Search Publications
Observations of the Gas Reservoir around a Star-Forming Galaxy in the Early Universe
Broadhurst, Tom; Frye, Brenda L.; Bowen, David V. +8 more
We present a high signal-to-noise spectrum of a bright galaxy at z = 4.9 in 14 hr of integration on VLT FORS2. This galaxy is extremely bright, i850 = 23.10 +/- 0.01, and is strongly lensed by the foreground massive galaxy cluster A1689 (z = 0.18). Stellar continuum is seen longward of the Lyα emission line at ~7100 Å, while intergalact…
Explosive Events and the Evolution of the Photospheric Magnetic Field
Muglach, K.
Transition region explosive events have long been suggested as direct signatures of magnetic reconnection in the solar atmosphere. In seeking further observational evidence to support this interpretation, we study the relation between explosive events and the evolution of the solar magnetic field as seen in line-of-sight photospheric magnetograms.…
XMM-Newton Observations of IGR J00291+5934: Signs of a Thermal Spectral Component during Quiescence
Stella, Luigi; Campana, Sergio; D'Avanzo, Paolo +1 more
We present X-ray observations of the transient accretion-powered millisecond pulsar IGR J00291+5934 during quiescence. IGR J00291+5934 is the first source among accretion-powered millisecond pulsars to show signs of a thermal component in its quiescent spectrum. Fitting this component with a neutron star atmosphere or a blackbody model we obtain s…
Bayesian Analysis of Solar Oscillations
Kucera, T.; Marsh, M. S.; Ireland, J.
A Bayesian probability-based approach is applied to the problem of detecting and parameterizing oscillations in the upper solar atmosphere for the first time. Due to its statistical origin, this method provides a mechanism for determining the number of oscillations present, gives precise estimates of the oscillation parameters with a self-consiste…
Transition Region Velocity Oscillations Observed by EUNIS-06
Mathioudakis, M.; Keenan, F. P.; Jess, D. B. +3 more
Spectroscopic measurements of NOAA AR 10871, obtained with the Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS) sounding rocket instrument on 2006 April 12, reveal velocity oscillations in the He II 303.8 Å emission line formed at T ≈ 5 × 104 K. The oscillations appear to arise in a bright active region loop arcade about 25
In Search of the Largest Velocity Dispersion Galaxies
Shields, G. A.; Gebhardt, K.; Bernardi, M. +2 more
We present Hobby-Eberly Telescope (HET) observations for galaxies at redshift z < 0.3 from the Sloan Digital Sky Survey (SDSS) showing large velocity dispersions while appearing to be single galaxies in HST images. The high signal-to-noise HET spectra provide more definitive velocity dispersions. The maximum velocity dispersion we find is σ
No Evidence of Morning or Large-Scale Drizzle on Titan
Geballe, Thomas R.; Kim, Sang J.; Trafton, Laurence M.
Widespread methane precipitation on Titan has been predicted by several authors since methane saturation in the upper troposphere was measured by the Huygens probe over its landing site. Recently, observational evidence of widespread morning drizzle has been suggested based on detection of a dark morning site in surface-subtracted 2 µm spect…
An Analysis of the Dust Halo and Extinction toward X Persei
Smith, Randall K.; Valencic, Lynne A.
Interstellar dust grain models are not sufficiently constrained by UV extinction curves to allow researchers to distinguish between them. By testing grain models in the X-ray regime and applying elemental abundance constraints, we show to what extent the models can reproduce the observables in these regimes and whether they are capable of doing so…
IRAS 04325+2402C: A Very Low Mass Object with an Edge-On Disk
Wood, Kenneth; Doyon, René; Lafrenière, David +3 more
IRAS 04325+2402C is a low-luminosity object located near a protostar in Taurus. We present new spatially resolved millimeter observations, near-infrared spectroscopy, and Spitzer photometry that improve the constraints on the nature of this source. The object is clearly detected in our 1.3 mm interferometry map, allowing us to estimate the mass in…
XMM-Newton Detection of a Compton-thick AGN in the 1 Jy ULIRG/LINER F04103-2838
Veilleux, S.; Sanders, D. B.; Young, A. J. +3 more
We report on the detection of Fe Kα emission in F04103-2838, an ultraluminous infrared galaxy [ULIRG; log (LIR/L⊙) >= 12] optically classified as a LINER. Previous Chandra observations suggested the presence of both a starburst and an active galactic nucleus (AGN) in this source. A deeper (~20 ks) XMM-Newton spectrum revea…