Search Publications
Lateral Offset of the Coronal Mass Ejections from the X-flare of 2006 December 13 and Its Two Precursor Eruptions
Harra, Louise K.; Moore, Ronald L.; Sterling, Alphonse C.
Two GOES sub-C-class precursor eruptions occurred within ~10 hr prior to and from the same active region as the 2006 December 13 X4.3-class flare. Each eruption generated a coronal mass ejection (CME) with center laterally far offset (gsim 45°) from the co-produced bright flare. Explaining such CME-to-flare lateral offsets in terms of the standard…
The Response of A Three-dimensional Solar Atmosphere to Wave-driven Jets
Doyle, J. G.; Erdélyi, R.; Scullion, E. +1 more
Global oscillations from the solar interior are, mainly, pressure-driven (p-modes) oscillations with a peak power of a five-minute period. These oscillations are considered to manifest in many phenomena in the lower solar atmosphere, most notably, in spicules. These small-scale jets may provide the key to understanding the powering mechanisms of t…
Ultraviolet and X-ray Variability of the Seyfert 1.5 Galaxy Markarian 817
Brandt, W. N.; Schneider, Donald P.; Shull, J. Michael +9 more
We present an investigation of the ultraviolet and X-ray spectra of the Seyfert 1.5 galaxy Markarian 817. The ultraviolet analysis includes two recent observations taken with the Cosmic Origins Spectrograph (COS) in 2009 August and December, as well as archival spectra from the International Ultraviolet Explorer and the Hubble Space Telescope. Twe…
Unveiling the Mask on the ULIRG-to-QSO Transition Object [H89]1821+643 at z = 0.3: A Gas-poor/Gas-rich Galaxy Merger and the Implications for Co-based Dynamical Mass Estimates
Aravena, M.; Wagg, J.; Papadopoulos, P. P. +1 more
We report the detection of the 12CO J = 1-0 emission line in [H89]1821+643, one of the most optically luminous quasi-stellar objects (QSOs) in the local universe, and a template ULIRG-to-QSO transition object, located in a rich, cool-core cluster at z = 0.297. The CO emission is likely to be extended, highly asymmetric with respect to t…
The Globular Cluster Population of NGC 7457: Clues to the Evolution of Field S0 Galaxies
Brodie, Jean P.; Strader, Jay; Rhode, Katherine L. +1 more
In this paper, we present the results of a wide-field imaging study of the globular cluster (GC) system of the field S0 galaxy NGC 7457. To derive the global properties of the GC system, we obtained deep BVR images with the WIYN 3.5 m telescope and Minimosaic Imager and studied the GC population of NGC 7457 to a projected radius of ~30 kpc. Our gr…
Suzaku Observes Weak Flares from IGR J17391-3021 Representing a Common Low-activity State in this Supergiant Fast X-ray Transient
Chaty, S.; Tomsick, J. A.; Rodriguez, J. +4 more
We present an analysis of a 37 ks observation of the supergiant fast X-ray transient IGR J17391-3021 (= XTE J1739-302) gathered with Suzaku. The source evolved from quiescence to a low-activity level culminating in three weak flares lasting ~3 ks each in which the peak luminosity is only a factor of five times that of the pre-flare luminosity. The…
Comparing Spatial Distributions of Solar Prominence Mass Derived from Coronal Absorption
Alexander, David; Kilper, Gary; Gilbert, Holly +1 more
In a previous study, Gilbert et al. derived the column density and total mass of solar prominences using a new technique, which measures how much coronal radiation in the Fe XII (195 Å) spectral band is absorbed by prominence material, while considering the effects of both foreground and background radiation. In the present work, we apply this met…
Interstellar Silicate Dust in Five Quasar Absorption Systems
York, Donald G.; Kulkarni, Varsha P.; Welty, Daniel E. +3 more
We report on a study of interstellar silicate dust in five quasar absorption systems at 0.44 < z abs < 1.31 toward quasars Q0235+164, 3C196, Q0852+3435, Q0937+5628, and Q1203+0634, using data from the Infrared Spectrograph on board the Spitzer Space Telescope. In the absorbers toward Q0235+164, 3C196, Q0852+3435, and Q0937+5628, t…
Fe K Line Complex in the Nuclear Region of NGC 253
Yamasaki, Noriko Y.; Mitsuishi, Ikuyuki; Takei, Yoh
A bright, nearby edge-on starburst galaxy, NGC 253, was studied using the Suzaku, XMM, and Chandra X-ray observatories. With Suzaku and XMM we detected complex line structure of Fe K, which is resolved into three lines (Fe I at 6.4 keV, Fe XXV at 6.7 keV, and Fe XXVI at 7.0 keV) around the center of NGC 253. Especially, the Fe I and Fe XXVI lines …
Gas and Dust Toward DG Tau B and VV CrA
Najita, Joan R.; Doppmann, Greg W.; Seifahrt, Andreas +3 more
We present findings for DG Tau B and VV CrA, two of the objects observed in our Spitzer Infrared Spectrograph (IRS) project to search for molecular absorption in edge-on disks, along with near-IR spectroscopy of the CO fundamental transitions and mid-IR imaging. While the only gas absorption seen in the Spitzer IRS spectrum toward DG Tau B is CO