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Articles 1 - 18 of 18
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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
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
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
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.
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.
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
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
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.
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.
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
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 …
Spectral Sensitivity Near Exceptional Points As A Resource For Hardware Encryption, Minye Yang, Liang Zhu, Qi Zhong, Ramy El-Ganainy, Pai Yen Chen
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 …
Electronic Structure Calculations Of Static Hyper(Polarizabilities) Of Substrate-Supported Group-Iv And -V Elemental Monolayers, Sumandeep Kaur, Ravindra Pandey, Shashi P. Karna
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 …
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.
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
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: …
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 …
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.
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 …
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 …
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.