The First Month Of Evolution Of The Slow-Rising Type Iip Sn 2013ej In M74,
2014
University of California, Santa Barbara
The First Month Of Evolution Of The Slow-Rising Type Iip Sn 2013ej In M74, S. Valenti, D. Sand, A. Pastorello, M. L. Graham, D. A. Howell, J. T. Parrent
Dartmouth Scholarship
We present early photometric and spectroscopic observations of SN 2013ej, a bright Type IIP supernova (SN) in M74. SN 2013ej is one of the closest SNe ever discovered. The available archive images and the early discovery help to constrain the nature of its progenitor. The earliest detection of this explosion was on 2013 July 24.125 ut and our spectroscopic monitoring with the FLOYDS spectrographs began on July 27.7 ut, continuing almost daily for two weeks. Daily optical photometric monitoring was achieved with the 1 m telescopes of the Las Cumbres Observatory Global Telescope (LCOGT) network, and was complemented by UV …
Chemical Potential In The First Law For Holographic Entanglement Entropy,
2014
University of Massachusetts - Amherst
Chemical Potential In The First Law For Holographic Entanglement Entropy, David Kastor, Sourya Ray, Jennie Traschen
David Kastor
Entanglement entropy in conformal field theories is known to satisfy a first law. For spherical entangling surfaces, this has been shown to follow via the AdS/CFT correspondence and the holographic prescription for entanglement entropy from the bulk first law for Killing horizons. The bulk first law can be extended to include variations in the cosmological constant Λ, which we established in earlier work. Here we show that this implies an extension of the boundary first law to include varying the number of degrees of freedom of the boundary CFT. The thermodynamic potential conjugate to Λ in the bulk is called …
Line-Driven Radiative Outflows In Luminous Quasars,
2014
University of Cambridge, UK
Line-Driven Radiative Outflows In Luminous Quasars, Rebecca A. A. Bowler, Paul C. Hewett, James T. Allen, Gary J. Ferland
Physics and Astronomy Faculty Publications
An analysis of ≃19 500 narrow ( ≲ 200 km s−1) C iv λλ1548.2,1550.8 absorbers in ≃34 000 Sloan Digital Sky Survey quasar spectra is presented. The statistics of the number of absorbers as a function of outflow velocity shows that in approximately two-thirds of outflows, with multiple C iv absorbers present, absorbers are line-locked at the 500 km s−1 velocity separation of the C iv absorber doublet; appearing as ‘triplets’ in the quasar spectra. Line-locking is an observational signature of radiative line-driving in outflowing material, where the successive shielding of ‘clouds’ of material in the outflow …
Should We Love Or Hate Big Data? The Good, The Bad, And The Ugly,
2014
La Salle University
Should We Love Or Hate Big Data? The Good, The Bad, And The Ugly, Dennis Crossen M.Sc., Mba, Karti Puranam Phd, Madjid Tavana Phd
Explorer Café
No abstract provided.
Multimessenger Search For Sources Of Gravitational Waves And High-Energy Neutrinos: Initial Results For Ligo-Virgo And Icecube,
2014
University of Texas Rio Grande Valley
Multimessenger Search For Sources Of Gravitational Waves And High-Energy Neutrinos: Initial Results For Ligo-Virgo And Icecube, M. G. Aartsen, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, D. Altmann, T. Anderson, C. Arguelles, T. C. Arlen, J. Auffenberg, X. Bai, S. W. Barwick, V. Baum, J. J. Beatty, J. Becker Tjus, K. H. Becker, S. Benzvi, P. Berghaus, D. Berley, E. Bernardini, A. Bernhard, D. Z. Besson, G. Binder, D. Bindig, M. Bissok, E. Blaufuss, J. Blumenthal, D. J. Boersma, C. Bohm
Physics and Astronomy Faculty Publications and Presentations
We report the results of a multimessenger search for coincident signals from the LIGO and Virgo gravitational-wave observatories and the partially completed IceCube high-energy neutrino detector, including periods of joint operation between 2007-2010. These include parts of the 2005-2007 run and the 2009-2010 run for LIGO-Virgo, and IceCube's observation periods with 22, 59 and 79 strings. We find no significant coincident events, and use the search results to derive upper limits on the rate of joint sources for a range of source emission parameters. For the optimistic assumption of gravitational-wave emission energy of 10-2M c2 at ∼150Hz with ∼60ms duration, …
Multimessenger Search For Sources Of Gravitational Waves And High-Energy Neutrinos: Initial Results For Ligo-Virgo And Icecube,
2014
Andrews University
Multimessenger Search For Sources Of Gravitational Waves And High-Energy Neutrinos: Initial Results For Ligo-Virgo And Icecube, Tiffany Summerscales, Icecube Collaboration, Ligo Scientific Collaboration And The Virgo Collaboration
Faculty Publications
We report the results of a multimessenger search for coincident signals from the LIGO and Virgo gravitational-wave observatories and the partially completed IceCube high-energy neutrino detector, including periods of joint operation between 2007–2010. These include parts of the 2005–2007 run and the 2009–2010 run for LIGO-Virgo, and IceCube’s observation periods with 22, 59 and 79 strings. We find no significant coincident events, and use the search results to derive upper limits on the rate of joint sources for a range of source emission parameters. For the optimistic assumption of gravitational-wave emission energy of 10−2 M⊙c2 at ∼150 Hz with ∼60 …
Non-Vacuum Ads Cosmologies And The Approach To Equilibrium Of Entanglement Entropy,
2014
University of Massachusetts - Amherst
Non-Vacuum Ads Cosmologies And The Approach To Equilibrium Of Entanglement Entropy, Sebastian Fischetti, David Kastor, Jennie Traschen
David Kastor
We extend standard results for vacuum asymptotically locally AdS (AlAdS) spacetimes, showing that such spacetimes can be constructed as foliations where the induced metric on each hypersurface satisfies Einstein's equation with stress-energy. By an appropriate choice of stress-energy on the hypersurfaces, the resulting AlAdS spacetime satisfies Einstein's equation with a negative cosmological constant and physical stress tensor. We use this construction to obtain AlAdS solutions whose boundaries are FRW cosmologies sourced by a massless scalar field or by a perfect fluid obeying the strong energy condition. We focus on FRW universes that approach Minkowski spacetime at late times, yielding AlAdS …
Thermal Structure Of An Exoplanet Atmosphere From Phase-Resolved Emission Spectroscopy,
2014
University of Chicago
Thermal Structure Of An Exoplanet Atmosphere From Phase-Resolved Emission Spectroscopy, Kevin B. Stevenson, Jean-Michel Désert, Michael R. Line, Jacob L. Bean, Jonathan J. Fortney, Adam P. Showman, Tiffany Kataria, Laura Kreidberg, Peter R. Mccullough, Gregory W. Henry, David Charbonneau, Adam Burrows, Sara Seager, Nikku Madhusudhan, Michael H. Williamson, Derek Homeier
Information Systems and Engineering Management Research Publications
Exoplanets that orbit close to their host stars are much more highly irradiated than their solar system counterparts. Understanding the thermal structures and appearances of these planets requires investigating how their atmospheres respond to such extreme stellar forcing. We present spectroscopic thermal emission measurements as a function of orbital phase (“phase-curve observations”) for the highly irradiated exoplanet WASP-43b spanning three full planet rotations using the Hubble Space Telescope. With these data, we construct a map of the planet’s atmospheric thermal structure, from which we find large day-night temperature variations at all measured altitudes and a monotonically decreasing temperature with pressure …
The Power Of Principled Bayesian Methods In The Study Of Stellar Evolution,
2014
Embry-Riddle Aeronautical University
The Power Of Principled Bayesian Methods In The Study Of Stellar Evolution, Ted Von Hippel, David Van Dyk, David Stenning, Elliot Robinson, Elizabeth Jeffery, Nathan Stein, William Jefferys, Erin M. O'Malley
Publications
It takes years of effort employing the best telescopes and in- struments to obtain high-quality stellar photometry, astrometry, and spectroscopy. Stellar evolution models contain the experience of life- times of theoretical calculations and testing. Yet most astronomers fit these valuable models to these precious datasets by eye. We show that a principled Bayesian approach to fitting models to stellar data yields substantially more information over a range of stellar astrophysics. We highlight advances in determining the ages of star clusters, mass ratios of binary stars, limitations in the accuracy of stellar models, post-main-sequence mass loss, and the ages of individual …
Bayesian Analysis For Stellar Evolution With Nine Parameters (Base-9): User's Manual,
2014
Embry-Riddle Aeronautical University
Bayesian Analysis For Stellar Evolution With Nine Parameters (Base-9): User's Manual, Ted Von Hippel, Elliot Robinson, Elizabeth Jeffery, Rachel Wagner-Kaiser, Steven Degennaro, Nathan Stein, David Stenning, William H. Jefferys, David Van Dyk
Publications
BASE-9 is a Bayesian software suite that recovers star cluster and stellar parameters from photometry. BASE-9 is useful for analyzing single-age, single-metallicity star clusters, binaries, or single stars, and for simulating such systems. BASE-9 uses Markov chain Monte Carlo and brute-force numerical integration techniques to estimate the posterior probability distributions for the age, metallicity, helium abundance, distance modulus, and line-of-sight absorption for a cluster, and the mass, binary mass ratio, and cluster membership probability for every stellar object. BASE-9 is provided as open source code on a version-controlled web server. The executables are also available as Amazon Elastic Compute Cloud …
On The Formation And Evolution Of Early-Type Galaxies,
2014
University of Massachusetts Amherst
On The Formation And Evolution Of Early-Type Galaxies, Christina Williams
Doctoral Dissertations
Galaxies in the local Universe are characterized by blue, star-forming disk galaxies, and red, massive early-type galaxies (ETGs) whose star-formation has been quenched early in the Universe's history. The ETGs are relics of the evolutionary processes that transform galaxies over cosmic time, but currently we still lack a comprehensive understanding of their evolution. An important link in the evolution of ETGs is that the first quenched galaxies (z~2) are both the most massive, and most compact, suggesting a physical connection between high stellar density and efficient, rapid cessation of star-formation. In this dissertation, I seek insight into the formation and …
Dusty Star Formation In Extreme Environments: Galaxies And Galaxy Clusters In The Distant Universe,
2014
University of Massachusetts Amherst
Dusty Star Formation In Extreme Environments: Galaxies And Galaxy Clusters In The Distant Universe, Stacey Alberts
Doctoral Dissertations
In this thesis, we present a comprehensive study of the dust-obscured star formation (SF) activity in galaxy clusters out to high redshift using infrared (IR) imaging. Using hundreds of galaxy clusters and wide-field far-IR imaging across nine square degrees, we quantify the average star formation rates (SFRs) out to the distant Universe for mass-limited cluster galaxy samples using stacking. We compare the evolution of this SF activity to field galaxies, finding that the evolution in clusters occurs more rapidly than in the field and clusters have field-like SF approximately nine billion years ago, during an epoch before SF quenching becomes …
Measuring The Shock-Heating Rate In The Winds Of O Stars Using X-Ray Line Spectra,
2014
Swarthmore College
Measuring The Shock-Heating Rate In The Winds Of O Stars Using X-Ray Line Spectra, David H. Cohen, Zequn Li , '16, K. G. Gayley, S. P. Owocki, J. O. Sundqvist, V. Petit, M. A. Leutenegger
Physics & Astronomy Faculty Works
We present a new method for using measured X-ray emission line fluxes from O stars to determine the shock-heating rate due to instabilities in their radiation-driven winds. The high densities of these winds means that their embedded shocks quickly cool by local radiative emission, while cooling by expansion should be negligible. Ignoring for simplicity any non-radiative mixing or conductive cooling, the method presented here exploits the idea that the cooling post-shock plasma systematically passes through the temperature characteristic of distinct emission lines in the X-ray spectrum. In this way, the observed flux distribution among these X-ray lines can be used …
The Optical Luminosity Function Of Gamma-Ray Bursts Deduced From Rotse-Iii Observations,
2014
College of Saint Benedict/Saint John's University
The Optical Luminosity Function Of Gamma-Ray Bursts Deduced From Rotse-Iii Observations, X. H. Cui, X. F. Wu, J. J. Wei, F. Yuan, W. K. Zheng, E. W. Liang, C. W. Akerlof, M. C. B. Ashley, H A. Flewelling, E. Göǧüş, T. Güver, Ü. Kızıloǧlu, T. A. Mckay, S. B. Pandey, E. S. Rykoff, W. Rujopakarn, B. E. Schaefer, J. C. Wheeler, Sarah A. Yost
Physics Faculty Publications
We present the optical luminosity function (LF) of gamma-ray bursts (GRBs) estimated from a uniform sample of 58 GRBs from observations with the Robotic Optical Transient Search Experiment III (ROTSE-III). Our GRB sample is divided into two sub-samples: detected afterglows (18 GRBs) and those with upper limits (40 GRBs). We derive R-band fluxes for these two sub-samples 100 s after the onset of the burst. The optical LFs at 100 s are fitted by assuming that the co-moving GRB rate traces the star formation rate. While fitting the optical LFs using Monte Carlo simulations, we take into account the …
Recoiling Supermassive Black Holes: A Search In The Nearby Universe,
2014
Rochester Institute of Technology
Recoiling Supermassive Black Holes: A Search In The Nearby Universe, Davide Lena, Andrew Edward Robinson, Alessandro Marconi, David J. Axon, Alessandro Capetti, David Merritt, Daniel P. Batcheldor
Aerospace, Physics, and Space Science Faculty Publications
The coalescence of a binary black hole can be accompanied by a large gravitational recoil due to anisotropic emission of gravitational waves. A recoiling supermassive black hole (SBH) can subsequently undergo long-lived oscillations in the potential well of its host galaxy, suggesting that offset SBHs may be common in the cores of massive ellipticals. We have analyzed Hubble Space Telescope archival images of 14 nearby core ellipticals, finding evidence for small (≲ 10 pc) displacements between the active galactic nucleus (AGN; the location of the SBH) and the center of the galaxy (the mean photocenter) in 10 of them. Excluding …
Ion Composition In Interchange Injection Events In Saturn's Magnetosphere,
2014
Planetary Science Institute - Tucson
Ion Composition In Interchange Injection Events In Saturn's Magnetosphere, M. F. Thomsen, Daniel B. Reisenfeld, R. J. Wilson, M. Andriopoulou, F. J. Crary, G. B. Hospodarsky, C. M. Jackman, X. Jia, K. K. Khurana, C. Paranicas, E. Roussos, N. Sergis, R. L. Tokar
Physics and Astronomy Faculty Publications
Interchange injection events are commonly observed by the Cassini spacecraft in the region between about 6 and 12 Rs (1 Rs = 60,268 km) and even frequently beyond. In this study, 13 examples of interchange injection events are identified in Cassini-Cassini Plasma Spectrometer data under special conditions such that time-of-flight (TOF) mass spectra could be obtained from entirely within the events. Using the TOF data to separate the main ion species H+, H2+, and W+, approximate densities of each species are calculated under the assumption that all distributions were isotropic. The …
Defining The Flora Family: Orbital Properties, Reflectance Properties And Age,
2014
The University of Arizona
Defining The Flora Family: Orbital Properties, Reflectance Properties And Age, Melissa J. Dykhuis, Lawrence Molnar, Samuel J. Van Kooten, Richard Greenberg
University Faculty Publications and Creative Works
The Flora family resides in the densely populated inner main belt, bounded in semimajor axis by the ν6 secular resonance and the Jupiter 3:1 mean motion resonance. The presence of several large families that overlap dynamically with the Floras (e.g., the Vesta, Baptistina, and Nysa-Polana families), and the removal of a significant fraction of Floras via the nearby ν6 resonance complicates the Flora family's distinction in both proper orbital elements and reflectance properties. Here we use orbital information from the Asteroids Dynamic Site (AstDyS), color information from the Sloan Digital Sky Survey (SDSS), and albedo information from the Wide-field Infrared …
Candels/Goods-S, Cdfs, And Ecdfs: Photometric Redshifts For Normal And X-Ray-Detected Galaxies,
2014
Max-Planck-Institut für extraterrestrische Physik, Germany
Candels/Goods-S, Cdfs, And Ecdfs: Photometric Redshifts For Normal And X-Ray-Detected Galaxies, Li-Ting Hsu, Mara Salvato, Kirpal Nandra, Marcella Brusa, Ralf Bender, Johannes Buchner, Jennifer L. Dooley, Dale D. Kocevski, Yicheng Guo, Nimish P. Hathi, Cyprian Rangel, S. P. Willner, Murray Brightman, Antonis Georgakakis, Tamás Budavári, Alexander S. Szalay, Matthew L.N. Ashby, Guillermo Barro, Tomas Dahlen, Sandra M. Faber, Henry C. Ferguson, Audrey Galametz, Andrea Grazian, Norman A. Grogin, Kuang-Han Huang, Anton M. Koekemoer, Ray A. Lucas, Elizabeth Mcgrath, Bahram Mobasher, Michael Peth, David J. Rosario, Jonathan R. Trump
Physics and Astronomy Faculty Publications
We present photometric redshifts and associated probability distributions for all detected sources in the Extended Chandra Deep Field South (ECDFS). This work makes use of the most up-to-date data from the Cosmic Assembly Near-IR Deep Legacy Survey (CANDELS) and the Taiwan ECDFS Near-Infrared Survey (TENIS) in addition to other data. We also revisit multi-wavelength counterparts for published X-ray sources from the 4 Ms CDFS and 250 ks ECDFS surveys, finding reliable counterparts for 1207 out of 1259 sources (~96%). Data used for photometric redshifts include intermediate-band photometry deblended using the TFIT method, which is used for the first time in …
Nasa's Search For Life Beyond The Earth,
2014
UAlbany
Nasa's Search For Life Beyond The Earth, John W. Delano Prof
Atmospheric and Environmental Science Faculty Scholarship
Invited presentation (November 3, 2014 for the 119th Annual Conference of the Science Teachers Association of New York State) provides an overview of NASA's search for worlds orbiting other nearby stars on the Milky Way galaxy.
Single Spin Asymmetries In Charged Kaon Production From Semi-Inclusive Deep Inelastic Scattering On A Transversely Polarized 3He Target,
2014
University of Kentucky
Single Spin Asymmetries In Charged Kaon Production From Semi-Inclusive Deep Inelastic Scattering On A Transversely Polarized 3He Target, C. Dutta, A. Kolarkar, Wolfgang Korsch, Y. X. Zhao, Y. Wang, K. Allada, K. Aniol, J. R. M. Annand, T. Averett, F. Benmokhtar, W. Bertozzi, P. C. Bradshaw, P. Bosted
Physics and Astronomy Faculty Publications
We report the first measurement of target single spin asymmetries of charged kaons produced in semi-inclusive deep inelastic scattering of electrons off a transversely polarized 3He target. Both the Collins and Sivers moments, which are related to the nucleon transversity and Sivers distributions, respectively, are extracted over the kinematic range of 0.1<xbj<0.4 for K+ and K− production. While the Collins and Sivers moments for K+ are consistent with zero within the experimental uncertainties, both moments for K− favor negative values. The Sivers moments are compared to the theoretical prediction from a phenomenological fit to the …
