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

Physical Sciences and Mathematics Commons

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

Astrophysics and Astronomy

Series

2019

Institution
Keyword
Publication
File Type

Articles 61 - 90 of 267

Full-Text Articles in Physical Sciences and Mathematics

A Near Horizon Extreme Binary Black Hole Geometry, Jacob Ciafre, Maria J. Rodriguez Sep 2019

A Near Horizon Extreme Binary Black Hole Geometry, Jacob Ciafre, Maria J. Rodriguez

All Physics Faculty Presentations

A new solution of four-dimensional vacuum General Relativity is presented. It describes the near horizon region of the extreme (maximally spinning) binary black hole system with two identical extreme Kerr black holes held in equilibrium by a massless strut. This is the first example of a non-supersymmetric, near horizon extreme binary black hole geometry of two uncharged black holes. The black holes are co-rotating, their relative distance is fixed, and the solution is uniquely specified by the mass. Asymptotically, the geometry corresponds to the near horizon extreme Kerr (NHEK) black hole. The binary extreme system has finite entropy.


Binary Black Hole Population Properties Inferred From The First And Second Observing Runs Of Advanced Ligo And Advanced Virgo, B. P. Abbott, T. D. Abbott, S. Abraham, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Karla E. Ramirez, Satzhan Sitmukhambetov, D. Tuyenbayev, W. H. Wang, Adam Zadrozny Sep 2019

Binary Black Hole Population Properties Inferred From The First And Second Observing Runs Of Advanced Ligo And Advanced Virgo, B. P. Abbott, T. D. Abbott, S. Abraham, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Karla E. Ramirez, Satzhan Sitmukhambetov, D. Tuyenbayev, W. H. Wang, Adam Zadrozny

Physics and Astronomy Faculty Publications and Presentations

We present results on the mass, spin, and redshift distributions with phenomenological population models using the 10 binary black hole (BBH) mergers detected in the first and second observing runs completed by Advanced LIGO and Advanced Virgo. We constrain properties of the BBH mass spectrum using models with a range of parameterizations of the BBH mass and spin distributions. We find that the mass distribution of the more massive BH in such binaries is well approximated by models with no more than 1% of BHs more massive than 45M(circle dot) and a power-law index of alpha = 1.3(-1.7)(+1.4) (90% credibility). …


Wallaby Early Science − V. Askap Hi Imaging Of The Lyon Group Of Galaxies 351, B. Q. For, L. Staveley-Smith, T. Westmeier, M. Whiting, S. -H. Oh, B. Koribalski, J. Wang, O. I. Wong, G. Bekiaris, L. Cortese, A. Elagali, D. Kleiner, K. Lee-Waddell, Juan P. Madrid, A. Popping, J. Rhee, T. N. Reynolds, J. D. Collier, C. J. Phillips, M. A. Voronkov, O. Mueller, H. Jerjen Sep 2019

Wallaby Early Science − V. Askap Hi Imaging Of The Lyon Group Of Galaxies 351, B. Q. For, L. Staveley-Smith, T. Westmeier, M. Whiting, S. -H. Oh, B. Koribalski, J. Wang, O. I. Wong, G. Bekiaris, L. Cortese, A. Elagali, D. Kleiner, K. Lee-Waddell, Juan P. Madrid, A. Popping, J. Rhee, T. N. Reynolds, J. D. Collier, C. J. Phillips, M. A. Voronkov, O. Mueller, H. Jerjen

Physics and Astronomy Faculty Publications and Presentations

We present an HI study of the galaxy group LGG 351 usingWidefield ASKAP L-band Legacy All-sky Blind Survey (WALLABY) early science data observed with the Australian Square Kilometre Array Pathfinder (ASKAP). LGG 351 resides behind the M 83 group at a velocity range (cz) of ∼3500–4800 km s−1 within the rich Hydra-Centaurus overdensity region. We detect 40 sources with the discovery of a tidally interacting galaxy pair and two new HI sources that are not presented in previous optical catalogues. 23 out of 40 sources have new redshifts derived from the new HI data. This study is the largest WALLABY …


Photoionization Calculations Of The Radiation Force Due To Spectral Lines In Agns, Randall C. Dannen, Daniel Proga, Timothy R. Kallman, Tim Waters Sep 2019

Photoionization Calculations Of The Radiation Force Due To Spectral Lines In Agns, Randall C. Dannen, Daniel Proga, Timothy R. Kallman, Tim Waters

Physics & Astronomy Faculty Research

One of the main mechanisms that could drive mass outflows in active galactic nuclei (AGNs) is radiation pressure due to spectral lines. Although straightforward to understand, the actual magnitude of the radiation force is challenging to compute because the force depends on the physical conditions in the gas, as well as the strength, spectral energy distribution (SED), and geometry of the radiation field. We present results from our photoionization and radiation transfer calculations of the force multiplier, M(ξ, t), using the same radiation field to compute the gas photoionization and thermal balance. We assume low gas density (n = 104 …


Large‐Amplitude Mountain Waves In The Mesosphere Observed On 21 June 2014 During Deepwave: 1.Wave Development, Scales, Momentum Fluxes, And Environmental Sensitivity, Michael J. Taylor, Pierre-Dominique Pautet, David C. Fritts, Bernd Kaifler, Steven M. Smith, Yucheng Zhao, Neal R. Criddle, Pattilyn Mclaughlin, William R. Pendleton Jr., Michael P. Mccarthy, Gonzalo Hernandez, Stephen D. Eckermann, James Doyle, Markus Rapp, Ben Liley, James M. Russell Iii Sep 2019

Large‐Amplitude Mountain Waves In The Mesosphere Observed On 21 June 2014 During Deepwave: 1.Wave Development, Scales, Momentum Fluxes, And Environmental Sensitivity, Michael J. Taylor, Pierre-Dominique Pautet, David C. Fritts, Bernd Kaifler, Steven M. Smith, Yucheng Zhao, Neal R. Criddle, Pattilyn Mclaughlin, William R. Pendleton Jr., Michael P. Mccarthy, Gonzalo Hernandez, Stephen D. Eckermann, James Doyle, Markus Rapp, Ben Liley, James M. Russell Iii

Publications

A remarkable, large‐amplitude, mountain wave (MW) breaking event was observed on the night of 21 June 2014 by ground‐based optical instruments operated on the New Zealand South Island during the Deep Propagating Gravity Wave Experiment (DEEPWAVE). Concurrent measurements of the MW structures, amplitudes, and background environment were made using an Advanced Mesospheric Temperature Mapper, a Rayleigh Lidar, an All‐Sky Imager, and a Fabry‐Perot Interferometer. The MW event was observed primarily in the OH airglow emission layer at an altitude of ~82 km, over an ~2‐hr interval (~10:30–12:30 UT), during strong eastward winds at the OH altitude and above, which weakened …


The Hubble Pancet Program: An Extensive Search For Metallic Ions In The Exosphere Of Gj 436 B, Leonardo A. Dos Santos, David Ehrenreich, Vincent Bourrier, Alain Lecavelier Des Etangs, Mercedes López-Morales, David K. Sing, Gilda E. Ballester, Lofti Ben-Jaffel, Lars A. Buchhave, Antonio García Muñoz, Gregory W. Henry, Tiffany Kataria, Baptiste Lavie, Panayotis Lavvas, Nikole K. Lewis, Thomas Mikal-Evans, Jorge Sanz-Forcada, Hannah R. Wakeford Sep 2019

The Hubble Pancet Program: An Extensive Search For Metallic Ions In The Exosphere Of Gj 436 B, Leonardo A. Dos Santos, David Ehrenreich, Vincent Bourrier, Alain Lecavelier Des Etangs, Mercedes López-Morales, David K. Sing, Gilda E. Ballester, Lofti Ben-Jaffel, Lars A. Buchhave, Antonio García Muñoz, Gregory W. Henry, Tiffany Kataria, Baptiste Lavie, Panayotis Lavvas, Nikole K. Lewis, Thomas Mikal-Evans, Jorge Sanz-Forcada, Hannah R. Wakeford

Information Systems and Engineering Management Research Publications

Context. The quiet M2.5 star GJ 436 hosts a warm Neptune that displays an extended atmosphere that dwarfs its own host star. Predictions of atmospheric escape in such planets state that H atoms escape from the upper atmosphere in a collisional regime and that the flow can drag heavier atoms to the upper atmosphere. It is unclear, however, what astrophysical mechanisms drive the process.

Aims. Our objective is to leverage the extensive coverage of observations of the far-ultraviolet (FUV) spectrum of GJ 436 obtained with the Cosmic Origins Spectrograph (COS) to search for signals of metallic ions in the upper …


"Collaborative Research: Cedar--Airglow Imaging Of Gravity Wave And Instability Dynamics,", Michael Taylor Sep 2019

"Collaborative Research: Cedar--Airglow Imaging Of Gravity Wave And Instability Dynamics,", Michael Taylor

Funded Research Records

No abstract provided.


On Newtonian Dynamics With A Variable Earth Mass: Geodetic Evidence And Its Implications On Pioneer Spacecraft Anomaly And Lageos Satellite, Victor Christianto, Florentin Smarandache Sep 2019

On Newtonian Dynamics With A Variable Earth Mass: Geodetic Evidence And Its Implications On Pioneer Spacecraft Anomaly And Lageos Satellite, Victor Christianto, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

Around 3 decades ago, Jayant Narlikar & Halton Arp argued on possible variable mass hypothesis cosmology (VMH). In the meantime, the Earth expansion problem has attracted great interest, and recent study gives geodetic evidence that the Earth has been expanding, at least over the recent several decades. Therefore, in the present article discusses some interesting effects related to varying G, but here we argue that instead of varying G we can think of varying mass (M). Among other things we discuss receding planets from the Sun, calculation of Pioneer spacecraft anomaly as proposed by B.G. Sidharth, and also possible slight …


Directional Limits On Persistent Gravitational Waves Using Data From Advanced Ligo’S First Two Observing Runs, B. P. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Karla E. Ramirez, Satzhan Sitmukhambetov, Robert Stone, D. Tuyenbayev, Wenhui Wang, Adam Zadrozny, Joseph D. Romano Sep 2019

Directional Limits On Persistent Gravitational Waves Using Data From Advanced Ligo’S First Two Observing Runs, B. P. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Karla E. Ramirez, Satzhan Sitmukhambetov, Robert Stone, D. Tuyenbayev, Wenhui Wang, Adam Zadrozny, Joseph D. Romano

Physics and Astronomy Faculty Publications and Presentations

We perform an unmodeled search for persistent, directional gravitational wave (GW) sources using data from the first and second observing runs of Advanced LIGO. We do not find evidence for any GW signals. We place limits on the broadband GW flux emitted at 25 Hz from point sources with a power law spectrum at Fα;Θ < ð0.05–25Þ × 10−8 erg cm−2 s−1 Hz−1 and the (normalized) energy density spectrum in GWs at 25 Hz from extended sources at ΩαðΘÞ < ð0.19–2.89Þ × 10−8 sr−1 where α is the spectral index of the energy density spectrum. These represent improvements of 2.5–3× over previous limits. We also consider point sources emitting GWs at a single frequency, targeting the directions of Sco X-1, SN 1987A, and the Galactic center. The best upper limits on the strain amplitude of a potential source in these three directions range from h0 < ð3.6–4.7Þ × 10−25, 1.5× better than previous limits set with the same analysis method. We also report on a marginally significant outlier at 36.06 Hz. This outlier is not consistent with a persistent gravitational-wave source as its significance diminishes when combining all of the available data


Gwtc-1: A Gravitational-Wave Transient Catalog Of Compact Binary Mergers Observed By Ligo And Virgo During The First And Second Observing Runs, Tiffany Summerscales, Ligo Scientific Collaboration And The Virgo Collaboration Sep 2019

Gwtc-1: A Gravitational-Wave Transient Catalog Of Compact Binary Mergers Observed By Ligo And Virgo During The First And Second Observing Runs, Tiffany Summerscales, Ligo Scientific Collaboration And The Virgo Collaboration

Faculty Publications

We present the results from three gravitational-wave searches for coalescing compact binaries with component masses above 1  M during the first and second observing runs of the advanced gravitational-wave detector network. During the first observing run (O1), from September 12, 2015 to January 19, 2016, gravitational waves from three binary black hole mergers were detected. The second observing run (O2), which ran from November 30, 2016 to August 25, 2017, saw the first detection of gravitational waves from a binary neutron star inspiral, in addition to the observation of gravitational waves from a total of seven binary black hole …


Search For The Isotropic Stochastic Background Using Data From Advanced Ligo's Second Observing Run, Tiffany Summerscales, Ligo Scientific Collaboration And The Virgo Collaboration Sep 2019

Search For The Isotropic Stochastic Background Using Data From Advanced Ligo's Second Observing Run, Tiffany Summerscales, Ligo Scientific Collaboration And The Virgo Collaboration

Faculty Publications

The stochastic gravitational-wave background is a superposition of sources that are either too weak or too numerous to detect individually. In this study we present the results from a cross-correlation analysis on data from Advanced LIGO's second observing run (O2), which we combine with the results of the first observing run (O1). We do not find evidence for a stochastic background, so we place upper limits on the normalized energy density in gravitational waves at the 95% credible level of ΩGW<6.0×10−8 for a frequency-independent (flat) background and ΩGW<4.8×10−8 at 25 Hz for a background of compact …


Limits On The Weak Equivalence Principle And Photon Mass With Frb 121102 Subpulses, Nan Xing, He Gao, Jun-Jie Wei, Zhengxiang Li, Weiyang Wang, Bing Zhang, Xue-Feng Wu, Peter Meszaros Sep 2019

Limits On The Weak Equivalence Principle And Photon Mass With Frb 121102 Subpulses, Nan Xing, He Gao, Jun-Jie Wei, Zhengxiang Li, Weiyang Wang, Bing Zhang, Xue-Feng Wu, Peter Meszaros

Physics & Astronomy Faculty Research

Fast radio bursts (FRBs) are short-duration (~millisecond) radio transients with cosmological origin. The simple sharp features of the FRB signal have been utilized to probe two fundamental laws of physics, namely, testing Einstein's weak equivalence principle and constraining the rest mass of the photon. Recently, Hessels et al. found that after correcting for dispersive delay, some of the bursts in FRB 121102 have complex time–frequency structures that include subpulses with a time–frequency downward drifting property. Using the delay time between subpulses in FRB 121102, here we show that the parameterized post-Newtonian parameter γ is the same for photons with different …


An Exo-Kuiper Belt With An Extended Halo Around Hd 191089 In Scattered Light, Bin Ren, Élodie Choquet, Marshall D. Perrin, Gaspard Duchěne, John H. Debes, Laurent Pueyo, Malena Rice, Christine Chen, Glenn Schneider, Thomas M. Esposito, Charles A. Poteet, Jason J. Wang, S. Mark Ammons, Megan Ansdell, Pauline Arriaga, Vanessa P. Bailey, Travis Barman, Juan Sebastián Bruzzone, Joanna Bulger, Jeffrey Chilcote, Tara Cotten, Robert J. De Rosa, Rene Doyon, Michael P. Fitzgerald, Katherine B. Follette, Stephen J. Goodsell, Benjamin L. Gerard, James R. Graham, Alexandra Z. Greenbaum, J. Brendan Hagan, Pascale Hibon, Dean C. Hines, Kimberly Ward-Duong, Et Al Sep 2019

An Exo-Kuiper Belt With An Extended Halo Around Hd 191089 In Scattered Light, Bin Ren, Élodie Choquet, Marshall D. Perrin, Gaspard Duchěne, John H. Debes, Laurent Pueyo, Malena Rice, Christine Chen, Glenn Schneider, Thomas M. Esposito, Charles A. Poteet, Jason J. Wang, S. Mark Ammons, Megan Ansdell, Pauline Arriaga, Vanessa P. Bailey, Travis Barman, Juan Sebastián Bruzzone, Joanna Bulger, Jeffrey Chilcote, Tara Cotten, Robert J. De Rosa, Rene Doyon, Michael P. Fitzgerald, Katherine B. Follette, Stephen J. Goodsell, Benjamin L. Gerard, James R. Graham, Alexandra Z. Greenbaum, J. Brendan Hagan, Pascale Hibon, Dean C. Hines, Kimberly Ward-Duong, Et Al

Astronomy: Faculty Publications

We have obtained Hubble Space Telescope STIS and NICMOS and Gemini/GPI scattered-light images of the HD 191089 debris disk. We identify two spatial components: a ring resembling the Kuiper Belt in radial extent (FWHM ∼ 25 au, centered at ∼46 au) and a halo extending to ∼640 au. We find that the halo is significantly bluer than the ring, consistent with the scenario that the ring serves as the "birth ring" for the smaller dust in the halo. We measure the scattering phase functions in the 30°-150° scattering-angle range and find that the halo dust is more forward- and backward-scattering …


The Super Eight Galaxies: Properties Of A Sample Of Very Bright Galaxies At 7 < Z < 8, Joanna S. Bridge, Benne W. Holwerda, Mauro Stefanon, Rychard J. Bouwens, Pascal A. Oesch, Michele Trenti, Stephanie R. Bernard, Larry D. Bradley, Garth D. Illingworth, Samir Kusmic, Dan Magee, Takahiro Morishita, Guido W. Roberts-Borsani, Renske Smit, Rebecca L. Steele Sep 2019

The Super Eight Galaxies: Properties Of A Sample Of Very Bright Galaxies At 7 < Z < 8, Joanna S. Bridge, Benne W. Holwerda, Mauro Stefanon, Rychard J. Bouwens, Pascal A. Oesch, Michele Trenti, Stephanie R. Bernard, Larry D. Bradley, Garth D. Illingworth, Samir Kusmic, Dan Magee, Takahiro Morishita, Guido W. Roberts-Borsani, Renske Smit, Rebecca L. Steele

Faculty Scholarship

We present the Super Eight galaxies - a set of very luminous, high-redshift (7.1 < z < 8.0) galaxy candidates found in the Brightest of Reionizing Galaxies (BoRG) Survey fields. The original sample includes eight galaxies that are Y-band dropout objects with H-band magnitudes of m H < 25.5. Four of these objects were originally reported in Calvi et al. Combining new Hubble Space Telescope (HST) WFC3/F814W imaging and Spitzer IRAC data with archival imaging from BoRG and other surveys, we explore the properties of these galaxies. Photometric redshift fitting places six of these galaxies in the redshift range of 7.1 < z < 8.0, resulting in three new high-redshift galaxies and confirming three of the four high-redshift galaxy candidates from Calvi et al. We calculate the half-light radii of the Super Eight galaxies using the HST F160W filter and find that the Super Eight sizes are in line with the typical evolution of size with redshift. The Super Eights have a mean mass of log (M ∗/M o) ∼10, which is typical for sources in this luminosity range. Finally, we place our sample on the UV z ∼ 8 luminosity function and find that the Super Eight number density is consistent with other surveys in this magnitude and redshift range.


Unitarity Of The Infinite-Volume Three-Particle Scattering Amplitude Arising From A Finite-Volume Formalism, Raúl A. Briceño, Maxwell T. Hansen, Stephen R. Sharpe, Adam P. Szczepaniak Sep 2019

Unitarity Of The Infinite-Volume Three-Particle Scattering Amplitude Arising From A Finite-Volume Formalism, Raúl A. Briceño, Maxwell T. Hansen, Stephen R. Sharpe, Adam P. Szczepaniak

Physics Faculty Publications

Hansen and Sharpe [Phys. Rev. D 92, 114509 (2015)] derived a relation between the scattering amplitude of three identical bosons,M3, and a real function referred to as the divergence-free K matrix and denoted Kdf;3. The result arose in the context of a relation between finite-volume energies and Kdf;3, derived to all orders in the perturbative expansion of a generic low-energy effective field theory. In this work we set aside the role of the finite volume and focus on the infinite-volume relation between Kdf;3 and M3. We show that, for any …


Wallaby Early Science − V. Askap Hi Imaging Of The Lyon Group Of Galaxies 351, B. Q. For, Lister Staveley-Smith, Tobias Westmeier, M. Whiting, S. -H. Oh, Baerbel Koribalski, Juan P. Madrid Aug 2019

Wallaby Early Science − V. Askap Hi Imaging Of The Lyon Group Of Galaxies 351, B. Q. For, Lister Staveley-Smith, Tobias Westmeier, M. Whiting, S. -H. Oh, Baerbel Koribalski, Juan P. Madrid

Physics and Astronomy Faculty Publications and Presentations

We present an HI study of the galaxy group LGG 351 using Widefield ASKAP L-band Legacy All-sky Blind Survey (WALLABY) early science data observed with the Australian Square Kilometre Array Pathfinder (ASKAP). LGG 351 resides behind the M 83 group at a velocity range (cz) of ∼3500–4800 km s−1 within the rich Hydra-Centaurus overdensity region. We detect 40 sources with the discovery of a tidally interacting galaxy pair and two new HI sources that are not presented in previous optical catalogues. 23 out of 40 sources have new redshifts derived from the new HI data. This study is the largest …


Space Telescope And Optical Reverberation Mapping Project. Viii. Time Variability Of Emission And Absorption In Ngc 5548 Based On Modeling The Ultraviolet Spectrum, Gerard A. Kriss, Gisella De Rosa, Justin Ely, Bradley M. Peterson, J. Kaastra, M. Mehdipour, Gary J. Ferland, Maryamossadat Dehghanian, S. Mathur, Rick Edelson, Kirk T. Korista, N. Arav, Aaron J. Barth, Misty C. Bentz, W. Niel Brandt, D. Michael Crenshaw, E. Dalla Bonta, K. D. Kenney, C. Done, Michael Eracleous, Michael M. Fausnaugh, E. Gardner, Michael R. Goad, Catherine J. Grier, Keith Horne, Christopher S. Kochanek, I. M. Mchardy, Hagai Netzer, Anna Pancoast, L. Pei, Richard W. Pogge, Daniel Proga Aug 2019

Space Telescope And Optical Reverberation Mapping Project. Viii. Time Variability Of Emission And Absorption In Ngc 5548 Based On Modeling The Ultraviolet Spectrum, Gerard A. Kriss, Gisella De Rosa, Justin Ely, Bradley M. Peterson, J. Kaastra, M. Mehdipour, Gary J. Ferland, Maryamossadat Dehghanian, S. Mathur, Rick Edelson, Kirk T. Korista, N. Arav, Aaron J. Barth, Misty C. Bentz, W. Niel Brandt, D. Michael Crenshaw, E. Dalla Bonta, K. D. Kenney, C. Done, Michael Eracleous, Michael M. Fausnaugh, E. Gardner, Michael R. Goad, Catherine J. Grier, Keith Horne, Christopher S. Kochanek, I. M. Mchardy, Hagai Netzer, Anna Pancoast, L. Pei, Richard W. Pogge, Daniel Proga

Physics & Astronomy Faculty Research

We model the ultraviolet spectra of the Seyfert 1 galaxy NGC 5548 obtained with the Hubble Space Telescope during the 6 month reverberation mapping campaign in 2014. Our model of the emission from NGC 5548 corrects for overlying absorption and deblends the individual emission lines. Using the modeled spectra, we measure the response to continuum variations for the deblended and absorption-corrected individual broad emission lines, the velocity-dependent profiles of Lyα and C iv, and the narrow and broad intrinsic absorption features. We find that the time lags for the corrected emission lines are comparable to those for the original data. …


The Gene Silencing Protein Morc-1 Topologically Entraps Dna And Forms Multimeric Assemblies To Cause Dna Compaction., Hyeongjun Kim, Linda Yen, Somsakul P. Wongpalee, Jessica A. Kirshner, Nicita Mehta, Yan Xue, Jonathan B. Johnston, Alma L. Burlingame, John K. Kim, Joseph J. Loparo, Steve E. Jacobsen Aug 2019

The Gene Silencing Protein Morc-1 Topologically Entraps Dna And Forms Multimeric Assemblies To Cause Dna Compaction., Hyeongjun Kim, Linda Yen, Somsakul P. Wongpalee, Jessica A. Kirshner, Nicita Mehta, Yan Xue, Jonathan B. Johnston, Alma L. Burlingame, John K. Kim, Joseph J. Loparo, Steve E. Jacobsen

Physics and Astronomy Faculty Publications and Presentations

Highlights

  • Caenorhabditis elegans MORC-1 traps DNA loops

  • Recruitment of additional MORC-1s cause further loop trapping and DNA compaction

  • MORC-1 assemblages become topologically entrapped on DNA

  • MORC-1 forms discrete foci in vivo and can phase transition in vitro

Summary

Microrchidia (MORC) ATPases are critical for gene silencing and chromatin compaction in multiple eukaryotic systems, but the mechanisms by which MORC proteins act are poorly understood. Here, we apply a series of biochemical, single-molecule, and cell-based imaging approaches to better understand the function of the Caenorhabditis elegans MORC-1 protein. We find that MORC-1 binds to DNA in a length-dependent but sequence non-specific …


Viewing Angle Constraints On S190425z And S190426c And The Joint Gravitational-Wave/Gamma-Ray Detection Fractions For Binary Neutron Star Mergers, Hao-Ran Song, Shun-Ke Ai, Min-Hao Wang, Nan Xing, He Gao, Bing Zhang Aug 2019

Viewing Angle Constraints On S190425z And S190426c And The Joint Gravitational-Wave/Gamma-Ray Detection Fractions For Binary Neutron Star Mergers, Hao-Ran Song, Shun-Ke Ai, Min-Hao Wang, Nan Xing, He Gao, Bing Zhang

Physics & Astronomy Faculty Research

The Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo scientific collaboration (LVC) detected two binary neutron star (BNS) merger candidates, S190425z and S190426c. The Fermi-Gamma-ray Burst Monitor (GBM) observed 55.6% (for S190425z) and 100% (for S190426c) of the probability regions of both events at the respective merger times, but no gamma-ray burst (GRB) was detected in either case. The derived luminosity upper limits suggest that a short GRB similar to GRB 170817A would not be detectable for both cases due to their distances, which are larger than that of GW170817. Assuming that the jet profile obtained from GW170817/GRB 170817A is quasi-universal …


Type I Outbursts In Low-Eccentricity Be/X-Ray Binaries, Alessia Franchini, Rebecca G. Martin Aug 2019

Type I Outbursts In Low-Eccentricity Be/X-Ray Binaries, Alessia Franchini, Rebecca G. Martin

Physics & Astronomy Faculty Research

Type I outbursts in Be/X-ray binaries are usually associated with the eccentricity of the binary orbit. The neutron star accretes gas from the outer parts of the decretion disk around the Be star at each periastron passage. However, this mechanism cannot explain type I outbursts that have been observed in nearly circular orbit Be/X-ray binaries. With hydrodynamical simulations and analytic estimates we find that in a circular orbit binary, a nearly coplanar disk around the Be star can become eccentric. The extreme mass ratio of the binary leads to the presence of the 3:1 Lindblad resonance inside the Be star …


The Frequency Of Kozai–Lidov Disc Oscillation Driven Giant Outbursts In Be/X-Ray Binaries, Rebecca G. Martin, Alessia Franchini Aug 2019

The Frequency Of Kozai–Lidov Disc Oscillation Driven Giant Outbursts In Be/X-Ray Binaries, Rebecca G. Martin, Alessia Franchini

Physics & Astronomy Faculty Research

Giant outbursts of Be/X-ray binaries may occur when a Be-star disc undergoes strong eccentricity growth due to the Kozai–Lidov (KL) mechanism. The KL effect acts on a disc that is highly inclined to the binary orbital plane provided that the disc aspect ratio is sufficiently small. The eccentric disc overflows its Roche lobe and material flows from the Be star disc over to the companion neutron star causing X-ray activity. With N-body simulations and steady state decretion disc models we explore system parameters for which a disc in the Be/X-ray binary 4U 0115+634 is KL unstable and the resulting time-scale …


Effect Of Field-Line Curvature On The Ionospheric Accessibility Of Relativistic Electron Beam Experiments, Jake M. Willard, Jay R. Johnson, Jesse M. Snelling, Andrew T. Powis, Igor D. Kaganovich, Ennio R, Sanchez Aug 2019

Effect Of Field-Line Curvature On The Ionospheric Accessibility Of Relativistic Electron Beam Experiments, Jake M. Willard, Jay R. Johnson, Jesse M. Snelling, Andrew T. Powis, Igor D. Kaganovich, Ennio R, Sanchez

Faculty Publications

Magnetosphere-ionosphere coupling is a particularly important process that regulates and controls magnetospheric dynamics such as storms and substorms. However, in order to understand magnetosphere-ionosphere coupling it is necessary to understand how regions of the magnetosphere are connected to the ionosphere. It has been proposed that this connection may be established by firing electron beams from satellites that can reach an ionospheric footpoint creating detectable emissions. This type of experiment would greatly aid in identifying the relationship between convection processes in the magnetotail and the ionosphere and how the plasma sheet current layer evolves during the growth phase preceding substorms. For …


A Precise Determination Of (Anti)Neutrino Fluxes With (Anti)Neutrino-Hydrogen Interactions, H. Duyang, B. Guo, Roberto Petti Aug 2019

A Precise Determination Of (Anti)Neutrino Fluxes With (Anti)Neutrino-Hydrogen Interactions, H. Duyang, B. Guo, Roberto Petti

Faculty Publications

We present a novel method to accurately determine the flux of neutrinos and antineutrinos, one of the dominant systematic uncertainty affecting current and future long-baseline neutrino experiments, as well as precision neutrino scattering experiment. Using exclusive topologies in v()-hydrogen interactions, vµp→µ+, µp → µ +pπ, and µp → µ + n with small hadronic energy, we achieve an overall accuracy on the relative fluxes better than 1% in the energy range covering most of the available flux. Since we cannot rely on simulations nor model …


Indigenous Astronomy As Told By The Haudenosaunee, Sasha Doxtator Aug 2019

Indigenous Astronomy As Told By The Haudenosaunee, Sasha Doxtator

Head and Heart Posters 2019

Colonization has greatly reduced the extent to which Indigenous astronomy is presently known and shared. Much sky lore has become lost or fragmented, and the connections between stories, night sky observations, and their relevance is not as obvious as it once was. A detrimental spiral has ensued with many Western-trained scientists being reluctant to share sky lore out of fear of being misunderstood, disrespected, and dismissed.


Formation Of Ultra-Diffuse Galaxies In The Field And In Galaxy Groups, Fangzhou Jiang, Avishai Dekel, Jonathan Freundlich, Aaron Romanowsky, Aaron Dutton, Andrea Macciò, Arianna Di Cintio Aug 2019

Formation Of Ultra-Diffuse Galaxies In The Field And In Galaxy Groups, Fangzhou Jiang, Avishai Dekel, Jonathan Freundlich, Aaron Romanowsky, Aaron Dutton, Andrea Macciò, Arianna Di Cintio

Faculty Publications

We study ultra-diffuse galaxies (UDGs) in zoom in cosmological simulations, seeking the origin of UDGs in the field versus galaxy groups. We find that while field UDGs arise from dwarfs in a characteristic mass range by multiple episodes of supernova feedback (Di Cintio et al.), group UDGs may also form by tidal puffing up and they become quiescent by ram-pressure stripping. The field and group UDGs share similar properties, independent of distance from the group centre. Their dark-matter haloes have ordinary spin parameters and centrally dominant dark-matter cores. Their stellar components tend to have a prolate shape with a Sérsic …


The Hubble Space Telescope Pancet Program: Exospheric Mg Ii And Fe Ii In The Near-Ultraviolet Transmission Spectrum Of Wasp-121b Using Jitter Decorrelation, David K. Sing, Panayotis Lavvas, Gilda E. Ballester, Alain Lecavelier Des Etangs, Mark S. Marley, Nikolay Nikolov, Lofti Ben-Jaffel, Vincent Bourrier, Lars A. Buchhave, Drake Deming, David Ehrenreich, Thomas Mikal-Evans, Tiffany Kataria, Nikole K. Lewis, Mercedes López-Morales, Antonio García Muñoz, Gregory W. Henry, Jorge Sanz-Forcada, Jessica J. Spake, Hannah R. Wakeford, The Pancet Collaboration Aug 2019

The Hubble Space Telescope Pancet Program: Exospheric Mg Ii And Fe Ii In The Near-Ultraviolet Transmission Spectrum Of Wasp-121b Using Jitter Decorrelation, David K. Sing, Panayotis Lavvas, Gilda E. Ballester, Alain Lecavelier Des Etangs, Mark S. Marley, Nikolay Nikolov, Lofti Ben-Jaffel, Vincent Bourrier, Lars A. Buchhave, Drake Deming, David Ehrenreich, Thomas Mikal-Evans, Tiffany Kataria, Nikole K. Lewis, Mercedes López-Morales, Antonio García Muñoz, Gregory W. Henry, Jorge Sanz-Forcada, Jessica J. Spake, Hannah R. Wakeford, The Pancet Collaboration

Information Systems and Engineering Management Research Publications

We present Hubble Space Telescope (HST) near-ultraviolet (NUV) transits of the hot Jupiter WASP-121b, acquired as part of the PanCET program. Time-series spectra during two transit events were used to measure the transmission spectra between 2280 and 3070 Å at a resolution of 30,000. Using HST data from 61 Space Telescope Imaging Spectrograph visits, we show that data from HST's Pointing Control System can be used to decorrelate the instrument systematic errors (jitter decorrelation), which we used to fit the WASP-121b light curves. The NUV spectra show very strong absorption features, with the NUV white light curve found to be …


One-Note-Samba Approach To Cosmology, Florentin Smarandache, Victor Christianto Aug 2019

One-Note-Samba Approach To Cosmology, Florentin Smarandache, Victor Christianto

Branch Mathematics and Statistics Faculty and Staff Publications

Inspired by One Note Samba, a standard jazz repertoire, we present an outline of Bose-Einstein Condensate Cosmology. Although this approach seems awkward and a bit off the wall at first glance, it is not impossible to connect altogether BEC, Scalar Field Cosmology and Feshbach Resonance with Ermakov-Pinney equation. We also briefly discuss possible link with our previous paper which describes Newtonian Universe with Vortex in terms of Ermakov equation.


Kelt-23ab: A Hot Jupiter Transiting A Near-Solar Twin Close To The Tess And Jwst Continuous Viewing Zones, D. Johns, P. A. Reed, J. E. Rodriguez, J. Pepper, K. A. Stassun, K. Penev, B. S. Gaudi, J. Labadie-Bartz, B. J. Fulton, S. N. Quinn, J. D. Eastman, D. R. Ciardi, L. Hirsch, D. J. Stevens, C. P. Stevens, T. E. Oberst, David H. Cohen, Eric L.N. Jensen, P. Benni, S. Villanueva Jr., G. Murawski, A, Bieryla, D. W. Latham, S. Vanaverbeke, F. Dubois, S. Rau, L. Logie, R. F. Rauenzahn, R. A. Wittenmyer, R. Zambelli, D. Bayliss, T. G. Beatty, K. A. Collins, K. D. Colón, I. A. Curtis, P. Evans, J. Gregorio, D. James, D. L. Depoy, M. C. Johnson, M. D. Joner, D. H. Kasper, S. Khakpash, J. F. Kielkopf, R. B. Kuhn, M. B. Lund, M. Manner, J. L. Marshall, K. K. Mcleod, M. T. Penny, H. Relles, R. J. Siverd, D. C. Stephens, C. Stockdale, T.-G. Tan, M. Trueblood, P. Trueblood, X. Yao Aug 2019

Kelt-23ab: A Hot Jupiter Transiting A Near-Solar Twin Close To The Tess And Jwst Continuous Viewing Zones, D. Johns, P. A. Reed, J. E. Rodriguez, J. Pepper, K. A. Stassun, K. Penev, B. S. Gaudi, J. Labadie-Bartz, B. J. Fulton, S. N. Quinn, J. D. Eastman, D. R. Ciardi, L. Hirsch, D. J. Stevens, C. P. Stevens, T. E. Oberst, David H. Cohen, Eric L.N. Jensen, P. Benni, S. Villanueva Jr., G. Murawski, A, Bieryla, D. W. Latham, S. Vanaverbeke, F. Dubois, S. Rau, L. Logie, R. F. Rauenzahn, R. A. Wittenmyer, R. Zambelli, D. Bayliss, T. G. Beatty, K. A. Collins, K. D. Colón, I. A. Curtis, P. Evans, J. Gregorio, D. James, D. L. Depoy, M. C. Johnson, M. D. Joner, D. H. Kasper, S. Khakpash, J. F. Kielkopf, R. B. Kuhn, M. B. Lund, M. Manner, J. L. Marshall, K. K. Mcleod, M. T. Penny, H. Relles, R. J. Siverd, D. C. Stephens, C. Stockdale, T.-G. Tan, M. Trueblood, P. Trueblood, X. Yao

Physics & Astronomy Faculty Works

We announce the discovery of KELT-23Ab, a hot Jupiter transiting the relatively bright (V = 10.3) star BD+66 911 (TYC 4187-996-1), and characterize the system using follow-up photometry and spectroscopy. A global fit to the system yields host-star properties of Teff = 5900 ± 49 K, M* = 0.945 ((+0.060)/(-0.054))M, R* = 0.995 ± 0.015 R, L* = 1.082 ((+0.051)/(-0.048)) L, log g* = 4.418 ((+0.026)/(-0.025) (cgs), and [Fe/H] = -0.105 ± 0.077. KELT-23Ab is a hot Jupiter with a mass of Mp = 0.938 ((+0.045)/-0.042)) M …


Electron Energization By Parallel Electric Fields In Poloidal Standing Waves, P. A. Damiano, Eun-Hwa Kim, Jay R. Johnson, P. Porazik Aug 2019

Electron Energization By Parallel Electric Fields In Poloidal Standing Waves, P. A. Damiano, Eun-Hwa Kim, Jay R. Johnson, P. Porazik

Faculty Publications

A hybrid gyrofluid‐kinetic electron model is adapted and used to simulate poloidal standing modes for different electron temperatures and azimuthal mode numbers. As in previous studies of toroidal standing modes, mirror force effects lead to increased parallel potential drops, monoenergetic electron energization, and wave energy dissipation as the ambient electron temperature is increased. A similar trend is also observed when the electron temperature is held fixed and the azimuthal mode number increased—owing to the narrowing of the azimuthal flux tube width, which necessitates more electron energization to carry the increased parallel current density. In both cases, the increase in electron …


Hyper Wide Field Imaging Of The Local Group Dwarf Irregular Galaxy Ic 1613: An Extended Component Of Metal-Poor Stars, Ragadeepika Pucha, Jeffrey Carlin, Beth Willman, Jay Strader, David Sand, Keith Bechtol, Jean Brodie, Denija Crnojević, Duncan Forbes, Christopher Garling, Jonathan Hargis, Annika Peter, Aaron Romanowsky Jul 2019

Hyper Wide Field Imaging Of The Local Group Dwarf Irregular Galaxy Ic 1613: An Extended Component Of Metal-Poor Stars, Ragadeepika Pucha, Jeffrey Carlin, Beth Willman, Jay Strader, David Sand, Keith Bechtol, Jean Brodie, Denija Crnojević, Duncan Forbes, Christopher Garling, Jonathan Hargis, Annika Peter, Aaron Romanowsky

Faculty Publications

Stellar halos offer fossil evidence for hierarchical structure formation. Since halo assembly is predicted to be scale-free, stellar halos around low-mass galaxies constrain properties such as star formation in the accreted subhalos and the formation of dwarf galaxies. However, few observational searches for stellar halos in dwarfs exist. Here we present gi photometry of resolved stars in isolated Local Group dwarf irregular galaxy IC 1613 (M sstarf ~ 108 M ⊙). These Subaru/Hyper Suprime-Cam observations are the widest and deepest of IC 1613 to date. We measure surface density profiles of young main-sequence, intermediate to old red giant branch, and …