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Modeling Minor Ion Abundances in Quiescent Coronal Loops
Lie-Svendsen, Øystein; Killie, Mari Anne
We model minor element abundances in quiescent coronal loops anchored in the chromosphere, solving transport equations that give an improved description of thermal forces. Ionization, recombination, and radiative loss are included. The plasma consists of hydrogen and a minor element (oxygen, silicon, or iron), and we solve for all relevant charge …
Light Superconducting Strings in the Galaxy
Ferrer, Francesc; Vachaspati, Tanmay
Observations of the Milky Way by the SPI/INTEGRAL satellite have confirmed the presence of a strong 511 keV gamma ray line emission from the bulge, which requires an intense source of positrons in the galactic center. These observations are hard to account for by conventional astrophysical scenarios, whereas other proposals, such as light DM, face…
Far-Infrared Distributions in Nearby Spiral GalaxiesNGC 2841 and NGC 2976 Observed with AKARI/Far-Infrared Surveyor (FIS)
Serjeant, S.; Nakagawa, T.; Okada, Y. +9 more
Far-infrared (IR) images of the nearby Sb galaxy NGC 2841 and the Sc galaxy NGC 2976 at wavelengths of 65, 90, 140, and 160 ∼ bridge in the M 81/M 82 group that NGC 2976 belongs to. By taking advantage of a wealth of the far-IR bands of the FIS, it has been demonstrated that the spectral energy distribution of NGC 2841 is spatially more variable t…
ARCRAIDER. I. Detailed optical and X-ray analysis of the cooling flow cluster Z3146
Schindler, S.; Erben, T.; Gitti, M. +1 more
We present a detailed analysis of the medium redshift (z = 0.2906) galaxy cluster Z3146 which is part of the ongoing ARCRAIDER project, a systematic search for gravitational arcs in massive clusters of galaxies. The analysis of Z3146 is based on deep optical wide field observations in the B, V and R bands obtained with the WFI@ESO2.2m, and shallow…
Extrasolar low-orbit planets: Dissipation of their atmospheres and probable magnetic field
Ksanfomality, L. V.
Analysis of the data obtained during transits of low-orbit extrasolar planets across the stellar disk yields different estimates of their atmospheric loss rates. Experimental data point to the probable existence of several distinct subtypes of extrasolar giant planets, including "hot Jupiters" of low density (HD 209458b), with massive cores compos…
Low Star Formation Rates for z = 1 Early-Type Galaxies in the Very Deep GOODS MIPS Imaging: Implications for Their Optical/Near-Infrared Spectral Energy Distributions
van der Wel, A.; Illingworth, G. D.; Franx, M. +1 more
We measure the obscured star formation in z~1 early-type galaxies. This constrains the influence of star formation on their optical/near-IR colors, which, we found, are redder than predicted by the model by Bruzual & Charlot. From deep ACS imaging we construct a sample of 95 morphologically selected early-type galaxies in the HDF-N and CDF-S w…
The CME-productivity associated with flares from two active regions
Gopalswamy, N.; Yashiro, S.; Akiyama, S.
We report on two flare-productive adjacent active regions (ARs), with different levels of coronal mass ejection (CME) association. AR 10039 and AR 10044 produced strong X-ray flares during their disk passages. We examined the CME association rate of X-ray flares and found it to be different between the two ARs. AR 10039 was CME-rich with 72% assoc…
Astrometric-Spectroscopic Determination of the Absolute Masses of the HgMn Binary Star φ Herculis
Torres, Guillermo
The mercury-manganese star φ Her is a well-known spectroscopic binary that has been the subject of a recent study by Zavala and coworkers in which they resolved the companion using long-baseline interferometry. The total mass of the binary is now fairly well established, but the combination of spectroscopy with astrometry has not resulted in indiv…
Magnetospheric Cusps under Extreme Conditions: Cluster Observations and MHD Simulations Compared
Siscoe, George; Kaymaz, Zerefşan; Bogdanova, Yulia V.
MHD simulations are here applied to aid in the interpretation of three apparent cusp encounters by the Cluster 4 spacecraft in unusual places when the magnetosphere was under extreme solar wind and interplanetary magnetic field (IMF) conditions associated with the passage of magnetic clouds imbedded within fast ICMEs. At the time of each cusp enco…
Does High Plasma-β Dynamics ``Load'' Active Regions?
McIntosh, Scott W.
Using long-duration observations in the He II 304 Å passband of SOHO EIT, we investigate the spatial and temporal appearance of impulsive intensity fluctuations in the pixel light curves. These passband intensity fluctuations come from plasma emitting in the chromosphere, in the transition region, and in the lowest portions of the corona. We see t…