Astrophysics and Astronomy Commons^™

Moments Of The Neutron G2 Structure Function At Intermediate Q2, Wolfgang Korsch, P. Solvignon, N. Liyanage, J.-P. Chen, Seonho Choi, K. Slifer, K. Aniol, T. Averett, W. Boeglin, A. Camsonne, G. D. Cates

Physics and Astronomy Faculty Publications

We present new experimental results for the ³He spin structure function g₂ in the resonance region at Q² values between 1.2 and 3.0(GeV/c)². Spin dependent moments of the neutron were extracted. Our main result, the inelastic contribution to the neutron d₂ matrix element, was found to be small at ⟨Q²⟩=2.4(GeV/c)² and in agreement with the lattice QCD calculation. The Burkhardt-Cottingham sum rule for ³He and the neutron was tested with the measured data and using the Wandzura-Wilczek relation for the low x unmeasured region.

Beam-Energy-Dependent Two-Pion Interferometry And The Freeze-Out Eccentricity Of Pions Measured In Heavy Ion Collisions At The Star Detector, J. Kevin Adkins, Renee Fatemi, Suvarna Ramachandran, G. Webb, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin

Physics and Astronomy Faculty Publications

We present results of analyses of two-pion interferometry in Au+Au collisions at √^S_NN=7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV measured in the STAR detector as part of the BNL Relativistic Heavy Ion Collider Beam Energy Scan program. The extracted correlation lengths (Hanbury-Brown–Twiss radii) are studied as a function of beam energy, azimuthal angle relative to the reaction plane, centrality, and transverse mass (m_T) of the particles. The azimuthal analysis allows extraction of the eccentricity of the entire fireball at kinetic freeze-out. The energy dependence of this observable is expected to be sensitive …

Smooth And Fast Versus Instantaneous Quenches In Quantum Field Theory, Sumit R. Das, Damián A. Galante, Robert C. Myers

Physics and Astronomy Faculty Publications

We examine in detail the relationship between smooth fast quantum quenches, characterized by a time scale δt, and instantaneous quenches, within the framework of exactly solvable mass quenches in free scalar field theory. Our earlier studies [1, 2] highlighted that the two protocols remain distinct in the limit δt → 0 because of the relation of the quench rate to the UV cut-off, i.e., 1/δt ≪ Λ always holds in the fast smooth quenches while 1/δt ∼ Λ for instantaneous quenches. Here we study UV finite quantities like correlators at …

Geometrization Conditions For Perfect Fluids, Scalar Fields, And Electromagnetic Fields, Charles G. Torre, Dionisios Krongos

Charles G. Torre

Rainich-type conditions giving a spacetime “geometrization” of matter fields in general relativity are reviewed and extended. Three types of matter are considered: perfect fluids, scalar fields, and electromagnetic fields. Necessary and sufficient conditions on a spacetime metric for it to be part of a perfect fluid solution of the Einstein equations are given. Formulas for constructing the fluid from the metric are obtained. All fluid results hold for any spacetime dimension. Geometric conditions on a metric which are necessary and sufficient for it to define a solution of the Einstein-scalar field equations and formulas for constructing the scalar field from …

Solubility And Detectability Of Hydrocarbons On The Surface Of Titan, Sandeep Singh

Graduate Theses and Dissertations

Titan’s thick atmosphere is enriched with organic compounds and its surface holds reservoirs of hydrocarbons. This makes Titan the only other candidate in our solar system (apart from Earth) to have stable liquid at the surface. The stability and characteristics of liquid and ices on the surface of Titan are of high importance in understanding its surface-atmosphere interactions. Titan’s hydrological cycle is similar to what we see on Earth, with the exception of methane (CH4) and ethane (C2H6) taking the place of water. The smoggy atmosphere veils the surface of Titan from the view of Cassini spacecraft, except at seven …

Origin Of The Diffuse, Far Ultraviolet Emission In The Interarm Regions Of M101., Alison F. Crocker, Rupali Chandar, Daniela Calzetti, Benne W. Holwerda, Claus Leitherer, Cristina C. Popescu, R. J. Tuffs

Faculty Scholarship

We present images from the Solar Blind Channel on the Hubble Space Telescope that resolve hundreds of farultraviolet (FUV) emitting stars in two ∼1 kpc2 interarm regions of the grand-design spiral M101. The luminosity functions of these stars are compared with predicted distributions from simple star formation histories, and are best reproduced when the star formation rate has recently declined (past 10–50 Myr). This pattern is consistent with stars forming within spiral arms and then streaming into the interarm regions. We measure the diffuse FUV surface brightness after subtracting all of the detected stars, clusters, and background galaxies. A residual …

The Spitzer Survey Of Stellar Structure In Galaxies (S4g) : Stellar Masses, Sizes, And Radial Profiles For 2352 Nearby Galaxies., Juan Carlos Muñoz-Mateos, Kartik Sheth, Michael Regan, Taehyun Kim, Jarkko Laine, Santiago Erroz-Ferrer, Armando Gil De Paz, Sebastien Comeron, Joannah Hinz, Eija Laurikainen, Heikki Salo, E. Athanassoula, Albert Bosma, Alexandre Y. Bouquin, Eva Schinnerer, Luis C. Ho, Johan H. Knapen, Sharon Meidt, Miguel Querejeta, Trisha Mizusawa, Mark Seibert, Seppo Laine, Helene M. Courtois

Faculty Scholarship

The Spitzer Survey of Stellar Structure in Galaxies is a volume, magnitude, and size-limited survey of 2352 nearby galaxies with deep imaging at 3.6 and 4.5 μm. In this paper, we describe our surface photometry pipeline and showcase the associated data products that we have released to the community. We also identify the physical mechanisms leading to different levels of central stellar mass concentration for galaxies with the same total stellar mass. Finally, we derive the local stellar mass–size relation at 3.6 μm for galaxies of different morphologies. Our radial profiles reach stellar mass surface densities below ~1 pc M …

Double Spin Asymmetries Of Inclusive Hadron Electroproduction From A Transversely Polarized 3He Target, C. Dutta, A. Kolarkar, Wolfgang Korsch, Y. X. Zhao, K. Allada, K. Aniol, J. R. M. Annand, T. Averett, F. Benmokhtar, W. Bertozzi, P. C. Bradshaw, P. Bosted, A. Camsonne

Physics and Astronomy Faculty Publications

We report the measurement of beam-target double spin asymmetries (A_LT) in the inclusive production of identified hadrons, e⃗ + ³He^↑→h+X, using a longitudinally polarized 5.9-GeV electron beam and a transversely polarized ³He target. Hadrons (π^±,K^±, and proton) were detected at 16^∘ with an average momentum ⟨P_h⟩=2.35 GeV/c and a transverse momentum (p_T) coverage from 0.60 to 0.68 GeV/c. Asymmetries from the ³He target were observed to be nonzero for π^± production when the target …

Hard Three-Loop Corrections To Hyperfine Splitting In Positronium And Muonium, Michael I. Eides, Valery A. Shelyuto

Physics and Astronomy Faculty Publications

We consider hard three-loop corrections to hyperfine splitting in muonium and positronium generated by the diagrams with closed electron loops. There are six gauge-invariant sets of such diagrams that generate corrections of order mα⁷. The contributions of these diagrams are calculated for an arbitrary electron-muon mass ratio without expansion in the small mass ratio. We obtain the formulas for contributions to hyperfine splitting that in the case of a small mass ratio describe corrections for muonium and in the case of equal masses describe corrections for positronium. The first few terms of the expansion of hard corrections in …

Observing Strategy For The Sdss-Iv/Manga Ifu Galaxy Survey, David R. Law, Renbin Yan, Matthew A. Bershady, Kevin Bundy, Brian Cherinka, Niv Drory, Nicholas Macdonald, José R. Sánchez-Gallego, David R. Wake, Anne-Marie Weijmans, Michael R. Blanton, Mark A. Klaene, Sean M. Moran, Sebastian F. Sanchez, Kai Zhang

Physics and Astronomy Faculty Publications

Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) is an integral-field spectroscopic survey that is one of three core programs in the fourth-generation Sloan Digital Sky Survey (SDSS-IV). MaNGA's 17 pluggable optical fiber-bundle integral field units (IFUs) will observe a sample of 10,000 nearby galaxies distributed throughout the SDSS imaging footprint (focusing particularly on the North Galactic Cap). In each pointing these IFUs are deployed across a 3° field; they yield spectral coverage 3600−10300 Å at a typical resolution R ~ 2000, and sample the sky with 2'' diameter fiber apertures with a total bundle fill factor of 56%. Observing …

The Spitzer Survey Of Stellar Structure In Galaxies (S4g): Stellar Masses, Sizes, And Radial Profiles For 2352 Nearby Galaxies, Juan Carlos Muñoz-Mateos, Kartik Sheth, Michael Regan, Trisha Mizusawa

Aerospace, Physics, and Space Science Faculty Publications

The Spitzer Survey of Stellar Structure in Galaxies is a volume, magnitude, and size-limited survey of 2352 nearby galaxies with deep imaging at 3.6 and 4.5 μm. In this paper, we describe our surface photometry pipeline and showcase the associated data products that we have released to the community. We also identify the physical mechanisms leading to different levels of central stellar mass concentration for galaxies with the same total stellar mass. Finally, we derive the local stellar mass–size relation at 3.6 μm for galaxies of different morphologies. Our radial profiles reach stellar mass surface densities below ~1 M pc-2 …

Kelt-7b: A Hot Jupiter Transiting A Bright V = 8.54 Rapidly Rotating F-Star, A. Bieryla, K. Collins, T. G. Beatty, J. Eastman, R. J. Siverd, J. Pepper, B. S. Gaudi, K. G. Stassun, C. Cañas, D. W. Latham, L. A. Buchhave, R. Sanchis-Ojeda, J. N. Winn, Eric L.N. Jensen, J. F. Kielkopf, K. K. Mcleod, J. Gregorio, K. D. Colón, R. Street, R. Ross, M. Penny, S. N. Mellon, T. E. Oberst, B. J. Fulton, J. Wang, P. Berlind, M. L. Calkins, G. A. Esquerdo, D. L. Depoy, A. Gould, J. Marshall, R. Pogge, M. Trueblood, P. Trueblood

Physics & Astronomy Faculty Works

We report the discovery of KELT-7b, a transiting hot Jupiter with a mass of 1.28+/- 0.18 M_J, radius of {1.533}_-0.047^+0.046 R_J, and an orbital period of 2.7347749+/- 0.0000039 days. The bright host star (HD 33643; KELT-7) is an F-star with V = 8.54, T_eff = 6789{}_-49⁺⁵⁰ K, [Fe/H] = {0.139}_-0.081^+0.075, and {log}\{\text{}}g\=4.149+/- 0.019. It has a mass of {1.535}_-0.054^+0.066 M_☉, a radius of {1.732}_-0.045^+0.043 R_☉, and is the fifth most massive, fifth hottest, and the ninth brightest star known to …

A Search For Planets And Brown Dwarfs Around Post Main Sequence Stars, Tomomi Otani

Theses and Dissertations

So far, the most promising theory for the existence of subdwarf B (sdB) stars is that they were formed during binary star evolution. This research was conducted to test this theory by searching for companions around six sdB pulsators (V391 Peg, HS 0702+6043, EC 20117-4014, PG 1219+534, PG 0911+456, and PG 1613+426) using the Observed-minus-Calculated (O-C) method. A star’s position in space will wobble due to the gravitational forces of any companion. If the star is emitting a periodic signal, the orbital motion of the star around the system’s center of mass causes periodic changes in the light pulse arrival …

Comparing Theory And Experiment For Analyte Transport In The First Vacuum Stage Of The Inductively Coupled Plasma Mass Spectrometer, Matthew R. Zachreson

Theses and Dissertations

The inductively coupled plasma mass spectrometer (ICP-MS) has been used in laboratories for many years. The majority of the improvements to the instrument have been done empirically through trial and error. A few fluid models have been made, which have given a general description of the flow through the mass spectrometer interface. However, due to long mean free path effects and other factors, it is very difficult to simulate the flow details well enough to predict how changing the interface design will change the formation of the ion beam. Towards this end, Spencer et al. developed FENIX, a direct simulation …

The Spitzer Survey Of Stellar Structure In Galaxies (S4g) : Precise Stellar Mass Distributions From Automated Dust Correction At 3.6 Μm., Miguel Querejeta, Sharon Meidt, Eva Schinnerer, Mauricio Cisternas, Juan Carlos Muñoz-Mateos, Kartik Sheth, Johan H. Knapen, Glenn Van De Ven, Mark A. Norris, Reynier Peletier, Eija Laurikainen, Heikki Salo, Benne W. Holwerda, E. Athanassoula, Albert Bosma, Brent Groves, Luis C. Ho, Dimitri A. Gadotti, Dennis Zaritsky, Michael Regan, Joannah Hinz, Armando Gil De Paz, Karin Menendez-Delmestre, Mark Seibert, Trisha Mizusawa, Taehyun Kim, Santiago Erroz-Ferrer, Jarkko Laine, Sebastien Comeron

Faculty Scholarship

The mid-infrared is an optimal window to trace stellar mass in nearby galaxies and the 3.6 mm IRAC band has been exploited to this effect, but such mass estimates can be biased by dust emission. We present our pipeline to reveal the old stellar flux at 3.6 μm and obtain stellar mass maps for more than 1600 galaxies available from the Spitzer Survey of Stellar Structure in Galaxies (S4 G). This survey consists of images in two infrared bands (3.6 and 4.5 mm ), and we use the Independent Component Analysis (ICA) method presented in Meidt et al. to separate …

The Sizes Of Candidate Z~9-10 Galaxies : Confirmation Of The Bright Candels Sample And Relation With Luminosity And Mass., Benne W. Holwerda, R. J. Bouwens, P. A. Oesch, R. Smit, G. D. Illingworth, I. Labbe

Faculty Scholarship

Recently, a small sample of six z ∼ 9–10 candidates was discovered in CANDELS that are ~-´ 10 20 more luminous than any of the previous z ∼ 9–10 galaxies identified over the HUDF/XDF and CLASH fields. We measure the sizes of these candidates to map out the size evolution of galaxies from the earliest observable times. Their sizes are also used to provide a valuable constraint on whether these unusual galaxy candidates are at high redshift. Using galfit to derive sizes from the CANDELS F160W images of these candidates, we find a mean size of 0. 13 0. 0 …

Analysis Of Angular Momentum In Planetary Systems And Host Stars, Stacy Ann Irwin

Theses and Dissertations

The spin angular momentum of single Main Sequence stars has long been shown to follow a primary power law of stellar mass, J ∝ Mα, excluding stars of <2 solar masses. Lower mass stars rotate more slowly with and have smaller moments of inertia, and as a result they contain much less spin angular momentum. A secondary power law describes the upper bound of angular momenta of these less massive stars with a steeper slope. The Solar System’s orbital angular momentum, however, is of the same order of magnitude as the primary law, whereas the Sun’s spin angular momentum is consistent with the secondary relationship. This suggests that planets are an important clue to answering questions about stellar angular momentum loss and transfer. With recent advances in exoplanet discovery and characterization, the angular momenta of exoplanetary systems can now be determined. A method is developed to calculate planetary system angular momenta from the spin and orbital angular momenta of a sample including 426 host stars and 532 planets. To maximize the size of the working sample, systems discovered by both the transit and radial velocity methods are included, and the biases of both techniques are identified. Self-consistent stellar moment of inertia parameters are interpolated from grids of stellar evolutionary models. Main Sequence host stars range from 0.6 to 1.7 solar masses, and their angular momenta are shown to agree well with previous studies of stellar angular momentum, generally falling on or below the appropriate power law, and exhibiting detection method biases. The systems’ angular momenta, including both the planetary orbital and stellar spin components, are widely spread above and below the primary power law, but on average agree well with the primary relationship. The results indicate that the primary power law describes angular momenta of stars of <2 solar masses well, when planetary angular momentum is included. This relationship also holds across host star evolutionary classifications. For 90% of the systems, the angular momentum contained in the planets is greater than the spin angular momentum of the host star, a characteristic shared by the Solar System. Undetected planets contribute significant bias to the system angular momentum as well as to the proportion of angular momentum contained in the planets. This bias is used to identify systems which are likely to harbor additional planets in already known planetary systems, assuming the Solar System’s proportions are typical.

Rotation Lightcurves Of Small Jovian Trojan Asteroids, Linda French, Robert Stephens, Daniel Coley, Lawrence Wasserman, Jennifer Sieben

Linda French

Coexisting Charge And Magnetic Orders In The Dimer-Chain Iridate Ba5Alir2O11, Jsaminka Terzic, J. C. Wang, Feng Ye, W. H. Song, Shujuan Yuan, Saicharan Aswartham, Lance E. De Long, S. V. Streltsov, D. I. Khomskii, Gang Cao

Physics and Astronomy Faculty Publications

We have synthesized and studied single-crystal Ba₅AlIr₂O₁₁ that features dimer chains of two inequivalent octahedra occupied by tetravalent Ir⁴⁺(5d⁵) and pentavalent Ir⁵⁺(5d⁴) ions, respectively. Ba₅AlIr₂O₁₁ is a Mott insulator that undergoes a subtle structural phase transition near T_S=210K and a magnetic transition at T_M=4.5K; the latter transition is surprisingly resistant to applied magnetic fields μ_oH≤12T but more sensitive to modest applied pressure (dT_M/dp≈+0.61K/GPa). All results indicate that the …

Solar Wind Energy Input To The Magnetosheath And At The Magnetopause, T. I. Pulkkinen, A. P. Dimmock, A. Osmane, K. Nykyri

Publications

Using Time History of Events and Macroscale Interactions During Substorms observations, we show that the efficiency of the energy entry through the magnetopause as measured by the Poynting vector normal component depends on the combination of the solar wind speed and the southward component of the interplanetary magnetic field (IMF): Most efficient energy transfer occurs when the IMF BZ is only moderately negative, and the solar wind speed is high. This means that for the same level of solar wind driver parameters (electric field, epsilon, or other), different combinations of V and BZ will produce different driving at the magnetopause. …