Search Publications

Vector Magnetic Fields and Electric Currents From the Imaging Vector Magnetograph
DOI: 10.1088/0004-637X/692/2/1543 Bibcode: 2009ApJ...692.1543L

van Ballegooijen, A. A.; Li, Jing; Mickey, Don

First, we describe a general procedure to produce high-quality vector magnetograms using the Imaging Vector Magnetograph (IVM) at Mees Solar Observatory. Two IVM effects are newly discussed and taken into account: (1) the central wavelength of the Fabry-Pérot is found to drift with time as a result of undiagnosed thermal or mechanical instabilitie…

2009 The Astrophysical Journal
SOHO 7
NSCC—A New Scheme of Classification of C-Rich Stars Devised from Optical and Infrared Observations
DOI: 10.1088/0004-637X/705/2/1298 Bibcode: 2009ApJ...705.1298D

de Araújo, F. X.; Lorenz-Martins, S.; De Mello, A. B. +2 more

A new classification system for carbon-rich stars is presented based on an analysis of 51 asymptotic giant branch carbon stars through the most relevant classifying indices available. The extension incorporated, which also represents the major advantage of this new system, is the combination of the usual optical indices that describe the photosphe…

2009 The Astrophysical Journal
ISO 7
Impacts of Source Properties on Strong Lensing by Rich Galaxy Clusters
DOI: 10.1088/0004-637X/707/1/472 Bibcode: 2009ApJ...707..472G

Mao, S.; Kong, X.; Jing, Y. P. +2 more

We use a high-resolution N-body simulation to investigate the influence of background galaxy properties, including redshift, size, shape, and clustering, on the efficiency of forming giant arcs by gravitational lensing of rich galaxy clusters. Two large sets of ray-tracing simulations are carried out for 10 massive clusters at two redshifts, i.e.,…

2009 The Astrophysical Journal
eHST 7
Observation of Universality in the Generalized Similarity of Evolving Solar Wind Turbulence as Seen by Ulysses
DOI: 10.1088/0004-637X/695/2/L185 Bibcode: 2009ApJ...695L.185C

Carbone, V.; Chapman, S. C.; Leonardis, E. +2 more

We perform statistical analysis of the fluctuating magnetic field observed in-situ by the Ulysses spacecraft, from the perspective of quantitative characterization of the evolving magnetohydrodynamic (MHD) turbulence. We focus on two successive polar passes around solar minimum which provide extended intervals of quiet, fast solar wind at a range …

2009 The Astrophysical Journal
Ulysses 7
The White Dwarf in EM Cygni: Beyond the Veil
DOI: 10.1088/0004-637X/699/2/1229 Bibcode: 2009ApJ...699.1229G

Sion, Edward M.; Godon, Patrick; Barrett, Paul E. +1 more

We present a spectral analysis of the Far Ultraviolet Spectroscopic Explorer (FUSE) spectra of the eclipsing double-line spectroscopic binary EM Cygni (EM Cyg), a Z Cam DN system. The FUSE spectrum, obtained in quiescence, consists of four individual exposures (orbits): two exposures, at orbital phases phi ~ 0.65 and phi ~ 0.90, have a lower flux;…

2009 The Astrophysical Journal
IUE 7
Far-Ultraviolet Dust Albedo Measurements in the Upper Scorpius Cloud Using the Spinr Sounding Rocket Experiment
DOI: 10.1088/0004-637X/706/1/306 Bibcode: 2009ApJ...706..306L

France, K.; Gordon, K. D.; Chakrabarti, S. +3 more

The Spectrograph for Photometric Imaging with Numeric Reconstruction sounding rocket experiment was launched on 2000 August 4 to record far-ultraviolet (912-1450 Å) spectral and spatial information for the giant reflection nebula in the Upper Scorpius region. The data were divided into three arbitrary bandpasses (912-1029 Å, 1030-1200 Å, and 1235-…

2009 The Astrophysical Journal
IUE 7
Analysis of Breit-Pauli Transition Probabilities for Lines in O III
DOI: 10.1088/0004-637X/703/1/500 Bibcode: 2009ApJ...703..500F

Rubin, R. H.; Froese Fischer, C.; Tachiev, G. +1 more

Accurate atomic data are essential for understanding the properties of both O III lines produced by the Bowen fluorescence mechanism and [O III] forbidden lines observed in numerous gaseous nebulae. Improved Breit-Pauli transition probabilities have been published for the carbon sequence. Included were revised data for O III. The present paper ana…

2009 The Astrophysical Journal
eHST 7
D/H Along the Line of Sight of REJ 1738+665
DOI: 10.1088/0004-637X/690/2/1045 Bibcode: 2009ApJ...690.1045D

Moos, H. W.; Dupuis, J.; Sonnentrucker, P. +2 more

We present a new D/H measurement along the sightline to REJ 1738+665, one of the hottest DA stars (T eff ~ 76,000 K, log g ~ 7.85), probing a line of sight in the direction (l = 96fdg89, b = 31fdg95) and extending over a path-length of ~243 pc. Hot DA stars are useful sources for mapping interstellar absorption because of the lack of me…

2009 The Astrophysical Journal
eHST 7
A Multi-Wavelength Investigation of the Unidentified Gamma-Ray Source HESS J1708-410
DOI: 10.1088/0004-637X/707/2/1717 Bibcode: 2009ApJ...707.1717V

Funk, Stefan; Hinton, Jim; Van Etten, Adam

We report on recent XMM-Newton observations, archival radio continuum and CO data, and spectral energy distribution (SED) modeling of the unidentified Galactic plane source HESS J1708-410. No significant extended X-ray emission is observed, and we place an upper limit of 3.2 × 10-13 erg cm-2 s-1 in the 2-4 keV rang…

2009 The Astrophysical Journal
XMM-Newton 6
Clustering of Red Galaxies Around the z = 1.53 Quasar 3C 270.1
DOI: 10.1088/0004-637X/695/1/724 Bibcode: 2009ApJ...695..724H

Wilkes, Belinda J.; Fazio, G. G.; Ashby, M. L. N. +6 more

In the paradigm of hierarchical galaxy formation, luminous radio galaxies mark mass assembly peaks that should contain clusters of galaxies. Observations of the z = 1.53 quasar 3C 270.1 with the Spitzer Space Telescope at 3.6-24 µm and with the 6.5 m MMT in the z' and Y bands allow the detection of potential cluster members via photometric r…

2009 The Astrophysical Journal
eHST 6