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An interferometric study of the post-AGB binary 89 Herculis. II. Radiative transfer models of the circumbinary disk
Regibo, S.; Wevers, T.; Verhoelst, T. +6 more
Context. The presence of stable disks around post-asymptotic giant branch (post-AGB) binaries is a widespread phenomenon. Also, the presence of (molecular) outflows is now commonly inferred in these systems.
Aims: In the first paper of this series, a surprisingly large fraction of optical light was found to be resolved in the 89 Her post-AGB …
A Comparison of X-Ray and Optical Emission in Cassiopeia A
Fesen, Robert A.; Patnaude, Daniel J.
Broadband optical and narrowband Si XIII X-ray images of the young Galactic supernova remnant Cassiopeia A (Cas A) obtained over several decades are used to investigate spatial and temporal emission correlations on both large and small angular scales. The data examined consist of optical and near-infrared ground-based and Hubble Space Telescope im…
The radial gradient of the near-surface shear layer of the Sun
Schou, J.; Gizon, L.; Barekat, A.
Context. Helioseismology has provided unprecedented information about the internal rotation of the Sun. One of the important achievements was the discovery of two radial shear layers: one near the bottom of the convection zone (the tachocline) and one near the surface. These shear layers may be important ingredients for explaining the magnetic cyc…
Determining Inclinations of Active Galactic Nuclei via Their Narrow-line Region Kinematics. II. Correlation with Observed Properties
Turner, T. J.; Kraemer, S. B.; Crenshaw, D. M. +2 more
Active galactic nuclei (AGNs) are axisymmetric systems to first order; their observed properties are likely strong functions of inclination with respect to our line of sight, yet the specific inclinations of all but a few AGNs are generally unknown. By determining the inclinations and geometries of nearby Seyfert galaxies using the kinematics of t…
Compilation of Catalog of Stellar Equatorial Coordinates and B-Magnitudes Using UKRVO Plate Database
Pakuliak, L. K.; Yatsenko, A. I.; Shatokhina, S. V. +6 more
To ensure the rational use of informational resources generated by UkrVO in MAO NASU, a catalog of equatorial coordinates (α, δ) and B-magnitudes of stars was created by using plates obtained during observational campaign named FON (ukr., Photographic Sky Survey). 102 plates with field of view of 8° were processed. Digitization of plates with size…
Solar Polar Fields and the 22-Year Activity Cycle: Observations and Models
Petrie, G. J. D.; Petrovay, K.; Schatten, K.
We explore observations and models of the interacting, cyclical behavior of the active regions and the polar magnetic fields of the Sun. We focus on observational evidence of these fields interacting across the corridor between active and polar latitudes. We present observations of diverse magnetic signatures on, above and beneath the solar surfac…
Reversal or no reversal: the evolution of the star formation rate-density relation up to z ∼ 1.6
Finoguenov, A.; Berta, S.; Magnelli, B. +27 more
We investigate the evolution of the star formation rate (SFR)-density relation in the Extended Chandra Deep Field South and the Great Observatories Origin Deep Survey fields up to z ∼ 1.6. In addition to the `traditional method', in which the environment is defined according to a statistical measurement of the local galaxy density, we use a `dynam…
Hubble Space Telescope Near-ultraviolet Spectroscopy of the Bright CEMP-no Star BD+44°493
Smith, Verne V.; Beers, Timothy C.; Placco, Vinicius M. +10 more
We present an elemental-abundance analysis, in the near-ultraviolet (NUV) spectral range, for the extremely metal-poor star BD+44°493 a ninth magnitude subgiant with [Fe/H] =-3.8 and enhanced carbon, based on data acquired with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. This star is the brightest example of a class of …
Plasma flows in Saturn's nightside magnetosphere
Thomsen, M. F.; Wilson, R. J.; Tokar, R. L. +1 more
The plasma properties, especially the flow parameters, obtained from numerical integration of Cassini Plasma Spectrometer (CAPS) Ion Mass Spectrometer measurements during intervals when the CAPS field of view encompassed both inward and outward flow directions relative to corotation are examined for nightside data (18-06 local time) during 2006, 2…
Vertical velocities from proper motions of red clump giants
López-Corredoira, M.; Figueras, F.; Garzón, F. +1 more
Aims: We derive the vertical velocities of disk stars in the range of Galactocentric radii of R = 5 - 16 kpc within 2 kpc in height from the Galactic plane. This kinematic information is connected to dynamical aspects in the formation and evolution of the Milky Way, such as the passage of satellites and vertical resonance and determines wheth…