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Articles 61 - 90 of 111

Full-Text Articles in Stars, Interstellar Medium and the Galaxy

Remark On Vacuum Fluctuation As The Cause Of Universe Creation: Or How Neutrosophic Logic And Material Point Method May Resolve Dispute On The Origin Of The Universe Through Re-Reading Gen. 1:1-2, Florentin Smarandache, Victor Christianto Apr 2018

Remark On Vacuum Fluctuation As The Cause Of Universe Creation: Or How Neutrosophic Logic And Material Point Method May Resolve Dispute On The Origin Of The Universe Through Re-Reading Gen. 1:1-2, Florentin Smarandache, Victor Christianto

Branch Mathematics and Statistics Faculty and Staff Publications

Questions regarding the formation of the Universe and what was there before the existence of Early Universe have been great interest to mankind of all times. In recent decades, the Big Bang as described by the Lambda CDMStandard Model Cosmology has become widely accepted by majority of physics and cosmology communities. Among other things, we can cite A.A. Grib Pavlov who pointed out some problems of heavy particles creation out of vacuum and also other proposal of Creatio ex nihilo theory (CET). But the philosophical problems remain, as Vaas pointed out: Did the universe have a beginning or does it …


Thinking Out Loud On Primeval Atom, Big Bang & Biblical Account Of Creation, Florentin Smarandache, Victor Christianto Feb 2018

Thinking Out Loud On Primeval Atom, Big Bang & Biblical Account Of Creation, Florentin Smarandache, Victor Christianto

Branch Mathematics and Statistics Faculty and Staff Publications

In recent years, the Big Bang as described by the Lambda CDM-Standard Model Cosmology has become widely accepted by majority of physics and cosmology communities. Some people even have concluded that it has no serious alternative in horizon. Is that true? First, as we argued elsewhere, Big Bang relies on singularity, so, when we are able to describe the observed data without invoking singularity, then Big Bang model is no longer required. In this paper, we explore a few alternatives other than Big Bang which most cosmologists believe is the closest to biblical account of creation. We argue that re-reading …


Thinking Out Loud On Early Creation Through The Lens Of Hermeneutics Of Sherlock Holmes (Towards A Model Of Universe Based On Turbulence-Generated Sound Theory), Victor Christianto, Florentin Smarandache Jan 2018

Thinking Out Loud On Early Creation Through The Lens Of Hermeneutics Of Sherlock Holmes (Towards A Model Of Universe Based On Turbulence-Generated Sound Theory), Victor Christianto, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

In recent years, apparently the Big Bang as described by the Lambda CDM-Standard Model Cosmology has become widely accepted by majority of physics and cosmology communities. Even some people have concluded that it has no serious alternative in horizon. Is that true? First, as we argued elsewhere, Big Bang story relies on singularity. In other words, when we are able to describe the observed data without invoking singularity, then Big Bang model is no longer required. Therefore, here we explore a few alternative stories other than Big Bang story, which most cosmologists believe it is the nearest to Biblical account …


Effects Of Mass And Distance Uncertainties On Calculations Of Flux From Giant Molecular Clouds, Matt Coel Jan 2018

Effects Of Mass And Distance Uncertainties On Calculations Of Flux From Giant Molecular Clouds, Matt Coel

Dissertations, Master's Theses and Master's Reports

It is assumed that the distribution of the Milky Way cosmic rays, the cosmic ray ‘sea,’ is even throughout the Galaxy. This assumption can be tested by measuring gamma rays produced from cosmic ray interactions with Giant Molecular Clouds. The gamma ray flux depends on the mass and distance of a given molecular cloud as well as the cosmic ray flux in its vicinity. Thus a predicted gamma ray flux can be compared to actual flux data from a detector. Uncertainties from measuring the mass of and distance to the clouds are taken into account for this prediction. This report …


Energy From Active Galactic Nuclei And The Effects On Host Spiral Galaxies, Amanda Schilling Dec 2017

Energy From Active Galactic Nuclei And The Effects On Host Spiral Galaxies, Amanda Schilling

Graduate Theses and Dissertations

I have investigated the energy output of active galactic nuclei (AGN) in order to understand how these objects evolve and the impact they may have on host galaxies. First, I looked at a sample of 96 AGN at redshifts $z \sim 2, 3,$ and $4$ which have imaging and thus luminosity measurements in the $griz$ and $JHK$ observed wavebands. For these galaxies, I have co-epochal data across those bands which accounted for variability in AGN luminosity. I used the luminosity measurements in the five bands to construct spectral energy distributions (SED) in the emitted optical-UV bands for each AGN. I …


Discovery Of Very-High-Energy Emission From Rgb J2243+203 And Derivation Of Its Redshift Upper Limit, P. T. Reynolds, Et Al Nov 2017

Discovery Of Very-High-Energy Emission From Rgb J2243+203 And Derivation Of Its Redshift Upper Limit, P. T. Reynolds, Et Al

Physical Sciences Publications

Very-high-energy (VHE; > 100 GeV) gamma-ray emission from the blazar RGB J2243+203 was discovered with the VERITAS Cherenkov telescope array, during the period between 2014 December 21 and 24. The VERITAS energy spectrum from this source can be fitted by a power law with a photon index of 4.6 ± 0.5, and a flux normalization at 0.15 TeV of . The integrated Fermi-LAT flux from 1 to 100 GeV during the VERITAS detection is , which is an order of magnitude larger than the four-year-averaged flux in the same energy range reported in the 3FGL catalog, (). The detection with …


Characterizing Cool Brown Dwarfs And Low-Mass Companions With Low-Resolution Near-Infrared Spectra, Paige Godfrey Jun 2017

Characterizing Cool Brown Dwarfs And Low-Mass Companions With Low-Resolution Near-Infrared Spectra, Paige Godfrey

Dissertations, Theses, and Capstone Projects

Exoplanet direct detections are reaching the temperature regime of cool brown dwarfs, motivating further understanding of the coolest substellar atmospheres. These objects, T and Y dwarfs, are numerous and isolated in the field, thus making them easier to study in detail than objects in companion systems. Brown dwarf spectral types are derived from spectral morphology and generally appear to correspond with decreasing mass and effective temperature (Teff). However, spectral subclasses of the colder objects do not share this monotonic temperature correlation, indicating that secondary parameters (gravity, metallicity, dust) significantly influence spectral morphology. These secondary atmospheric parameters can provide …


Have We Found Our Neighbors? The Search For Habitable Planets Outside Our Solar System, Madeline Galbraith Apr 2017

Have We Found Our Neighbors? The Search For Habitable Planets Outside Our Solar System, Madeline Galbraith

D.U.Quark

No abstract provided.


Prospecting For Iron In The Galactic Supernova Remnant W49b, Eddi Akers, Taylor Ray, Thomas G. Pannuti Apr 2017

Prospecting For Iron In The Galactic Supernova Remnant W49b, Eddi Akers, Taylor Ray, Thomas G. Pannuti

Celebration of Student Scholarship Poster Sessions Archive

No abstract provided.


Diffuse Gamma-Ray Emission From Nearby Molecular Clouds As A Probe Of Cosmic Ray Density Variations, Ryan Abrahams Feb 2017

Diffuse Gamma-Ray Emission From Nearby Molecular Clouds As A Probe Of Cosmic Ray Density Variations, Ryan Abrahams

Dissertations, Theses, and Capstone Projects

We analyze gamma-ray emission from nearby, interstellar molecular clouds in order to calibrate current tracers of the interstellar medium and to probe local cosmic ray gradients. Gamma-rays detected by the Fermi Gamma-ray Space Telescope are created when cosmic rays collide with atomic nuclei in the interstellar medium, and thus provide a unique, unbiased view of the distribution of gas. The gamma-ray flux per proton in the interstellar medium, also known as the gamma-ray emissivity, contains information about the density of high energy cosmic rays. These cosmic rays are born in supernovae shock waves and diffuse throughout the Galaxy. The cosmic …


Data Mining By Grid Computing In The Search For Extrasolar Planets, Oisin Creaner [Thesis] Jan 2017

Data Mining By Grid Computing In The Search For Extrasolar Planets, Oisin Creaner [Thesis]

Doctoral

A system is presented here to provide improved precision in ensemble differential photometry. This is achieved by using the power of grid computing to analyse astronomical catalogues. This produces new catalogues of optimised pointings for each star, which maximise the number and quality of reference stars available. Astronomical phenomena such as exoplanet transits and small-scale structure within quasars may be observed by means of millimagnitude photometric variability on the timescale of minutes to hours. Because of atmospheric distortion, ground-based observations of these phenomena require the use of differential photometry whereby the target is compared with one or more reference stars. …


Fundamental Parameters Of The Lowest Mass Stars To The Highest Mass Planets, Joseph C. Filippazzo Sep 2016

Fundamental Parameters Of The Lowest Mass Stars To The Highest Mass Planets, Joseph C. Filippazzo

Dissertations, Theses, and Capstone Projects

The physical and atmospheric properties of ultracool dwarfs are deeply entangled due to the degenerate effects of mass, age, metallicity, clouds and dust, activity, rotation, and possibly formation mechanism on their observed properties. Accurate fundamental parameters for a wide range of substellar objects are crucial to testing stellar and planetary formation theories. To determine these quantities, we construct flux-calibrated spectral energy distributions (SEDs) for 234 M, L, T, and Y dwarfs and calculate bolometric luminosity (Lbol), effective temperature (Teff), mass, surface gravity, radius, spectral indexes, synthetic photometry, and bolometric corrections (BCs) for each object. We use …


Experimental Simulations Of Recurring Slope Lineae And Other Flow Formation Features On Mars, Julia Ann Heydenreich Aug 2016

Experimental Simulations Of Recurring Slope Lineae And Other Flow Formation Features On Mars, Julia Ann Heydenreich

Graduate Theses and Dissertations

Various flow formation features from gullies to recurring slope lineae (RSL) have been identified across the martian surface. The formation of these geologic features are still being determined. Recently, several aspects of these flow features indicate that salt water flows in the subsurface during the warmer months when the ice melts. This paper explores the formation of these processes using laboratory experimental simulations. Experiments were conducted in a wooden flume under varying martian conditions of temperature, slope angle, regolith simulant and a liquid subsurface flow. By adjusting the flume at specific heights, several slopes were obtained to mimic the slopes …


Studying Solar Limb Darkening In H-Alpha With A Coronado Pst, Jessica N. Farrell, Jennifer Birriel May 2016

Studying Solar Limb Darkening In H-Alpha With A Coronado Pst, Jessica N. Farrell, Jennifer Birriel

Celebration of Student Scholarship Poster Sessions Archive

No abstract provided.


Probing The Fitting Accuracy Of Active Galaxy Spectra, Aaron T. Line Mar 2016

Probing The Fitting Accuracy Of Active Galaxy Spectra, Aaron T. Line

Physics

Prior to this study, Dr. Vardha N. Bennert and collaborators selected a sample of ~100 local active galaxies to study the relationships between black hole mass and host galaxy properties. The broad Hβ width is necessary to determine black hole mass. This value is determined using a spectral decomposition code was scripted in IDL by Dr. Daeseong Park. The script fit spectral features and collected data for properties such as width of emission lines and continuum contribution percentages. The results were logged for further analysis.

To probe the accuracy of the fitting process, artificial spectra were created and fitted to …


A Search For Brief Optical Flashes Associated With The Seti Target Kic 8462852, P. T. Reynolds, Et Al Feb 2016

A Search For Brief Optical Flashes Associated With The Seti Target Kic 8462852, P. T. Reynolds, Et Al

Physical Sciences Publications

The F-type star KIC 8462852 has recently been identified as an exceptional target for search for extraterrestrial intelligence (SETI) observations. We describe an analysis methodology for optical SETI, which we have used to analyze nine hours of serendipitous archival observations of KIC 8462852 made with the VERITAS gamma-ray observatory between 2009 and 2015. No evidence of pulsed optical beacons, above a pulse intensity at the Earth of approximately , is found. We also discuss the potential use of imaging atmospheric Cherenkov telescope arrays in searching for extremely short duration optical transients in general.


Exceptionally Bright Tev Flares From The Binary Ls I+61 Degrees 303, P. T. Reynolds, Et Al Jan 2016

Exceptionally Bright Tev Flares From The Binary Ls I+61 Degrees 303, P. T. Reynolds, Et Al

Physical Sciences Publications

The TeV binary system LS I +61° 303 is known for its regular, non-thermal emission pattern that traces the orbital period of the compact object in its 26.5 day orbit around its B0 Ve star companion. The system typically presents elevated TeV emission around apastron passage with flux levels between 5% and 15% of the steady flux from the Crab Nebula (>300 GeV). In this article, VERITAS observations of LS I +61° 303 taken in late 2014 are presented, during which bright TeV flares around apastron at flux levels peaking above 30% of the Crab Nebula flux were detected. …


Modeling Extrasolar Trojan Asteroids In Gravitational Potentials Of Migrating Jovian-Like Planets To Inform Future Observations, Austin Hinkel Jan 2016

Modeling Extrasolar Trojan Asteroids In Gravitational Potentials Of Migrating Jovian-Like Planets To Inform Future Observations, Austin Hinkel

Lewis Honors College Capstone Collection

In this paper, I construct a program to map the evolution of the potential in a planet-star system where a planet with a few Jupiter masses migrates inward. Given a trojan asteroid librating around the fourth or fifth Lagrange point, the asteroid follows the evolving equipotential lines of the slowly changing potential map. As the planet and its trojan asteroids migrate inward towards the host star, the trojan asteroid librations become tighter, providing a denser “cloud” of trojan asteroids. Such a change in the density of trojan asteroids is examined with the intent to deduce the likelihood of detection via …


Determining The Relationship Between The [Oiii] 5007 Å Emission Line Profile And The Stellar Velocity Dispersion In Active Galaxies, Nathaniel Milgram Jun 2015

Determining The Relationship Between The [Oiii] 5007 Å Emission Line Profile And The Stellar Velocity Dispersion In Active Galaxies, Nathaniel Milgram

Physics

The empirical relation between the stellar velocity dispersion (SVD) of the bulge and the mass of the central supermassive black hole (BH) suggests a link between host galaxy and BH evolution. For active galactic nuclei (AGNs), the BH mass (MBH) can be estimated in a straightforward way from the Doppler broadening of the broad emission lines using the so-called virial method. However, the powerful AGN continuum emission often outshines the underlying stellar absorption lines, making it difficult to measure SVD of the host galaxy. Thus, the MBH - SVD relation is difficult to establish for galaxies containing AGNs. As a …


Defining The Circumstellar Habitable Zone, Blake Cervetti, Joanna Mccall May 2015

Defining The Circumstellar Habitable Zone, Blake Cervetti, Joanna Mccall

DePaul Discoveries

The study of habitable exoplanets is a rapidly expanding field in astronomy. Exoplanets are planets that orbit stars other than our own sun. One of the keys to knowing whether or not an exoplanet is habitable is by studying the circumstellar habitable zone, or CHZ. Over the past several years, the defined limits of the CHZ have become susceptible to change as new parameters and factors are found to affect a planets habitability. There are many factors that affect its habitability, including the composition of the star, the mass of the planet, the planets atmosphere, etc. Our focus is divided …


Unmatter Plasma, Relativistic Oblique-Length Contraction Factor, Neutrosophic Diagram And Neutrosophic Degree Of Paradoxicity: Articles And Notes, Florentin Smarandache Jan 2015

Unmatter Plasma, Relativistic Oblique-Length Contraction Factor, Neutrosophic Diagram And Neutrosophic Degree Of Paradoxicity: Articles And Notes, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

This book has four parts. In the first part, we collected five recent papers, published before in Progress in Physics, but reviewed. In the first paper, we approach a novel form of plasma, Unmatter Plasma. The electron-positron beam plasma was generated in the laboratory in the beginning of 2015. This experimental fact shows that unmatter, a new form of matter that is formed by matter and antimatter bind together (mathematically predicted a decade ago) really exists. That is the electron-positron plasma experiment of 2015 is the experimentum crucis verifying the mathematically predicted unmatter. In the second paper, we generalize the …


Constraints On Very High Energy Emission From Grb 130427a, P. T. Reynolds, Et Al Oct 2014

Constraints On Very High Energy Emission From Grb 130427a, P. T. Reynolds, Et Al

Physical Sciences Publications

Prompt emission from the very fluent and nearby (z = 0.34) gamma-ray burst GRB 130427A was detected by several orbiting telescopes and by ground-based, wide-field-of-view optical transient monitors. Apart from the intensity and proximity of this GRB, it is exceptional due to the extremely long-lived high-energy (100 MeV to 100 GeV) gamma-ray emission, which was detected by the Large Area Telescope on the Fermi Gamma-Ray Space Telescope for ~70 ks after the initial burst. The persistent, hard-spectrum, high-energy emission suggests that the highest-energy gamma rays may have been produced via synchrotron self-Compton processes though there is also evidence that …


Dipole Bound Excited States Of Polycyclic Aromatic Hydrocarbons Containing Nitrogen And Their Relation To The Interstellar Medium, Mallory L. Theis Apr 2014

Dipole Bound Excited States Of Polycyclic Aromatic Hydrocarbons Containing Nitrogen And Their Relation To The Interstellar Medium, Mallory L. Theis

Honors College Theses

Polycyclic aromatic hydrocarbons (PAHs) are the most abundant type of molecule present in the interstellar medium (ISM). It has been hypothesized that nitrogen replacement within a ring is likely for PAHs present in the ISM. Additionally, electrons, protons, and hydrogen atoms are readily added to or removed from PAHs creating a truly diverse set of chemistries in various interstellar regions. The presence of a nitrogen within a PAH (called a PANH herein) that is additionally dehydrogenated leads to a neutral radical with a large dipole moment. It has recently been shown through the use of high-level quantum chemical computations for …


[Sabbatical Report], Louis-Gregory Strolger Jan 2014

[Sabbatical Report], Louis-Gregory Strolger

Sabbatical Reports

I spent my AY2014 sabbatical year at the Space Telescope Science Institute (STScI), with plans of completing the analyses of supernova rates for both thermonuclear and corecolliape events in high redshift galaxies from the Multi-cycle Treasury Projects with the Hubble Space Telescope.


Characterization Of Samples For Optimization Of Infrared Stray Light Coatings, Carey L. Baxter, Rebecca Salvemini, Zaheer A. Ali, Patrick Waddell, Greg Perryman, Bob Thompson Aug 2013

Characterization Of Samples For Optimization Of Infrared Stray Light Coatings, Carey L. Baxter, Rebecca Salvemini, Zaheer A. Ali, Patrick Waddell, Greg Perryman, Bob Thompson

STAR Program Research Presentations

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) is a converted 747SP that houses a 2.5 m telescope that observes the sky through an opening in the side of the aircraft. Because it flies at altitudes up to 45,000 feet, SOFIA gets 99.99% transmission in the infrared. Multiple science instruments mount one at a time on the telescope to interpret infrared and visible light from target sources. Ball Infrared Black (BIRB) currently coats everything that the optics sees inside the telescope assembly (TA) cavity in order to eliminate noise from the glow of background sky, aircraft exhaust, and other sources. A …


Analyzing The Performance Of The Sofia Infrared Telescope, Sarah M. Bass, Jeffrey Van Cleve, Zaheer Ali Aug 2013

Analyzing The Performance Of The Sofia Infrared Telescope, Sarah M. Bass, Jeffrey Van Cleve, Zaheer Ali

STAR Program Research Presentations

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is an airborne near-space observatory onboard a modified Boeing 747-SP aircraft, which flies at altitudes of 45,000 ft., above 99% of the Earth’s water vapor. SOFIA contains an effective 2.5 m infrared (IR) telescope that has a dichroic tertiary mirror, reflecting IR and visible wavelengths to the science instrument (SI) and focal plane imager (FPI), respectively. To date, seven different SIs have been designed to cover a wide range of wavelengths and spectral resolutions. Since the telescope operates in the infrared, different techniques, including chopping, nodding, and dithering, are used to reduce the …


Unsolved Problems In Special And General Relativity, Florentin Smarandache, Fu Yuhua, Zhao Fengjuan Jan 2013

Unsolved Problems In Special And General Relativity, Florentin Smarandache, Fu Yuhua, Zhao Fengjuan

Branch Mathematics and Statistics Faculty and Staff Publications

This book includes 21 papers written by 23 authors and co-authors. All papers included herein are produced by scholars from People’s Republic of China, except two papers written by Prof. L. Sapogin, V. A. Dzhanibekov, Yu. A. Ryabov from Russia, and by Prof. Florentin Smarandache from USA. The editors hope that all these papers will contribute to the advance of scholarly research on several aspects of Special and General Relativity. This book is suitable for students and scholars interested in studies on physics. The first paper is written by Hua Di. He writes that Einstein’s general theory of relativity cannot …


Telescope Assembly Alignment Simulator Performance Optimization, Joshua G. Thompson, Brian Eney, Zaheer Ali, Bob Thompson Aug 2012

Telescope Assembly Alignment Simulator Performance Optimization, Joshua G. Thompson, Brian Eney, Zaheer Ali, Bob Thompson

STAR Program Research Presentations

The Telescope Assembly Alignment Simulator (TAAS) calibrates scientific instruments (SI’s) that are installed on the Stratospheric Observatory For Infrared Astronomy (SOFIA). An SI’s accuracy is directly dependent on the consistent performance of the TAAS, which has never been fully characterized. After designing various thermal and optical experiments to identify the current unknowns of TAAS, we now have a far better grasp on how the equipment behaves.


Light Vs. Quantum Gravity, Irving Martinez^* Apr 2012

Light Vs. Quantum Gravity, Irving Martinez^*

COURI Symposium Abstracts, Spring 2012

No abstract provided.


A Possible Detection Of Occultation By A Proto-Planetary Clump In Gm Cephei, W. P. Chen, S. C.-L. Hu, R. Errmann, Ch. Adam, Laurence A. Marschall Jan 2012

A Possible Detection Of Occultation By A Proto-Planetary Clump In Gm Cephei, W. P. Chen, S. C.-L. Hu, R. Errmann, Ch. Adam, Laurence A. Marschall

Physics and Astronomy Faculty Publications

GM Cep in the young (~ 4 Myr) open cluster Trumpler 37 has been known to be an abrupt variable and to have a circumstellar disk with very active accretion. Our monitoring observations in 2009–2011 revealed the star to show sporadic ?are events, each with brightening of . 0.5 mag lasting for days. These brightening events, associated with a color change toward the blue, should originate from an increased accretion activity. Moreover, the star also underwent a brightness drop of ~ 1 mag lasting for about a month, during which the star became bluer when fainter. Such brightness drops seem …