Search Publications
Discovery of Hot Gas in Outflow in NGC 3379
Zezas, A.; Gallagher, J.; King, A. R. +10 more
We report the discovery of a faint (LX ~ 4 +/- 1.5 × 1037 ergs s-1, 0.5-2 keV), outflowing gaseous hot interstellar medium (ISM) in NGC 3379. This represents the lowest X-ray luminosity ever measured from a hot phase of the ISM in a nearby early-type galaxy. The discovery of the hot ISM in a very deep Chandra obser…
A Comparison of Solar Open Field Regions Found by Type III Radio Bursts and the Potential Field Source Surface Model
DeRosa, Marc L.; Nitta, Nariaki V.
For heliophysics research and applications, the potential field source surface (PFSS) model is often employed to extrapolate the photospheric magnetic field to the corona. In an attempt to evaluate the performance of the PFSS model, we compare the computed footpoints of the heliospheric magnetic field with the locations of flares associated with t…
A Study of the Long-Term Evolution of Quasi-Periodic Oscillations in the Accretion-Powered X-Ray Pulsar 4U 1626-67
Paul, Biswajit; Kumar, Brijesh; Kaur, Ramanpreet +1 more
We report here a study of the long-term properties of quasiperiodic oscillations (QPOs) in an unusual accreting X-ray pulsar, 4U 1626-67. This is a unique accretion-powered X-ray pulsar in which we have found the QPOs to be present during all sufficiently long X-ray observations with a wide range of X-ray observatories. In the present spin-down er…
Anisotropy Signatures of Solar Energetic Particle Transport in a Closed Interplanetary Magnetic Loop
Sáiz, A.; Ruffolo, D.; Bieber, J. W. +2 more
Recent studies have stressed the importance of solar energetic particle (SEP) transport under disturbed interplanetary conditions, including the case of detection inside a closed interplanetary magnetic loop ejected by a preceding solar event. In this case, particles might be observed to arrive from the far leg of the loop, thus arriving at the de…
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…