Search Publications
Modeling the Jovian magnetic field and its secular variation using all available magnetic field observations
Ridley, Victoria A.; Holme, Richard
We present new models of Jupiter's internal magnetic field and secular variation from all available direct measurements from three decades of spacecraft observation. A regularized minimum norm approach allows the creation of smooth, numerically stable models displaying a high degree of structure. External field from the magnetodisk is modeled iter…
Wavelength dependence of scattering properties in the VIS-NIR and links with grain-scale physical and compositional properties
Schmidt, F.; Ehlmann, B. L.; Pilorget, C. +2 more
Surface scattered sunlight carries important information about the composition and microtexture of surface materials, thus enabling tracing back the geological and climatic processes that occurred on the planetary body. Here we perform laboratory spectro-goniometric measurements of granular samples (45-75 µ m fraction) with different composi…
A spectral line list for water isotopologues in the 1100-4100 cm-1 region for application to CO2-rich planetary atmospheres
Gamache, Robert R.; Farese, Michaella; Renaud, Candice L.
A line list of transitions for seven isotopologues of water vapor in the 1100-4100 wavenumber range has been constructed for application to atmospheres rich in CO2. The quantum transitions for H216O, H218O, H217O, HD16O, HD18O, and HD17O a…
Fragmentation Kinematics in Comet 332P/Ikeya-Murakami
Mutchler, Max; Jewitt, David; Weryk, Robert +9 more
We present initial time-resolved observations of the split comet 332P/Ikeya-Murakami taken using the Hubble Space Telescope. Our images reveal a dust-bathed cluster of fragments receding from their parent nucleus at projected speeds in the range 0.06-3.5 m s-1 from which we estimate ejection times from 2015 October to December. The numb…
Pulsation-triggered Mass Loss from AGB Stars: The 60 Day Critical Period
Zijlstra, A. A.; McDonald, I.
Low- and intermediate-mass stars eject much of their mass during the late, red giant branch (RGB) phase of evolution. The physics of their strong stellar winds is still poorly understood. In the standard model, stellar pulsations extend the atmosphere, allowing a wind to be driven through radiation pressure on condensing dust particles. Here, we i…
High-redshift supernova rates measured with the gravitational telescope A 1689
Dahle, H.; Lidman, C.; Amanullah, R. +12 more
Aims: We present a ground-based, near-infrared search for lensed supernovae behind the massive cluster Abell 1689 at z = 0.18, which is one of the most powerful gravitational telescopes that nature provides.
Methods: Our survey was based on multi-epoch J-band observations with the HAWK-I instrument on VLT, with supporting optical data fr…
Observations of Magnetic Flux-rope Oscillation during the Precursor Phase of a Solar Eruption
Zhang, J.; Wang, J. X.; Zhou, G. P.
Based on combined observations from the Interface Region Imaging Spectrograph (IRIS) spectrometer with the coronal emission line of Fe xxi at 1354.08 Å and SDO/AIA images in multiple passbands, we report the finding of the precursor activity manifested as the transverse oscillation of a sigmoid, which is likely a pre-existing magnetic flux rope (M…
Overconfidence in photometric redshift estimation
Wittman, David; Bhaskar, Ramya; Tobin, Ryan
We describe a new test of photometric redshift performance given a spectroscopic redshift sample. This test complements the traditional comparison of redshift differences by testing whether the probability density functions p(z) have the correct width. We test two photometric redshift codes, BPZ and EAZY, on each of two data sets and find that BPZ…
IDCS J1426.5+3508: The Most Massive Galaxy Cluster at z > 1.5
Eisenhardt, Peter R.; Gonzalez, Anthony H.; Stanford, S. A. +4 more
We present a deep (100 ks) Chandra observation of IDCS J1426.5+3508, a spectroscopically confirmed, infrared-selected galaxy cluster at z = 1.75. This cluster is the most massive galaxy cluster currently known at z > 1.5, based on existing Sunyaev-Zel’dovich (SZ) and gravitational lensing detections. We confirm this high mass via a variety of X…
A weak gravitational lensing recalibration of the scaling relations linking the gas properties of dark haloes to their mass
Wang, Wenting; White, Simon D. M.; Mandelbaum, Rachel +3 more
We use weak gravitational lensing to measure mean mass profiles around locally brightest galaxies (LBGs). These are selected from the Seventh Data Release of the Sloan Digital Sky Survey spectroscopic and photometric catalogues to be brighter than any neighbour projected within 1.0 Mpc and differing in redshift by <1000 km s-1. Most …