Search Publications
Signatures of extended discs and outflows in the circumgalactic medium using the Q0107 quasar triplet
Tejos, Nicolas; Beckett, Alexander; Morris, Simon L. +3 more
We use H I absorption along the lines-of-sight to the Q0107 quasar triplet in order to model potential disc and outflow structures in the circumgalactic medium of intervening galaxies at z ≲ 1, as well as the intergalactic medium on scales of up to a few virial radii. We consider a sample of twelve isolated galaxies in the Q0107 field with positio…
The Young Embedded Disk L1527 IRS: Constraints on the Water Snowline and Cosmic-Ray Ionization Rate from HCO+ Observations
Bergin, Edwin A.; Harsono, Daniel; Tobin, John J. +3 more
The water snowline in circumstellar disks is a crucial component in planet formation, but direct observational constraints on its location remain sparse owing to the difficulty of observing water in both young embedded and mature protoplanetary disks. Chemical imaging provides an alternative route to locate the snowline, and HCO+ isotop…
Searching for outbursts in the ground-based photometry of 67P/Churyumov-Gerasimenko
Gardener, Daniel; Snodgrass, Colin; Ligier, Nicolas
67P/Churyumov-Gerasimenko is a Jupiter-family comet that was the target of the Rosetta mission, the first mission to successfully orbit and land a probe on a comet. This mission was accompanied by a large ground-based observing campaign. We have developed a pipeline to calibrate and measure photometry of comet 67P during its 2016 perihelion passag…
Evidence of the Alfvén Transition Layer and Particle Precipitation in the Cusp Region: 3D Global PIC Simulation of the Solar Wind-Earth Magnetosphere Interaction
Lembège, B.; Cai, D. S.; Ekawati, Sri
A transition layer, named the Alfvénic transition layer (or ATL), has been clearly evidenced near the outer boundary of the cusp by experimental observations from the Cluster mission. This layer characterized by a local value of Log M A ~ 1, where M A is the Alfvén Mach number, allows the bulk flow to transit from super-Alfvé…
Solar Wind Electron Pressure Gradients, Suprathermal Spectral Hardness, and Strahl Localization Organized by Single-point Measurements of 0.1 nV m-1 Ambipolar E ∥
Scudder, Jack D.
A new, fast technique to measure the solar wind's ambipolar E ∥ routinely with 10% precision and accuracy is demonstrated using 4 yr of 1 au electron data from the Wind 3DP experiment. The 3DP electron instrument duty cycle determines E ∥ ≃ 0.1 nV m-1 from a single spectrum over much shorter time intervals than tho…
A Kepler K2 view of subdwarf A-type stars
Mösenlechner, G.; Paunzen, E.; Pelisoli, I. +3 more
Context. The spectroscopic class of subdwarf A-type (sdA) stars has come into focus in recent years because of their possible link to extremely low-mass white dwarfs, a rare class of objects resulting from binary evolution. Although most sdA stars are consistent with metal-poor halo main-sequence stars, the formation and evolution of a fraction of…
Estimating spectral photometric properties of the 67P/Churyumov-Gerasimenko comet nucleus
Statella, Thiago
Kepler binary stars in NGC 6791 open cluster: KIC 2437060, KIC 2437149, and KIC 2438490
Çakırlı, Ömür; Hoyman, Barış
The study of detached eclipsing binaries in open clusters can provide powerful tests of theoretical stellar evolutionary models. These models must simultaneously fit the masses, radii, and radiative properties of the eclipsing stars with essentially the same distance, age, and initial composition. In this way, clusters are ideal test benches for v…
MAPPS as a multi-mission and multi-body Science Planning and Simulation Tool for ESA solar system missions
Merrit, Donald; Sierra, Mar; Martin, Patrick +5 more
The Mission Analysis and Payload Planning System (MAPPS) is a multi-mission software system developed during the last 20 years to support the science operations planning for the ESA solar system missions at the European Space Astronomy Centre (ESAC) near Madrid.Developed initially only to visualise the coverage of MEX experiments onto the Martian …
Ion-Ion Cross-Field Instability of Lower Hybrid Waves in the Inner Coma of Comet 67P
Karlsson, Tomas; Stenberg Wieser, Gabriella; Odelstad, Elias +2 more
We show that an ion-ion cross-field streaming instability between cold newborn cometary ions and heated heavy ions that were picked up upstream is likely a contributing source of observed lower hybrid (LH) waves in the inner coma of comet 67P/Churyumov-Gerasimenko. Electric field oscillations in the LH frequency range are common here, and have pre…