Search Publications
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…
Faint X-Ray Binaries and their Optical Counterparts in M31
Barmby, P.; Vulic, N.; Gallagher, S. C.
X-ray binaries (XRBs) are probes of both star formation and stellar mass, but more importantly remain one of the only direct tracers of the compact object population. To investigate the XRB population in M31, we utilized all 121 publicly available observations of M31 totalling over 1 Ms from Chandra's ACIS instrument. We studied 83 star clusters i…
Spectroscopic Study of a Dark Lane and a Cool Loop in a Solar Limb Active Region by Hinode/EIS
Moon, Y. -J.; Lee, Kyoung-Sun; Lee, Jin-Yi +1 more
We investigated a cool loop and a dark lane over a limb active region on 2007 March 14 using the Hinode/EUV Imaging Spectrometer. The cool loop is clearly seen in the spectral lines formed at the transition region temperature. The dark lane is characterized by an elongated faint structure in the coronal spectral lines and is rooted on a bright poi…
Dynamical Behavior of X-Ray Spectra from Markarian 766
Takahashi, M.; Liebmann, A. C.; Haba, Y. +3 more
Mrk 766, a bright narrow-line Seyfert 1, has been observed eight times by the XMM-Newton satellite. We carried out the analysis of the composite data from all of these observations together by applying a dynamical method. Through this analysis, we noted a longer timescale variability in addition to rapid short-time variability. This longer term va…