Astrophysics and Astronomy Commons^™

Trapped Surfaces, Topology Of Black Holes, And The Positive Mass Theorem, Lan-Hsuan Huang, Dan A. Lee

Publications and Research

No abstract provided.

Collision-System And Beam-Energy Dependence Of Anisotropic Flow Fluctuations, Star Collaboration

Physics and Astronomy Faculty Publications

Elliptic flow measurements from two-, four-, and six-particle correlations are used to investigate flow fluctuations in collisions of U+U at √𝑠NN=193  GeV, Cu+Au at √𝑠NN=200  GeV and Au+Au spanning the range √𝑠NN=11.5–200  GeV. The measurements show a strong dependence of the flow fluctuations on collision centrality, a modest dependence on system size, and very little if any, dependence on particle species and beam energy. The results, when compared to similar LHC measurements, viscous hydrodynamic calculations, and trento model eccentricities, indicate that initial-state-driven fluctuations predominate the flow fluctuations generated in the collisions studied.

Differential Measurements Of Jet Substructure And Partonic Energy Loss In Au + Au Collisions At √𝑠𝑁⁢𝑁=200 Gev, Star Collaboration

Physics and Astronomy Faculty Publications

The STAR collaboration presents jet substructure measurements related to both the momentum fraction and the opening angle within jets in 𝑝+𝑝 and Au+Au collisions at √𝑠𝑁⁢𝑁 =200GeV. The substructure observables include SoftDrop groomed momentum fraction (𝑧𝑔), groomed jet radius (𝑅𝑔), and subjet momentum fraction (𝑧SJ) and opening angle (𝜃SJ). The latter observable is introduced for the first time. Fully corrected subjet measurements are presented for 𝑝+𝑝 collisions and are compared to leading-order Monte Carlo models. The subjet 𝜃SJ distributions reflect the jets leading opening angle and are utilized as a proxy for the resolution scale of the medium in Au+Au …

Disappearance Of Partonic Collectivity In √Snn = 3 Gev Au+Au Collisions At Rhic, Star Collaboration

Physics and Astronomy Faculty Publications

We report on the measurements of directed flow v1 and elliptic flow v2 for hadrons (π±, K ±, K 0 S , p, φ, Λ and Ξ−) from Au+Au collisions at √sNN = 3 GeV and v2 for (π±, K ±, p and p) at 27 and 54.4 GeV with the STAR experiment. While at the two higher energy midcentral collisions the number-of-constituent-quark (NCQ) scaling holds, at 3 GeV the v2 at midrapidity is negative for all hadrons and the NCQ scaling is absent. In addition, the v1 slopes at midrapidity for almost all observed hadrons are found to be …

Long-Term Rotational Evolution Of The Stis Ccd Flatfields, Kimberly Ward-Huong, S. Lockwood, J. Debes, R. J. De Rosa

Astronomy: Faculty Publications

We confirm a long-term rotational drift of 0.0031 degrees/year of the STIS CCD based upon analysis of 50CCD flatfields spanning over 20 years of calibration data. Using the dust motes present in the flatfields, we extract the positions of the motes in each image, allowing us to develop a catalog of stable, high ‘signal-to-noise’ mote features and track their relative positions over time. We find that the motes appear to be moving at the aforementioned rate relative to an approximate center of rotation located at X=468.02, Y=411.18 in detector pixel coordinates. Given the relatively large errors in centroiding the unusually-shaped …

Magnetic Microscopy And Search For Exotic Interaction Detection With Color Centers In Diamond, Nathaniel Ristoff

Physics & Astronomy ETDs

Nitrogen vacancy (NV) centers have been used extensively for the measurement of magnetic fields in applications of geology, biology, medicine, and fundamental physics. In regard to fundamental physics, NV centers offer a unique opportunity to test potential velocity dependant spin-spin interactions as well as velocity-spin interactions at the micron scale. In regards to magnetic materials, NV centers offer a platform to investigate magnetic properties of nanoparticles in an individual, but highly parallelized measurement. In this work, an experiment is proposed to measure a potential fundamental interaction between spins, mediated by an integer spin boson. These velocity dependent interactions will couple …

Superluminal Propagation On A Moving Braneworld, Brian Greene, Daniel Kabat, Janna Levin, Arjun S. Menon

Publications and Research

We consider a braneworld scenario in the simplest setting, M₄ × S¹, with a four-dimensional (4D) Minkowski metric induced on the brane, and establish the possibility of superluminal propagation. If the brane is at rest, the 4D Lorentz symmetry of the brane is exact, but if the brane is in motion, it is broken globally by the compactification. By measuring bulk fields, an observer on the brane sees a slice through a higher-dimensional field profile, which carries an imprint of the extra dimensions even when the brane is at rest. If the brane is in motion, we …

The Octagon At Large M, Riccardo Argurio, Matteo Bertolini, Sebastían Franco, Eduardo García-Valdecasas, Shani Meynet, Antoine Pasternak, Valdo Tatitscheff

Publications and Research

Recently, the first instance of a model of D-branes at Calabi-Yau singularities where supersymmetry is broken dynamically into stable vacua has been proposed. This construction was based on a system of N regular and M = 1 fractional branes placed at the tip of the so-called (orientifolded) Octagon singularity. In this paper we show that this model admits a large M generalization, having the same low energy effective dynamics. This opens up the possibility that the effect on geometry is smooth, and amenable to describing the gauge theory all along the RG flow, including the deep IR, in terms of …

Characterizing The Particle Size Distribution In Saturn's Rings Using Cassini Uvis Stellar Occultation Data, Stephanie Eckert

Electronic Theses and Dissertations, 2020-2023

NASA's Cassini mission to Saturn revolutionized modern understanding of the planet's vast and intricate ring system. We use stellar occultation data from Cassini's UVIS High Speed Photometer (HSP) to characterize the particle size distribution in the rings with two methods. First, we discern the sizes of the smallest particles at ring edges by forward-modeling observed diffraction signatures which appear as spikes in the signal, the shape and amplitude of which depends on the size and abundance of the smallest particles. We then probe the upper end of the size distribution using occultation statistics. Although the distribution of photon counts in …

Atmospheric Retrieval: Bayesian Methods, Machine Learning, And Application To Exoplanets, Michael Himes

Electronic Theses and Dissertations, 2020-2023

Atmospheric retrieval is the inverse modeling method where atmospheric properties are constrained based on measured spectra. Due to the low signal-to-noise ratios of exoplanet observations, exoplanetary retrieval codes pair a radiative transfer (RT) simulator with a Bayesian statistical framework in order to characterize the distribution of atmospheric parameters that could explain the observations (the posterior distribution). This requires on the order of 106 RT model evaluations, which requires hours to days of compute time depending on model complexity. In this work, I investigate atmospheric retrieval methods and apply them to observations of hot Jupiters. Chapter 2 presents a set of …

Surface Morphologies In A Mars-Analog Ca-Sulfate Salar, High Andes, Northern Chile, Nancy W. Hinman, Michael H. Hofmann, Kimberly Warren-Rhodes, Michael S. Phillips, Nora Noffke, Nathalie A. Cabrol, Guillermo Chong Diaz, Cecilia Demergasso, Cinthya Tebes-Cayo, Oscar Cabestro, Janice L. Bishop, Virginia C. Gulick, David Summers, Pablo Sobron, Michael Mcinenly, Jeffrey Moersch, Constanza Rodriguez, Philippe Sarazzin, Kevin L. Rhodes, Camila Javiera Riffo Contreras, David Wettergreen, Victor Parro

OES Faculty Publications

Salar de Pajonales, a Ca-sulfate salt flat in the Chilean High Andes, showcases the type of polyextreme environment recognized as one of the best terrestrial analogs for early Mars because of its aridity, high solar irradiance, salinity, and oxidation. The surface of the salar represents a natural climate-transition experiment where contemporary lagoons transition into infrequently inundated areas, salt crusts, and lastly dry exposed paleoterraces. These surface features represent different evolutionary stages in the transition from previously wetter climatic conditions to much drier conditions today. These same stages closely mirror the climate transition on Mars from a wetter early Noachian to …

Visible Opacity Of M Dwarfs And Hot Jupiters: The Tio B³Π-X³Δ Band System, W. Doug Cameron, Peter Bernath

Chemistry & Biochemistry Faculty Publications

The TiO B³Π−X³Δ electronic transition (𝛾' system) is an important opacity source in the atmospheres of M dwarfs and hot Jupiter exoplanets. The 0–0, 1–0, and 2–1 bands of the B³Π−X³Δ band system have been analyzed using a TiO emission spectrum recorded at the McMath-Pierce Solar Telescope, operated by the National Solar Observatory at Kitt Peak, Arizona. Improved spectroscopic and equilibrium constants were determined. Line strengths were calculated from an ab initio transition-dipole moment function scaled using an experimental lifetime. A new line list for v' = 0–2 and v′′ = 0–4 …

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

Faculty Publications

Lorentz invariance violation (LIV) is often described by dispersion relations of the form E-i(2) = m(i)(2) + p(i)(2) + delta E-i,n(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 delta(i,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 …

Bending Waves Excited By Irregular Gas Inflow Along Warps, Tigran Khachaturyants, Leandro Beraldo E Silva, Victor P. Debattista, Kathryne J. Daniel

Physics Faculty Research and Scholarship

Gaia has revealed clear evidence of bending waves in the vertical kinematics of stars in the solar neighbourhood. We study bending waves in two simulations, one warped, with the warp due to misaligned gas inflow, and the other unwarped. We find slow, retrograde bending waves in both models, with the ones in the warped model having larger amplitudes. We also find fast, prograde bending waves. Prograde bending waves in the unwarped model are very weak, in agreement with the expectation that these waves should decay on short, approximately crossing, time-scales, due to strong winding. However, prograde bending waves are much …

Development Of A Fluxgate Magnetometer Model, Eleonora Olsmats

Honors Theses and Capstones

As a part of the UNH SWFO-L1 mission to monitor space weather and the sun’s behavior, the fluxgate magnetometer is an important component to measure external magnetic fields. The basic principle of a fluxgate magnetometer is to detect changes in the ambient magnetic field by inducing a magnetic field in a ferromagnetic material via a drive winding. Each magnetometer is unique due to the ferromagnetic properties of the core material which can be seen in the hysteresis loop which is a relationship between the magnetic field strength (H) and the induced magnetic field (B). Measuring the hysteresis of a fluxgate …

Direct Imaging & Spectroscopy Of Exoplanetary Systems With The Jwst Early Release Science Program, Sasha Hinkley, Aarynn L. Carter, Shrishmoy Ray, Beth Biller, Andrew Skemer, Elodie Choquet, Maxwell A. Millar-Blanchaer, Stephanie Sallum, Brittany Miles, Niall Whiteford, Polychronis Patapis, Marshall Perrin, Laurent Pueyo, Karl Stapelfeldt, Jason Wang, Kimberly Ward-Duong, Julien H. Girard, Dean Hines, Jens Kammerer, Jarron Leisenring, Yifan Zhou, Michael Meyer, Michael C. Liu, Mickael Bonnefoy, Simon Petrus, Mariangela Bonavita, Gael Chauvin, Christine Chen, Thayne Currie, Kielan K.W. Hoch, Cecilia Lazzoni, Elisabeth C. Matthews

Astronomy: Faculty Publications

The direct characterization of exoplanetary systems with high contrast imaging is among the highest priorities for the broader exoplanet community. As large space missions will be necessary for detecting and characterizing exo-Earth twins, developing the techniques and technology for direct imaging of exoplanets is a driving focus for the community. For the first time, JWST will directly observe extrasolar planets at mid-infrared wavelengths beyond 5 μm, deliver detailed spectroscopy revealing much more precise chemical abundances and atmospheric conditions, and provide sensitivity to analogs of our solar system ice-giant planets at wide orbital separations, an entirely new class of exoplanet. However, …

Performance Of Near-Infrared High-Contrast Imaging Methods With Jwst From Commissioning, Jens Kammerer, Julien Girard, Aarynn L. Carter, Marshall D. Perrin, Rachel Cooper, Deepashri Thatte, Thomas Vandal, Jarron Leisenring, Jason Wang, William O. Balmer, Anand Sivaramakrishnan, Laurent Pueyo, Kimberly Ward-Duong, Ben Sunnquist, Jéa Adams Redai

Astronomy: Faculty Publications

The James Webb Space Telescope (JWST) will revolutionize the field of high-contrast imaging and enable both the direct detection of Saturn-mass planets and the characterization of substellar companions in the mid-infrared. While JWST will feature unprecedented sensitivity, angular resolution will be the key factor when competing with ground-based telescopes. Here, we aim to characterize the performance of several extreme angular resolution imaging techniques available with JWST in the 3-5 µm regime based on data taken during the instrument commissioning. Firstly, we introduce custom tools to simulate, reduce, and analyze JWST NIRCam and MIRI coronagraphy data and use these tools to …

Centrality And Transverse-Momentum Dependence Of Higher-Order Flow Harmonics Of Identified Hadrons In Au+Au Collisions At √𝑠𝑁⁢𝑁=200 Gev, Star Collaboration

Physics and Astronomy Faculty Publications

We present high-precision measurements of elliptic, triangular, and quadrangular flow 𝑣2, 𝑣3, and 𝑣4, respectively, at midrapidity for identified hadrons 𝜋, 𝑝, 𝐾, 𝜑, 𝐾𝑠, Λ as a function of centrality and transverse momentum in Au+Au collisions at the center-of-mass energy √𝑠𝑁⁢𝑁=200 GeV. We observe similar 𝑣𝑛 trends between light and strange mesons which indicates that the heavier strange quarks flow as strongly as the lighter up and down quarks. The number-of-constituent-quark scaling for 𝑣2, 𝑣3, and 𝑣4 is found to hold within statistical uncertainty for 0–10%, 10–40%, and 40–80% collision centrality intervals. The results are compared to several viscous …

Azimuthal Transverse Single-Spin Asymmetries Of Inclusive Jets And Identified Hadrons Within Jets From Polarized 𝑝⁢𝑝 Collisions At √𝑠 =200  Gev, Star Collaboration

Physics and Astronomy Faculty Publications

The STAR Collaboration reports measurements of the transverse single-spin asymmetries, 𝐴𝑁, for inclusive jets and identified “hadrons within jets” production at midrapidity from transversely polarized 𝑝⁢𝑝 collisions at √𝑠 =200  GeV, based on data recorded in 2012 and 2015. The inclusive jet asymmetry measurements include 𝐴𝑁 for inclusive jets and 𝐴𝑁 for jets containing a charged pion carrying a momentum fraction 𝑧 >0.3 of the jet momentum. The identified hadron within jet asymmetry measurements include the Collins effect for charged pions, kaons, and protons, and the Collins-like effect for charged pions. The measured asymmetries are determined for several distinct kinematic …

Evidence For Nonlinear Gluon Effects In Qcd And Their Mass Number Dependence At Star, Star Collaboration

Physics and Astronomy Faculty Publications

The STAR Collaboration reports measurements of back-to-back azimuthal correlations of di-𝜋0s produced at forward pseudorapidities (2.6 < 𝜂 < 4.0) in 𝑝 +𝑝, 𝑝+Al, and 𝑝+Au collisions at a center-of-mass energy of 200 GeV. We observe a clear suppression of the correlated yields of back-to-back 𝜋0 pairs in 𝑝+Al and 𝑝+Au collisions compared to the 𝑝 +𝑝 data. The observed suppression of back-to-back pairs as a function of transverse momentum suggests nonlinear gluon dynamics arising at high parton densities. The larger suppression found in 𝑝+Au relative to 𝑝+Al collisions exhibits a dependence of the saturation scale 𝑄2/𝑠 on the mass number 𝐴. A linear scaling of the suppression with 𝐴1/3 is observed with a slope of −0.09 ±0.01.

Osiris-Rex Surface Imaging To Constrain Properties Of The Asteroid (101955) Bennu, Alicia Allen

Honors Undergraduate Theses

This study used images taken from the OSIRIS-REx spacecraft sample-return mission and projected onto a three-dimensional shape model to determine surface properties of the asteroid (101955) Bennu. Two major projects were completed. For the first project, images of the pre-sampled Nightingale site and post-sampled Nightingale were compared to determine how the TAGSAM sampling maneuver effected the surface of the asteroid directly at the sampling site and in the surrounding area. This analysis demonstrated how spacecraft can potentially affect a small body during this and future sample-return missions. For the second project, several craters on Bennu’s surface were selected and all …

Characterizing The Effects Of Porosity And Particle Size On Tir Emissivity Spectral Features Of Olivine, Ryan Galinkin

Electronic Theses and Dissertations, 2020-2023

We generated a series of 15 particulate San Carlos olivine samples with varying porosity and particle size. We created five different particle size distributions and each particle size distribution was prepared with three different packing techniques. These samples were then imaged under a microscope and a binarization thresholding technique was used to determine each sample's surface porosity by the ratio of dark, void pixels to the total number of pixels in each image. Our results show that we could estimate surface porosity from the analysis of a microscopic image, a non-destructive technique. These samples were then placed in the Planetary …

Characterizing Agn Influence On The Calculated Metallicities Of Adjacent Star-Forming Spaxels, Aidan Khelil

Honors Papers

In this thesis, I introduce a method to identify and characterize the effects of active galactic nuclei (AGN) on the spectra of nearby star-forming regions. I analyze spatially-resolved areas of galaxies called “spaxels” within Data Release 15 of the Sloan Digital Sky Survey (SDSS) with the goal of locating those which are physically close to AGN. I find those spaxels with calculated metallicities which lie adjacent to AGN-flagged spaxels and characterize their metallicity values relative to the spaxels which are not adjacent to AGN-flagged spaxels, using a total of 11 separate metallicity calibrations. I find that the current methods to …

Investigating Signs Of Orbital Decay In The Tres-1 Exoplanetary System, Amanda F. Wester

Honors Theses and Capstones

Transit observations of exoplanetary systems can be used to investigate orbital decay. TrES-1b is an exoplanet hypothesized to be experiencing orbital decay due to observed transit timing variations (TTVs) [12]. Numerous transits must be observed to establish a long term pattern to conclusively determine if the planet’s orbit is decaying. Measurements were made using the UNH Observatory where 2 transits were observed of the TrES-1b transiting system on February 27, 2022 and March 5, 2022. A CCD camera was used to image the transit and capture calibration images. The software AstroImageJ (AIJ) was used to calibrate the images and perform …

Nidus Idearum. Scilogs, Viii: Painting By Numbers, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

In this eighth book of scilogs collected from my nest of ideas, one may find new and old questions and solutions, – in email messages to research colleagues, or replies, and personal notes handwritten on the planes to, and from international conferences, about all kind of topics, centered mostly on Paradoxism and Neutrosophy.

Exchanging ideas with: Robert Neil Boyd, Joseph Brenner, Ahmed Cevik, Victor Christianto, Adrian Curaj, Jean Dezert, Andrei-Lucian Drăgoi, Ervin Goldfain, Young Bae Jun, Yale Landsberg, Radu Munteanu, Paul Piștea, Viorel Roman, Ridvan Sahin, Said Broumi, Selcuk Topal, Eric W. Weisstein, Xiaohing Zhang.

Feasibility Study On Emission Line Spectroscopy Between 350 Nm And 750 Nm Of Runaway Star Bow Shocks In The Milky Way Using Currently Operating Observatories With Open Submission Policies, John Scheele

All Graduate Theses, Dissertations, and Other Capstone Projects

Numerous runaway stars with bow shocks have been observed distributed around the Galaxy. These shocks have previously been observed in the infrared,Hα, [O I I I], and[N I I] lines. Recently hydrodynamic simulations allow for theoretical emissions of a runway star bow shock to be calculated. Expanding on these simulations shows that simultaneous observations in visible spectrum for Hα, H I eλ5876Å, and [O I I I] by the GMOS instruments of the Gemini Observatories are possible, allowing direct composition measurements of the ISM in the Milky Way Galaxy.

Perturbative Unitarity And Nec Violation In Genesis Cosmology, Yong Cai, Ji Xu, Shuai Zhao, Siyi Zhou

Physics Faculty Publications

Explorations of the violation of null energy condition (NEC) in cosmology could enrich our understanding of the very early universe and the related gravity theories. Although a fully stable NEC violation can be realized in the “beyond Horndeski” theory, it remains an open question whether a violation of the NEC is allowed by some fundamental properties of UV-complete theories or the consistency requirements of effective field theory (EFT). We investigate the tree-level perturbative unitarity for stable NEC violations in the contexts of both Galileon and “beyond Horndeski” genesis cosmology, in which the universe is asymptotically Minkowskian in the past. We …

Updated Analysis Of An Unexpected Correlation Between Dark Matter And Galactic Ellipticity, D. M. Winters, Alexandre Deur, X. Zheng

Physics Faculty Publications

We investigate a correlation between the dark matter content of elliptical galaxies and their ellipticity ϵ that was initially reported in 2014. We use new determinations of dark matter and ellipticities that are posterior to that time. Our data set consists of 237 elliptical galaxies passing a strict set of criteria that selects a homogeneous sample of typical elliptical galaxies. We find a relation between the mass-to-light ratio and ellipticity ϵ that is well fitted by M/L = (14.1 ± 5.4)ϵ, which agrees with the result reported in 2014. Our analysis includes 135 galaxies that were not in …

𝒯, 𝒫-Odd Effects In The Luoh⁺ Cation, Daniel E. Maison, Leonid V. Skripnikov, Gleb Penyazkov, Matt Grau, Alexander N. Petrov

Physics Faculty Publications

The LuOH⁺ cation is a promising system to search for manifestations of time reversal and spatial parity violation effects. Such effects in LuOH⁺ induced by the electron electric dipole moment eEDM and the scalar-pseudoscalar interaction of the nucleus with electrons, characterized by k_s constant, in LuOH⁺ are studied. The enhancement factors, polarization in the external electric field, hyperfine interaction, and rovibrational structure are calculated. The study is required for the experiment preparation and extraction of the eEDM and k_s values from experimental data.

Comparative Study Of High Order Methods For Subsonic Turbulence Simulation With Stochastic Forcing, Alexei G. Kritsuk, H. C. Yee, Björn Sjögreen, Dmitry Kotov

United States National Aeronautics and Space Administration: Publications

A class of spatially seventh-order nonlinear filter methods with adaptive dissipation control developed by Yee & Sjögreen [1, 2] is tested on three-dimensional subsonic turbulence simulations with stochastic forcing. The Euler equations are solved using the Strang operator splitting of the homogeneous part of the equations and the stochastic forcing term, with an ODE solver used to integrate the latter. Both Ducros et al. and Kennedy-Gruber skew-symmetric split formulations of the inviscid flux derivatives are considered to minimize the use of numerical dissipation. The nonlinear filter methods are shown to be numerically stable for this application at least up to …