Astrophysics and Astronomy Commons^™

The Subaru Hsc Weak Lensing Mass-Observable Scaling Relations Of Spectroscopic Galaxy Groups From The Gama Survey, Divya Rana, Surhud More, Hironao Miyatake, Takahiro Nishimichi, Masahiro Takada, Aaron S G Robotham, Andrew M. Hopkins, Benne Holwerda

Faculty and Staff Scholarship

We utilize the galaxy shape catalogue from the first-year data release of the Subaru Hyper Suprime-Cam (HSC) survey to study the dark matter content of galaxy groups in the Universe using weak lensing. We use galaxy groups from the Galaxy Mass and Assembly galaxy survey in approximately 100 sq. degrees of the sky that overlap with the HSC survey as lenses. We restrict our analysis to the 1587 groups with at least five members. We divide these groups into six bins each of group luminosity and group member velocity dispersion and measure the lensing signal with a signal-to-noise ratio of …

Eccentric Dust-Ring Formation In Kozai-Lidov Gas Disks, Rebecca G. Martin, Stephen H. Lubow

Physics & Astronomy Faculty Research

A highly misaligned gas disk around one component of a binary star system can undergo global Kozai-Lidov (KL) oscillations for which the disk inclination and eccentricity are exchanged. With hydrodynamical simulations of a gas and dust disk we explore the effects of these oscillations on the dust density distribution. For dust that is marginally coupled to the gas (St ≈ 1), we find that the dust undergoes dynamical behavior similar to that of the gas disk but the radial distribution of dust may be very different from that of the gas. The inward radial drift of the dust is faster …

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, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

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, 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 …

Spectroscopic Properties Relevant To Astronomical And Laboratory Detection Of Mch And Mch+ (M = Al, Mg), Vincent J. Esposito, Tarek Trabelsi, Joseph S. Francisco

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

New spectroscopic parameters have been calculated to aid in the laboratory and observational detection of AlCH, AlCH⁺, MgCH, MgCH⁺, and their deuterated analogs. All species exist in linear geometry except for AlCH+, which exhibits a bent structure. Rotational frequencies have been calculated and the transition with maximum intensity is discussed for three temperature regions present in space: 100 K for a central circumstellar envelope (CSE), 30 K for an outer CSE, and 3 K indicative of the interstellar medium. Pertinent frequencies range from 25 to 250 GHz, depending on the species. At 30 K, the most …

On The Horizon: Nanosatellite Constellations Will Revolutionize The Internet Of Things (Iot), Diane Janosek

Seattle Journal of Technology, Environmental, & Innovation Law

The Internet of Things has experienced exponential growth and use across the globe with 25.1 billion devices currently in use. Until recently, the functionality of the IoT was dependent on secure data flow between internet terrestrial stations and the IoT devices. Now, a new alternative path of data flow is on the horizon.

IoT device manufacturers are now looking to outer space nanosatellite constellations to connect to a different type of internet. This new internet is no longer terrestrial with fiber cables six feet underground but now looking up, literally, 200 to 300 miles above the earth, to communicate, connect …

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, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Volker Quetschke, Wenhui Wang

Physics & Astronomy 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 …

Detection Of Ongoing Mass Loss From Hd 63433c, A Young Mini-Neptune, Michael Zhang, Heather A. Knutson, Lile Wang, Fei Dai, Leonardo A. Dos Santos, Luca Fossati, Gregory W. Henry, David Ehrenreich, Yann Alibert, Sergio Hoyer, Thomas G. Wilson, Andrea Bonfanti

Information Systems and Engineering Management Research Publications

We detect Lyα absorption from the escaping atmosphere of HD 63433c, a R = 2.67R_⊕, P = 20.5 day mini-Neptune orbiting a young (440 Myr) solar analog in the Ursa Major Moving Group. Using Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph, we measure a transit depth of 11.1 ± 1.5% in the blue wing and 8 ± 3% in the red. This signal is unlikely to be due to stellar variability, but should be confirmed by an upcoming second transit observation with HST. We do not detect Lyα absorption from the inner planet, a smaller …

James Webb Space Telescope's Enlightening Journey Is Underway, Erik Johnson

Natural Science Faculty

A rocket carrying the successor to the Hubble Space Telescope launched on Christmas. Astronomers hope that the James Webb Space Telescope will provide insight about the earliest stage of the universe when it orbits about one million miles from Earth. The Staerkel Planetarium collaborated with the Illinois Space Grant Consortium to promote the launch of this revolutionary device.

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 …

Comparison Of Maximum-Likelihood Mapping Methods For Gravitational-Wave Backgrounds, Arianna I. Renzini, Joseph D. Romano, Carlo R. Contaldi, Neil Cornish

Physics & Astronomy Faculty Publications

Detection of a stochastic background of gravitational waves is likely to occur in the next few years. Beyond searches for the isotropic component of a stochastic gravitational-wave background, there have been various mapping methods proposed to target anisotropic backgrounds. Some of these methods have been applied to data taken by the Laser Interferometer Gravitational-wave Observatory (LIGO) and Virgo. Specifically, these directional searches have focused on mapping the intensity of the signal on the sky via maximum-likelihood solutions. We compare this intensity mapping approach to a previously proposed, but never employed, amplitude-phase mapping method to understand whether this latter approach may …

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 …

Dr. Jennifer Hoffman, Anit Tyagi

DU Undergraduate Research Journal Archive

An interview with Dr. Jennifer Hoffman.

Dark And Quiet Skies Ii Working Group Reports, James Lowenthal, Connie Walker, Piero Benvenuti

Astronomy: Faculty Publications

This Report presents the main results of the Conference “Dark and Quiet Skies for Science and Society II” which took place on-line on 3–7 October 2021. This conference was the logical follow-up of the first one, organized as an on-line workshop with the same title on 5–9 October 2020. Both conferences were co-organized by UNOOSA, IAU and the Government of Spain and were well attended. The focus of the second conference was about the feasibility of implementing the recommendations presented by the first one in its extensive report. The main qualifying difference between the first and the second conferences was …

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 …

Deep Extragalactic Visible Legacy Survey: Data Release 1 Blended Spectra Search For Candidate Strong Gravitational Lenses, Benne Holwerda, S Knabel, J E. Thorne, S Bellstedt, M Siudek, L J M Davies

Faculty and Staff Scholarship

Here, we present a catalogue of blended spectra in Data Release 1 of the Deep Extragalactic VIsible Legacy Survey (DEVILS) on the Anglo-Australian Telescope. Of the 23 197 spectra, 181 showed signs of a blend of redshifts and spectral templates. We examine these blends in detail for signs of either a candidate strong lensing galaxy or a useful overlapping galaxy pair. One of the three DEVILS target fields, COSMOS (D10), is close to complete and it is fully imaged with Hubble Space Telescope Advanced Camera for Surveys, and we visually examine the 57 blended spectra in this field in the …

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. …