Publications (28)
GaiaUnlimited: The old stellar disc of the Milky Way as traced by the Red Clump
Shourya Khanna, Jie Yu, Ronald Drimmel +9
We present an exploration of the Milky Way's structural parameters using an all-sky sample of RC giants to map the stellar density from the Galactic disc beyond 3 kpc. These evolve…
Nanofluidic platform for studying the first-order phase transitions in superfluid helium-3
Petri J. Heikkinen, Nathan Eng, Lev V. Levitin +9
The symmetry-breaking first-order phase transition between superfluid phases He-A and He-B can be triggered extrinsically by ionising radiation or heterogeneous nucleation…
Verification of Wiedemann-Franz law in silver with moderate residual resistivity ratio
Marijn Lucas, Lev V. Levitin, Petra Knappová +3
Electrical and thermal transport were studied in a vacuum-annealed polycrystalline silver wire with residual resistivity ratio 200-400, in the temperature range 0.1-1.2K and in mag…
The GALAH survey and Gaia DR2: dissecting the stellar disc's phase space by age, action, chemistry and location
Joss Bland-Hawthorn, Sanjib Sharma, Thor Tepper-Garcia +24
We use the second data releases of the ESA Gaia astrometric survey and the high-resolution GALAH spectroscopic survey to analyse the structure of our Galaxy's disc components. With…
Optical Spectroscopy Reveals Hidden Neutron-capture Elemental Abundance Differences among APOGEE-identified Chemical Doppelgängers
Catherine Manea, Melissa Ness, Keith Hawkins +9
Grouping stars by chemical similarity has the potential to reveal the Milky Way's evolutionary history. The APOGEE stellar spectroscopic survey has the resolution and sensitivity f…
paired: A Statistical Framework for Detecting Stellar Binarity with Gaia RVs. I. Sensitivity to Unresolved Binaries
Quadry Chance, Daniel Foreman-Mackey, Sarah Ballard +3
Data Release 3 (DR3) from the Gaia Mission includes radial velocity measurements of over 33 million targets. Among many scientific applications, the overlap of this stellar sample…
Selection Functions in Astronomical Data Modeling, with the Space Density of White Dwarfs as Worked Example
Hans-Walter Rix, David W. Hogg, Douglas Boubert +6
Statistical studies of astronomical data sets, in particular of cataloged properties for discrete objects, are central to astrophysics. One cannot model those objects' population p…
Magnetic Confinement of a Bubble of Supercooled He-A
Luke Whitehead, Andrew Casey, Richard P. Haley +9
We have designed and constructed a magnet surrounding a cylindrical volume of superfluid helium-3 to isolate a region of metastable, supercooled A-phase, entirely surrounded by bul…
Odd-parity superconductivity underpinned by antiferromagnetism in heavy fermion metal YbRhSi
Lev V. Levitin, Jan Knapp, Petra Knappová +13
Topological superconductors are essential elements of the periodic table of topological quantum matter. However, the relevant odd-parity spin-triplet superconductors are rare. We r…
First Light Results from the Hermes Spectrograph at the AAT
Andrew Sheinis, Borja Anguiano, Martin Asplund +60
The High Efficiency and Resolution Multi Element Spectrograph, HERMES, is a facility-class optical spectrograph for the Anglo-Australian Telescope (AAT). It is designed primarily f…
Diverse influences of hyperfine interactions on strongly correlated electron states
Femke Bangma, Lev Levitin, Marijn Lucas +8
The motivation to develop materials for quantum technologies has put exploration of novel quantum states of matter at the focus of several research fields, with particular efforts…
Dihadron Fragmentation Functions from the NJL-jet model and their QCD Evolution
Andrew Casey, Ian C. Cloët, Hrayr H. Matevosyan +1
We present results for dihadron fragmentation functions from the NJL-jet model evolved from the model scale to a typical experimental scale of . The numerical met…
Long nanomechanical resonators with circular cross-section
Samuli Autti, Andrew Casey, Marie Connelly +23
Fabrication of superconducting nanomechanical resonators for quantum research, detectors and devices traditionally relies on a lithographic process, resulting in oscillators with s…
Roman Early-Definition Astrophysics Survey Opportunity: Galactic Roman Infrared Plane Survey (GRIPS)
Roberta Paladini, Catherine Zucker, Robert Benjamin +67
A wide-field near-infrared survey of the Galactic disk and bulge/bar(s) is supported by a large representation of the community of Galactic astronomers. The combination of sensitiv…
Current Sensing Noise Thermometry: A fast practical solution to low temperature measurement
Andrew Casey, Frank Arnold, Lev V. Levitin +9
We describe the design and performance of a series of fast, precise current sensing noise thermometers. The thermometers have been fabricated with a range of resistances from 1.290…
Hunting the Parent of the Orphan Stream II: The First High-Resolution Spectroscopic Study
Andrew Casey, Stefan Keller, Gary Da Costa +2
We present the first high-resolution spectroscopic study on the Orphan Stream for five stream candidates, observed with the Magellan Inamori Kyocera Echelle (MIKE) spectrograph on…
The language of exoplanet ranking metrics needs to change
Elizabeth Tasker, Joshua Tan, Kevin Heng +14
We have found many Earth-sized worlds but we have no way of determining if their surfaces are Earth-like. This makes it impossible to quantitatively compare habitability, and prete…
High performance cryogen-free microkelvin platform
Jan Nyéki, Marijn Lucas, Petra Knappová +5
Improved accessibility to the microkelvin temperature regime is important for future research in quantum materials; for quantum information science; and for applications of quantum…
A microkelvin cryogen-free experimental platform with integrated noise thermometry
Graham Batey, Andrew Casey, Michael Cuthbert +3
We report experimental demonstration of the feasibility of reaching temperatures below 1 mK using cryogen-free technology. Our prototype system comprises an adiabatic nuclear demag…
Study of superfluid He under nanoscale confinement. A new approach to the investigation of superfluid He films
Lev Levitin, Robert Bennett, Andrew Casey +7
We review recent experiments in which superfluid He has been studied under highly controlled confinement in nanofluidic sample chambers. We discuss the experimental challenges…
Micro-coil detection of Nuclear Magnetic Resonance for nanofluidic samples
Aya Shibahara, Andrew Casey, Chris Lusher +4
We have developed a novel dc SQUID system with a micro-coil input circuit to act as a local probe of quantum matter and nanosystems. The planar niobium micro-coil pickup loop is lo…
Nucleosynthesis in a Primordial Supernova: Carbon and Oxygen Abundances in SMSS J031300.36-670839.31
Michael Bessell, Remo Collett, Stefan Keller +15
SMSS J031300.36-670839.3 (hereafter SM0313-6708) is a sub-giant halo star, with no detectable Fe lines and large overabundances of C and Mg relative to Ca. We obtained VLT-UVES spe…
Discovery of the First Five Carbon-Enhanced Metal-Poor Stars in the LMC
Madeline Lucey, Vedant Chandra, Alexander Ji +7
A substantial fraction of metal-poor stars in the local Milky Way halo exhibit large overabundances of carbon. These stars, dubbed Carbon-Enhanced Metal-Poor (CEMP) stars, provide…
The GALAH Survey: Observational Overview and Gaia DR1 companion
Sarah Martell, Sanjib Sharma, Sven Buder +30
The Galactic Archaeology with HERMES (GALAH) Survey is a massive observational project to trace the Milky Way's history of star formation, chemical enrichment, stellar migration an…
Calculating Dihadron Fragmentation Functions in the NJL-jet model
Andrew Casey, Hrayr H. Matevosyan, Anthony W. Thomas
The NJL-jet model provides a framework for calculating fragmentation functions without the introduction of ad hoc parameters. We develop the NJL-jet model to investigate dihadron f…
Chiral superfluid helium-3 in the quasi-two-dimensional limit
Petri J. Heikkinen, Lev V. Levitin, Xavier Rojas +8
Anisotropic pair breaking close to surfaces favors the chiral A phase of the superfluid He over the time-reversal invariant B phase. Confining the superfluid He into a cavi…
Gluon polarization in the proton
Steven D. Bass, Andrew Casey, Anthony W. Thomas
We combine heavy-quark renormalization group arguments with our understanding of the nucleon's wavefunction to deduce a bound on the gluon polarization Delta g in the proton. The b…
APOGEE Data Releases 13 and 14: Data and Analysis
Jon A. Holtzman, Sten Hasselquist, Matthew Shetrone +23
Data and analysis methodology used for the SDSS/APOGEE Data Releases 13 and 14 are described, highlighting differences from the DR12 analysis presented in Holtzman (2015). Some imp…