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Full-Text Articles in Physics

Light Curve And Hardness Tests For Millilensing In Grb 081122a, Grb 081126a, Grb 110517b, And Grb 210812a, Oindabi Mukherjee, Robert J. Nemiroff Mar 2024

Light Curve And Hardness Tests For Millilensing In Grb 081122a, Grb 081126a, Grb 110517b, And Grb 210812a, Oindabi Mukherjee, Robert J. Nemiroff

Michigan Tech Publications, Part 2

Analyses are given on four recent gravitational millilensing claims on gamma-ray bursts (GRBs): GRB 081122A, GRB 081126A, GRB 110517B, and GRB 210812A. Two tests, a light curve similarity test and a hardness similarity test, compare different temporal sections of a single GRB to see if they are statistically similar. The hardness similarity test shows that the ratio between the second and the first emission episodes in each energy channel differed from the same ratio averaged over all energy channels at above 90 per cent confidence level in GRB 081122A. Additionally, the light curve similarity test applied to GRB 081122A, GRB …


First-Principles Study Of Hydrogen Storage Application Of Ti3c2tx Monolayer Mxene, Yi Zhi Chu, Kah Chun Lau Feb 2024

First-Principles Study Of Hydrogen Storage Application Of Ti3c2tx Monolayer Mxene, Yi Zhi Chu, Kah Chun Lau

Michigan Tech Publications, Part 2

MXene, with its high aspect ratio and adjustable surface properties, has garnered significant attention in the realm of hydrogen storage research. For the first time, considering a ternary/quaternary mixed terminated MXene surface, the authors have investigated comprehensively the hydrogen storage potential of two-dimensional (2D) titanium carbide Ti3C2Tx monolayer MXene using density functional theory (DFT). By considering mixed terminated surfaces, this study indicated the locally induced dipole due to the mixed termination is beneficial in facilitating hydrogen adsorption with stronger average adsorption energies than that of the uniform F-/O-/OH-/H-terminated surfaces. The authors estimated a compelling average H2 surface adsorption energy on …


First-Principles Study Of Mxene Properties With Varying Hydrofluoric Acid Concentration, Yi Zhi Chu, Megan Hoover, Patrick Ward, Kah Chun Lau Feb 2024

First-Principles Study Of Mxene Properties With Varying Hydrofluoric Acid Concentration, Yi Zhi Chu, Megan Hoover, Patrick Ward, Kah Chun Lau

Michigan Tech Publications, Part 2

With varying hydrofluoric acid (HF) concentrations under three etching conditions, we presented a comparative study of the effects of both the ordered and randomly ternary mixed terminated Ti3C2Tx surfaces with a wide variation of O/OH/F stoichiometry on the thermodynamic stability and electronic properties. Regardless of the HF concentration, an OH-rich surface is found to be thermodynamically stable and the electrical conductivity of Ti3C2Tx is substantially affected by the OH concentration. The charge density difference and electron localization function demonstrated a significant electron localization at the hydroxyl group on the O/OH/F mixed terminated surface, which could yield a locally induced dipole …


Resolving The Topology Of Encircling Multiple Exceptional Points, Chitres Guria, Qi Zhong, Sahin Kaya Ozdemir, Yogesh S.S. Patil, Ramy El-Ganainy, Jack Gwynne Emmet Harris Feb 2024

Resolving The Topology Of Encircling Multiple Exceptional Points, Chitres Guria, Qi Zhong, Sahin Kaya Ozdemir, Yogesh S.S. Patil, Ramy El-Ganainy, Jack Gwynne Emmet Harris

Michigan Tech Publications, Part 2

Non-Hermiticity has emerged as a new paradigm for controlling coupled-mode systems in ways that cannot be achieved with conventional techniques. One aspect of this control that has received considerable attention recently is the encircling of exceptional points (EPs). To date, most work has focused on systems consisting of two modes that are tuned by two control parameters and have isolated EPs. While these systems exhibit exotic features related to EP encircling, it has been shown that richer behavior occurs in systems with more than two modes. Such systems can be tuned by more than two control parameters, and contain EPs …


Galactic Gamma-Ray Diffuse Emission At Tev Energies With Hawc Data, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, K. P. Arunbabu, D. Avila Rojas, R. Babu, Et Al. Jan 2024

Galactic Gamma-Ray Diffuse Emission At Tev Energies With Hawc Data, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, K. P. Arunbabu, D. Avila Rojas, R. Babu, Et Al.

Michigan Tech Publications, Part 2

Galactic gamma-ray diffuse emission (GDE) is emitted by cosmic rays (CRs), ultra-relativistic protons, and electrons, interacting with gas and electromagnetic radiation fields in the interstellar medium. Here we present the analysis of teraelectronvolt diffuse emission from a region of the Galactic plane over the range in longitude of l ∈ [43°, 73°], using data collected with the High Altitude Water Cherenkov (HAWC) detector. Spectral, longitudinal, and latitudinal distributions of the teraelectronvolt diffuse emission are shown. The radiation spectrum is compatible with the spectrum of the emission arising from a CR population with an index similar to that of the observed …


Radio Measurements Of The Depth Of Air-Shower Maximum At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, K. Nguyen, A. Puyleart, Et Al. Jan 2024

Radio Measurements Of The Depth Of Air-Shower Maximum At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, K. Nguyen, A. Puyleart, Et Al.

Michigan Tech Publications, Part 2

The Auger Engineering Radio Array (AERA), part of the Pierre Auger Observatory, is currently the largest array of radio antenna stations deployed for the detection of cosmic rays, spanning an area of 17 km2 with 153 radio stations. It detects the radio emission of extensive air showers produced by cosmic rays in the 30-80 MHz band. Here, we report the AERA measurements of the depth of the shower maximum (Xmax), a probe for mass composition, at cosmic-ray energies between 1017.5 and 1018.8 eV, which show agreement with earlier measurements with the fluorescence technique at the Pierre Auger Observatory. We show …


Demonstrating Agreement Between Radio And Fluorescence Measurements Of The Depth Of Maximum Of Extensive Air Showers At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, K. Nguyen, A. Puyleart, Et Al. Jan 2024

Demonstrating Agreement Between Radio And Fluorescence Measurements Of The Depth Of Maximum Of Extensive Air Showers At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, K. Nguyen, A. Puyleart, Et Al.

Michigan Tech Publications, Part 2

We show, for the first time, radio measurements of the depth of shower maximum (Xmax) of air showers induced by cosmic rays that are compared to measurements of the established fluorescence method at the same location. Using measurements at the Pierre Auger Observatory we show full compatibility between our radio and the previously published fluorescence dataset, and between a subset of air showers observed simultaneously with both radio and fluorescence techniques, a measurement setup unique to the Pierre Auger Observatory. Furthermore, we show radio Xmax resolution as a function of energy and demonstrate the ability to make competitive high-resolution Xmax …


Designing A Convection-Cloud Chamber For Collision-Coalescence Using Large-Eddy Simulation With Bin Microphysics, Aaron Wang, Mikhail Ovchinnikov, Fan Yang, Silvio Schmalfuss, Raymond A. Shaw Jan 2024

Designing A Convection-Cloud Chamber For Collision-Coalescence Using Large-Eddy Simulation With Bin Microphysics, Aaron Wang, Mikhail Ovchinnikov, Fan Yang, Silvio Schmalfuss, Raymond A. Shaw

Michigan Tech Publications, Part 2

Collisional growth of cloud droplets is an essential yet uncertain process for drizzle and precipitation formation. To improve the quantitative understanding of this key component of cloud-aerosol-turbulence interactions, observational studies of collision-coalescence in a controlled laboratory environment are needed. In an existing convection-cloud chamber (the Pi Chamber), collisional growth is limited by low liquid water content and short droplet residence times. In this work, we use numerical simulations to explore various configurations of a convection-cloud chamber that may intensify collision-coalescence. We employ a large-eddy simulation (LES) model with a size-resolved (bin) cloud microphysics scheme to explore how cloud properties and …


Light Curve And Hardness Tests For Millilensing In Grb 950830, Grb 090717a, And Grb 200716c, Oindabi Mukherjee, Robert J. Nemiroff Jan 2024

Light Curve And Hardness Tests For Millilensing In Grb 950830, Grb 090717a, And Grb 200716c, Oindabi Mukherjee, Robert J. Nemiroff

Michigan Tech Publications, Part 2

Two different temporal sections of a single gamma-ray burst (GRB) must be statistically similar to show an internal gravitational lensing signature. Here, two straightforward gravitational lensing tests are defined and applied: a light curve similarity test and a hardness similarity test. Gravitational millilensing has been claimed to be detected within several individual GRBs that contain two emission episodes separated by a time-delay. However, our analyses indicate that none of those claims satisfy both tests. The hardness similarity test performed on GRB 950830 and GRB 090717A found that the ratio between the second and the first emission episodes in each energy …


Constraining Models For The Origin Of Ultra-High-Energy Cosmic Rays With A Novel Combined Analysis Of Arrival Directions, Spectrum, And Composition Data Measured At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, A. Puyleart, Et Al. Jan 2024

Constraining Models For The Origin Of Ultra-High-Energy Cosmic Rays With A Novel Combined Analysis Of Arrival Directions, Spectrum, And Composition Data Measured At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, A. Puyleart, Et Al.

Michigan Tech Publications, Part 2

The combined fit of the measured energy spectrum and shower maximum depth distributions of ultra-high-energy cosmic rays is known to constrain the parameters of astrophysical models with homogeneous source distributions. Studies of the distribution of the cosmic-ray arrival directions show a better agreement with models in which a fraction of the flux is non-isotropic and associated with the nearby radio galaxy Centaurus A or with catalogs such as that of starburst galaxies. Here, we present a novel combination of both analyses by a simultaneous fit of arrival directions, energy spectrum, and composition data measured at the Pierre Auger Observatory. The …


Identification Of Selected Persistent Organic Pollutants In Agricultural Land By Carbon Nitride (C3n5) Based Nano Sensors, Puspamitra Panigrahi, P. S. Anuroop, Hoonkyung Lee, Hyeonhu Bae, Thanayut Kaewmaraya, Ravindra Pandey, Tanveer Hussain, Akshaya Panigrahi Nov 2023

Identification Of Selected Persistent Organic Pollutants In Agricultural Land By Carbon Nitride (C3n5) Based Nano Sensors, Puspamitra Panigrahi, P. S. Anuroop, Hoonkyung Lee, Hyeonhu Bae, Thanayut Kaewmaraya, Ravindra Pandey, Tanveer Hussain, Akshaya Panigrahi

Michigan Tech Publications, Part 2

Efficient detection of selected persistent organic pollutants (POPs) is extremely important for the safety of humans and for the moderation of agriculture. This calls for the design of versatile nanosensors capable of sensing toxic POPs with high sensitivity and selectivity. Inspired by this, the sensing characteristics of carbon nitride (C3N5) monolayers toward selected POPs are reported, such as Dichlorodiphenyltrichloroethane (DDT), Methoxychlor (DMDT), Fenthion (FT), Fenitrothion (FNT), and Rennol (RL), employing density functional theory calculations. Analysis of results predicts adsorption energies of −0.93, −1.55, −1.44, −0.98, and −1.15 eV for DDT, DMDT, FT, FNT, and RM, respectively, on C3N5 monolayers. Significant …


Fast And Slow Microphysics Regimes In A Minimalist Model Of Cloudy Rayleigh-Bénard Convection, Raymond A. Shaw, Subin Thomas, Prasanth Prabhakaran, Will Cantrell, Mikhail Ovchinnikov, Fan Yang Oct 2023

Fast And Slow Microphysics Regimes In A Minimalist Model Of Cloudy Rayleigh-Bénard Convection, Raymond A. Shaw, Subin Thomas, Prasanth Prabhakaran, Will Cantrell, Mikhail Ovchinnikov, Fan Yang

Michigan Tech Publications, Part 2

A minimalist model of microphysical properties in cloudy Rayleigh-Bénard convection is developed based on mass and number balances for cloud droplets growing by vapor condensation. The model is relevant to a turbulent mixed-layer in which a steady forcing of supersaturation can be defined, e.g., a model of the cloudy boundary layer or a convection-cloud chamber. The model assumes steady injection of aerosol particles that are activated to form cloud droplets, and the removal of cloud droplets through sedimentation. Simplifying assumptions include the consideration of mean properties in steady state, neglect of coalescence growth, and no detailed representation of the droplet …


Augerprime Surface Detector Electronics, A. Abdul Halim, P. Abreu, M. Aglietta, P. Allison, I. Allekotte, K. Almeida Cheminant, B. Fick, K. Nguyen, D. Nitz, A. Puyleart, Et Al. Oct 2023

Augerprime Surface Detector Electronics, A. Abdul Halim, P. Abreu, M. Aglietta, P. Allison, I. Allekotte, K. Almeida Cheminant, B. Fick, K. Nguyen, D. Nitz, A. Puyleart, Et Al.

Michigan Tech Publications, Part 2

Operating since 2004, the Pierre Auger Observatory has led to major advances in our understanding of the ultra-high-energy cosmic rays. The latest findings have revealed new insights that led to the upgrade of the Observatory, with the primary goal of obtaining information on the primary mass of the most energetic cosmic rays on a shower-by-shower basis. In the framework of the upgrade, called AugerPrime, the 1660 water-Cherenkov detectors of the surface array are equipped with plastic scintillators and radio antennas, allowing us to enhance the composition sensitivity. To accommodate new detectors and to increase experimental capabilities, the electronics is also …


Hawc Study Of The Very-High-Energy Γ-Ray Spectrum Of Hawc J1844−034, A. Albert, C. Alvarez, D. Avila Rojas, H. A.Ayala Solares, R. Babu, E. Belmont-Moreno, S. Groetsch, D. Huang, P. Huntemeyer, R. Turner, X. Wang, Et Al. Sep 2023

Hawc Study Of The Very-High-Energy Γ-Ray Spectrum Of Hawc J1844−034, A. Albert, C. Alvarez, D. Avila Rojas, H. A.Ayala Solares, R. Babu, E. Belmont-Moreno, S. Groetsch, D. Huang, P. Huntemeyer, R. Turner, X. Wang, Et Al.

Michigan Tech Publications, Part 2

Recently, the region surrounding eHWC J1842−035 has been studied extensively by γ-ray observatories due to its extended emission reaching up to a few hundred TeV and potential as a hadronic accelerator. In this work, we use 1910 days of cumulative data from the High Altitude Water Cherenkov (HAWC) observatory to carry out a dedicated systematic source search of the eHWC J1842−035 region. During the search, we found three sources in the region, namely, HAWC J1844−034, HAWC J1843−032, and HAWC J1846−025. We have identified HAWC J1844−034 as the extended source that emits photons with energies up to 175 TeV. We compute …


A Search For Relativistic Ejecta In A Sample Of Ztf Broad-Lined Type Ic Supernovae, Alessandra Corsi, Anna Y.Q. Ho, S. Bradley Cenko, Shrinivas R. Kulkarni, Shreya Anand, Sheng Yang, Jesper Sollerman, Gokul P. Srinivasaragavan, Conor M.B. Omand, Arvind Balasubramanian, Dale A. Frail, Christoffer Fremling, Daniel A. Perley, Yuhan Yao, Aishwarya S. Dahiwale, Kishalay De, Alison Dugas, Matthew Hankins, Jacob Jencson, Mansi M. Kasliwal, Anastasios Tzanidakis, Eric C. Bellm, Russ R. Laher, Frank J. Masci, Josiah N. Purdum, Nicolas Regnault Aug 2023

A Search For Relativistic Ejecta In A Sample Of Ztf Broad-Lined Type Ic Supernovae, Alessandra Corsi, Anna Y.Q. Ho, S. Bradley Cenko, Shrinivas R. Kulkarni, Shreya Anand, Sheng Yang, Jesper Sollerman, Gokul P. Srinivasaragavan, Conor M.B. Omand, Arvind Balasubramanian, Dale A. Frail, Christoffer Fremling, Daniel A. Perley, Yuhan Yao, Aishwarya S. Dahiwale, Kishalay De, Alison Dugas, Matthew Hankins, Jacob Jencson, Mansi M. Kasliwal, Anastasios Tzanidakis, Eric C. Bellm, Russ R. Laher, Frank J. Masci, Josiah N. Purdum, Nicolas Regnault

Michigan Tech Publications, Part 2

The dividing line between gamma-ray bursts (GRBs) and ordinary stripped-envelope core-collapse supernovae (SNe) is yet to be fully understood. Observationally mapping the variety of ejecta outcomes (ultrarelativistic, mildly relativistic, or nonrelativistic) in SNe of Type Ic with broad lines (Ic - BL) can provide a key test to stellar explosion models. However, this requires large samples of the rare SN Ic - BL events with follow-up observations in the radio, where fast ejecta can be probed largely free of geometry and viewing angle effects. Here, we present the results of a radio (and X-ray) follow-up campaign of 16 SNe Ic …


Single-Mode Quasi Pt-Symmetric Laser With High Power Emission, Enes Şeker, Babak Olyaeefar, Khalil Dadashi, Serdar Şengül, Mohammad Hosain Teimourpour, Ramy El-Ganainy, Abdullah Demir Jun 2023

Single-Mode Quasi Pt-Symmetric Laser With High Power Emission, Enes Şeker, Babak Olyaeefar, Khalil Dadashi, Serdar Şengül, Mohammad Hosain Teimourpour, Ramy El-Ganainy, Abdullah Demir

Michigan Tech Publications

Large-area lasers are practical for generating high output powers. However, this often comes at the expense of lower beam quality due to the introduction of higher-order modes. Here, we experimentally demonstrate a new type of electrically pumped, large-area edge-emitting lasers that exhibit a high power emission (∼ 0.4 W) and a high-quality beam (M ∼ 1.25). These favorable operational characteristics are enabled by establishing a quasi PT-symmetry between the second-order mode of a large area two-mode laser cavity and that of a single-mode auxiliary partner cavity, i.e., by implementing a partial isospectrality between the two coupled cavities. This in turn …


Limits On Leptonic Tev Emission From The Cygnus Cocoon With Swift-Xrt, David Guevel, Andrew Beardmore, Kim L. Page, Amy Lien, Ke Fang, Luigi Tibaldo, Sabrina Casanova, Petra Huentemeyer Jun 2023

Limits On Leptonic Tev Emission From The Cygnus Cocoon With Swift-Xrt, David Guevel, Andrew Beardmore, Kim L. Page, Amy Lien, Ke Fang, Luigi Tibaldo, Sabrina Casanova, Petra Huentemeyer

Michigan Tech Publications

3-ray observations of the Cygnus Cocoon, an extended source surrounding the Cygnus X star-forming region, suggest the presence of a cosmic-ray accelerator reaching energies up to a few PeV. The very-high-energy (VHE, 0.1-100 TeV) 3-ray emission may be explained by the interaction of cosmic-ray hadrons with matter inside the Cocoon, but an origin of inverse Compton radiation by relativistic electrons cannot be ruled out. Inverse Compton 3-rays at VHE are accompanied by synchrotron radiation peaked in X-rays. Hence, X-ray observations may probe the electron population and magnetic field of the source. We observed 11 fields in or near the Cygnus …


Learning Neutrino Effects In Cosmology With Convolutional Neural Network, Elena Giusarma, Mauricio Reyes, Francisco Villaescusa-Navarro, Siyu He, Shirley Ho, Chang Hoon Hahn Jun 2023

Learning Neutrino Effects In Cosmology With Convolutional Neural Network, Elena Giusarma, Mauricio Reyes, Francisco Villaescusa-Navarro, Siyu He, Shirley Ho, Chang Hoon Hahn

Michigan Tech Publications

Measuring the sum of the three active neutrino masses, M ν , is one of the most important challenges in modern cosmology. Massive neutrinos imprint characteristic signatures on several cosmological observables, in particular, on the large-scale structure of the universe. In order to maximize the information that can be retrieved from galaxy surveys, accurate theoretical predictions in the nonlinear regime are needed. Currently, one way to achieve those predictions is by running cosmological numerical simulations. Unfortunately, producing those simulations requires high computational resources—several hundred to thousand core hours for each neutrino mass case. In this work, we propose a new …


Constraining The Sources Of Ultra-High-Energy Cosmic Rays Across And Above The Ankle With The Spectrum And Composition Data Measured At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, Et Al. May 2023

Constraining The Sources Of Ultra-High-Energy Cosmic Rays Across And Above The Ankle With The Spectrum And Composition Data Measured At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, Et Al.

Michigan Tech Publications

In this work we present the interpretation of the energy spectrum and mass composition data as measured by the Pierre Auger Collaboration above 6 × 1017 eV. We use an astrophysical model with two extragalactic source populations to model the hardening of the cosmic-ray flux at around 5 × 1018 eV (the so-called "ankle" feature) as a transition between these two components. We find our data to be well reproduced if sources above the ankle emit a mixed composition with a hard spectrum and a low rigidity cutoff. The component below the ankle is required to have a very soft …


Search For Photons Above 1019ev With The Surface Detector Of The Pierre Auger Observatory, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, J. Alvarez-Muñiz, B. Fick, D. Nitz, I. Norwood, A. Puyleart, Et Al. May 2023

Search For Photons Above 1019ev With The Surface Detector Of The Pierre Auger Observatory, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, J. Alvarez-Muñiz, B. Fick, D. Nitz, I. Norwood, A. Puyleart, Et Al.

Michigan Tech Publications

We use the surface detector of the Pierre Auger Observatory to search for air showers initiated by photons with an energy above 1019 eV. Photons in the zenith angle range from 30° to 60° can be identified in the overwhelming background of showers initiated by charged cosmic rays through the broader time structure of the signals induced in the water-Cherenkov detectors of the array and the steeper lateral distribution of shower particles reaching ground. Applying the search method to data collected between January 2004 and June 2020, upper limits at 95% CL are set to an E-2 diffuse flux of …


An Intercomparison Of Large-Eddy Simulations Of A Convection Cloud Chamber Using Haze-Capable Bin And Lagrangian Cloud Microphysics Schemes, Fan Yang, Fabian Hoffmann, Raymond Shaw, Mikhail Ovchinnikov, Andrew M. Vogelmann May 2023

An Intercomparison Of Large-Eddy Simulations Of A Convection Cloud Chamber Using Haze-Capable Bin And Lagrangian Cloud Microphysics Schemes, Fan Yang, Fabian Hoffmann, Raymond Shaw, Mikhail Ovchinnikov, Andrew M. Vogelmann

Michigan Tech Publications

Recent in situ observations show that haze particles exist in a convection cloud chamber. The microphysics schemes previously used for large-eddy simulations of the cloud chamber could not fully resolve haze particles and the associated processes, including their activation and deactivation. Specifically, cloud droplet activation was modeled based on Twomey-type parameterizations, wherein cloud droplets were formed when a critical supersaturation for the available cloud condensation nuclei (CCN) was exceeded and haze particles were not explicitly resolved. Here, we develop and adapt haze-capable bin and Lagrangian microphysics schemes to properly resolve the activation and deactivation processes. Results are compared with the …


Constraining The Sources Of Ultra-High-Energy Cosmic Rays Across And Above The Ankle With The Spectrum And Composition Data Measured At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, I. Norwood, A. Puyleart, Et. Al May 2023

Constraining The Sources Of Ultra-High-Energy Cosmic Rays Across And Above The Ankle With The Spectrum And Composition Data Measured At The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, I. Norwood, A. Puyleart, Et. Al

Michigan Tech Publications

In this work we present the interpretation of the energy spectrum and mass composition data as measured by the Pierre Auger Collaboration above 6 × 1017 eV. We use an astrophysical model with two extragalactic source populations to model the hardening of the cosmic-ray flux at around 5 × 1018 eV (the so-called "ankle"feature) as a transition between these two components. We find our data to be well reproduced if sources above the ankle emit a mixed composition with a hard spectrum and a low rigidity cutoff. The component below the ankle is required to have a very soft spectrum …


The Camels Project: Public Data Release, Francisco Villaescusa-Navarro, Shy Genel, Daniel Anglés-Alcázar, Lucia A. Perez, Pablo Villanueva-Domingo, Digvijay Wadekar, Helen Shao, Faizan G. Mohammad, Sultan Hassan, Emily Moser, Erwin T. Lau, Luis Fernando Machado Poletti Valle, Andrina Nicola, Leander Thiele, Yongseok Jo, Oliver H.E. Philcox, Benjamin D. Oppenheimer, Megan Tillman, Chang Hoon Hahn, Neerav Kaushal, Et Al. Apr 2023

The Camels Project: Public Data Release, Francisco Villaescusa-Navarro, Shy Genel, Daniel Anglés-Alcázar, Lucia A. Perez, Pablo Villanueva-Domingo, Digvijay Wadekar, Helen Shao, Faizan G. Mohammad, Sultan Hassan, Emily Moser, Erwin T. Lau, Luis Fernando Machado Poletti Valle, Andrina Nicola, Leander Thiele, Yongseok Jo, Oliver H.E. Philcox, Benjamin D. Oppenheimer, Megan Tillman, Chang Hoon Hahn, Neerav Kaushal, Et Al.

Michigan Tech Publications

The Cosmology and Astrophysics with Machine Learning Simulations (CAMELS) project was developed to combine cosmology with astrophysics through thousands of cosmological hydrodynamic simulations and machine learning. CAMELS contains 4233 cosmological simulations, 2049 N-body simulations, and 2184 state-of-the-art hydrodynamic simulations that sample a vast volume in parameter space. In this paper, we present the CAMELS public data release, describing the characteristics of the CAMELS simulations and a variety of data products generated from them, including halo, subhalo, galaxy, and void catalogs, power spectra, bispectra, Lyα spectra, probability distribution functions, halo radial profiles, and X-rays photon lists. We also release over 1000 …


Searching For Tev Dark Matter In Irregular Dwarf Galaxies With Hawc Observatory, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A.Ayala Solares, R. Babu, D. Huang, R. Turner, Et Al. Mar 2023

Searching For Tev Dark Matter In Irregular Dwarf Galaxies With Hawc Observatory, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A.Ayala Solares, R. Babu, D. Huang, R. Turner, Et Al.

Michigan Tech Publications

We present the results of dark matter (DM) searches in a sample of 31 dwarf irregular (dIrr) galaxies within the field of view of the HAWC Observatory. dIrr galaxies are DM-dominated objects in which astrophysical gamma-ray emission is estimated to be negligible with respect to the secondary gamma-ray flux expected by annihilation or decay of weakly interacting massive particles (WIMPs). While we do not see any statistically significant DM signal in dIrr galaxies, we present the exclusion limits (95% C.L.) for annihilation cross section and decay lifetime for WIMP candidates with masses between 1 and 100 TeV. Exclusion limits from …


Insights Into Receptor Structure And Dynamics At The Surface Of Living Cells, Frederik Steiert, Peter Schultz, Siegfried Höfinger, Thomas D. Müller, Petra Schwille, Thomas Weidemann Mar 2023

Insights Into Receptor Structure And Dynamics At The Surface Of Living Cells, Frederik Steiert, Peter Schultz, Siegfried Höfinger, Thomas D. Müller, Petra Schwille, Thomas Weidemann

Michigan Tech Publications

Evaluating protein structures in living cells remains a challenge. Here, we investigate Interleukin-4 receptor alpha (IL-4Rα) into which the non-canonical amino acid bicyclo[6.1.0]nonyne-lysine (BCNK) is incorporated by genetic code expansion. Bioorthogonal click labeling is performed with tetrazine-conjugated dyes. To quantify the reaction yield in situ, we develop brightness-calibrated ratiometric imaging, a protocol where fluorescent signals in confocal multi-color images are ascribed to local concentrations. Screening receptor mutants bearing BCNK in the extracellular domain uncovered site-specific variations of both click efficiency and Interleukin-4 binding affinity, indicating subtle well-defined structural perturbations. Molecular dynamics and continuum electrostatics calculations suggest solvent polarization to determine …


Electronic Structure Calculations Of Static Hyper(Polarizabilities) Of Substrate-Supported Group-Iv And -V Elemental Monolayers, Sumandeep Kaur, Ravindra Pandey, Shashi P. Karna Feb 2023

Electronic Structure Calculations Of Static Hyper(Polarizabilities) Of Substrate-Supported Group-Iv And -V Elemental Monolayers, Sumandeep Kaur, Ravindra Pandey, Shashi P. Karna

Michigan Tech Publications

The substrate-induced effects on the polarizability (α) and first dipole hyperpolarizability (β) of group-IV (i.e., graphene, silicene, germanene, stanene) and group-V (i.e., phosphorene, arsenene, antimonene, and bismuthene) elemental monolayer nanoflakes are investigated. Density functional theory calculations show that these monolayers are bound with varying degrees of interaction strength with the Ag(111) substrate surface. Calculated dipole moment and β values are zero for the centrosymmetric configurations of the pristine elemental monolayers. On the other hand, substrate-induced changes in the electronic densities at the interface lead to substantially enhanced values of β, making these materials attractive for applications in the next-generation photonic …


Spectral Sensitivity Near Exceptional Points As A Resource For Hardware Encryption, Minye Yang, Liang Zhu, Qi Zhong, Ramy El-Ganainy, Pai Yen Chen Feb 2023

Spectral Sensitivity Near Exceptional Points As A Resource For Hardware Encryption, Minye Yang, Liang Zhu, Qi Zhong, Ramy El-Ganainy, Pai Yen Chen

Michigan Tech Publications

The spectral sensitivity near exceptional points (EPs) has been recently explored as an avenue for building sensors with enhanced sensitivity. However, to date, it is not clear whether this class of sensors does indeed outperform traditional sensors in terms of signal-to-noise ratio. In this work, we investigate the spectral sensitivity associated with EPs under a different lens and propose to utilize it as a resource for hardware security. In particular, we introduce a physically unclonable function (PUF) based on analogue electronic circuits that benefit from the drastic eigenvalues bifurcation near a divergent exceptional point to enhance the stochastic entropy caused …


Hawc Detection Of A Tev Halo Candidate Surrounding A Radio-Quiet Pulsar, A. Albert, R. Alfaro, J. C. Arteaga-Velázquez, H. A. Ayala Solares, E. Belmont-Moreno, T. Capistrán, A. Carramiñana, S. Casanova, J. Cotzomi, S. Coutiño De León, E. De La Fuente, C. De León, R. Diaz Hernandez, M. A. Duvernois, J. C. Díaz-Vélez, C. Espinoza, K. L. Fan, N. Fraija, K. Fang, J. A. García-González, F. Garfias, A. Jardin-Blicq, M. M. González, J. A. Goodman, J. P. Harding, S. Hernandez, D. Huang, F. Hueyotl-Zahuantitla, P. Hüntemeyer, A. Iriarte, V. Joshi, Et. Al. Feb 2023

Hawc Detection Of A Tev Halo Candidate Surrounding A Radio-Quiet Pulsar, A. Albert, R. Alfaro, J. C. Arteaga-Velázquez, H. A. Ayala Solares, E. Belmont-Moreno, T. Capistrán, A. Carramiñana, S. Casanova, J. Cotzomi, S. Coutiño De León, E. De La Fuente, C. De León, R. Diaz Hernandez, M. A. Duvernois, J. C. Díaz-Vélez, C. Espinoza, K. L. Fan, N. Fraija, K. Fang, J. A. García-González, F. Garfias, A. Jardin-Blicq, M. M. González, J. A. Goodman, J. P. Harding, S. Hernandez, D. Huang, F. Hueyotl-Zahuantitla, P. Hüntemeyer, A. Iriarte, V. Joshi, Et. Al.

Michigan Tech Publications

Extended very-high-energy (VHE; 0.1-100 TeV) γ-ray emission has been observed around several middle-aged pulsars and referred to as “TeV halos.” Their formation mechanism remains under debate. It is also unknown whether they are ubiquitous or related to a certain subgroup of pulsars. With 2321 days of observation, the High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory detected VHE γ-ray emission at the location of the radio-quiet pulsar PSR J0359+5414 with >6σ significance. By performing likelihood tests with different spectral and spatial models and comparing the TeV spectrum with multiwavelength observations of nearby sources, we show that this excess is consistent with …


Scaling Of Turbulence And Microphysics In A Convection–Cloud Chamber Of Varying Height, Subin Thomas, Fan Yang, Mikhail Ovchinnikov, Will Cantrell, Raymond Shaw Feb 2023

Scaling Of Turbulence And Microphysics In A Convection–Cloud Chamber Of Varying Height, Subin Thomas, Fan Yang, Mikhail Ovchinnikov, Will Cantrell, Raymond Shaw

Michigan Tech Publications

The convection–cloud chamber enables measurement of aerosol and cloud microphysics, as well as their interactions, within a turbulent environment under steady-state conditions. Increasing the size of a convection–cloud chamber, while holding the imposed temperature difference constant, leads to increased Rayleigh, Reynolds and Nusselt numbers. Large–eddy simulation coupled with a bin microphysics model allows the influence of increased velocity, time, and spatial scales on cloud microphysical properties to be explored. Simulations of a convection–cloud chamber, with fixed aspect ratio and increasing heights of H = 1, 2, 4, and (for dry conditions only) 8 m are performed. The key findings are: …


A Catalog Of The Highest-Energy Cosmic Rays Recorded During Phase I Of Operation Of The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, P. Allison, K. Almeida Cheminant, J. Chirinos, B. Fick, D. Nitz, I. Norwood, A. Puyleart, Et Al. Feb 2023

A Catalog Of The Highest-Energy Cosmic Rays Recorded During Phase I Of Operation Of The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, P. Allison, K. Almeida Cheminant, J. Chirinos, B. Fick, D. Nitz, I. Norwood, A. Puyleart, Et Al.

Michigan Tech Publications

A catalog containing details of the highest-energy cosmic rays recorded through the detection of extensive air showers at the Pierre Auger Observatory is presented with the aim of opening the data to detailed examination. Descriptions of the 100 showers created by the highest-energy particles recorded between 2004 January 1 and 2020 December 31 are given for cosmic rays that have energies in the range 78-166 EeV. Details are also given on a further nine very energetic events that have been used in the calibration procedure adopted to determine the energy of each primary. A sky plot of the arrival directions …