Search Publications
The inner small satellites of Saturn: A variety of worlds
Burns, J. A.; Hedman, M.; Helfenstein, P. +4 more
More than a dozen small (<150 km mean radius) satellites occupy distinct dynamical positions extending from within Saturn’s classical rings to the orbit of Dione. The Cassini mission has gradually accumulated image and spectral coverage of these objects to the point where some generalizations on surface morphology may be made. Objects in differ…
High-resolution Radio Observations of the Remnant of SN 1987A at High Frequencies
Gaensler, B. M.; Manchester, R. N.; Ng, C. -Y. +4 more
We present new imaging observations of the remnant of Supernova (SN) 1987A at 44 GHz, performed in 2011 with the Australia Telescope Compact Array (ATCA). The 0.''35 × 0.''23 resolution of the diffraction-limited image is the highest achieved to date in high-dynamic range. We also present a new ATCA image at 18 GHz derived from 2011 observations, …
Storm-induced energization of radiation belt electrons: Effect of wave obliquity
Zelenyi, L. M.; Krasnoselskikh, V.; Artemyev, A. V. +2 more
New Cluster statistics allow us to determine for the first time the variations of both the obliquity and intensity of lower-band chorus waves as functions of latitude and geomagnetic activity near L∼5. The portion of wave power in very oblique waves decreases during highly disturbed periods, consistent with increased Landau damping by inward-penet…
High-pressure, low-abundance water in bipolar outflows. Results from a Herschel-WISH survey
Liseau, R.; van Dishoeck, E. F.; Bachiller, R. +6 more
Context. Water is a potential tracer of outflow activity because it is heavily depleted in cold ambient gas and is copiously produced in shocks.
Aims: We present a survey of the water emission in a sample of more than 20 outflows from low-mass young stellar objects with the goal of characterizing the physical and chemical conditions of the em…
Time lags in the ultraluminous X-ray source NGC 5408 X-1: implications for the black hole mass
Belloni, T.; Cappi, M.; Ponti, G. +4 more
We present the analysis of the X-ray variability and spectral timing properties of the ultraluminous X-ray source (ULX) NGC 5408 X-1, one of the most variable ULXs known so far. The variability properties are used as a diagnostic of the accretion state of the source and to derive estimates of the black hole (BH) mass. The observed high level of fa…
Plasma in the near Venus tail: Venus Express observations
Fedorov, A.; Barabash, S.; Lundin, R. +5 more
Although Venus has no global intrinsic magnetic fields, it possesses a long magnetotail of induced origin. The topology of the tail is determined by the interplanetary magnetic field orientation. We present recent plasma and magnetic field observations in the near Venus tail (X≥-3RV) made by the Venus Express spacecraft. We show that io…
A non-pulsating neutron star in the supernova remnant HESS J1731-347/G353.6-0.7 with a carbon atmosphere
Werner, K.; Klochkov, D.; Santangelo, A. +3 more
Context. The central compact object (CCO) candidate in the center of the supernova remnant shell HESS J1731-347/G353.6-0.7 shows no pulsations and exhibits a blackbody-like X-ray spectrum. If the absence of pulsations is interpreted as evidence for the emitting surface area being the entire neutron star surface, the assumption of the measured flux…
Ionisation impact of high-mass stars on interstellar filaments. A Herschel study of the RCW 36 bipolar nebula in Vela C
Hill, T.; White, G. J.; André, Ph. +19 more
Context. Ionising stars reshape their original molecular cloud and impact star formation, leading to spectacular morphologies such as bipolar nebulae around H ii regions. Molecular clouds are structured in filaments where stars principally form, as revealed by the Herschel space observatory. The prominent southern hemisphere H ii region, RCW 36, i…
Optical interferometry of early-type stars with PAVO@CHARA - I. Fundamental stellar properties
White, T. R.; Tuthill, P. G.; Huber, D. +8 more
We present interferometric observations of seven main-sequence and three giant stars with spectral types from B2 to F6 using the Precision Astronomical Visible Observations beam combiner at the Center for High Angular Resolution Astronomy array. We have directly determined the angular diameters for these objects with an average precision of 2.3 pe…
Importance of thermal reactivity for hexamethylenetetramine formation from simulated interstellar ices
Vinogradoff, V.; Duvernay, F.; Danger, G. +5 more
Context. Complex organic molecules are observed in a broad variety of astrophysical objects, but little is known about their formation mechanism. Laboratory simulations on interstellar ice analogues are therefore crucial for understanding the origin of these complex organic molecules. In this context, we focus on the thermal reactivity for the for…