Search Publications
Detection in the Interstellar Medium of the Weak [Mg II] Transition at 1398.8 Å
Snow, Theodore P.; Destree, Joshua D.; Williamson, Karen E.
High- and medium-resolution ultraviolet spectra from the Space Telescope Imaging Spectrograph and the Goddard High Resolution Spectrograph were used to search for the weak electric quadrupole transitions of [Mg II] near 1398.8 Å. This forbidden doublet was detected in eight sight lines. We calculate an empirical f-value of (1.29 ± 0.13) × 10-…
Assessment of Stellar Stratification in Three Young Star Clusters in the Large Magellanic Cloud
Gouliermis, Dimitrios A.; Mackey, Dougal; Rochau, Boyke +1 more
We present a comprehensive study of stellar stratification in young star clusters in the Large Magellanic Cloud (LMC). We apply our recently developed effective radius method for the assessment of stellar stratification on imaging data obtained with the Advanced Camera for Surveys of three young LMC clusters to characterize the phenomenon and deve…
Multi-strand Coronal Loop Model and Filter-ratio Analysis
Marsch, Eckart; Bourouaine, Sofiane
We model a coronal loop as a bundle of seven separate strands or filaments. Each of the loop strands used in this model can independently be heated (near their left footpoints) by Alfvén/ion-cyclotron waves via wave-particle interactions. The Alfvén waves are assumed to penetrate the strands from their footpoints, at which we consider different wa…
Physical Conditions in Orion's Veil. III. UV Iron Absorption Lines toward θ1B Orionis
Abel, N.; Lykins, M. L.; Troland, T. H.
We have used archival Space Telescope Imaging Spectrograph (STIS) data in the range 2100-2500 Å toward the Trapezium star Θ1 B Orionis (HD 37021) to estimate the Fe column density and other parameters in the neutral Veil of Orion. The Veil lies 1-3 pc in front of the Orion H+ region, it has an estimated volume density of 10
Independent Signals from the Influence of Internal Magnetic Layers on the Frequencies of Solar p-modes
Foullon, C.; Nakariakov, V. M.
The discovery that p-mode frequencies of low degree do not follow changes of solar surface activity during the recent solar minimum offers the possibility of a new diagnostic signature of the responsible pressure perturbation in the wave guiding medium, potentially rich of information regarding the structure of the Sun and the cause of the unusual…
XMM-NEWTON Observations of Three Low X-ray Luminosity Galaxy Clusters
Donahue, Megan; Voit, G. Mark; Conselice, Christopher J. +2 more
We present new XMM-Newton measurements of the X-ray luminosities (Lx ) and temperatures (Tx ) for three clusters of galaxies. Two are low Lx (<3 × 1043 erg s-1) clusters, RXJ0110.3+1938 (z = 0.317) and RXJ1011.0+5339 (z = 0.329). These clusters were selected from the 160 Square Degree Surve…
Hot Gas in the Galactic Thick Disk and Halo Near the Draco Cloud
Shelton, R. L.; Henley, D. B.; Dixon, W. V.
This paper examines the ultraviolet and X-ray photons generated by hot gas in the Galactic thick disk or halo in the Draco region of the northern hemisphere. Our analysis uses the intensities from four ions, C IV, O VI, O VII, and O VIII, sampling temperatures of ~105 to ~3 × 106 K. We measured the O VI, O VII, and O VIII int…
Environmental Effects in the Evolution of Galactic Bulges
Treu, Tommaso; Ellis, Richard S.; Moran, Sean M. +1 more
We investigate possible environmental trends in the evolution of galactic bulges over the redshift range 0 < z < 0.6. For this purpose, we construct the fundamental plane (FP) for cluster and field samples at redshifts langzrang = 0.4 and langzrang = 0.54 using surface photometry based on Hubble Space Telescope imaging and velocity dispersio…
On a Method to Resolve the Nuclear Activity in Galaxies as Applied to the Seyfert 2 Galaxy NGC 1358
Fathi, Kambiz; Nelson, Charles H.; Lindblad, Per Olof +1 more
Nuclear regions of galaxies generally host a mixture of components with different excitations, compositions, and kinematics. Derivation of emission line ratios and kinematics could then be misleading if due correction is not made for the limited spatial and spectral resolutions of the observations. The aim of this paper is to demonstrate, with app…
Toward Understanding the Environment of R Monocerotis from High-Resolution Near-Infrared Polarimetric Observations
Doyon, R.; Bastien, P.; Lafrenière, D. +3 more
High-resolution H-band imaging polarimetric observations of R Mon obtained at the Canada-France-Hawaii telescope are presented. These data show a centrosymmetric pattern with elongated intensity contours mostly due to the presence of the companion R Mon B. We also consider published R-band data, which show an extended right-angle conical reflectio…