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Gamma Rays and the Evolving, Compact Structures of the 2003 October 28 X17 Flare
Schrijver, C. J.; Hudson, H. S.; Tarbell, T. D. +2 more
The X17 flare on 2003 October 28 was observed by high-resolution imaging or spectroscopic instruments on CORONAS, GOES, INTEGRAL, RHESSI, SOHO, and TRACE. These spacecraft observed the temporal evolution of the γ-ray positron-annihilation and nuclear de-excitation line spectra, imaged the hard X-ray bremsstrahlung and EUV and UV emission, and meas…
XMM-Newton Observes Cl J0152.7-1357: A Massive Galaxy Cluster Forming at Merger Crossroads at z=0.83
Priedhorsky, W.; Córdova, F. A.; Maughan, B. J. +3 more
We present an analysis of a 50 ks XMM-Newton observation of the merging galaxy cluster Cl J0152.7-1357 at z=0.83. In addition to the two main subclusters and an infalling group detected in an earlier Chandra observation of the system, XMM-Newton detects another group of galaxies possibly associated with the cluster. This group may be connected to …
XMM-Newton Observations of the Bipolar Planetary Nebulae NGC 2346 and NGC 7026
Guerrero, Martín A.; Chu, You-Hua; Gruendl, Robert A. +1 more
We have obtained X-ray observations of the bipolar planetary nebulae (PNe) NGC 2346 and NGC 7026 with XMM-Newton. These observations detected diffuse X-ray emission from NGC 7026 but not from NGC 2346. The X-ray emission from NGC 7026 appears to be confined within the bipolar lobes of the PN and has spectral properties suggesting a thermal plasma …
Enigma of a Flare Involving Multiple-Loop Interactions: Emerging, Colliding Loops or Magnetic Breakout?
Holman, Gordon D.; Dennis, Brian R.; Sui, Linhui
We present observations of a C9.4 flare on 2002 June 2 in EUV (TRACE), X-rays (RHESSI), and Hα (Meudon and Ondrejov) showing evidence for multiple-loop interactions as the cause of the flare. The multiwavelength data reveal some striking phenomena that can be used to test different models for solar eruptive events: (1) involvement of a quadrupolar…
Is There Any Evident Effect of Coronal Holes on Gradual Solar Energetic Particle Events?
Wang, Yuming; Shen, Chenglong; Wang, S. +1 more
Gradual solar energetic particle (SEP) events are thought to be produced by shocks, which are usually driven by fast coronal mass ejections (CMEs). The strength and magnetic field configuration of the shock are considered the two most important factors for shock acceleration. Theoretically, both of these factors should be unfavorable for producing…
The Possible z=0.83 Precursors of z=0, M* Early-Type Cluster Galaxies
Kelson, D. D.; Ford, H. C.; Demarco, R. +8 more
We examine the distribution of stellar masses of galaxies in MS 1054.4-0321 and Cl 0152.7-1357, two X-ray-selected clusters of galaxies at z=0.83. Our stellar mass estimates, from spectral energy distribution fitting, reproduce the dynamical masses as measured from velocity dispersions and half-light radii with a scatter of 0.2 dex in the mass for…
The X-Ray Properties of Active Galactic Nuclei with Double-peaked Balmer Lines
Brandt, W. N.; Schneider, Donald P.; Eracleous, Michael +2 more
Double-peaked Balmer line profiles originate in the accretion disks of a few percent of optically selected active galactic nuclei (AGNs). The reasons behind the strong low-ionization line emission from the accretion disks of these objects are still uncertain. In this paper, we characterize the X-ray properties of 39 double-peaked Balmer line AGNs,…
Variations in the D/H Ratio of Extended Sight Lines from Far Ultraviolet Spectroscopic Explorer Observations
Hébrard, Guillaume; Oliveira, Cristina M.
We use new FUSE data to determine the column densities of interstellar D I, N I, O I, Fe II, and H2 along the HD 41161 and HD 53975 sight lines. Together with N(H I) from the literature, we derive D/H, N/H, and O/H ratios. These sight lines have logN(H I)>21.00 and probe gas up to ~1300 pc, allowing us to determine the gas-phase D/H …
The Prediction of a Supersoft X-Ray Phase during the 2006 Outburst of RS Ophiuchi
Kato, Mariko; Hachisu, Izumi
RS Ophiuchi is one of the well-observed recurrent novae and also a candidate progenitor of Type Ia supernovae. Its sixth recorded outburst was discovered on 2006 February 12. Detection of a supersoft X-ray phase will provide us with a firm confirmation of hydrogen shell burning on the white dwarf, and its turn-on/turnoff dates strongly constrain t…
Coronal Magnetic Field Topology over Filament Channels: Implication for Coronal Mass Ejection Initiations
Luhmann, Janet; Li, Yan
The magnetic field topology at the coronal mass ejection (CME) source regions has been one of the major focuses of CME initiation models. While the ``breakout'' model requires a quadrupolar magnetic topology in the solar corona to enable an eruption, other models have shown that a bipolar magnetic topology can be the source region of a CME. In thi…