Open Access. Powered by Scholars. Published by Universities.®

Astrophysics and Astronomy Commons™

Open Access. Powered by Scholars. Published by Universities.®

8,900 Full-Text Articles 23,878 Authors 2,753,071 Downloads 208 Institutions

All Articles in Astrophysics and Astronomy

Faceted Search

8,900 full-text articles. Page 36 of 310.

Swarm Intelligence Methods For Extreme Mass Ratio Inspiral Search: First Application Of Particle Swarm Optimization, Xiao-Bo Zou, Soumya D. Mohanty, Hong-Gang Luo, Yu-Xiao Liu 2024 The University of Texas Rio Grande Valley

Swarm Intelligence Methods For Extreme Mass Ratio Inspiral Search: First Application Of Particle Swarm Optimization, Xiao-Bo Zou, Soumya D. Mohanty, Hong-Gang Luo, Yu-Xiao Liu

Physics & Astronomy Faculty Publications

Swarm intelligence (SI) methods are nature-inspired metaheuristics for global optimization that exploit a coordinated stochastic search strategy by a group of agents. Particle swarm optimization (PSO) is an established SI method that has been applied successfully to the optimization of rugged high-dimensional likelihood functions, a problem that represents the main bottleneck across a variety of gravitational wave (GW) data analysis challenges. We present results from the first application of PSO to one of the most difficult of these challenges, namely the search for the Extreme Mass Ratio Inspiral (EMRI) in data from future spaceborne GW detectors such as LISA, Taiji, …


Radiation From An Oscillating Dipole In The Presence Of Photon-Sector Cpt And Lorentz Violation, Joshua O'Connor, Brett Altschul 2024 University of South Carolina

Radiation From An Oscillating Dipole In The Presence Of Photon-Sector Cpt And Lorentz Violation, Joshua O'Connor, Brett Altschul

Faculty Publications

We examine one of the standard loci for studying electromagnetic wave emission - the radiation from an oscillating electric dipole - in a model in which the electromagnetic sector is modified to include novel CPT- and Lorentz-violating propagation effects involving a preferred axial vector background. We evaluate the vacuum-birefringent radiation fields, including nonperturbative terms where appropriate. In general, the energy momentum carried by the fields in this model is known to have a complicated nonperturbative structure, which cannot be captured by naive power-series expansions in the components of the preferred background vector. However, we nevertheless find that at the lowest …


There Is Life On Mars, Colin M. Johnston, Olivier B. Cohen 2024 Gettysburg College

There Is Life On Mars, Colin M. Johnston, Olivier B. Cohen

CAFE Symposium 2024

An extensive research project that involved the research of multiple major experiments and discoveries about possible life on the planet Mars. Facts, Data, conspiracies and theories have all been taken into account and provided in this project.


Extraterrestrial Life: The Possibility Of A Human-Alien Interaction, Ariana M. Piscoya 2024 Gettysburg College

Extraterrestrial Life: The Possibility Of A Human-Alien Interaction, Ariana M. Piscoya

CAFE Symposium 2024

We all have heard of at least one case where someone assured having seen a flying extraterrestrial object. There are thousands of thousands of videos we can find online that “prove” the existence of aliens. In the hypothetical case where aliens are really out there, why haven't we been able to talk to them and look at them face-to-face? A human-extraterrestrial interaction has not yet been achieved for two reasons. First, alien energy is much more powerful than that of humans, so it would require thousands of thousands of years for the human race to develop a technology able to …


Muse-Alma Haloes X: The Stellar Masses Of Gas-Rich Absorbing Galaxies, Ramona Augustin, Céline Péroux, Arjun Karki, Varsha Kulkarni, Simon Weng, A Hamanowicz, M Hayes, J C. Howk, G G. Kacprzak, A Klitsch, M A. Zwaan, A Fox, A Biggs, A Y. Fresco, S Kassin, H. Kuntschner 2024 University of South Carolina

Muse-Alma Haloes X: The Stellar Masses Of Gas-Rich Absorbing Galaxies, Ramona Augustin, Céline Péroux, Arjun Karki, Varsha Kulkarni, Simon Weng, A Hamanowicz, M Hayes, J C. Howk, G G. Kacprzak, A Klitsch, M A. Zwaan, A Fox, A Biggs, A Y. Fresco, S Kassin, H. Kuntschner

Faculty Publications

The physical processes by which gas is accreted onto galaxies, transformed into stars, and then expelled from galaxies are of paramount importance to galaxy evolution studies. Observationally constraining each of these baryonic components in the same system, however, is challenging. Furthermore, simulations indicate that the stellar mass of galaxies is a key factor influencing CGM properties. Indeed, absorption lines detected against background quasars offer the most compelling way to study the cold gas in the circumgalactic medium (CGM). The MUSE-ALMA Haloes survey is composed of quasar fields covered with VLT/MUSE observations, comprising 32 H i absorbers at 0.2 < z < 1.4 and 79 associated galaxies, with available or upcoming molecular gas measurements from ALMA. We use a dedicated 40-orbit HST …


Axion-Polaritons In Quark Stars: A Possible Solution To The Missing Pulsar Problem, Efrain J. Ferrer, Vivian de la Incera 2024 The University of Texas Rio Grande Valley

Axion-Polaritons In Quark Stars: A Possible Solution To The Missing Pulsar Problem, Efrain J. Ferrer, Vivian De La Incera

Physics & Astronomy Faculty Publications

This paper proposes an alternative mechanism to solve the so-called missing pulsar problem, a standing paradox between the theoretical expectations about the number of pulsars that should exist in the galaxy center of the Milky Way and their absence in the observations. The mechanism is based on the transformation of incident γ rays into hybridized modes, known as axion-polaritons, which can exist inside highly magnetized quark stars with a quark matter phase known as the magnetic dual chiral density wave phase. This phase, which is favored over several other dense matter phases candidates at densities a few times nuclear saturation …


Flavors And Frailties Of Globalization, Nikhilesh Dholakia, Deniz Atik 2024 University of Rhode Island

Flavors And Frailties Of Globalization, Nikhilesh Dholakia, Deniz Atik

Markets, Globalization & Development Review

No abstract provided.


Jwst-Tsthigh Contrast: Asymmetries, Dust Populations, And Hints Of A Collision In The Β Pictoris Disk With Nircam And Miri, Isabel Rebollido, Christopher C. Stark, Jens Kammerer, Marshall D. Perrin, Kellen Lawson, Laurent Pueyo, Christine Chen, Dean Hines, Julien H. Girard, Kadin Worthen, Carl Ingerbretsen, Sarah Betti, Mark Clampin, David Golimowski, Kielan Hoch, Nikole K. Lewis, Cicero X. Lu, Roeland P. van der Marel, Emily Rickman, Sara Seager, Rémi Soummer, Jeff A. Valenti, Kimberly Ward-Duong, C. Matt Mountain 2024 CSIC-INTA - Centro de Astrobiología (CAB)

Jwst-Tsthigh Contrast: Asymmetries, Dust Populations, And Hints Of A Collision In The Β Pictoris Disk With Nircam And Miri, Isabel Rebollido, Christopher C. Stark, Jens Kammerer, Marshall D. Perrin, Kellen Lawson, Laurent Pueyo, Christine Chen, Dean Hines, Julien H. Girard, Kadin Worthen, Carl Ingerbretsen, Sarah Betti, Mark Clampin, David Golimowski, Kielan Hoch, Nikole K. Lewis, Cicero X. Lu, Roeland P. Van Der Marel, Emily Rickman, Sara Seager, Rémi Soummer, Jeff A. Valenti, Kimberly Ward-Duong, C. Matt Mountain

Astronomy: Faculty Publications

We present the first JWST Mid-Infrared Instrument (MIRI) and Near Infrared Camera (NIRCam) observations of the prominent debris disk around β Pictoris. Coronagraphic observations in eight filters spanning from 1.8 to 23 μm provide an unprecedentedly clear view of the disk at these wavelengths. The objectives of the observing program were to investigate the dust composition and distribution and to investigate the presence of planets in the system. In this paper, we focus on the disk components, providing surface brightness measurements for all images and a detailed investigation of the asymmetries observed. A companion paper by Kammerer et al. will …


Vlti/Gravity Provides Evidence The Young, Substellar Companion Hd 136164 Ab Formed Like A “Failed Star”, William O. Balmer, L. Pueyo, S. Lacour, J. J. Wang, T. Stolker, J. Kammerer, N. Pourré, M. Nowak, E. Rickman, S. Blunt, A. Sivaramakrishnan, D. Sing, K. Wagner, G. D. Marleau, A. M. Lagrange, R. Abuter, A. Amorim, R. Asensio-Torres, J. P. Berger, H. Beust, A. Boccaletti, A. Bohn, M. Bonnefoy, H. Bonnet, M. S. Bordoni, G. Bourdarot, W. Brandner, F. Cantalloube, P. Caselli, B. Charnay, et al, Kimberly Ward-Duong 2024 Johns Hopkins University

Vlti/Gravity Provides Evidence The Young, Substellar Companion Hd 136164 Ab Formed Like A “Failed Star”, William O. Balmer, L. Pueyo, S. Lacour, J. J. Wang, T. Stolker, J. Kammerer, N. Pourré, M. Nowak, E. Rickman, S. Blunt, A. Sivaramakrishnan, D. Sing, K. Wagner, G. D. Marleau, A. M. Lagrange, R. Abuter, A. Amorim, R. Asensio-Torres, J. P. Berger, H. Beust, A. Boccaletti, A. Bohn, M. Bonnefoy, H. Bonnet, M. S. Bordoni, G. Bourdarot, W. Brandner, F. Cantalloube, P. Caselli, B. Charnay, Et Al, Kimberly Ward-Duong

Astronomy: Faculty Publications

Young, low-mass brown dwarfs orbiting early-type stars, with low mass ratios (q ≲ 0.01), appear to be intrinsically rare and present a formation dilemma: could a handful of these objects be the highest-mass outcomes of “planetary” formation channels (bottom up within a protoplanetary disk), or are they more representative of the lowest-mass “failed binaries” (formed via disk fragmentation or core fragmentation)? Additionally, their orbits can yield model-independent dynamical masses, and when paired with wide wavelength coverage and accurate system age estimates, can constrain evolutionary models in a regime where the models have a wide dispersion depending on the initial conditions. …


X-Ray Detection Of The Most Extreme Star-Forming Galaxies At The Cosmic Noon Via Strong Lensing, Q. Daniel Wang, Carlos Garcia Diaz, Patrick S. Kamieneski, Kevin C. Harrington, Min S. Yun, Nicholas Foo, Brenda L. Frye, Eric F. Jimenez-Andrade, Daizhong Liu, James D. Lowenthal, Belén Alcalde Pampliega, Massimo Pascale, Amit Vishwas, Mark A. Gurwell 2024 University of Massachusetts Amherst

X-Ray Detection Of The Most Extreme Star-Forming Galaxies At The Cosmic Noon Via Strong Lensing, Q. Daniel Wang, Carlos Garcia Diaz, Patrick S. Kamieneski, Kevin C. Harrington, Min S. Yun, Nicholas Foo, Brenda L. Frye, Eric F. Jimenez-Andrade, Daizhong Liu, James D. Lowenthal, Belén Alcalde Pampliega, Massimo Pascale, Amit Vishwas, Mark A. Gurwell

Astronomy: Faculty Publications

Hyperluminous infrared galaxies (HyLIRGs)ãre the most extreme star-forming systems observed in the early Universe,ãnd their properties still elude comprehensive understanding. We have undertakenã large XMM -Newton observing programme to probe the totalãccreting black hole population in three HyLIRGsãt z = 2.12, 3.25,ãnd 3.55, gravitationally lensed by foreground galaxies. Selected from the Planck All-Sky Survey to Analyse Gravitationally lensed Extreme Starbursts (PASSAGES), these HyLIRGs haveãpparent infrared luminosities > 10 14 L⊙. Our observãtions re vealed X-ray emission in each of them. PJ1336 + 49ãppears to be dominated by high-mass X-ray binaries (HMXBs). Remarkably, the luminosity of this non-AGN X-ray emission exceeds byã …


Life Beyond The Horizon: The Universe Was Born In A Black Hole, Zahria Patrick 2024 University of Missouri, St. Louis

Life Beyond The Horizon: The Universe Was Born In A Black Hole, Zahria Patrick

Undergraduate Research Symposium

It is a widely accepted fact that obtaining information about a black hole is a near-impossible task without being stretched like a spaghetti noodle and trapped in one due to its strong gravitational pull. If the universe exists in a black hole, however, it will mean that it could be possible to survive after crossing its inescapable borders. As surprising as all of this may seem, this theory has existed for quite a while amongst a few different physicists. One person that has shed light on and expanded people’s knowledge of this frightening theory is theoretical physicist, Nikodem Poplawski. The …


Toward The Ir Detection Of Carbon Acid: Absorption And Emission Spectrum, Ryan C. Fortenberry, Vincent J. Esposito 2024 University of Mississippi

Toward The Ir Detection Of Carbon Acid: Absorption And Emission Spectrum, Ryan C. Fortenberry, Vincent J. Esposito

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

With the recent radioastronomical detection of cis-trans-carbonic acid (H2CO3) in a molecular cloud toward the Galactic center, the more stable but currently unobserved cis-cis conformer is shown here to have strong IR features. While the higher-energy cis-trans-carbonic acid was detected at millimeter and centimeter wavelengths, owing to its larger dipole moment, the vibrational structure of cis-cis-carbonic acid is more amenable to its observation at micron wavelengths. Even so, both conformers have relatively large IR intensities, and some of these fall in regions not dominated by polycyclic aromatic hydrocarbons. Water features may inhibit observation …


Discord In Concordance Cosmology And Anomalously Massive Early Galaxies, Stacy S. McGaugh 2024 Case Western Reserve University

Discord In Concordance Cosmology And Anomalously Massive Early Galaxies, Stacy S. Mcgaugh

Faculty Scholarship

Cosmological parameters are constrained by a wide variety of observations. We examine the concordance diagram for modern measurements of the Hubble constant, the shape parameter from the large-scale structure, the cluster baryon fraction, and the age of the universe, all from non-CMB data. There is good agreement for (Formula presented.) and (Formula presented.). This concordance value is indistinguishable from the WMAP3 cosmology but is not consistent with that of Planck: there is a tension in (Formula presented.) as well as (Formula presented.). These tensions have emerged as progressively higher multipoles have been incorporated into CMB fits. This temporal evolution is …


Low Complexity Radio Frequency Interference Mitigation For Radio Astronomy Using Large Antenna Array, Zaid Bin Tariq, Teviet Creighton, Louis Percy Dartez, Naofal Al-Dhahir, Murat Torlak 2024 The University of Texas Rio Grande Valley

Low Complexity Radio Frequency Interference Mitigation For Radio Astronomy Using Large Antenna Array, Zaid Bin Tariq, Teviet Creighton, Louis Percy Dartez, Naofal Al-Dhahir, Murat Torlak

Physics & Astronomy Faculty Publications

With the ongoing growth in radio communications, there is an increased contamination of radio astronomical source data, which hinders the study of celestial radio sources. In many cases, fast mitigation of strong radio frequency interference (RFI) is valuable for studying short lived radio transients so that the astronomers can perform detailed observations of celestial radio sources. The standard method to manually excise contaminated blocks in time and frequency makes the removed data useless for radio astronomy analyses. This motivates the need for better radio frequency interference (RFI) mitigation techniques for array of size M antennas. Although many solutions for mitigating …


Gwtc-2.1: Deep Extended Catalog Of Compact Binary Coalescences Observed By Ligo And Virgo During The First Half Of The Third Observing Run, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Volker Quetschke, Wenhui Wang 2024 The University of Texas Rio Grande Valley

Gwtc-2.1: Deep Extended Catalog Of Compact Binary Coalescences Observed By Ligo And Virgo During The First Half Of The Third Observing Run, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Volker Quetschke, Wenhui Wang

Physics & Astronomy Faculty Publications

The second Gravitational-Wave Transient Catalog, GWTC-2, reported on 39 compact binary coalescences observed by the Advanced LIGO and Advanced Virgo detectors between 1 April 2019 15∶00 UTC and 1 October 2019 15∶00 UTC. Here, we present GWTC-2.1, which reports on a deeper list of candidate events observed over the same period. We analyze the final version of the strain data over this period with improved calibration and better subtraction of excess noise, which has been publicly released. We employ three matched-filter search pipelines for candidate identification, and estimate the probability of astrophysical origin for each candidate event. While GWTC-2 used …


Synchronicity: An Analysis Of Einstein's Halfway Rule, Preslava Nikolova 2024 Wayne State University

Synchronicity: An Analysis Of Einstein's Halfway Rule, Preslava Nikolova

Rushton Journal of Undergraduate Humanities Research

For the modern world to function, Global Positioning System satellites must synchronize to clocks on Earth. This paper examines a concept that underlies GPS systems, namely Albert Einstein’s halfway rule—the idea that a line of simultaneity exists between two events in different systems. This essay discusses how Einstein used conventionalist methods to establish ½ as a constant value for σ to take advantage of the property of symmetry.


Analysis Of Neutron Star Structure And Equation Of State Using Computational Simulations, Sohila Sameh 2024 Fayoum University, Egypt

Analysis Of Neutron Star Structure And Equation Of State Using Computational Simulations, Sohila Sameh

2024 REYES Proceedings

Understanding neutron star structures is crucial for advancing astrophysical research. This study explores the structure of neutron stars using advanced equations, including the Tolman-Oppenheimer-Volkoff (TOV) equations, and various equations of state (EoS). We investigate the mass-radius relationship, stability criteria, and cooling mechanisms. Key findings highlight the impact of relativistic corrections and rotational effects on neutron star properties. The results demonstrate how integrating these advanced equations enhances the understanding of neutron star behavior and stability. This research provides a comprehensive framework for analyzing neutron star structures, with implications for future astrophysical studies.


Replicating Calculations Of A White Dwarf’S Mass And Size Using The Tov Equation, William (Ha Quang) Dang 2024 University of Adelaide, Australia

Replicating Calculations Of A White Dwarf’S Mass And Size Using The Tov Equation, William (Ha Quang) Dang

2024 REYES Proceedings

In this project we followed the instructions in the ”Neutron Stars for Undergraduates” paper to simulate the mass and size of a white dwarf star to be 1.233 solar masses and 0.0144 solar radius.


Nuclear Physics And Neutron Stars: Structure Of Compact Stellar Objects, Michel Geralddi Coria Magaña 2024 Palermo University, Argentina

Nuclear Physics And Neutron Stars: Structure Of Compact Stellar Objects, Michel Geralddi Coria Magaña

2024 REYES Proceedings

The Tolman-Oppenheimer-Volkoff (TOV) equations provide a theoretical framework for modeling the structure of neutron stars and white dwarfs in hydrostatic equilibrium. Using Python and MATLAB, we simulate the mass-radius relationship, pressure, and density profiles of these compact stars, focusing on how ionized plasma dynamics contribute to their stability. By incorporating particle simulations into the visualization process, we model the internal forces of neutron stars and white dwarfs, demonstrating how computational tools offer unique insights into these celestial objects. The results align well with theoretical predictions and provide a solid foundation for future studies incorporating additional physical effects such as magnetic …


A Computational Study On The Structural Limits Of Neutron Stars Under Relativistic Conditions And Nuclear Phenomena, Marcelo Siles 2024 University of Costa Rica, San José, San Pedro, Montes de Oca, Costa Rica

A Computational Study On The Structural Limits Of Neutron Stars Under Relativistic Conditions And Nuclear Phenomena, Marcelo Siles

2024 REYES Proceedings

This project investigates the modeling of neutron stars and white dwarfs using polytropic equations of state and relativistic corrections. By integrating relativistic effects into the Tolman-Oppenheimer-Volkoff (TOV) equations, we obtain more accurate predictions of neutron star properties, including mass-radius relationships and neutron degeneracy pressure. Non-relativistic models are inadequate under high pressures. Considering nucleon-nucleon interactions suggests that neutron stars can surpass the Tolman-Oppenheimer-Volkoff limit, theoretically reaching masses up to 2.3 𝑀⊙. However, empirical data supports a more realistic mass range of 1.5 to 2.3 𝑀⊙. The inclusion of neutron star crust modeling refines these predictions, indicating possible …


Digital Commons powered by bepress