Introduction Room: G192

The Satellite Population Around Luminous Red Galaxies in the Legacy Surveys

• Mindy Townsend (University of Kansas)

Room: G192 Early-type galaxies have low specific star formation rates, old stellar populations, and little cold gas. Luminous Red Galaxies, or LRGs, were originally selected in the Sloan Digital Sky Survey as good tracers of large scale structure. Subsequent investigations have shown them to be among the most massive galaxies in the Universe, dominated by uniformly old stellar populations, and good tracers of this early-type galaxy population. Despite having old stellar populations, studies have shown that they have grown their stellar mass since z=1, implying that they grow predominantly via the accretion of satellites. This picture has not yet been tested because of the lack of deep imaging data sets that both covers a large enough area of the sky to contain substantial numbers of LRGs and also is deep enough to detect faint satellites. We present our initial characterization of the satellite galaxy population of LRGs out to z=0.65. To accomplish this we use the 25 deg$^{2}$ Early Data Release (EDR) of the DESI Legacy Imaging Surveys, which are comprised of $grz$ imaging to 2-2.5 mag deeper than SDSS and with better image quality. Specifically, we present our first measurement of the number of satellite galaxies around LRGs in bins of redshift and luminosity completeness, as well as LRG satellite color distribution. In addition, we forward model the distribution of the number of satellite galaxies that surround LRGs and constrain the average number of satellite galaxies in each bin of luminosity and redshift.

The Effect of Nitrogen Chemistry on Photochemical Escape of Oxygen from Mars

• Antonio Renzaglia (University of Kansas - Dept of Physics and Astronomy)

Room: G192 The atmosphere of Mars is CO2 dominated at lower altitudes, below around 225-250km altitude. Through multiple photochemistry paths, the dominant ion species is O2+. Dissociative recombination of O2+ ions produces neutral O atoms which have sufficient energy to escape from the planet. The amount of oxygen lost over geological time periods due to this process is very large(several meters of equivalent water over the surface). In this talk we describe the results of an investigation of how photochemical loss of O from Mars is altered when the N2 and NO neutral densities are enhanced over current abundances. Higher N2 and NO density profiles lead to higher N2+ density, and more importantly, higher NO+ density, and thus, lower O2+ density. But the dissociative recombination of NO+ does not produce atomic O atoms that exceed the escape energy. Additionally, higher abundances of N2 would lead to more neutral-neutral collisions between N2 and O, which would lead to energy loss of hot O atoms. Thus, for a Mars atmosphere (or a Mars-like exoplanet) atmospheric loss could be inhibited with higher atmospheric N2 abundances.

Magnetohydrodynamic Waves in the Presence of Magnetic Monopoles

• Ryan Low

Room: G192 Maxwell's equations in vacuum exhibit a duality between electric and magnetic fields. This duality is spoiled in the presence of electric sources and the absence of magnetic sources. We derive the equations for magnetohydrodynamics (MHD) in the presence of magnetic monopoles. Using these equations, we construct a four-fluid model consisting of electrons, ions, monopoles, and anti-monopoles. The resulting plasma is shown to support generalizations of the familiar plasma waves, such as Langmuir waves, electromagnetic waves, and magnetosonic waves.

Pinning efficiency of BaZrO3 Nanorods in YBa2Cu3O7-x /Ca0.3Y0.7Ba2Cu3O7-x multilayer nanocomposite films with variable BaZrO3 doping

• Mohan Panth

Room: G192 In this paper, BaZrO3 doped YBa2Cu3O7 (BZO/YBCO) nanocomposite films with 2-8 vol.% BZO doping were fabricated in a multilayer (ML) format by insertion of two 10 nm thick Ca0.3Y0.7Ba2Cu3O7-x spacer layers in BZO/YBCO nanocomposite. By measuring critical current density Jc in these ML samples, we aims to probe the effect of strain field overlap increased with BZO doping on the BZO/YBCO interface modification via ML scheme. Significant Jc enhancement was observed in ML films as compared to their SL counterpart’s, which results in overall higher pinning force density (Fp) while the enhancement is affected by the BZO doping quantitatively. At 65 K, the enhancement of peak Fp (or Fp,max) is 71%, 67%, 296%, and 47% for 2 vol.%, 4 vol.%, 6 vol.%, and 8 vol.% ML films respectively. In addition, the Bmax (the location of the Fp,max) is shifted towards higher values for BZO/YBCO ML films by up to 60%. This result illustrates the improved pinning efficiency of the BZO 1D-APCs in the BZO/YBCO ML films with a broad BZO doping range of 2-8 vol.% while the peak enhancement may be a compromise of the modulated strain field in facilitating preferential Ca ion diffusion along the BZO/YBCO interface for improved BZO/YBCO interface and hence pinning efficiency and other Ca ion diffusion into BZO/YBCO with primarily reduced the Tc values to impact pinning negatively.

Optical Contrast: a Review and Application of Chi-Square Analysis

• Neema Rafizadeh

Room: G192 Optical contrast is a tool used in many research areas to predict the thickness of thin films. While it has been applied widely from improving our detection of oil spills on sea surfaces to analysis of organic tissues, it has mainly found its usefulness in the field of nanotechnology for studying novel materials. However, novel materials do not usually have a documented refractive index and monolayer thickness, which can be difficult parameters to measure. We apply a general chi-square analysis to the optical contrast analysis of few-layer platinum diselenide (PtSe$_2$) to further the predictive power of optical contrast as a research tool. We also demonstrate its use in estimating both thickness and refractive index in novel materials.

Timing Detector R&D For The CMS Experiment At KU

• Andres Abreu (University of Kansas)

Room: G192 With the CMS Phase-1 detector nearing the end of its lifetime and the construction of the High-Luminosity LHC in the horizon, technologies for the new Phase-2 detector are approaching completion. One such technology, the so called low-gain avalanche detectors (LGADs), are being designed to provide valuable timing information for proton-proton collisions on an event-by-event basis. As one of several efforts in KU to study these sensors, a test system has been designed to be able to characterize their performance without the need of large particle accelerators, such as the ones in Fermilab and CERN. Furthermore, it has been designed to efficiently test large quantities of sensors in a short amount of time by using a movable radiation source. Development of the test platform system is well underway but there is still much to be done.

Virgo WISESize: Investigating Environmental Processes of Galaxies in the Virgo Cluster

• Kim Conger (University of Kansas)

Room: G192 The large-scale structure of the universe, colloquially known as the cosmic web, consists of a patchwork of dense clusters and low-density “field” regions, with strands of filamentary networks connecting and feeding these central clusters. Observations up until now have demonstrated that these clusters feature a lower fraction of star-forming galaxies relative to the isolated galaxies of the field, but astronomers have largely “washed out” filaments in their descriptions of cosmic environments, considering only the distance from the cluster center. Semi-analytic models, which currently predict a fraction of quenched galaxies that is much higher than observed, do not consider the effect of filaments on galaxies. Specifically, proposed solutions to this “over-quenching” problem currently neglect pre-processing of galaxy gas reservoirs that may be ongoing in filaments as these galaxies travel from the lower density filaments to the high density cluster. The aim of the Virgo-WISESize project is to use WISE 12-micron images of filamentary galaxies in the Virgo cluster to measure the spatial extent of the galaxy’s dust disk compared to the stellar disk and how it depends on environment. This can be used to determine the role of environmental quenching in filaments. With our results, we can then identify the physical processes contributing to this quenching, and in so doing help improve prevailing models of galaxy evolution.

A Role of Beam Energy Calibration

• Brendon Madison (KU HEP , ILC)

Room: G192 The precision of beam energies at LEP, LHC, ILC, FCC-ee will be discussed and compared. A general introduction to the proposed ILC, FCC-ee experiments will also be given. Energy calibration methods of resonant depolarization (RDP) and some "standard candle" energy calibration events will be presented. Emphasis will be given on ILC's Z->mu+mu- method. The experiments are then compared in a mockup, only considering beam calibration, of their ability to measure invariant mass and transverse energy.