Search Publications
A New Twist to an Old Story: HE 0450-2958 and the ULIRG → Optically Bright QSO Transition Hypothesis
Wilner, David J.; Wagg, Jeff; Papadopoulos, Padeli P. +1 more
We report on interferometric imaging of the CO J = 1-0 and J = 3-2 line emission from the controversial QSO/galaxy pair HE 0450-2958. The detected CO J = 1-0 line emission is found associated with the disturbed companion galaxy, not the luminous QSO, and implies Mgal(H2) ~ (1-2) × 1010 M⊙, which is gtrsi…
Evidence That Solar Flares Drive Global Oscillations in the Sun
Kjeldsen, H.; Karoff, C.
Solar flares are large explosions on the Sun's surface caused by a sudden release of magnetic energy. They are known to cause local short-lived oscillations traveling away from the explosion like water rings. Here we show that the energy in the solar acoustic spectrum is correlated with flares. This means that the flares drive global oscillations …
Suzaku Observation of the TeV Blazar 1ES 1218+304: Clues on Particle Acceleration in an Extreme TeV Blazar
Kataoka, J.; Madejski, G. M.; Sato, R. +3 more
We observed the TeV blazar 1ES 1218+304 with the X-ray astronomy satellite Suzaku in 2006 May. At the beginning of the 2 day continuous observation, we detected a large flare in which the 5-10 keV flux changed by a factor of ~2 on a timescale of 5 × 104 s. During the flare, the increase in the hard X-ray flux clearly lagged behind that …
Color Gradients Detected in the HD 15115 Circumstellar Disk
Weinberger, Alycia J.; Debes, John H.; Song, Inseok
We report HST NICMOS coronagraphic images of the HD 15115 circumstellar disk at 1.1 µm. We find a similar morphology to that seen in the visible and at H band—an edge-on disk that is asymmetric in surface brightness. Several aspects of the 1.1 µm data are different, highlighting the need for multiwavelength images of each circumstellar…
Physical and Chemical Inhomogeneities Inside the Vela SNR Shell: Indications of Ejecta Shrapnels
Miceli, M.; Bocchino, F.; Reale, F.
We present the results of the combined analysis of three XMM-Newton EPIC observations of the northern rim of the Vela supernova remnant (SNR). The three pointings cover an area of gtrsim10 pc2 (at 250 pc) behind the main shock front, and we aim to study with high resolution the spatial distribution of the physical and chemical propertie…
On the Penumbral Jetlike Features and Chromospheric Bow Shocks
Title, A.; Berger, T.; Frank, Z. +1 more
We present observations of sunspot penumbrae obtained during the disk passage of AR 10923 (2006 November 10-20) with the SOT instrument on Hinode in 4305 Å G band and Ca II λ3968 H line. Along with recently discovered jetlike features (Katsukawa et al. 2007), we find other kinds of bright elongated transients abundantly pervading the entire penumb…
Isolated X-Ray-Infrared Sources in the Region of Interaction of the Supernova Remnant IC 443 with a Molecular Cloud
Bocchino, F.; Pavlov, G. G.; Bykov, A. M. +5 more
The nature of the extended hard X-ray source XMMU J061804.3+222732 and its surroundings is investigated using XMM-Newton, Chandra, and Spitzer observations. This source is located in an interaction region of the IC 443 supernova remnant with a neighboring molecular cloud. The X-ray emission consists of a number of bright clumps embedded in an exte…
Prominence Seismology: Wavelet Analysis of Filament Oscillations
Isobe, Hiroaki; Tripathi, Durgesh; Pintér, Balázs +1 more
The temporal and spatial behavior of a large-amplitude filament oscillation is investigated using wavelet analysis. The extreme-ultraviolet (EUV) images of the phenomenon, which occurred on 2002 October 15, were taken from the EUV Imaging Telescope on board the Solar and Heliospheric Observatory (SOHO). The wavelet spectra, extracted from the inte…
Near-Infrared Adaptive Optics Imaging of High-Redshift Quasars
Uslenghi, Michela; Scarpa, Riccardo; Treves, Aldo +2 more
The properties of high-redshift quasar host galaxies are studied in order to investigate the connection between galaxy evolution, nuclear activity, and the formation of supermassive black holes. We combine new near-IR observations of three high-redshift quasars (2 < z < 3), obtained at the ESO Very Large Telescope equipped with adaptive opti…
Probing the Relation Between X-Ray-Derived and Weak-Lensing-Derived Masses for Shear-Selected Galaxy Clusters. I. A781
Hughes, John P.; Sehgal, Neelima; Tyson, J. Anthony +4 more
We compare X-ray and weak-lensing masses for four galaxy clusters that comprise the top-ranked shear-selected cluster system in the Deep Lens Survey. The weak-lensing observations of this system, which is associated with A781, are from the Kitt Peak Mayall 4 m telescope, and the X-ray observations are from both Chandra and XMM-Newton. For a faithf…