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Multiwavelength Study of the Northeastern Outskirts of the Extended TeV Source HESS J1809-193
Pavlov, George G.; Kargaltsev, Oleg; Hare, Jeremy +3 more
HESS J1809-193 is an extended TeV γ-ray source in the Galactic plane. Multiwavelength observations of the HESS J1809-193 field reveal a complex picture. We present results from three Chandra X-Ray Observatory and two Suzaku observations of a region in the northeastern outskirts of HESS J1809-193, where enhanced TeV emission has been reported. Our …
X-Ray Detection of the Cluster Containing the Cepheid S Mus
Schaefer, Gail H.; Bond, Howard E.; Evans, Nancy Remage +7 more
The galactic Cepheid S Muscae has recently been added to the important list of Cepheids linked to open clusters, in this case the sparse young cluster ASCC 69. Low-mass members of a young cluster are expected to have rapid rotation and X-ray activity, making X-ray emission an excellent way to discriminate them from old field stars. We have made an…
A Fourier-transformed Bremsstrahlung Flash Model for the Production of X-Ray Time Lags in Accreting Black Hole Sources
Becker, Peter A.; Kroon, John J.
Accreting black hole sources show a wide variety of rapid time variability, including the manifestation of time lags during X-ray transients, in which a delay (phase shift) is observed between the Fourier components of the hard and soft spectra. Despite a large body of observational evidence for time lags, no fundamental physical explanation for t…
Extreme-ultraviolet Observations of Global Coronal Wave Rotation
Long, D. M.; van Driel-Gesztelyi, L.; Green, L. M. +2 more
We present evidence of global coronal wave rotation in EUV data from SOHO/EIT, STEREO/EUVI, and SDO/AIA. The sense of rotation is found to be consistent with the helicity of the source region (clockwise for positive helicity, anticlockwise for negative helicity), with the source regions hosting sigmoidal structures. We also study two coronal wave …
Photospheric Properties of Warm EUV Loops and Hot X-Ray Loops
Kano, R.; Tsuneta, S.; Ueda, K.
We investigate the photospheric properties (vector magnetic fields and horizontal velocity) of a well-developed active region, NOAA AR 10978, using the Hinode Solar Optical Telescope specifically to determine what gives rise to the temperature difference between "warm loops" (1-2 MK), which are coronal loops observed in EUV wavelengths, and "hot l…
Transmission and Emission of Solar Energetic Particles in Semi-transparent Shocks
Vainio, Rami; Kocharov, Leon; Laitinen, Timo +1 more
While major solar energetic particle (SEP) events are associated with coronal mass ejection (CME)-driven shocks in solar wind, accurate SEP measurements reveal that more than one component of energetic ions exist in the beginning of the events. Solar electromagnetic emissions, including nuclear gamma-rays, suggest that high-energy ions could also …
Vibrationally Excited Molecular Hydrogen near Herschel 36
Snow, Theodore P.; Rachford, Brian L.; Ross, Teresa L.
We present the first high resolution UV spectra toward Herschel 36, a Trapezium-like system of high-mass stars contained within the Lagoon Nebula (M8, NGC 6523). The spectra reveal extreme rovibrational excitation of molecular hydrogen in material at a single velocity or very small range of velocities, with this component presumably lying near the…
The Quiescent Counterpart of the Peculiar X-Ray Burster SAX J2224.9+5421
Degenaar, N.; Wijnands, R.; Miller, J. M.
SAX J2224.9+5421 is an extraordinary neutron star low-mass X-ray binary. It was discovered when it was exhibiting a ~= 10 s long thermonuclear X-ray burst, but it had faded to a 0.5-10 keV luminosity of L X <~ 8 × 1032(D/7.1 kpc)2 erg s-1 only ~= 8 hr later. It is generally assumed that neutron stars …
Hubble Space Telescope Detection of the Double Pulsar System J0737-3039 in the Far-ultraviolet
Pavlov, George G.; Kargaltsev, Oleg; Durant, Martin
We report on detection of the double pulsar system J0737-3039 in the far-UV with the Advanced Camera for Surveys/Solar-blind Channel detector aboard Hubble Space Telescope. We measured the energy flux F = (4.6 ± 1.0) × 10-17 erg cm-2 s-1 in the 1250-1550 Å band, which corresponds to the extinction-corrected luminos…
Near-infrared Brightness of the Galilean Satellites Eclipsed in Jovian Shadow: A New Technique to Investigate Jovian Upper Atmosphere
Honda, C.; Egami, E.; Surace, J. +12 more
Based on observations from the Hubble Space Telescope and the Subaru Telescope, we have discovered that Europa, Ganymede, and Callisto are bright around 1.5 µm even when not directly lit by sunlight. The observations were conducted with non-sidereal tracking on Jupiter outside of the field of view to reduce the stray light subtraction uncert…