium Resolution Spectrometer spectrum (4.9–27.9 μm) of the local ultraluminous infrared galaxy IRAS 07251-0248. We find that the molecular absorptions are blueshifted by 160 km s relative to the systemic velocity of the target. Using local thermal equilibrium excitation models, we derive rotational temperatures () from 42 to 185 K for these absorption bands. This range of measured can be explained by infrared radiative pumping as a by-product of the strength, effective critical density, and opacity of each molecular band. Thus, these results suggest that these absorptions originate in a warm expanding gas shell (90–330 yr), which might be the base of the larger scale cold molecular outflow detected in this source. Finally, the elevated abundance of molecular cations can be explained by a high cosmic ray ionization rate, with log(/n in the range of -18.2 (from H) to -19.1 (inferred from HCO and NH, which are likely tracing denser gas), consistent with a cosmic ray dominated chemistry as predicted by chemical models.

Abstract:

The WALOPControl software is designed to facilitate comprehensive control and operation of the Wide Area Linear Optical Polarimeter (WALOP) polarimeters, ensuring safe and concurrent management of various instrument components and functionalities. This software encompasses several critical requirements, including control of the filter wheel, calibration half-wave plate, calibration polarizer, guider positioning, focusers, and four concurrent charge-coupled device cameras. It also manages the host telescope and dome operations while logging operational parameters, user commands, and environmental conditions for troubleshooting and stability. It provides a user-friendly graphical user interface and secure access control, a notification system for errors, and a modular configuration for troubleshooting that are integral to the software's architecture. It is accessible over the internet with the backend developed using NodeJS and ExpressJS, featuring a RESTful API that interacts with a MongoDB database, facilitating real-time status updates and data logging. The frontend utilizes the React.JS framework, with Redux for state management and Material UI for the graphical components. The system also allows for automatic observations based on user-defined schedules. A continuous integration and continuous deployment pipeline ensures the software's reliability through automated testing and streamlined deployment. The WALOPControl software is a key component of the Polar-Areas Stellar Imaging in Polarimetry High Accuracy Experiment project, which aims to study the dust and magnetic field of the Milky Way by observing the polarization of starlight.

Abstract:

We present a new measurement of the dark and luminous matter distribution of massive elliptical galaxies, and their evolution with redshift, by combining strong lensing and dynamical observables. Our sample of 56 lens galaxies covers a redshift range of . By combining new Hubble Space Telescope imaging with previously observed velocity dispersion and line-of-sight measurements, we decompose the luminous matter profile from the dark matter profile and perform a Bayesian hierarchical analysis to constrain the population-level properties of both profiles. We find that the inner slope of the dark matter density profile (‘cusp’; ) is consistent ( with intrinsic scatter) with a standard Navarro–Frenk–White (NFW; ) at . Additionally, we find an appreciable evolution with redshift () resulting in a shallower slope (of tension from NFW) at redshifts . This is in excellent agreement with previous population-level observational studies, as well as with predictions from hydrodynamical simulations such as IllustrisTNG. We also find the stellar mass-to-light ratio at the population level is consistent with that of a Salpeter initial mass function, a small stellar mass-to-light gradient [, with ], and isotropic stellar orbits. Our averaged total mass density profile is consistent with a power-law profile within 0.25 to 4 Einstein radii (), with an internal mass-sheet transformation parameter consistent with no mass sheet. Our findings confirm the validity of the standard mass models used for time-delay cosmography.