Search Publications
The Herschel Planetary Nebula Survey (HerPlaNS): A Comprehensive Dusty Photoionization Model of NGC6781
Villaver, Eva; Ueta, Toshiya; Szczerba, Ryszard +9 more
We perform a comprehensive analysis of the planetary nebula (PN) NGC 6781 to investigate the physical conditions of each of its ionized, atomic, and molecular gas and dust components and the object’s evolution, based on panchromatic observational data ranging from UV to radio. Empirical nebular elemental abundances, compared with theoretical predi…
Our evolving understanding of aeolian bedforms, based on observation of dunes on different worlds
Radebaugh, Jani; Tirsch, Daniela; Kreslavsky, Mikhail +3 more
Dunes, dune fields, and ripples are unique and useful records of the interaction between wind and granular materials - finding such features on a planetary surface immediately suggests certain information about climate and surface conditions (at least during the dunes' formation and evolution). Additionally, studies of dune characteristics under n…
Venus cloud-tracked and doppler velocimetry winds from CFHT/ESPaDOnS and Venus Express/VIRTIS in April 2014
Widemann, Thomas; Donati, Jean-François; Machado, Pedro +3 more
We present new coordinated observations and measurements of the wind amplitude and its variability at Venus cloud-tops based on the two complementary techniques of Ground-based Doppler velocimetry (Widemann et al., 2007, 2008; Machado et al., 2012, 2014) and cloud-tracked winds using ESA Venus Express/ VIRTIS-M imaging at 0.38 µm (Drossart e…
An observational study of dust nucleation in Mira (o Ceti). II. Titanium oxides are negligible for nucleation at high temperatures
Menten, K. M.; Müller, H. S. P.; Patel, N. A. +7 more
Context. The formation of silicate dust in oxygen-rich envelopes of evolved stars is thought to be initiated by the formation of seed particles that can withstand the high temperatures close to the stellar photosphere and act as condensation cores farther away from the star. TiO and TiO2 are among the candidate species considered as fir…
The Relationship Between Brightest Cluster Galaxy Star Formation and the Intracluster Medium in CLASH
Donahue, Megan; Moustakas, John; Postman, Marc +2 more
We study the nature of feedback mechanisms in the 11 CLASH brightest cluster galaxies (BCGs) that exhibit extended ultraviolet and nebular line emission features. We estimate star formation rates (SFRs), dust masses, and starburst durations using a Bayesian photometry-fitting technique that accounts for both stellar and dust emission from the UV t…
Atmospheric loss from the dayside open polar region and its dependence on geomagnetic activity: implications for atmospheric escape on evolutionary timescales
Nilsson, Hans; Dandouras, Iannis; Slapak, Rikard +3 more
We have investigated the total O+ escape rate from the dayside open polar region and its dependence on geomagnetic activity, specifically Kp. Two different escape routes of magnetospheric plasma into the solar wind, the plasma mantle, and the high-latitude dayside magnetosheath have been investigated separately. The flux of O+
Effective ion speeds at ∼200-250 km from comet 67P/Churyumov-Gerasimenko near perihelion
Nilsson, H.; André, M.; Goetz, C. +13 more
In 2015 August, comet 67P/Churyumov-Gerasimenko, the target comet of the ESA Rosetta mission, reached its perihelion at ∼1.24 au. Here, we estimate for a three-day period near perihelion, effective ion speeds at distances ∼200-250 km from the nucleus. We utilize two different methods combining measurements from the Rosetta Plasma Consortium (RPC)/…
Relic gravitational waves from quintessential inflation
Myrzakulov, R.; Sami, M.; Ahmad, Safia
We study relic gravitational waves in the paradigm of quintessential inflation. In this framework, irrespective of the underlying model, inflation is followed by the kinetic regime. Thereafter, the field energy density remains subdominant before the onset of acceleration. We carry out model-independent analysis to obtain the temperature at the end…
The Young Substellar Companion ROXs 12 B: Near-infrared Spectrum, System Architecture, and Spin-Orbit Misalignment
Vanderburg, Andrew; Brogi, Matteo; Knutson, Heather A. +8 more
ROXs 12 (2MASS J16262803-2526477) is a young star hosting a directly imaged companion near the deuterium-burning limit. We present a suite of spectroscopic, imaging, and time-series observations to characterize the physical and environmental properties of this system. Moderate-resolution near-infrared spectroscopy of ROXs 12 B from Gemini-North/NI…
A WISE-based search for debris discs amongst M dwarfs in nearby, young, moving groups
Jeffries, R. D.; Binks, A. S.
We present a search for debris discs amongst M-dwarf members of nearby, young (5-150 Myr) moving groups (MGs) using infrared (IR) photometry, primarily from the Wide Infrared Survey Explorer (WISE). A catalogue of 100 MG M dwarfs that have suitable WISE data is compiled, and 19 of these are found to have significant IR excess emission at 22 µ…