Search Publications
Evidence for two modes of water release in Comet 103P/Hartley 2: Distributions of column density, rotational temperature, and ortho-para ratio
Villanueva, Geronimo L.; Mumma, Michael J.; Meech, Karen J. +5 more
This paper presents long-slit spectra of H2O emission from the inner coma of Comet 103P/Hartley 2, acquired with NIRSPEC/Keck 2 during the comet's close approach to Earth in 2010. On UT 19.6 October 2010 the slit was oriented nearly orthogonal to the projected (in the plane of the sky) Sun-comet line, and the H2O rotational t…
Time-dependent Modeling of Pulsar Wind Nebulae
Tibolla, O.; Ferreira, S. E. S.; Kaufmann, S. +1 more
A spatially independent model that calculates the time evolution of the electron spectrum in a spherically expanding pulsar wind nebula (PWN) is presented, allowing one to make broadband predictions for the PWN's non-thermal radiation. The source spectrum of electrons injected at the termination shock of the PWN is chosen to be a broken power law.…
Updating constraints on inflationary features in the primordial power spectrum with the Planck data
Benetti, Micol
We present new constraints on possible features in the primordial inflationary density perturbation power spectrum in light of the recent cosmic microwave background anisotropy measurements from the Planck satellite. We found that the Planck data hints for the presence of features in two different ranges of angular scales, corresponding to multipo…
An X-Ray Survey of the Young Stellar Population of the Lynds 1641 and Iota Orionis Regions
Walter, F.; Micela, G.; Megeath, S. T. +12 more
We present an XMM-Newton survey of the part of the Orion A cloud south of the Orion Nebula. This survey includes the Lynds 1641 (L1641) dark cloud, a region of the Orion A cloud with very few massive stars and hence a relatively low ambient UV flux, and the region around the O9 III star ι Orionis. In addition to proprietary data, we used archival …
Binary Cepheids: Separations and Mass Ratios in 5 M ⊙ Binaries
Schaefer, Gail H.; Bond, Howard E.; Karovska, Margarita +3 more
Deriving the distribution of binary parameters for a particular class of stars over the full range of orbital separations usually requires the combination of results from many different observing techniques (radial velocities, interferometry, astrometry, photometry, direct imaging), each with selection biases. However, Cepheids—cool, evolved stars…
Impact basin relaxation on Rhea and Iapetus and relation to past heat flow
Schenk, Paul M.; White, Oliver L.; Dombard, Andrew J.
Evidence for relaxation of impact crater topography has been observed on many icy satellites, including those of Saturn, and the magnitude of relaxation can be related to past heat flow (e.g. Moore, J.M., Schenk, P.M., Bruesch, L.S., Asphaug, E., McKinnon, W.B. [2004]. Icarus 171, 421-443; Dombard, A.J., McKinnon, W.B. [2006]. J. Geophys. Res. 111…
Auroral signatures of multiple magnetopause reconnection at Saturn
Bonfond, B.; Gérard, J. -C.; Grodent, D. +5 more
Auroral observations capture the ionospheric response to dynamics of the whole magnetosphere and may provide evidence of the significance of reconnection at Saturn. Bifurcations of the main dayside auroral emission have been related to reconnection at the magnetopause and their surface is suggested to represent the amount of newly opened flux. Thi…
DIGIT survey of far-infrared lines from protoplanetary discs. II. CO
Henning, Thomas; Bouwman, Jeroen; van Dishoeck, Ewine F. +11 more
CO is an important component of a protoplanetary disc as it is one of the most abundant gas phase species. Furthermore, observations of CO transitions can be used as a diagnostic of the gas, tracing conditions in both the inner and outer disc. We present Herschel/PACS spectroscopy of a sample of 22 Herbig Ae/Be (HAEBEs) and eight T Tauri stars (TT…
X-Ray Outflows and Super-Eddington Accretion in the Ultraluminous X-Ray Source Holmberg IX X-1
Harrison, F. A.; Fabian, A. C.; Miller, J. M. +4 more
Studies of X-ray continuum emission and flux variability have not conclusively revealed the nature of ultraluminous X-ray sources (ULXs) at the high-luminosity end of the distribution (those with L X >= 1040 erg s-1). These are of particular interest because the luminosity requires either super-Eddington accreti…
Crater topography on Titan: Implications for landscape evolution
Lorenz, R. D.; Kirk, R. L.; Cassini Radar Team +7 more
We present a comprehensive review of available crater topography measurements for Saturn’s moon Titan. In general, the depths of Titan’s craters are within the range of depths observed for similarly sized fresh craters on Ganymede, but several hundreds of meters shallower than Ganymede’s average depth vs. diameter trend. Depth-to-diameter ratios a…