Astrophysics and Astronomy Commons^™

On The Progenitors Of Type Ia Supernovae, Mario Livio, Paolo Mazzali

Physics & Astronomy Faculty Research

We review all the models proposed for the progenitor systems of Type Ia supernovae and discuss the strengths and weaknesses of each scenario when confronted with observations. We show that all scenarios encounter at least a few serious difficulties, if taken to represent a comprehensive model for the progenitors of all Type Ia supernovae (SNe Ia). Consequently, we tentatively conclude that there is probably more than one channel leading SNe Ia. While the single-degenerate scenario (in which a single white dwarf accretes mass from a normal stellar companion) has been studied in some detail, the other scenarios will need a …

Palfa Discovery Of A Highly Relativistic Double Neutron Star Binary, K. Stovall, P. C.C. Freire, S. Chatterjee, P. B. Demorest, D. R. Lorimer, M. A. Mclaughlin, N. Pol, Keeisi Caballero, Richard S. Camuccio, Fredrick A. Jenet

Physics & Astronomy Faculty Publications

We report the discovery and initial follow-up of a double neutron star (DNS) system, PSR J1946+2052, with the Arecibo L-Band Feed Array pulsar (PALFA) survey. PSR J1946+2052 is a 17 ms pulsar in a 1.88 hr, eccentric (e = 0.06) orbit with a 1.2 M o companion. We have used the Jansky Very Large Array to localize PSR J1946+2052 to a precision of 0.″09 using a new phase binning mode. We have searched multiwavelength catalogs for coincident sources but did not find any counterparts. The improved position enabled a measurement of the spin period derivative of the pulsar (P = …

Precise Ages Of Field Stars From White Dwarf Companions, M. Fouesneau, H-W. Rix, T. Von Hippel, D. W. Hogg, H. Tian

Publications

Observational tests of stellar and Galactic chemical evolution call for the joint knowledge of a star’s physical parameters, detailed element abundances, and precise age. For cool main-sequence (MS) stars the abundances of many elements can be measured from spectroscopy, but ages are very hard to determine. The situation is different if the MS star has a white dwarf (WD) companion and a known distance, as the age of such a binary system can then be determined precisely from the photometric properties of the cooling WD. As a pilot study for obtaining precise age determinations of field MS stars, we identify …

Sdss-Iv Manga: Modelling The Metallicity Gradients Of Gas And Stars – Radially Dependent Metal Outflow Versus Imf, Jianhui Lian, Daniel Thomas, Claudia Maraston, Daniel Goddard, Taniya Parikh, J. G. Fernández-Trincado, Alexandre Roman-Lopes, Yu Rong, Baitian Tang, Renbin Yan

Physics and Astronomy Faculty Publications

In our previous work, we found that only two scenarios are capable of reproducing the observed integrated mass–metallicity relations for the gas and stellar components of local star-forming galaxies simultaneously. One scenario invokes a time-dependent metal outflow loading factor with stronger outflows at early times. The other scenario uses a time-dependent initial mass function (IMF) slope with a steeper IMF at early times. In this work, we extend our study to investigate the radial profile of gas and stellar metallicity in local star-forming galaxies using spatially resolved spectroscopic data from the SDSS-IV MaNGA survey. We find that most galaxies show …

Frb 121102: A Repeatedly Combed Neutron Star By A Nearby Low-Luminosity Accreting Supermassive Black Hole, Bing Zhang

Physics & Astronomy Faculty Research

The origin of fast radio bursts (FRBs) remains mysterious. Recently, the only repeating FRB source, FRB 121102, was reported to possess an extremely large and variable rotation measure (RM). The inferred magnetic field strength in the burst environment is comparable to that in the vicinity of the supermassive black hole Sagittarius A* of our Galaxy. Here, we show that all of the observational properties of FRB 121102 (including the high RM and its evolution, the high linear polarization degree, an invariant polarization angle across each burst and other properties previously known) can be interpreted within the "cosmic comb" model, which …

Where Is Oh And Does It Trace The Dark Molecular Gas (Dmg)?, Di Li, Ningyu Tang, Hiep Nguyen, J. R. Dawson, Carl Heiles, Duo Xu, Zhichen Pan, Paul F. Goldsmith, Steven J. Gibson, Claire E. Murray, Tim Robishaw, N. M. Mcclure-Griffiths, John Dickey, Jorge Pineda, Snežana Stanimirović, L. Bronfman, Thomas Troland

Physics and Astronomy Faculty Publications

Hydroxyl (OH) is expected to be abundant in diffuse interstellar molecular gas because it forms along with H₂ under similar conditions and forms within a similar extinction range.

For the remainder of the abstract, please download this article or visit: https://doi.org/10.3847/1538-4365/aaa762

Cosmological Consequences Of Classical Flavor-Space Locked Gauge Field Radiation, Jannis Bielefeld, Robert R. Caldwell

Dartmouth Scholarship

We propose a classical SU(2) gauge field in a flavor-space locked configuration as a species of radiation in the early Universe, and show that it would have a significant imprint on a primordial stochastic gravitational wave spectrum. In the flavor-space locked configuration, the electric and magnetic fields of each flavor are parallel and mutually orthogonal to other flavors, with isotropic and homogeneous stress energy. Due to the non-Abelian coupling, the gauge field breaks the symmetry between left- and right-circularly polarized gravitational waves. This broken chiral symmetry results in a unique signal: nonzero cross-correlation of the cosmic microwave background temperature and …

All-Sky Search For Long-Duration Gravitational Wave Transients In The First Advanced Ligo Observing Run, B. P. Abbott, K. Gill, B. Hughey, J. W. W. Pratt, E. Rhoades, E. Schmidt, S. G. Schwalbe, M. J. Szczepańczyk, M. Zanolin, Et Al.

Publications

We present the results of a search for long-duration gravitational wave transients in the data of the LIGO Hanford and LIGO Livingston second generation detectors between and , with a total observational time of . The search targets gravitational wave transients of 10–500 s duration in a frequency band of 24–2048 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. No significant events were observed. As a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. We also show that the …

Effects Of Data Quality Vetoes On A Search For Compact Binary Coalescences In Advanced Ligo's First Observing Run, B. P. Abbott, K. Gill, B. Hughey, J. Pratt, M. J. Szczepańczyk, M. Zanolin, Et Al.

Publications

The first observing run of Advanced LIGO spanned 4 months, from 12 September 2015 to 19 January 2016, during which gravitational waves were directly detected from two binary black hole systems, namely GW150914 and GW151226. Confident detection of gravitational waves requires an understanding of instrumental transients and artifacts that can reduce the sensitivity of a search. Studies of the quality of the detector data yield insights into the cause of instrumental artifacts and data quality vetoes specific to a search are produced to mitigate the effects of problematic data. In this paper, the systematic removal of noisy data from analysis …

Scientometric Study Of Research Productivity Of Aries, Nainital, Satish Kumar

Library Philosophy and Practice (e-journal)

This paper describes scientometric study of research productivity of Scientists of Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital. The purpose of this study is to evaluate the research performance of ARIES, Nainital. For this study, the data is collected from Web of Science (WoS) bibliographical database for the period of 15 years from 2001-2015 and analyzed. 574 research paper has been published over 15 years of time in which 510 research publications are in referred journals and 64 research publications are in conferences, symposiums, bulletins etc. This paper identifies the scientists of ARIES those are active; the areas in …

Direct Collapse To Supermassive Black Hole Seeds With Radiative Transfer: Isolated Halos, Yang Luo, Kazem Ardaneh, Isaac Shlosman, Kentaro Nagamine, John H. Wise, Mitchell C. Begelman

Physics and Astronomy Faculty Publications

Direct collapse within dark matter haloes is a promising path to form supermassive black hole seeds at high redshifts. The outer part of this collapse remains optically thin. However, the innermost region of the collapse is expected to become optically thick and requires to follow the radiation field in order to understand its evolution. So far, the adiabatic approximation has been used exclusively for this purpose. We apply radiative transfer in the flux-limited diffusion (FLD) approximation to solve the evolution of coupled gas and radiation for isolated haloes. We find that (1) the photosphere forms at 10⁻⁶ pc and …

A Disk Origin For The Monoceros Ring And A13 Stellar Overdensities, Allyson A. Sheffield, Adrian M. Price-Whelan, Anastasios Tzanidakis, Kathryn V. Johnston, Chervin F.P. Laporte, Branimir Sesar

Publications and Research

The Monoceros Ring (also known as the Galactic Anticenter Stellar Structure) and A13 are stellar overdensities at estimated heliocentric distances of d ~ 11 kpc and 15 kpc observed at low Galactic latitudes toward the anticenter of our Galaxy. While these overdensities were initially thought to be remnants of a tidally disrupted satellite galaxy, an alternate scenario is that they are composed of stars from the Milky Way (MW) disk kicked out to their current location due to interactions between a satellite galaxy and the disk. To test this scenario, we study the stellar populations of the Monoceros Ring and …

Spectroscopic Characterization Of Galaxy Clusters In Rcs-1: Spectroscopic Confirmation, Redshift Accuracy, And Dynamical Mass–Richness Relation, David G. Gilbank, L. Felipe Barrientos, Erica Ellingson, Kris Blindert, H. K. C. Lee, T. Anguita, M. D. Gladders, P. B. Hall, G. Hertling, L. Infante, Renbin Yan, M. Carrasco, Cristina Garcia-Vergara, K. S. Dawson, C. Lidman, T. Morokuma

Physics and Astronomy Faculty Publications

We present follow-up spectroscopic observations of galaxy clusters from the first Red-sequence Cluster Survey (RCS-1). This work focuses on two samples, a lower redshift sample of ∼30 clusters ranging in redshift from z ∼ 0.2–0.6 observed with multiobject spectroscopy (MOS) on 4–6.5-m class telescopes and a z ∼ 1 sample of ∼10 clusters 8-m class telescope observations. We examine the detection efficiency and redshift accuracy of the now widely used red-sequence technique for selecting clusters via overdensities of red-sequence galaxies. Using both these data and extended samples including previously published RCS-1 spectroscopy and spectroscopic redshifts from SDSS, we find that …

A Search For Tensor, Vector, And Scalar Polarizations In The Stochastic Gravitational-Wave Background, Tiffany Summerscales, Ligo Scientific Collaboration And The Virgo Collaboration

Faculty Publications

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually-unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically-polarized gravitational waves. We find no evidence …

The Prospect Of Human Spiritual Unity Through The Cosmic Story, Philip Novak

Collected Faculty Scholarship

Thomas Berry and Brian Swimme have noted that, “we seem to be moving beyond any religious expression so far known to the human into a meta-religious age that seems to be a new comprehensive context for all religions.” That “new comprehensive context” is of course now known as Big History -- a.k.a. the Evolutionary Epic, Universe Story, or New Cosmic Story—the astonishing contemporary synthesis of modern sciences that tells a coherent story of the evolution of the universe from the Big Bang 13.7 billion years ago to the present.

Yet with the notable exception of the writings of Berry and …

What Makes The Family Of Barred Disc Galaxies So Rich: Damping Stellar Bars In Spinning Haloes, Angela Collier, Isaac Shlosman, Clayton Heller

Physics and Astronomy Faculty Publications

We model and analyse the secular evolution of stellar bars in spinning dark matter (DM) haloes with the cosmological spin λ ∼ 0–0.09. Using high-resolution stellar and DM numerical simulations, we focus on angular momentum exchange between stellar discs and DM haloes of various axisymmetric shapes – spherical, oblate, and prolate. We find that stellar bars experience a diverse evolution that is guided by the ability of parent haloes to absorb angular momentum, J, lost by the disc through the action of gravitational torques, resonant and non-resonant. We confirm that dynamical bar instability is accelerated via resonant J-transfer …

Metallic Mxenes: A New Family Of Materials For Flexible Triboelectric Nanogenerators, Yongchang Dong, Sai Sunil Kumar Mallineni, Kathleen Maleski, Herbert Behlow, Vadym N. Mochalin, Apparao M. Rao, Yury Gogosti, Ramakrishna Podila

Publications

Wearable and flexible electronics warrant the development of self-powered devices to circumvent the limitations imposed by traditional energy storage devices. Triboelectric nanogenerators (TENGs) that convert waste mechanical energy from human motion into electric power offer a solution. Highly electronegative and conducting TENG materials that support the generation of both large potential differences and high currents are imperative for effectively harvesting electric power from human muscle movements. Here, we demonstrate that two-dimensional MXenes (e.g., titanium carbide Ti3C2Tx, where Tx stands for surface functional groups such as -O, -OH, and -F) are a family of electrically conducting materials that are triboelectrically more …

Kelt-21b: A Hot Jupiter Transiting The Rapidly Rotating Metal-Poor Late-A Primary Of A Likely Hierarchical Triple System, M. C. Johnson, J. E. Rodriguez, G. Zhou, E. J. Gonzales, P. A. Cargile, J. R. Crepp, K. Penev, K. G. Stassun, B. S. Gaudi, K. D. Colón, D. J. Stevens, K. G. Strassmeier, I. Ilyin, K. A. Collins, J. F. Kielkopf, T. E. Oberst, L. Maritch, P. A. Reed, J. Gregorio, V. Bozza, S. Calchi Novati, G. D'Ago, G. Scarpetta, R. Zambelli, D. W. Latham, A. Bieryla, W. D. Cochran, M. Endl, J. Tayar, A. Serenelli, V. S. Aguirre, S. P. Clarke, M. Martinez, M. Spencer, J. Trump, M. D. Joner, A. G. Bugg, E. G. Hintz, D. C. Stephens, A. Arredondo, A. Benzaid, S. Yazdi, K. K. Mcleod, Eric L.N. Jensen, D. A. Hancock, R. L. Sorber, D. H. Kasper, H. Jang-Condell, T. G. Beatty, T. Carroll, J. Eastman, D. James, R. B. Kuhn, J. Labadie-Bartz, M. B. Lund, M. Mallonn, J. Pepper, R. J. Siverd, X. Yao, David H. Cohen, I. A. Curtis, D. L. Depoy, B. J. Fulton, M. T. Penny, H. Relles, C. Stockdale, T.-G. Tan, S. Villanueva Jr.

Physics & Astronomy Faculty Works

We present the discovery of KELT-21b, a hot Jupiter transiting the V = 10.5 A8V star HD 332124. The planet has an orbital period of P = 3.6127647 ± 0.0000033 days and a radius of 1.586 (+0.039)/(-0.040) R_J. We set an upper limit on the planetary mass of M_P < 3.91 M_J at 3σ confidence. We confirmed the planetary nature of the transiting companion using this mass limit and Doppler tomographic observations to verify that the companion transits HD 332124. These data also demonstrate that the planetary orbit is well-aligned with the stellar spin, with a sky-projected …

Grb 130427a Afterglow: A Test For Grb Models, Massimiliano De Pasquale, M. J. Page, D. A. Kann, S. R. Oates, S. Schulze, Bing Zhang, Z. Cano, B. Gendre, D. Malesani, A. Rossi, N. Gehrels, E. Troja, L. Piro, M. Boër, G. Stratta

Physics & Astronomy Faculty Research

Gamma-ray Burst 130427A had the largest fluence for almost 30 years. With an isotropic energy output of 8.5×1053 erg and redshift of 0.34, it combined a very high energy release with a relative proximity to Earth in an unprecedented fashion. Sensitive X-ray facilities such as {\it XMM-Newton} and {\it Chandra} detected the afterglow of this event for a record-breaking baseline of 90 Ms. We show the X-ray light curve of GRB 130427A of this event over such an interval. The light curve shows an unbroken power law decay with a slope of α=1.31 over more than three decades in time. …

May The Forces Be With You!, Christopher Sirola

Faculty Publications

In everyday life, we usually directly note two basic forces: gravity and electromagnetism. Gravity—as in the acceleration due to Earth’s gravity—tends to be a background force of sorts, something that is always present and always the same. We don’t always see electricity and/or magnetism as such, but their subsidiaries are all around us—friction, normal force, tension, springs, and the like.

The Taurus Boundary Of Stellar/Substellar (Tboss) Survey. Ii. Disk Masses From Alma Continuum Observations, Kimberly Ward-Duong, J. Patience, J. Bulger, G. Van Der Plas, F. Ménard, C. Pinte, A. P. Jackson, G. Bryden, N. J. Turner, P. Harvey, A. Hales, R. J. De Rosa

Astronomy: Faculty Publications

We report 885 μm ALMA continuum flux densities for 24 Taurus members spanning the stellar/substellar boundary with spectral types from M4 to M7.75. Of the 24 systems, 22 are detected at levels ranging from 1.0 to 55.7 mJy. The two nondetections are transition disks, though other transition disks in the sample are detected. Converting ALMA continuum measurements to masses using standard scaling laws and radiative transfer modeling yields dust mass estimates ranging from ∼0.3 to 20 M ⊕. The dust mass shows a declining trend with central object mass when combined with results from submillimeter surveys of more massive Taurus …

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 …

Nonreciprocal Localization Of Photons, Hamidreza Ramezani, Pankaj K. Jha, Yuan Wang, Xiang Zhang

Physics & Astronomy Faculty Publications

We demonstrate that it is possible to localize photons nonreciprocally in a moving photonic lattice made by spatiotemporally modulating the atomic response, where the dispersion acquires a spectral Doppler shift with respect to the probe direction. A static defect placed in such a moving lattice produces a spatial localization of light in the band gap with a shifting frequency that depends on the direction of incident field with respect to the moving lattice. This phenomenon has an impact not only in photonics but also in broader areas such as condensed matter and acoustics, opening the doors for designing new devices …

A Young Solar Twin In The Rosette Cluster Ngc 2244 Line Of Sight, Jeremy M. Huber, John F. Kielkopf, Matthew Mengel, Bradley D. Carter, Gary J. Ferland, Frank O. Clark

Physics and Astronomy Faculty Publications

Based on prior precision photometry and cluster age analysis, the bright star GSC 00154−01819 is a possible young pre-main sequence member of the Rosette cluster, NGC 2244. As part of a comprehensive study of the large-scale structure of the Rosette and its excitation by the cluster stars, we noted this star as a potential backlight for a probe of the interstellar medium and extinction along the sight line towards a distinctive nebular feature projected on to the cluster centre. New high-resolution spectra of the star were taken with the University College London Echelle Spectrograph of the AAT. They reveal that …

Transfer Entropy And Cumulant Based Cost As Measures Of Nonlinear Causal Relationships In Space Plasmas: Applications To D St., Jay R. Johnson, Simon Wing, Enrico Camporeale

Faculty Publications

It is well known that the magnetospheric response to the solar wind is nonlinear. Information theoretical tools such as mutual information, transfer entropy, and cumulant based analysis are able to characterize the nonlinearities in the system. Using cumulant based cost, we show that nonlinear significance of D st peaks at 3–12 hours lags that can be attributed to VBs which also exhibit similar behavior. However, the nonlinear significance that peaks at lags 25, 50, and 90 hours can be attributed to internal dynamics, which may be related to the relaxation of the ring current. These peaks are absent in the …

The First Post-Kepler Brightness Dips Of Kic 8462852, Tabetha S. Boyajian, Roi Alonso, Alex Ammerman, David Armstrong

University Faculty Publications and Creative Works

We present a photometric detection of the first brightness dips of the unique variable star KIC 8462852 since the end of the Kepler space mission in 2013 May. Our regular photometric surveillance started in 2015 October, and a sequence of dipping began in 2017 May continuing on through the end of 2017, when the star was no longer visible from Earth. We distinguish four main 1%-2.5% dips, named "Elsie," "Celeste," "Skara Brae," and "Angkor," which persist on timescales from several days to weeks. Our main results so far are as follows: (i) there are no apparent changes of the stellar …

The First Post-Kepler Brightness Dips Of Kic 8462852, Tabetha S. Boyajian, Roi Alonso, Alex Ammerman, David Armstrong, Andrés Asensio Ramos, K. Barkaoui, Thomas G. Beatty, Zouhair Benkhaldoun, Paul Benni, Rory O. Bentley, Andrei Berdyugin, Svetlana Berdyugina, Serge Bergeron, Allyson Bieryla, Michaela G. Blain, Alicia Capetillo Blanco, Eva H. L. Bodman, Anne Boucher, Mark Bradley, Stephen M. Brincat, Thomas G. Brink, John Briol, David J. A. Brown, Jan Budaj, Artem Burdanov, Bryson Cale, Miguel Aznar Carbo, R. Castillo García, Wendy J. Clark, Geoffrey C. Clayton, James L. Clem, Phillip H. Coker, Evan M. Cook, Chris M. Copperwheat, Jason L. Curtis, Roc M. Cutri, Borbála Cseh, C. H. Cynamon, Alex J. Daniels, James R. A. Davenport, Hans J. Deeg, Roberto De Lorenzo, Thomas De Jaeger, Jean-Bruno Desrosiers, John Dolan, D. J. Dowhos, Franky Dubois, Russell Durkee, Shawn Dvorak, Lynn Easley, Nick Edwards, Tyler G. Ellis, Emery Erdelyi, Steve Ertel, Rafael G. Farfán, Jay Farihi, Alexei V. Filippenko, Emma Foxell, Davide Gandolfi, Faustino Garcia, Frank Giddens, Michaël Gillon, Juan-Luis González-Carballo, Carlos González-Fernández, Jonay I. González Hernández, Keith A. Graham, Kenton A. Greene, Joao Gregorio, Na'ama Hallakoun, Ottó Hanyecz, Gerry R. Harp, Gregory W. Henry, E. Herrero, Caleb F. Hildbold, D. Hinzel, Gonzalo Holgado, Bernadett Ignácz, Ilya Ilyin, Valentin D. Ivanov, ‪Emmanuel Jehin, Helen E. Jermak, Steve Johnston, Stella Kafka, Csilla Kalup, Emmanuel Kardasis, Shai Kaspi, Grant M. Kennedy, F. Kiefer, Collin L. Kielty, Dennis Kessler, Harri Kiiskinen, Thomas L. Killestein, Ronald A. King, Vladimír Kollar, Heidi Korhonen, C. Kotnik, Réka Könyves-Tóth, Levente Kriskovics, Nathan Krumm, Vadim Krushinsky, E. Kundra, Francois-Rene Lachapelle, Daryll Lacourse, P. Lake, Kristine Lam, Gavin P. Lamb, Dave Lane, Marie Wingyee Lau, Pablo Lewin, Chris Lintott, Carey Lisse, Ludwig Logie, Nicolas Longeard, M. Lopez Villanueva, E. Whit Ludington, Amy Mainzer, Lison Malo, Chris Maloney, Andrew Mann, A. Mantero, Massimo Marengo, Jon Marchant, María Jesús Martínez González, Joseph R. Masiero, Jon C. Mauerhan, James Mccormac, Aaron Mcneely, Huan Y. A. Meng, Mike Miller, Lawrence A. Molnar, Juan Carlos Morales, Brett M. Morris, Matthew W. Muterspaugh, David Nespra, Carrie R. Nugent, Katherine M. Nugent, A. Odasso, Derek O'Keeffe, Arto Oksanen, John M. O'Meara, András Ordasi, Hugh Osborn, John J. Ott, J. R. Parks, Diego Rodriguez Perez, Vance Petriew, Roger Pickard, András Pál, Peter Plavchan, Don Pollacco, Francisco Pozo-Nuñez, Francisco J. Pozuelos, Steve Rau, Seth Redfield, Howard Relles, Ignasi Ribas, Jon Richards, Joonas L. O. Saario, Emily J. Safron, J. Martin Sallai, Krisztián Sárneczky, Bradley E. Schaefer, Clea F. Schumer, Madison Schwartzendruber, Michael H. Siegel, Andrew P. V. Siemion, Brooke D. Simmons, Joshua D. Simon, Sergio Simón-Díaz, Michael L. Sitko, Hector Socas-Navarro, Ádám Sódor, Donn Starkey, Iain A. Steele, Geoff Stone, Klaus G. Strassmeier, Rachel A. Street, Tricia Sullivan, Jari Suomela, Jon J. Swift, Gyula M. Szabó, Róbert Szabó, Róbert Szakáts, Tamás Szalai, Angelle M. Tanner, Borja Toledo-Padrón, Tamás Tordai, Amaury H. M. J. Triaud, Jake D. Turner, Joseph H. Ulowetz, Marian Urbanik, Siegfried Vanaverbeke, Andrew Vanderburg, Krisztián Vida, Brad P. Vietje, József Vinkó, Kaspar Von Braun, Elizabeth O. Waagen, Dan Walsh, Christopher A. Watson, R. C. Weir, Klaus Wenzel, Carlos Westendorp, Michael W. Williamson, Jason T. Wright, Mark C. Wyatt, Weikang Zheng, Gabriella Zsidi

Information Systems and Engineering Management Research Publications

We present a photometric detection of the first brightness dips of the unique variable star KIC 8462852 since the end of the Kepler space mission in 2013 May. Our regular photometric surveillance started in 2015 October, and a sequence of dipping began in 2017 May continuing on through the end of 2017, when the star was no longer visible from Earth. We distinguish four main 1%–2.5% dips, named "Elsie," "Celeste," "Skara Brae," and "Angkor," which persist on timescales from several days to weeks. Our main results so far are as follows: (i) there are no apparent changes of the stellar …

First Search For Nontensorial Gravitational Waves From Known Pulsars, B. P. Abbott, Teviet Creighton, Mario C. Diaz, S. R. Morriss, Marc E. Normandin, Volker Quetschke, Malik Rakhmanov, Karla E. Ramirez, Robert Stone, Darkhan Tuyenbayev, Guillermo Valdes

Physics & Astronomy Faculty Publications

We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper …

First Search For Nontensorial Gravitational Waves From Known Pulsars, B. P. Abbott, K. Aultoneal, S. Gaudio, K. Gill, B. Hughey, J. W. W. Pratt, E. Schmidt, S. G. Schwalbe, M. J. Szczepańczyk, M. Zanolin, Et Al.

Publications

We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper …

An Hst/Stis Optical Transmission Spectrum Of Warm Neptune Gj 436b, Joshua D. Lothringer, Björn Benneke, Ian J. M. Crossfield, Gregory W. Henry, Caroline Morley, Diana Dragomir, Travis Barman, Heather Knutson, Eliza Kempton, Jonathan J. Fortney, Peter Mccullough, Andrew W. Howard

Information Systems and Engineering Management Research Publications

GJ 436b is a prime target for understanding warm Neptune exoplanet atmospheres and a target for multiple James Webb Space Telescope (JWST) Guaranteed Time Observation programs. Here, we report the first space-based optical transmission spectrum of the planet using two Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) transit observations from 0.53 to 1.03 μm. We find no evidence for alkali absorption features, nor evidence of a scattering slope longward of 0.53 μm. The spectrum is indicative of moderate to high metallicity (∼100–1000× solar), while moderate-metallicity scenarios (∼100× solar) require aerosol opacity. The optical spectrum also rules out some …