Search Publications
Co-analysis of Solar Microwave and Hard X-Ray Spectral Evolutions. II. In Three Sources of a Flaring Loop
Huang, Guangli; Li, Jianping
Based on the spatially resolvable data of the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and Nobeyama Radio Heliograph (NoRH), co-analysis of solar hard X-ray and microwave spectral evolution is performed in three separate sources located in one looptop (LT) and two footpoints (FPs) of a huge flaring loop in the 2003 October 24 …
An Envelope Disrupted by a Quadrupolar Outflow in the Pre-planetary Nebula IRAS 19475+3119
Lee, Chin-Fei; Hsu, Ming-Chien
IRAS 19475+3119 is a quadrupolar pre-planetary nebula (PPN), with two bipolar lobes, one in the east-west (E-W) direction and one in the southeast-northwest (SE-NW) direction. We have observed it in CO J = 2-1 with the Submillimeter Array at ~1'' resolution. The E-W bipolar lobe is known to trace a bipolar outflow and it is detected at high veloci…
Is the Young Star Cluster NGC 376 Dissolving in the Field of the Small Magellanic Cloud?
Cignoni, M.; Tosi, M.; Sabbi, E. +3 more
We use deep images acquired with the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope in the filters F555W and F814W to characterize the properties of NGC 376, a young star cluster located in the wing of the Small Magellanic Cloud. Using isochrone fitting we derive for NGC 376 an age of 28 ± 7 Myr, in good agreement with previ…
High-resolution Observations of Siphon Flows in a Solar Magnetic Pore
Guglielmino, Salvo L.; Zuccarello, Francesca
We investigate signatures of siphon flows in a region around a solar magnetic pore, observed in the photosphere at µ = 0.6, during its decay phase. We analyze high-resolution Stokes spectra acquired by Hinode/Solar Optical Telescope along the Fe I pair at 630.2 nm. We determine the vector magnetic field and the line-of-sight velocity by an i…
Far-infrared Emission from the Intergalactic Medium in Stephan's Quintet Revealed by AKARI
Onaka, Takashi; Kaneda, Hidehiro; Kitayama, Tetsu +1 more
Stephan's Quintet (SQ, HCG92) was observed with the Far-Infrared Surveyor on board AKARI in four far-infrared (IR) bands at 65, 90, 140, and 160 µm. The AKARI four-band images show far-IR emission in the intergalactic medium of SQ. In particular, the 160 µm band image shows single peak emission in addition to the structure extending in…
A Strong Emission Line near 24.8 Å in the X-Ray Binary System MAXI J0556-332: Gravitational Redshift or Unusual Donor?
Raymond, John C.; Miller, Jon M.; Reynolds, Mark T. +1 more
We report the discovery of a strong emission line near 24.8 Å (0.5 keV) in the newly discovered X-ray binary system MAXI J0556-332 with the reflection grating spectrometer (RGS) on board the XMM-Newton observatory. The X-ray light curve morphology during these observations is complex and shows occasional dipping behavior. Here we present time- and…
Observational Evidences for the Existence of 17.4 keV Decaying Degenerate Sterile Neutrinos Near the Galactic Center
Chan, M. H.; Chu, M. -C.
We show that the existence of a degenerate halo of sterile neutrinos with rest mass of 17.4 keV near the Galactic center (GC) can account for both the excess 8.7 keV emission observed by the Suzaku mission and the power needed (1040 erg s-1) to maintain the high temperature of the hot gas (8 keV) near the GC. The required dec…
Time Variable Broad-line Emission in NGC 4203: Evidence for Stellar Contrails
Devereux, Nick
Dual epoch spectroscopy of the lenticular galaxy, NGC 4203, obtained with the Hubble Space Telescope has revealed that the double-peaked component of the broad Hα emission line is time variable, increasing by a factor of 2.2 in brightness between 1999 and 2010. Modeling the gas distribution responsible for the double-peaked profiles indicates that…
Regular Versus Diffusive Photospheric Flux Cancellation
Litvinenko, Yuri E.
Observations of photospheric flux cancellation on the Sun imply that cancellation can be a diffusive rather than regular process. A criterion is derived, which quantifies the parameter range in which diffusive photospheric cancellation should occur. Numerical estimates show that regular cancellation models should be expected to give a quantitative…
Contemporaneous XMM-Newton Investigation of a Giant X-ray Flare and Quiescent State from a Cool M-Class Dwarf in the Local Cavity
Gupta, A.; Williams, B.; Galeazzi, M.
We report the serendipitous detection of a giant X-ray flare from the source 2XMM J043527.2-144301 during an XMM-Newton observation of the high latitude molecular cloud MBM20. The source has not been previously studied at any wavelength. The X-ray flux increases by a factor of more than 52 from quiescent state to peak of flare. A 2MASS counterpart…