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Articles 31 - 60 of 224
Full-Text Articles in Physics
The Phangs-Jwst Treasury Survey: Star Formation, Feedback, And Dust Physics At High Angular Resolution In Nearby Galaxies, Janice C. Lee, Karin M. Sandstrom, Adam K. Leroy, David A. Thilker, Eva Schinnerer, Erik Rosolowsky, Judy Schmidt, Et Al.
The Phangs-Jwst Treasury Survey: Star Formation, Feedback, And Dust Physics At High Angular Resolution In Nearby Galaxies, Janice C. Lee, Karin M. Sandstrom, Adam K. Leroy, David A. Thilker, Eva Schinnerer, Erik Rosolowsky, Judy Schmidt, Et Al.
Michigan Tech Publications
The PHANGS collaboration has been building a reference data set for the multiscale, multiphase study of star formation and the interstellar medium (ISM) in nearby galaxies. With the successful launch and commissioning of JWST, we can now obtain high-resolution infrared imaging to probe the youngest stellar populations and dust emission on the scales of star clusters and molecular clouds (∼5-50 pc). In Cycle 1, PHANGS is conducting an eight-band imaging survey from 2 to 21 μm of 19 nearby spiral galaxies. Optical integral field spectroscopy, CO(2-1) mapping, and UV-optical imaging for all 19 galaxies have been obtained through large programs …
Detailed Analysis Of The Tev Γ-Ray Sources 3hwc J1928+178, 3hwc J1930+188, And The New Source Hawc J1932+192, A. Albert, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A.Ayala Solares, R. Babu, D. Huang, P. Hüntemeyer, R. Turner, X. Wang, Et Al.
Detailed Analysis Of The Tev Γ-Ray Sources 3hwc J1928+178, 3hwc J1930+188, And The New Source Hawc J1932+192, A. Albert, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A.Ayala Solares, R. Babu, D. Huang, P. Hüntemeyer, R. Turner, X. Wang, Et Al.
Michigan Tech Publications
The latest High Altitude Water Cherenkov (HAWC) point-like source catalog up to 56 TeV reported the detection of two sources in the region of the Galactic plane at galactic longitude 52° < ℓ < 55°, 3HWC J1930+188 and 3HWC J1928+178. The first one is associated with a known TeV source, the supernova remnant SNR G054.1+00.3. It was discovered by one of the currently operating Imaging Atmospheric Cherenkov Telescope (IACT), the Very Energetic Radiation Imaging Telescope Array System (VERITAS), detected by the High Energy Stereoscopic System (H.E.S.S), and identified as a composite SNR. However, the source 3HWC J1928+178, discovered by HAWC and coincident with the pulsar PSR J1928+1746, was not detected by any IACT despite their long exposure on the region, until a recent new analysis of H.E.S.S. data was able to confirm it. Moreover, no X-ray counterpart has been detected from this pulsar. We present a multicomponent fit of this region using the latest HAWC data. This reveals an additional new source, HAWC J1932+192, which is potentially associated with the pulsar PSR J1932+1916, whose γ-ray emission could come from the acceleration of particles in its pulsar wind nebula. In the case of 3HWC J1928+178, several possible explanations are explored, in an attempt to unveil the origins of the very-high-energy γ-ray emission.
Novel Compact Magnetless Isolator Based On A Magneto-Optical Garnet Material, Gianni Portela, Miguel Levy, Hugo E. Hernandez-Figueroa
Novel Compact Magnetless Isolator Based On A Magneto-Optical Garnet Material, Gianni Portela, Miguel Levy, Hugo E. Hernandez-Figueroa
Michigan Tech Publications
A compact magnetless isolator for optical communication systems based on a ring resonator with an outer layer made of silicon and an inner layer made of a magneto-optical material that does not require an external magnet to keep its magnetization saturated is suggested. Three-dimensional computational simulations of the device performed with the full-wave electromagnetic solver COMSOL Multiphysics show that the insertion loss and isolation levels are about −1.9 dB and −23 dB, respectively, thus confirming the feasibility of the isolator. An analytical model of the device based on the temporal coupled-mode theory method has been formulated and there is a …
Direct Parameter Fitting Of Action Potentials In Skeletal Muscle Cells Which Include Longitudinal Segments, Tyme Suda
Browse all Theses and Dissertations
Excitation of skeletal muscle cells triggers a large voltage spike known as an action potential (AP), leading to muscle contraction. Modeling of an AP is typically done using the method developed by scientists Hodgkin and Huxley (HH). In the HH method, voltage and time gated Na+ and K+ ionic currents are simulated, along with a positive “Leak” ionic current and capacitive current. Due to the complexity and the computational time required for simulation, direct fitting of HH parameters to experimental APs has rarely been attempted. A previous thesis at Wright State performed direct fitting for the case of a single …
Γ-Ray Emission From Classical Nova V392 Per: Measurements From Fermi And Hawc, A. Albert, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A.Ayala Solares, R. Babu, E. Belmont-Moreno, C. Blochwitz, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, S. Casanova, O. Chaparro-Amaro, U. Cotti, J. Cotzomi, E. De La Fuente, C. De León, S. Coutiño De León, R. Diaz Hernandez, B. L. Dingus, M. A. Duvernois, M. Durocher, J. C. Díaz-Vélez, K. Engel, C. Espinoza, K. L. Fan, K. Fang, N. Fraija, J. A. García-González, F. Garfias
Γ-Ray Emission From Classical Nova V392 Per: Measurements From Fermi And Hawc, A. Albert, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A.Ayala Solares, R. Babu, E. Belmont-Moreno, C. Blochwitz, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, S. Casanova, O. Chaparro-Amaro, U. Cotti, J. Cotzomi, E. De La Fuente, C. De León, S. Coutiño De León, R. Diaz Hernandez, B. L. Dingus, M. A. Duvernois, M. Durocher, J. C. Díaz-Vélez, K. Engel, C. Espinoza, K. L. Fan, K. Fang, N. Fraija, J. A. García-González, F. Garfias
Michigan Tech Publications
This paper reports on the γ-ray properties of the 2018 Galactic nova V392 Per, spanning photon energies ∼0.1 GeV-100 TeV by combining observations from the Fermi Gamma-ray Space Telescope and the HAWC Observatory. As one of the most rapidly evolving γ-ray signals yet observed for a nova, GeV γ-rays with a power-law spectrum with an index Γ = 2.0 ± 0.1 were detected over 8 days following V392 Per’s optical maximum. HAWC observations constrain the TeV γ-ray signal during this time and also before and after. We observe no statistically significant evidence of TeV γ-ray emission from V392 Per, but …
Misfit-Generated Structural And Optical Anisotropies Of The Natural Mos2-Pbs Van Der Waals Heterostructure Merelaniite, Luca Bindi, Arindam Dasgupta, Pinaki Mukherjee, Jie Gao, Xiaodong Yang, John Jaszczak
Misfit-Generated Structural And Optical Anisotropies Of The Natural Mos2-Pbs Van Der Waals Heterostructure Merelaniite, Luca Bindi, Arindam Dasgupta, Pinaki Mukherjee, Jie Gao, Xiaodong Yang, John Jaszczak
Michigan Tech Publications
Significant efforts developing MoS2-PbS-based heterostructure devices with several different architectures show promise for photosensor, solar cell, and chemical sensor applications. Merelaniite (Mo4Pb4VSbS15) is a newly discovered natural van der Waals heterostructure of the cylindrite type, composed predominantly of heavily modulated pseudotetragonal PbS layers and pseudohexagonal MoS2 layers with large misfit-induced anisotropy. For an incommensurate modulated structure, the refined structural model from single-crystal x-ray diffraction analysis is in reasonable agreement with the results obtained by high-resolution scanning transmission electron microscopy, especially in light of the fact that that the two isolated single-crystal domains used for the x-ray and electron diffraction experiments …
Searches For Ultra-High-Energy Photons At The Pierre Auger Observatory, The Pierre Auger Collaboration, B. Fick, D. Nitz, I. Norwood, A. Puyleart, Et Al.
Searches For Ultra-High-Energy Photons At The Pierre Auger Observatory, The Pierre Auger Collaboration, B. Fick, D. Nitz, I. Norwood, A. Puyleart, Et Al.
Michigan Tech Publications
No abstract provided.
Nonuniversality Of Quantum Noise In Optical Amplifiers Operating At Exceptional Points, L. Simonson, S. K. Ozdemir, A. Eisfeld, A. Metelmann, R. El-Ganainy
Nonuniversality Of Quantum Noise In Optical Amplifiers Operating At Exceptional Points, L. Simonson, S. K. Ozdemir, A. Eisfeld, A. Metelmann, R. El-Ganainy
Michigan Tech Publications
The concept of exceptional points-based optical amplifiers (EPOAs) has been recently proposed as a new paradigm for miniaturizing optical amplifiers while simultaneously enhancing their gain-bandwidth product. While the operation of this new family of amplifiers in the classical domain provides a clear advantage, their performance in the quantum domain has not yet been evaluated. Particularly, it is not clear how the quantum noise introduced by vacuum fluctuations will affect their operation. Here, we investigate this problem by considering three archetypal EPOA structures that rely either on unidirectional coupling, parity-time symmetry, or particle-hole symmetry for implementing the exceptional point. By using …
Structural And Compositional Properties Of 2d Ch3nh3pbi3 Hybrid Halide Perovskite: A Dft Study, Sandip R. Kumavat, Geeta Sachdeva, Yogesh Sonvane, Sanjeev K. Gupta
Structural And Compositional Properties Of 2d Ch3nh3pbi3 Hybrid Halide Perovskite: A Dft Study, Sandip R. Kumavat, Geeta Sachdeva, Yogesh Sonvane, Sanjeev K. Gupta
Michigan Tech Publications
Two-dimensional (2D) hybrid halide perovskites have been scrutinized as candidate materials for solar cells because of their tunable structural and compositional properties. Results based on density functional theory demonstrate its thickness-dependent stability. We have observed that the bandgap decreases from the mono- to quad-layer because of the transformation from 2D towards 3D. Due to the transformation, the carrier mobility is lowered with the corresponding smaller effective mass. On the other hand, the multilayer structures have good optical properties with an absorption coefficient of about 105 cm−1. The calculated absorption spectra lie between 248 nm and 496 nm, leading to optical …
Constraints On The Very High Energy Gamma-Ray Emission From Short Grbs With Hawc, A. Albert, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, K. P. Arunbabu, D. Avila Rojas, H. A.Ayala Solares, R. Babu, E. Belmont-Moreno, C. Brisbois, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, S. Casanova, O. Chaparro-Amaro, U. Cotti, J. Cotzomi, S. Coutiño De León, C. De León, E. De La Fuente, R. Diaz Hernandez, S. Dichiara, B. L. Dingus, M. A. Duvernois, M. Durocher, J. C. Díaz-Vélez, K. Engel, C. Espinoza, K. L. Fan, N. Fraija, A. Galván-Gámez
Constraints On The Very High Energy Gamma-Ray Emission From Short Grbs With Hawc, A. Albert, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, K. P. Arunbabu, D. Avila Rojas, H. A.Ayala Solares, R. Babu, E. Belmont-Moreno, C. Brisbois, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, S. Casanova, O. Chaparro-Amaro, U. Cotti, J. Cotzomi, S. Coutiño De León, C. De León, E. De La Fuente, R. Diaz Hernandez, S. Dichiara, B. L. Dingus, M. A. Duvernois, M. Durocher, J. C. Díaz-Vélez, K. Engel, C. Espinoza, K. L. Fan, N. Fraija, A. Galván-Gámez
Michigan Tech Publications
Many gamma-ray bursts (GRBs) have been observed from radio wavelengths, and a few at very high energies (VHEs, >100 GeV). The High Altitude Water Cherenkov (HAWC) gamma-ray observatory is well suited to study transient phenomena at VHEs owing to its large field of view and duty cycle. These features allow for searches of VHE emission and can probe different model assumptions of duration and spectra. In this paper, we use data collected by HAWC between 2014 December and 2020 May to search for emission in the energy range from 80 to 800 GeV coming from a sample of 47 short …
A Novel Rid Algorithm Of Muon Trajectory Reconstruction In Water Cherenkov Detectors, Neerav Kaushal
A Novel Rid Algorithm Of Muon Trajectory Reconstruction In Water Cherenkov Detectors, Neerav Kaushal
Michigan Tech Publications
Cosmic rays that strike the top of the Earth’s atmosphere generate a shower of secondary particles that move toward the surface with relativistic speeds. Water Cherenkov detectors (WCDs) on the ground can detect charged muons, which are one of the many particles generated in the shower, with the Cherenkov imaging technique. A large number of these muons travel in WCD tanks near the speed of light in a vacuum, faster than the speed of light in water, and so trigger isotropic Cherenkov radiation, which is detected by the photomultiplier tubes (PMTs) placed inside the tanks. When the radial component of …
Arrival Directions Of Cosmic Rays Above 32 Eev From Phase One Of The Pierre Auger Observatory, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, I. Norwood, A. Puyleart, Et. Al.
Arrival Directions Of Cosmic Rays Above 32 Eev From Phase One Of The Pierre Auger Observatory, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, I. Norwood, A. Puyleart, Et. Al.
Michigan Tech Publications
A promising energy range to look for angular correlations between cosmic rays of extragalactic origin and their sources is at the highest energies, above a few tens of EeV (1 EeV 1018 eV). Despite the flux of these particles being extremely low, the area of ∼3000 km2 covered at the Pierre Auger Observatory, and the 17 yr data-taking period of the Phase 1 of its operations, have enabled us to measure the arrival directions of more than 2600 ultra-high-energy cosmic rays above 32 EeV. We publish this data set, the largest available at such energies from an integrated exposure of …
The Missing Link Between Standing-And Traveling-Wave Resonators, Qi Zhong, Haoqi Zhao, Liang Feng, Kurt Busch, Sahin K. Özdemir, Ramy El-Ganainy
The Missing Link Between Standing-And Traveling-Wave Resonators, Qi Zhong, Haoqi Zhao, Liang Feng, Kurt Busch, Sahin K. Özdemir, Ramy El-Ganainy
Michigan Tech Publications
Optical resonators are structures that utilize wave interference and feedback to confine light in all three dimensions. Depending on the feedback mechanism, resonators can support either standing-or traveling-wave modes. Over the years, the distinction between these two different types of modes has become so prevalent that nowadays it is one of the main characteristics for classifying optical resonators. Here, we show that an intermediate link between these two rather different groups exists. In particular, we introduce a new class of photonic resonators that supports a hybrid optical mode, i.e. at one location along the resonator the electromagnetic fields associated with …
Study Of The Very High Energy Emission Of M87 Through Its Broadband Spectral Energy Distribution, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A. Ayala Solares, E. Belmont-Moreno, D. Huang, P. Huntemeyer, Et. Al.
Study Of The Very High Energy Emission Of M87 Through Its Broadband Spectral Energy Distribution, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A. Ayala Solares, E. Belmont-Moreno, D. Huang, P. Huntemeyer, Et. Al.
Michigan Tech Publications
The radio galaxy M87 is the central dominant galaxy of the Virgo Cluster. Very high-energy (VHE, ≳0.1 TeV) emission from M87 has been detected by imaging air Cherenkov telescopes. Recently, marginal evidence for VHE long-term emission has also been observed by the High Altitude Water Cherenkov Observatory, a gamma-ray and cosmic-ray detector array located in Puebla, Mexico. The mechanism that produces VHE emission in M87 remains unclear. This emission originates in its prominent jet, which has been spatially resolved from radio to X-rays. In this paper, we construct a spectral energy distribution from radio to gamma rays that is representative …
Search For Spatial Correlations Of Neutrinos With Ultra-High-Energy Cosmic Rays, A. Albert, S. Alves, M. André, M. Anghinolfi, S. Ardid, J. J. Aubert, B. Fick, D. Nitz, A. Puyleart, Et. Al.
Search For Spatial Correlations Of Neutrinos With Ultra-High-Energy Cosmic Rays, A. Albert, S. Alves, M. André, M. Anghinolfi, S. Ardid, J. J. Aubert, B. Fick, D. Nitz, A. Puyleart, Et. Al.
Michigan Tech Publications
For several decades, the origin of ultra-high-energy cosmic rays (UHECRs) has been an unsolved question of high-energy astrophysics. One approach for solving this puzzle is to correlate UHECRs with high-energy neutrinos, since neutrinos are a direct probe of hadronic interactions of cosmic rays and are not deflected by magnetic fields. In this paper, we present three different approaches for correlating the arrival directions of neutrinos with the arrival directions of UHECRs. The neutrino data are provided by the IceCube Neutrino Observatory and ANTARES, while the UHECR data with energies above ∼50 EeV are provided by the Pierre Auger Observatory and …
A Simple Parameterization To Enhance The Computational Time In The Three Layer Dry Deposition Model For Smooth Surfaces, Omar M.M. Nofal, Omar Al-Jaghbeer, Zaid Bakri, Tareq Hussein
A Simple Parameterization To Enhance The Computational Time In The Three Layer Dry Deposition Model For Smooth Surfaces, Omar M.M. Nofal, Omar Al-Jaghbeer, Zaid Bakri, Tareq Hussein
Michigan Tech Publications
Optimization of dry deposition velocity calculation has been of great interest. Every time, determining the value of the concentration boundary layer (CBL) thickness led to a waste of numerical calculation time, which appears as a huge time in large-scale climate models. The goal of this study is to optimize the numerical calculation time in the three-layer deposition model for smooth surfaces through the development of a MATLAB code that can parameterize the appropriate concentration boundary layer height (y+cbl) and internal integral calculation intervals for each particle diameter Dp (0.01–100 µm) and friction velocity u* (0.01–100 m/s). The particle concentration, as …
Probing The Extragalactic Mid-Infrared Background With Hawc, A. Albert, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A.Ayala Solares, R. Babu, Et. Al.
Probing The Extragalactic Mid-Infrared Background With Hawc, A. Albert, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A.Ayala Solares, R. Babu, Et. Al.
Michigan Tech Publications
The extragalactic background light (EBL) contains all the radiation emitted by nuclear and accretion processes in stars and compact objects since the epoch of recombination. Measuring the EBL density directly is challenging, especially in the near-to-far-infrared wave band, mainly due to the zodiacal light foreground. Instead, gamma-ray astronomy offers the possibility to indirectly set limits on the EBL by studying the effects of gamma-ray absorption in the very high energy (VHE: >100 GeV) spectra of distant blazars. The High Altitude Water Cherenkov Gamma Ray Observatory (HAWC) is one of the few instruments sensitive to gamma rays with energies above 10 …
A Search For Photons With Energies Above 2 × 10 17 Ev Using Hybrid Data From The Low-Energy Extensions Of The Pierre Auger Observatory, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, I. Norwood, A. Puyleart, Et. Al.
A Search For Photons With Energies Above 2 × 10 17 Ev Using Hybrid Data From The Low-Energy Extensions Of The Pierre Auger Observatory, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, I. Norwood, A. Puyleart, Et. Al.
Michigan Tech Publications
Ultra-high-energy photons with energies exceeding 1017 eV offer a wealth of connections to different aspects of cosmic-ray astrophysics as well as to gamma-ray and neutrino astronomy. The recent observations of photons with energies in the 1015 eV range further motivate searches for even higher-energy photons. In this paper, we present a search for photons with energies exceeding 2 × 1017 eV using about 5.5 yr of hybrid data from the low-energy extensions of the Pierre Auger Observatory. The upper limits on the integral photon flux derived here are the most stringent ones to date in the energy region between 1017 …
Black Carbon Aerosol Number And Mass Concentration Measurements By Picosecond Short-Range Elastic Backscatter Lidar, Romain Ceolato, Andrés E. Bedoya-Velásquez, Frédéric Fossard, Vincent Mouysset, Lucas Paulien, Sidonie Lefebvre, Claudio Mazzoleni, Christopher Sorensen, Matthew J. Berg, Jérôme Yon
Black Carbon Aerosol Number And Mass Concentration Measurements By Picosecond Short-Range Elastic Backscatter Lidar, Romain Ceolato, Andrés E. Bedoya-Velásquez, Frédéric Fossard, Vincent Mouysset, Lucas Paulien, Sidonie Lefebvre, Claudio Mazzoleni, Christopher Sorensen, Matthew J. Berg, Jérôme Yon
Michigan Tech Publications
Black carbon aerosol emissions are recognized as contributors to global warming and air pollution. There remains, however, a lack of techniques to remotely measure black carbon aerosol particles with high range and time resolution. This article presents a direct and contact-free remote technique to estimate the black carbon aerosol number and mass concentration at a few meters from the emission source. This is done using the Colibri instrument based on a novel technique, referred to here as Picosecond Short-Range Elastic Backscatter Lidar (PSR-EBL). To address the complexity of retrieving lidar products at short measurement ranges, we apply a forward inversion …
Large-Eddy Simulations Of A Convection Cloud Chamber: Sensitivity To Bin Microphysics And Advection, Fan Yang, Mikhail Ovchinnikov, Subin Thomas, Alexander Khain, Robert Mcgraw, Raymond Shaw, Andrew M. Vogelmann
Large-Eddy Simulations Of A Convection Cloud Chamber: Sensitivity To Bin Microphysics And Advection, Fan Yang, Mikhail Ovchinnikov, Subin Thomas, Alexander Khain, Robert Mcgraw, Raymond Shaw, Andrew M. Vogelmann
Michigan Tech Publications
Bin microphysics schemes are useful tools for cloud simulations and are often considered to provide a benchmark for model intercomparison. However, they may experience issues with numerical diffusion, which are not well quantified, and the transport of hydrometeors depends on the choice of advection scheme, which can also change cloud simulation results. Here, an atmospheric large-eddy simulation model is adapted to simulate a statistically steady-state cloud in a convection cloud chamber under well-constrained conditions. Two bin microphysics schemes, a spectral bin method and the method of moments, as well as several advection methods for the transport of the microphysical variables …
Long-Term Spectra Of The Blazars Mrk 421 And Mrk 501 At Tev Energies Seen By Hawc, A. Albert, R. Alfaro, C. Alvarez, J. R.Angeles Camacho, J. C. Arteaga-Velázquez, K. P. Arunbabu, D. Huang, P. Huntemeyer, X. Wang, Et. Al.
Long-Term Spectra Of The Blazars Mrk 421 And Mrk 501 At Tev Energies Seen By Hawc, A. Albert, R. Alfaro, C. Alvarez, J. R.Angeles Camacho, J. C. Arteaga-Velázquez, K. P. Arunbabu, D. Huang, P. Huntemeyer, X. Wang, Et. Al.
Michigan Tech Publications
The High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory surveys the very high-energy sky in the 300 GeV to >100 TeV energy range. HAWC has detected two blazars above 11σ, Markarian 421 (Mrk 421) and Markarian 501 (Mrk 501). The observations are comprised of data taken in the period between 2015 June and 2018 July, resulting in ∼1038 days of exposure. In this work, we report the time-averaged spectral analyses for both sources, above 0.5 TeV. Taking into account the flux attenuation due to the extragalactic background light, the intrinsic spectrum of Mrk 421 is described by a power law with …
Hawc Study Of The Ultra-High-Energy Spectrum Of Mgro J1908+06, A. Albert, R. Alfaro, C. Alvarez, J. D. Álvarez, J. R.Angeles Camacho, J. C. Arteaga-Velázquez, R. Babu, D. Huang, P. Hüntemeyer, R. Turner, X. Wang, Et. Al.
Hawc Study Of The Ultra-High-Energy Spectrum Of Mgro J1908+06, A. Albert, R. Alfaro, C. Alvarez, J. D. Álvarez, J. R.Angeles Camacho, J. C. Arteaga-Velázquez, R. Babu, D. Huang, P. Hüntemeyer, R. Turner, X. Wang, Et. Al.
Michigan Tech Publications
We report TeV gamma-ray observations of the ultra-high-energy source MGRO J1908+06 using data from the High Altitude Water Cherenkov Observatory. This source is one of the highest-energy known gamma-ray sources, with emission extending past 200 TeV. Modeling suggests that the bulk of the TeV gamma-ray emission is leptonic in nature, driven by the energetic radio-faint pulsar PSR J1907+0602. Depending on what assumptions are included in the model, a hadronic component may also be allowed. Using the results of the modeling, we discuss implications for detection prospects by multi-messenger campaigns.
Light Curve Test Of Grb 200716c As A Gravitationally Lensed Echo, Oindabi Mukherjee, Robert J. Nemiroff
Light Curve Test Of Grb 200716c As A Gravitationally Lensed Echo, Oindabi Mukherjee, Robert J. Nemiroff
Michigan Tech Publications
A gravitational lens can imprint distinct features on the light curve of a gamma-ray burst (GRB). Most prominently, when creating multiple images, the light curves for all images should be identical, within a scale factor in amplitude. For GRB images that are bright enough to have significant counts in multiple time bins, the similarity of the light curves can be assessed with a straightforward χ2 test. In response to a recent claim that the two pulses in GRB 200716C are lensed images of the same pulse, such a χ2 test was computed. The test indicated that the likelihood …
Light Curve Test Of Grb 200716c As A Gravitationally Lensed Echo, Oindabi Mukherjee, Robert J. Nemiroff
Light Curve Test Of Grb 200716c As A Gravitationally Lensed Echo, Oindabi Mukherjee, Robert J. Nemiroff
Michigan Tech Publications
A gravitational lens can imprint distinct features on the light curve of a gamma-ray burst (GRB). Most prominently, when creating multiple images, the light curves for all images should be identical, within a scale factor in amplitude. For GRB images that are bright enough to have significant counts in multiple time bins, the similarity of the light curves can be assessed with a straightforward χ2 test. In response to a recent claim that the two pulses in GRB 200716C are lensed images of the same pulse, such a χ2 test was computed. The test indicated that the likelihood …
Organic And Elemental Carbon In The Urban Background In An Eastern Mediterranean City, Tareq Hussein, Xinyang Li, Zaid Bakri, Andres Alastuey, Sharif Arar, Afnan Al-Hunaiti, Mar Viana, Tuukka Petäjä
Organic And Elemental Carbon In The Urban Background In An Eastern Mediterranean City, Tareq Hussein, Xinyang Li, Zaid Bakri, Andres Alastuey, Sharif Arar, Afnan Al-Hunaiti, Mar Viana, Tuukka Petäjä
Michigan Tech Publications
The Mediterranean region is an important area for air pollution as it is the crossroads between three continents; therefore, the concentrations of atmospheric aerosol particles are influenced by emissions from Africa, Asia, and Europe. Here we concentrate on an eleven-month time series of the ambient concentration of organic carbon (OC) and elemental carbon (EC) between May 2018– March 2019 in Amman, Jordan. Such a dataset is unique in Jordan. The results show that the OC and EC annual mean concentrations in PM2.5 samples were 5.9 ± 2.8 µg m–3 and 1.7 ± 1.1 µg m–3, respectively. It was found that …
Testing Effects Of Lorentz Invariance Violation In The Propagation Of Astroparticles With The Pierre Auger Observatory, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, A. Puyleart, Et. Al.
Testing Effects Of Lorentz Invariance Violation In The Propagation Of Astroparticles With The Pierre Auger Observatory, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, D. Nitz, A. Puyleart, Et. Al.
Michigan Tech Publications
Lorentz invariance violation (LIV) is often described by dispersion relations of the form E i2 = m i2+p i2+δi,n E 2+n with delta different based on particle type i, with energy E, momentum p and rest mass m. Kinematics and energy thresholds of interactions are modified once the LIV terms become comparable to the squared masses of the particles involved. Thus, the strongest constraints on the LIV coefficients δi,n tend to come from the highest energies. At sufficiently high energies, photons produced by cosmic ray interactions as they propagate through the Universe could be subluminal and unattenuated over cosmological distances. …
Using Network Analysis To Contrast Three Models Of Student Forum Discussions, Hannah N. Benston
Using Network Analysis To Contrast Three Models Of Student Forum Discussions, Hannah N. Benston
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There is much research about how actors and events in social networks affect each other. In this research, three network models were created for discussion forums in three semesters of undergraduate general physics courses. This study seeks to understand what social network measures are most telling of a online forum classroom dynamic. That is, I wanted to understand more about things like what students are most central to the networks and whether this is consistent across different network models. I also wanted to better understand how students may or may not group together. What relationships (student to student, student to …
Establishing A Machine Learning Framework For Discovering Novel Phononic Crystal Designs, Drew Feltner
Establishing A Machine Learning Framework For Discovering Novel Phononic Crystal Designs, Drew Feltner
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A phonon is a discrete unit of vibrational motion that occurs in a crystal lattice. Phonons and the frequency at which they propagate play a significant role in the thermal, optical, and electronic properties of a material. A phononic material/device is similar to a photonic material/device, except that it is fabricated to manipulate certain bands of acoustic waves instead of electromagnetic waves. Phononic materials and devices have been studied much less than their photonic analogues and as such current materials exhibit control over a smaller range of frequencies. This study aims to test the viability of machine learning, specifically neural …
The Effects Of An Ultrafast Pulsed Laser On Ybco Thin Film Circuit Transients, Matthew L. Rustad
The Effects Of An Ultrafast Pulsed Laser On Ybco Thin Film Circuit Transients, Matthew L. Rustad
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Terahertz (THz) frequency light has shown promise for a wide variety of applications due to its material characterization and imaging capabilities. Its nondestructive nature coupled with its submillimeter spatial resolution provides the most value for terahertz light as an imaging tool. The application of terahertz technology has been limited by a lack of novel and powerful sources. It has been shown that that Yttrium Barium Copper Oxide (YBCO), a type II superconductor, has certain properties that would allow YBCO to be an effective source for THz light. Recent microwave work has shown that when a persistent supercurrent is placed on …
Operational Detection Of Sun Glints In Dscovr Epic Images, Tamás Várnai, Alexander Marshak, Alexander Kostinski
Operational Detection Of Sun Glints In Dscovr Epic Images, Tamás Várnai, Alexander Marshak, Alexander Kostinski
Michigan Tech Publications
Satellite images often feature sun glints caused by the specular reflection of sunlight from water surfaces or from horizontally oriented ice crystals occurring in clouds. Such glints can prevent accurate retrievals of atmospheric and surface properties using existing algorithms, but the glints can also be used to infer more about the glint-causing objects—for example about the microphysical properties and radiative effects of ice clouds. This paper introduces the recently released operational glint product of the Earth Polychromatic Camera (EPIC) onboard the Deep Space Climate Observatory (DSCOVR) spacecraft. Most importantly, the paper describes the algorithm used for generating the key component …