The Noble Element Simulation Technique (NEST) is an exhaustive collection of models explaining both the scintillation light and ionization yields of noble elements as a function of particle type (nuclear recoil, electron recoil, alphas), electric field, and incident energy or energy loss (dE/dx). It is packaged as C++ code for Geant4 that implements said models, overriding the default model which does not account for certain complexities, such as the reduction in yields for nuclear recoils (NR) compared to electron recoils (ER). We present here improvements to the existing NEST models and updates to the code which make the package even more realistic and turn it into a more full-fledged Monte Carlo simulation. All available liquid xenon data on NR and ER to date have been taken into consideration in arriving at the current models. Furthermore, NEST addresses the question of the magnitude of the light and charge yields of nuclear recoils, including their electric field dependence, thereby shedding light on the possibility of detection or exclusion of a low-mass dark matter WIMP by liquid xenon detectors.

ALMA cycle 3 observations of 12CO J = 3 → 2, 13CO J = 4 → 3, SiO J = 8 → 7, and HCN J = 5 → 4 are presented. Significant extended emission is detected in 12CO J = 3 → 2 with a morphology that is indicative of m = 2 tidal features, suggesting gas inflow. In addition, outflows for both nuclei are found in 12CO J = 3 → 2. Significant SiO absorption is detected in the western nucleus. HCN that is morphologically distinct from CO is detected in both nuclei. These observations are compared to non-LTE radiative transfer models created using the Line Modeling Engine for simple gas dynamics to gain insight into how physical parameters, such as rotational velocity, turbulent velocity, gas temperature, dust temperature, and gas mass, can reproduce the observed kinematic and spatial features. The eastern nucleus is found to be best modeled with an inclusion of a temperature asymmetry from one side of the disk to the other. It is also found that the western nucleus is optically thick even in the less abundant species of 13CO, absorbing significant amounts of continuum radiation.

The galaxy evolution probe (GEP) is a concept for a probe-class space observatory to study the physical processes related to star formation over cosmic time. To do so, the mid-and far-infrared (IR) spectra of galaxies must be studied. These mid-and far-IR observations require large multi-frequency arrays, sensitive detectors. Our goal is to develop low NEP aluminum kinetic inductance detectors (KIDs) for wavelengths of 10-400 μm for the GEP and a pathfinder long-duration balloon (GEP-B) that will perform precursor GEP science. KIDs for the lower wavelength range (10-100 μm) have not been previously implemented. We present an absorber design for KIDs sensitive to wavelengths of 10 μm shown to have around 75-80% absorption efficiency through ANSYS HFSS (high-frequency structure simulator) simulations, challenges that come with optimizing our design to increase the wavelength range, initial tests on our design of fabricated 10 μm KIDs, and theoretical NEP calculations.

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Future generations of far-infrared (FIR) telescopes will need detectors with noise-equivalent powers on the order of 5x10 −20 W/Hz 1/2 in order to be photon background limited by astrophysical sources. One such mission concept in development is the Galaxy Evolution Probe (GEP), which will characterize galaxy formation and evolution from z=0 to beyond z=4. Kinetic inductance detectors (KIDs) have been baselined for the GEP for spectroscopy and imaging science between 10 µm and 400 µm due to their intrinsic frequency multiplexability and simple readout schemes. We focus on quasiparticle recombination times as a strategy for increasing detector responsivities to move towards the NEP requirements of the GEP. We present a new model for quantifying time constants from the responses of detectors to pulses of light, and test this model on a 40 nm thick 1/4 λ Al coplanar waveguide KID. We intend to use this measurement scheme to quantify the dependence of the quasiparticle recombination time on Al thickness.