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New insights on Stephan's Quintet: exploring the shock in three dimensions
Vílchez, J. M.; Petropoulou, V.; López-Martín, L. +2 more
Aims: We study the ionized gas emission from the large scale shock region of Stephan's Quintet (SQ).
Methods: We carried out integral field unit (IFU) optical spectroscopy on three pointings in and near the SQ shock. We used Potsdam MultiAperture Spectrometer (PMAS) on the 3.5 m Calar Alto telescope to obtain measures of emission lines t…
Working models for the gravitational field of Phobos
Shi, Xian; Willner, Konrad; Oberst, Jürgen +2 more
Models for the gravitational field of Mars moon Phobos were developed using the latest shape model and assuming homogeneous density distribution. Three methods were applied in our study. Comparisons were made between these methods and all were shown to yield consistent results. Notably, the most accurate shape model of Phobos to date, complete up …
NGC 2207/IC 2163: A Grazing Encounter with Large-scale Shocks
Brinks, Elias; Struck, Curtis; Elmegreen, Bruce G. +3 more
Radio continuum, Spitzer infrared, optical, and XMM-Newton X-ray and ultraviolet observations (UVW1 and UVM2) are used to study large-scale shock fronts, young star complexes, and the galactic nuclei in the interacting galaxies NGC 2207/IC 2163. There are two types of large-scale shock fronts in this galaxy pair. The large-scale shock front along …
Scattering of the f-mode by Small Magnetic Flux Elements from Observations and Numerical Simulations
Felipe, T.; Braun, D.; Crouch, A. +1 more
The scattering of f-modes by magnetic tubes is analyzed using three-dimensional numerical simulations. An f-mode wave packet is propagated through a solar atmosphere embedded with three different flux tube models that differ in radius and total magnetic flux. A quiet-Sun simulation without a tube present is also performed as a reference. Waves are…
Global Modeling of X-Ray Spectra Produced in O-type Star Winds
Nazé, Y.; Rauw, G.; Hervé, A. +1 more
High-resolution X-ray spectra of O-type stars revealed less wind absorption than expected from smooth winds with conventional mass-loss rates. Various solutions have been proposed, including porous winds, optically thick clumps, or an overall reduction of the mass-loss rates. The latter has a strong impact on the evolution of the star. Our final g…
A Fast Model for the Reconstruction of Spectral Solar Irradiance in the Near- and Mid-Ultraviolet
Charbonneau, P.; Crouch, A. D.; Bolduc, C. +2 more
We present a model for the reconstruction of spectral solar irradiance between 200 and 400 nm. This model is an extension of the total solar irradiance (TSI) model of Crouch et al. (Astrophys. J.677, 723, 2008) which is based on a data-driven Monte Carlo simulation of sunspot emergence, fragmentation, and erosion. The resulting time-evolving daily…
Optimizing Automated Classification of Variable Stars in New Synoptic Surveys
Bloom, Joshua S.; Richards, Joseph W.; Long, James P. +2 more
Efficient and automated classification of periodic variable stars is becoming increasingly important as the scale of astronomical surveys grows. Several recent articles have used methods from machine learning and statistics to construct classifiers on databases of labeled, multi-epoch sources with the intention of using these classifiers to automa…
Evolution of massive galaxy structural properties and sizes via star formation in the GOODS NICMOS Survey
Conselice, Christopher J.; Hartley, William G.; Mortlock, Alice +2 more
We present a study of the resolved star-forming properties of a sample of distant massive (M > 1011 M⊙) galaxies in the GOODS NICMOS Survey (GNS), based on deep Hubble Space Telescope imaging from the GOODS North and South fields. We derive dust corrected ultraviolet star formation rates (SFRs) as a function of radius for …
An Empirical Measure of the Rate of White Dwarf Cooling in 47 Tucanae
Tremblay, P. -E.; Stetson, P. B.; Bergeron, P. +8 more
We present an empirical determination of the white dwarf cooling sequence in the globular cluster 47 Tucanae. Using spectral models, we determine temperatures for 887 objects from Wide Field Camera 3 data, as well as 292 objects from data taken with the Advanced Camera for Surveys. We make the assumption that the rate of white dwarf formation in t…
Herschel/HIFI observation of highly excited rotational lines of HNC toward IRC +10 216
Cernicharo, J.; Daniel, F.; Müller, H. S. P. +6 more
We report the detection in emission of various highly excited rotational transitions of HNC (J = 6-5 through J = 12-11) toward the carbon-star envelope IRC +10 216 using the HIFI instrument on-board the Herschel Space Observatory. Observations of the J = 1-0 and J = 3-2 lines of HNC with the IRAM 30-m telescope are also presented. The lines observ…