Astrophysics and Astronomy Commons^™

The Majorana Demonstrator Readout Electronics System, N. Abgrall, M. Amman, I. J. Arnquist, Frank Avignone Iii, A. S. Barabash, C. J. Barton, P. J. Barton, F. E. Bertrand, K. H. Bhimani, B. Bos, A. W. Bradley, T. H. Burritt, M. Busch, M. Buuck, T. S. Caldwell, Y-D. Chan, C. D. Christofferson, P.-H. Chu, M. L. Clark, R. J. Cooper, C. Cuesta, Et. Al.

Faculty Publications

The Majorana Demonstrator comprises two arrays of high-purity germanium detectors constructed to search for neutrinoless double-beta decay in 76Ge and other physics beyond the Standard Model. Its readout electronics were designed to have low electronic noise, and radioactive backgrounds were minimized by using low-mass components and low-radioactivity materials near the detectors. This paper provides a description of all components of the Majorana Demonstrator readout electronics, spanning the front-end electronics and internal cabling, back-end electronics, digitizer, and power supplies, along with the grounding scheme. The spectroscopic performance achieved with these readout electronics is also demonstrated.

Search Of The Early O3 Ligo Data For Continuous Gravitational Waves From The Cassiopeia A And Vela Jr. Supernova Remnants, Ligo Scientific Collaboration, Virgo Collaboration, Tiffany Z. Summerscales

Faculty Publications

We present directed searches for continuous gravitational waves from the neutron stars in the Cassiopeia A (Cas A) and Vela Jr. supernova remnants. We carry out the searches in the LIGO detector data from the first six months of the third Advanced LIGO and Virgo observing run using the weave semicoherent method, which sums matched-filter detection-statistic values over many time segments spanning the observation period. No gravitational wave signal is detected in the search band of 20–976 Hz for assumed source ages greater than 300 years for Cas A and greater than 700 years for Vela Jr. Estimates from simulated …

Beam-Spin Asymmetry Σ For Σ- Hyperon Photoproduction Off The Neutron, N. Zachariou, E. Munevar, B. L. Berman, P. Bydžovský, A. Cieplý, G. Feldman, Y. Ilieva, P. Nadel-Turonski, D. Skoupil, A. V. Sarantsev, D. P. Watts, M. J. Amaryan, G. Angelini, W. R. Armstrong, H. Atac, H. Avakian, L. Barion, M. Bashkanov, M. Battaglieri, Steffen Strauch, Et. Al.

Faculty Publications

We report a new measurement of the beam-spin asymmetry, Σ, for the γn → K ⁺ Σ− reaction using quasi-free neutrons in a liquid-deuterium target. The new dataset includes data at previously unmeasured photon energy and angular ranges, thereby providing new constraints on partial wave analyses used to extract properties of the excited nucleon states. The experimental data were obtained using the CEBAF Large Acceptance Spectrometer (CLAS), housed in Hall B of the Thomas Jefferson National Accelerator Facility (JLab). The CLAS detector measured reaction products from a liquid-deuterium target produced by an energy-tagged, linearly polarised photon beam with energies in …

Untangling The Solar Wind And Magnetospheric Drivers Of The Radiation Belt Electrons, Simon Wing, Jay R. Johnson, Drew L. Turner, Aleksandr Y. Ukhorskiy, Alexander J. Boyd

Faculty Publications

Plain Language Summary

Many solar wind parameters correlate with one another, which complicates the causal-effect studies of solar wind driving of the magnetosphere. We use conditional mutual information, which is part of information theory, to untangle and isolate the effect of individual solar wind and magnetospheric drivers of the radiation belt electrons. For example, the solar wind density negatively correlates with electron phase space density (PSD) (average energy ∼1.6 MeV) with the response time lag of 15 hr. This has been attributed to the electron loss process such as magnetopause shadowing. The time lag suggests the time scale for this …

Search For Gravitational Waves Associated With Gamma-Ray Bursts Detected By Fermi And Swift During The Ligo–Virgo Run O3b, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales

Faculty Publications

We search for gravitational-wave signals associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the second half of the third observing run of Advanced LIGO and Advanced Virgo (2019 November 1 15:00 UTC–2020 March 27 17:00 UTC). We conduct two independent searches: a generic gravitational-wave transients search to analyze 86 GRBs and an analysis to target binary mergers with at least one neutron star as short GRB progenitors for 17 events. We find no significant evidence for gravitational-wave signals associated with any of these GRBs. A weighted binomial test of the combined results finds no evidence …

Possible Studies On Generalized Parton Distributions And Gravitational Form Factors In Neutrino Reactions, Shunzo Kumano, Roberto Petti

Faculty Publications

Spacelike and timelike generalized parton distributions (GPDs) have been investigated in charged-lepton scattering and electron-positron collisions via deeply virtual Compton scattering and two-photon processes, respectively. Furthermore, we expect that hadron-accelerator-facility measurements will be performed in future. The GPDs will play a crucial role in clarifying the origins of hadron spins and masses in terms of quarks and gluons. It is also possible to probe internal pressure within hadrons for understanding their stability. Gravitational form factors of hadrons used to be considered as a purely academic subject because gravitational interactions are too weak to be measured in microscopic systems. However, due …

Constraints On Dark Photon Dark Matter Using Data From Ligo’S And Virgo’S Third Observing Run, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales

Faculty Publications

We present a search for dark photon dark matter that could couple to gravitational-wave interferometers using data from Advanced LIGO and Virgo’s third observing run. To perform this analysis, we use two methods, one based on cross-correlation of the strain channels in the two nearly aligned LIGO detectors, and one that looks for excess power in the strain channels of the LIGO and Virgo detectors. The excess power method optimizes the Fourier transform coherence time as a function of frequency, to account for the expected signal width due to Doppler modulations. We do not find any evidence of dark photon …

Low Exposure Long-Baseline Neutrino Oscillation Sensitivity Of The Dune Experiment, A. Aduszkiewicz, J. Aguilar, Z. Ahmad, B. Aimard, B. Ali-Mohammadzadeh, T. Alion, K. Allison, S. Alonso Monnsalve, M. Alrashed, C. Alt, A. Alton, P. Amedo, J. Anderson, C. Andreopooulos, M. Andreotti, M. P. Andrews, F. Andrianala, S. Andringa, N. Anfimov, Roberto Petti, Sanjib R. Mishra Ph.D., Et. Al.

Faculty Publications

The Deep Underground Neutrino Experiment (DUNE) will produce world-leading neutrino oscillation measurements over the lifetime of the experiment. In this work, we explore DUNE’s sensitivity to observe charge-parity violation (CPV) in the neutrino sector, and to resolve the mass ordering, for exposures of up to 100 kiloton-megawatt-calendar years (kt-MW-CY), where calendar years include an assumption of 57% accelerator uptime based on past accelerator performance at Fermilab. The analysis includes detailed uncertainties on the flux prediction, the neutrino interaction model, and detector effects. We demonstrate that DUNE will be able to unambiguously resolve the neutrino mass ordering at a 4⁢𝜎 (5⁢𝜎) …

Measurement Of Structure Dependent Radiative K+ -> E,Sup>(+) Vy Gamma Decays Using Stopped Positive Kaons, H. Ito, A. Kobayashi, S. Bianchin, T. Cao, C. Djalali, D. H. Dongwi, T. Gautam, D. Gill, M. D. Hasinoff, K. Horie, Y. Igarashi, J. Imazato, N. Kalantarians, H. Kawai, S. Kimura, S. Kodama, M. Kohl, H. Lu, O. Mineev, Steffen Strauch, Et. Al.

Faculty Publications

The structure dependent radiative K + → e+νγ (K^SD+_e2γ) decay was investigated with stopped positive kaons. The e⁺ momentum spectra containing 574±30 K^SD+_e2γ events with a K + → μ+ν (K_μ2) background of 28 ± 19 events were measured with and without a photon in coincidence and analyzed with Monte Carlo simulations for acceptance and detector response to extract the ratio of the branching ratio of the K^SD+_e2γ decay and the K + → e+ν decay including the internal bremsstrahlung process (K_{e2(γ )}). …

Gaia Gral: Gaia Dr2 Gravitational Lens Systems. Vii. Xmm-Newton Observations Of Lensed Quasars, Thomas Connor, Daniel Stern, Alberto Krone-Martins, S. G. Djorgovski, Matthew J. Graham

Faculty Publications

We present XMM-Newton X-ray observations of nine confirmed lensed quasars at 1 less than or similar to z less than or similar to 3 identified by the Gaia Gravitational Lens program. Eight systems are strongly detected, with 0.3-8.0 keV fluxes F (0.3-8.0) greater than or similar to 5 x10(-14) erg cm(-2) s(-1). Modeling the X-ray spectra with an absorbed power law, we derive power-law photon indices and 2-10 keV luminosities for the eight detected quasars. In addition to presenting sample properties for larger quasar population studies and for use in planning for future caustic-crossing events, we also identify three quasars …

A Multiparameter Degeneracy In Microlensing Events With Extreme Finite Source Effects, Samson A. Johnson, Matthew T. Penny, B. Scott Gaudi

Faculty Publications

For microlenses with sufficiently low mass, the angular radius of the source star can be much larger than the angular Einstein ring radius of the lens. For such extreme finite source effect (EFSE) events, finite source effects dominate throughout the duration of the event. Here, we demonstrate and explore a continuous degeneracy between multiple parameters of such EFSE events. The first component in the degeneracy arises from the fact that the directly observable peak change of the flux depends on both the ratio of the angular source radius to the angular Einstein ring radius and the fraction of the baseline …

Multidimensional, High Precision Measurements Of Beam Single Spin Asymmetries In Semi-Inclusive Pi+ Electroproduction Off Protons In The Valence Region, S. Diehl, A. Kim, G. Angelini, K. Joo, S. Adhikari, M. Amaryan, M. Arratia, H. Atac, H. Avakian, C. Ayerbe Gayoso, N. A. Baltzell, L. Barion, S. Bastami, M. Battaglieri, I. Bedlinskiy, F. Benmokhtar, A. Bianconi, A. S. Biselli, M. Bondi, F. Bossù, Steffen Strauch, Et. Al.

Faculty Publications

High precision measurements of the polarized electron beam-spin asymmetry in semi-inclusive deep inelastic scattering (SIDIS) from the proton have been performed using a 10.6 GeV incident electron beam and the CLAS12 spectrometer at Jefferson Lab. We report here a high precision multidimensional study of single πþ SIDIS data over a large kinematic range in Bjorken x, fractional energy, and transverse momentum of the hadron as well as photon virtualities Q² ranging from 1–7 GeV². In particular, the structure function ratio ^sinϕ _LU/ F_UU has been determined, where ^sinϕ _LU is a twist-3 quantity that …

Measurement Of The Nucleon F N2 / F P2 Tructure Function Ratio By The Jefferson Lab Marathon Tritium/Helium-3 Deep Inelastic Scattering Experiment, D. Abrams, H. Albataineh, B. S. Aljawrneh, S. Alsalmi, D. Androic, K. Aniol, W. Armstrong, J. Arrington, H. Atac, T. Averett, C. Ayerbe Gayoso, X. Bai, J. Bane, S. Barcus, A. Beck, V. Bellini, H. Bhatt, D. Bhetuwal, D. Biswas, D. Blyth, Roberto Petti, Et. Al.

Faculty Publications

The ratio of the nucleon F₂ structure functions, F ⁿ₂ / F ^p₂ is determined by the MARATHON experiment from measurements of deep inelastic scattering of electrons from ³H and ³He nuclei. The experiment was performed in the Hall A Facility of Jefferson Lab using two high-resolution spectrometers for electron detection, and a cryogenic target system which included a low-activity tritium cell. The data analysis used a novel technique exploiting the mirror symmetry of the two nuclei, which essentially eliminates many theoretical uncertainties in the extraction of the ratio. The results, which cover the Bjorken …

Search Full Text Options Here 2 Of 4 Kmt-2021-Blg-0912lb: A Microlensing Super Earth Around A K-Type Star, Cheongho Han, Ian A. Bond, Jennifer C. Yee, Weicheng Zang, Michael D. Albrow

Faculty Publications

Aims. The light curve of the microlensing event KMT-2021-BLG-0912 exhibits a very short anomaly relative to a single-lens single-source form. We investigate the light curve for the purpose of identifying the origin of the anomaly.

Methods. We model the light curve under various interpretations. From this, we find four solutions, in which three solutions are found under the assumption that the lens is composed of two masses (2L1S models), and the other solution is found under the assumption that the source is comprised of binary stars (1L2S model). The 1L2S model is ruled out based on the contradiction that the …

Search For Single Top-Quark Production Via Flavour-Changing Neutral Currents At 8 Tev With The Atlas Detector (Vol 76, 55, 2016), G. Aad, B. Abbott, J. Abdallah, O. Abdinov, R. Aben, M. Abolins, O.S. Abouzeid, H. Abramowicz, H. Abreu, R. Abreu, Y. Abulaiti, B.S. Acharya, L. Adamczyk, D.L. Adams, J. Adelman, S. Adomeit, T. Adye, A. A. Affolder, T. Agatonovic-Jovin, J. Agricola, Milind Purohit

Faculty Publications

No abstract provided.

Search For Continuous Gravitational Waves From 20 Accreting Millisecond X-Ray Pulsars In O3 Ligo Data, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, C. Adams

Faculty Publications

Results are presented of searches for continuous gravitational waves from 20 accreting millisecond x-ray pulsars with accurately measured spin frequencies and orbital parameters, using data from the third observing run of the Advanced LIGO and Advanced Virgo detectors. The search algorithm uses a hidden Markov model, where the transition probabilities allow the frequency to wander according to an unbiased random walk, while the J-statistic maximum-likelihood matched filter tracks the binary orbital phase. Three narrow subbands are searched for each target, centered on harmonics of the measured spin frequency. The search yields 16 candidates, consistent with a false alarm probability of …

Search For Continuous Gravitational Waves From 20 Accreting Millisecond X-Ray Pulsars In O3 Ligo Data, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales

Faculty Publications

Results are presented of searches for continuous gravitational waves from 20 accreting millisecond x-ray pulsars with accurately measured spin frequencies and orbital parameters, using data from the third observing run of the Advanced LIGO and Advanced Virgo detectors. The search algorithm uses a hidden Markov model, where the transition probabilities allow the frequency to wander according to an unbiased random walk, while the J-statistic maximum-likelihood matched filter tracks the binary orbital phase. Three narrow subbands are searched for each target, centered on harmonics of the measured spin frequency. The search yields 16 candidates, consistent with a false alarm probability of …

Coupling Between Alfvén Wave And Kelvin–Helmholtz Waves In The Low Latitude Boundary Layer, Eun-Hwa Kim, Jay R. Johnson

Faculty Publications

The Kelvin–Helmholtz (KH) instability of magnetohydrodynamic surface waves at the low latitude boundary layer is examined using both an eigenfrequency analysis and a time-dependent wave simulation. The analysis includes the effects of sheared flow and Alfvén velocity gradient. When the magnetosheath flows are perpendicular to the ambient magnetic field direction, unstable KH waves that propagate obliquely to the sheared flow direction occur at the sheared flow surface when the Alfvén Mach number is higher than an instability threshold. Including a shear transition layer between the magnetosphere and magnetosheath leads to secondary KH waves (driven by the sheared flow) that are …

Towards A Quantum Notion Of Covariance In Spherically Symmetric Loop Quantum Gravity, Rodolfo Gambini, Javier Olmedo, Jorge Pullin

Faculty Publications

The covariance of loop quantum gravity studies of spherically symmetric space-times has recently been questioned. This is a reasonable worry, given that they are formulated in terms of slicing-dependent variables. We show explicitly that the resulting space-times, obtained from Dirac observables of the quantum theory, are covariant in the usual sense of the way-they preserve the quantum line element-for any gauge that is stationary (in the exterior, if there is a horizon). The construction depends crucially on the details of the Abelianized quantization considered, the satisfaction of the quantum constraints, and the recovery of standard general relativity in the classical …

Towards A Quantum Notion Of Covariance In Spherically Symmetric Loop Quantum Gravity, Rodolfo Gambini, Javier Olmedo, Jorge Pullin

Faculty Publications

The covariance of loop quantum gravity studies of spherically symmetric space-times has recently been questioned. This is a reasonable worry, given that they are formulated in terms of slicing-dependent variables. We show explicitly that the resulting space-times, obtained from Dirac observables of the quantum theory, are covariant in the usual sense of the way-they preserve the quantum line element-for any gauge that is stationary (in the exterior, if there is a horizon). The construction depends crucially on the details of the Abelianized quantization considered, the satisfaction of the quantum constraints, and the recovery of standard general relativity in the classical …

Measurements Of The Electron-Helicity Asymmetry In The Quasi-Elastic A ((E) Over Right Arrow, E' O) Process, T. Kolar, S. J. Paul, P. Achenbach, H. Arenhoevel, A. Ashkenazi, J. Beričič, R. Böhm, D. Bosnar, T. Brecelj, E. Cline, E. O. Cohen, M. O. Distler, A. Esser, I. Friščić, R. Gilman, C. Giusti, M. Heilig, M. Hoek, D, Izraeli, Steffen Strauch, Et. Al.

Faculty Publications

We present measurements of the electron helicity asymmetry in quasi-elastic proton knockout from ²H and ¹²C nuclei by polarized electrons. This asymmetry depends on the fifth structure function, is antisymmetric with respect to the scattering plane, and vanishes in the absence of final-state interactions, and thus it provides a sensitive tool for their study. Our kinematics cover the full range in off-coplanarity angle θ_pq, with a polar angle θ_pq coverage up to about 8^◦. The missing energy resolution enabled us to determine the asymmetries for knock-out resulting in different states of the residual …

Characterization Of Ti/Sno2 Interface By X-Ray Photoelectron Spectroscopy, Miranda Martinez, Chourasia R. Anil

Faculty Publications

The Ti/SnO2 interface has been investigated in situ via the technique of x-ray photoelectron spectroscopy. Thin films (in the range from 0.3 to 1.1 nm) of titanium were deposited on SnO2 substrates via the e-beam technique. The deposition was carried out at two different substrate temperatures, namely room temperature and 200 C. The photoelectron spectra of tin and titanium in the samples were found to exhibit significant differences upon comparison with the corresponding elemental and the oxide spectra. These changes result from chemical interaction between SnO2 and the titanium overlayer at the interface. The SnO2 was observed to be reduced …

Design, Construction And Operation Of The Protodune-Sp Liquid Argon Tpc, The Dune Collaboration, A. Abed Abud, B. Abi, R. Acciarri, M. A. Acero, M. R. Adames, G. Adamov, D. Adams, M. Adinolfi, A. Aduszkiewicz, J. Aguilar, Z. Ahmad, J. Ahmed, B. Ali-Mohammadzadeh, T. Alion, K. Allison, S. Alonso Monsalve, M. Alrashed, C. Alt, A. Alton, Roberto Petti, Et. Al.

Faculty Publications

The ProtoDUNE-SP detector is a single-phase liquid argon time projection chamber (LArTPC) that was constructed and operated in the CERN North Area at the end of the H4 beamline. This detector is a prototype for the first far detector module of the Deep Underground Neutrino Experiment (DUNE), which will be constructed at the Sandford Underground Research Facility (SURF) in Lead, South Dakota, U.S.A. The ProtoDUNE-SP detector incorporates full-size components as designed for DUNE and has an active volume of 7 × 6 × 7.2 m³. The H4 beam delivers incident particles with well-measured momenta and high-purity particle identification. …

Testing Effects Of Lorentz Invariance Violation In The Propagation Of Astroparticles With The Pierre Auger Observatory, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, K. Almeida Cheminant

Faculty Publications

Lorentz invariance violation (LIV) is often described by dispersion relations of the form E-i(2) = m(i)(2) + p(i)(2) + delta E-i,n(2+ n) with delta different based on particle type i, with energy E, momentum p and rest mass m. Kinematics and energy thresholds of interactions are modified once the LIV terms become comparable to the squared masses of the particles involved. Thus, the strongest constraints on the LIV coefficients delta(i,n) tend to come from the highest energies. At sufficiently high energies, photons produced by cosmic ray interactions as they propagate through the Universe could be subluminal and unattenuated over cosmological …

The Kelvin-Helmholtz Instability From The Perspective Of Hybrid Simulations, Peter A. Delamere, Nathan P. Barnes, Xuanye Ma, Jay R. Johnson

Faculty Publications

The flow shear-driven Kelvin-Helmholtz (KH) instability is ubiquitous in planetary magnetospheres. At Earth these surface waves are important along the dawn and dusk flanks of the magnetopause boundary while at Jupiter and Saturn the entire dayside magnetopause boundary can exhibit KH activity due to corotational flows in the magnetosphere. Kelvin-Helmholtz waves can be a major ingredient in the so-called viscous-like interaction with the solar wind. In this paper, we review the KH instability from the perspective of hybrid (kinetic ions, fluid electrons) simulations. Many of the simulations are based on parameters typically found at Saturn’s magnetopause boundary, but the results …

Search For Lensing Signatures In The Gravitational-Wave Observations From The First Half Of Ligo–Virgo's Third Observing Run, Ligo Scientific Collaboration, Virgo Collaboration, Tiffany Z. Summerscales

Faculty Publications

We search for signatures of gravitational lensing in the gravitational-wave signals from compact binary coalescences detected by Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) and Advanced Virgo during O3a, the first half of their third observing run. We study: (1) the expected rate of lensing at current detector sensitivity and the implications of a non-observation of strong lensing or a stochastic gravitational-wave background on the merger-rate density at high redshift; (2) how the interpretation of individual high-mass events would change if they were found to be lensed; (3) the possibility of multiple images due to strong lensing by galaxies or galaxy …

A Gravitational-Wave Measurement Of The Hubble Constant Following The Second Observing Run Of Advanced Ligo And Virgo (Vol 908, 218, 2021), B. P. Abbott, R. Abbott, T. D. Abbott

Faculty Publications

No abstract provided.

Multi-Scale Feedback And Feeding In The Closest Radio Galaxy Centaurus A, B. Mckinley, S. J. Tingay, M. Gaspari, R. P. Kraft, C. Matherne, A. R. Offringa, M. Mcdonald, M. S. Calzadilla, S Veilleux, S. S. Shabala, S. D. J. Gwyn, J. Bland-Hawthorn, D. Crnojevic, B. M. Gaensler, M. Johnston-Hollitt

Faculty Publications

Supermassive black holes and supernova explosions at the centres of active galaxies power cycles of outflowing and inflowing gas that affect galactic evolution and the overall structure of the Universe(1,2). While simulations and observations show that this must be the case, the range of physical scales (over ten orders of magnitude) and paucity of available tracers make both the simulation and observation of these effects difficult(3,4). By serendipity, there lies an active galaxy, Centaurus A (NGC 5128)(5,6), at such a close proximity as to allow its observation over this entire range of scales and across the entire electromagnetic spectrum. In …

Diving Beneath The Sea Of Stellar Activity: Chromatic Radial Velocities Of The Young Au Mic Planetary System, Bryson Cale, Michael Reefe, Peter Plavchan, Angelle Tanner, Eric Gaidos, Jonathan Gagne, Peter Gao, Stephen R. Kane, Victor J. S. Bejar, Nicolas Lodieu, Guillem Anglada-Escude, Ignasi Ribas, Enric Palle, Andreas Quirrenbach, Pedro Amado, Ansgar Reiners, Jose A. Caballero, Maria Rosa Zapatero Osorio, Stefan Dreizler, Andrew W. Howard, Benjamin J. Fulton, Sharon Xuesong Wang, Kevin I. Collins, Mohammed El Mufti, Justin Wittrock, Emily A. Gilbert, Thomas Barclay, Baptiste Klein, Eder Martioli, Robert Wittenmyer, Duncan Wright, Brett Addison, Teruyuki Hirano, Motohide Tamura, Takayuki Kotani, Norio Narita, David Vermilion, Rena A. Lee, Claire Geneser, Johanna Teske, Samuel N. Quinn, David W. Latham, Gilbert A. Esquerdo, Michael L. Calkins, Perry Berlind, Farzaneh Zohrabi, Caitlin Stibbards, Srihan Kotnana, Jon Jenkins, Joseph D. Twicken, Christopher Henze, Richard Kidwell, Jr., Christopher Burke, Joel Villasenor, Patricia Boyd

Faculty Publications

We present updated radial-velocity (RV) analyses of the AU Mic system. AU Mic is a young (22 Myr) early-M dwarf known to host two transiting planets-P-b similar to 8.46 days, R-b = 4.381(-0.18)(+0.18) R-circle plus, P-c similar to 18.86 days, R-c = 3.5(-0.16)(+0.16) R-circle plus. With visible RVs from Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical echelle Spectrographs (CARMENES)-VIS, CHIRON, HARPS, HIRES, MINERVA-Australis, and Tillinghast Reflector Echelle Spectrograph, as well as near-infrared (NIR) RVs from CARMENES-NIR, CSHELL, IRD, iSHELL, NIRSPEC, and SPIRou, we provide a 5 sigma upper limit to the mass of AU …

Search For Lensing Signatures In The Gravitational-Wave Observations From The First Half Of Ligo-Virgo's Third Observing Run, R. Abbott, T. D. Abbott

Faculty Publications

We search for signatures of gravitational lensing in the gravitational-wave signals from compact binary coalescences detected by Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) and Advanced Virgo during O3a, the first half of their third observing run. We study: (1) the expected rate of lensing at current detector sensitivity and the implications of a non-observation of strong lensing or a stochastic gravitational-wave background on the merger-rate density at high redshift; (2) how the interpretation of individual high-mass events would change if they were found to be lensed; (3) the possibility of multiple images due to strong lensing by galaxies or galaxy …