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61.
Diego F. Torres Shu Zhang Olaf Reimer Xavier Barcons Amalia Corral Valentí Bosch-Ramon Josep M. Paredes Gustavo E. Romero Jin Qu Werner Collmar Volker Schönfelder Yousaf Butt 《Astrophysics and Space Science》2007,309(1-4):17-21
The COMPTEL unidentified source GRO J 1411-64 was observed by INTEGRAL and XMM-Newton in 2005. The Circinus Galaxy is the
only source detected within the 4σ location error of GRO J1411-64, but in here excluded as the possible counterpart. At soft X-rays, 22 reliable and statistically
significant sources (likelihood >10) were extracted and analyzed from XMM-Newton data. Only one of these sources, XMMU J141255.6-635932,
is spectrally compatible with GRO J1411-64 although the fact the soft X-ray observations do not cover the full extent of the
COMPTEL source position uncertainty make an association hard to quantify and thus risky. At the best location of the source,
detections at hard X-rays show only upper limits, which, together with MeV results obtained by COMPTEL suggest the existence
of a peak in power output located somewhere between 300–700 keV for the so-called low state. Such a spectrum resembles those
in blazars or microquasars, and might suggest at work by the models accordingly. However, an analysis using a microquasar
model consisting on a magnetized conical jet filled with relativistic electrons, shows that it is hard to comply with all
observational constrains. This fact and the non-detection at hard X-rays introduce an a-posteriori question mark upon the
physical reality of this source, what is discussed here. 相似文献
62.
The energy balance over land and oceans: an assessment based on direct observations and CMIP5 climate models 总被引:2,自引:0,他引:2
63.
Noah Jäggi Antoine S. G. Roth Miriam Rüfenacht Maria Schönbächler André Galli 《Meteoritics & planetary science》2023,58(7):1039-1055
Chondrules are microscopic, recrystallized melt droplets found in chondritic meteorites. High-resolution isotope analyses of minor elements require large enough element quantities which are obtained by dissolving entire chondrules. This work emphasizes the importance of X-ray computed tomography (XCT) to detect features that can significantly affect the bulk chondrule isotope composition. It thereby expands on other works by looking into chondrules from a wide range of chondrites including CR, CV, CB, CM, L, and EL samples before turning toward complex and time-consuming chemical processing. The features considered are metal and igneous rims, compound chondrules, matrix remnants, and metal contents. In addition to the identification of these features, computed tomography prevents the inclusion of non-chondrule samples (pure matrix or metal) as well as samples where two different chondrule fragments with potentially different isotope compositions are held together by matrix. Matrix surrounding chondrules is also easily detected and the affected chondrules can be omitted or reprocessed. The results strongly encourage to perform XCT before dissolution of chondrules for isotope analysis as a non-invasive method. 相似文献
64.
W. Curdt D. Germerott K. Wilhelm U. Schühle L. Teriaca D. Innes K. Bocchialini P. Lemaire 《Solar physics》2014,289(6):2345-2376
We have released an archive of all observational data of the VUV spectrometer Solar Ultraviolet Measurements of Emitted Radiation (SUMER) on SOHO that have been acquired until now. The operational phase started with ‘first light’ observations on 27 January 1996 and will end in 2014. Future data will be added to the archive when they become available. The archive consists of a set of raw data (Level 0) and a set of data that are processed and calibrated to the best knowledge we have today (Level 1). This communication describes step by step the data acquisition and processing that has been applied in an automated manner to build the archive. It summarizes the expertise and insights into the scientific use of SUMER spectra that has accumulated over the years. It also indicates possibilities for further enhancement of the data quality. With this article we intend to convey our own understanding of the instrument performance to the scientific community and to introduce the new, standard FITS-format database. 相似文献
65.
66.
The magnetic flux tubes that rise across the convection zone to produce active regions are shown to develop a difference in inclination between their preceding and follower sides. This asymmetry is such that the follower wing is more vertical (i.e., closer to the radial direction) than the preceding side. An asymmetry of this kind can be obtained as a natural consequence of the conservation of angular momentum along the rise. This process may explain a number of the observed asymmetries in morphology and behavior of the preceding and follower parts of the active regions. We present results of numerical simulations showing this effect and discuss possible observational consequences. 相似文献
67.
Galateia Terti Isabelle Ruin Sandrine Anquetin Jonathan J. Gourley 《Natural Hazards》2015,79(3):1481-1497
68.
69.
70.
N. V. Chukanov S. M. Aksenov R. K. Rastsvetaeva K. V. Van D. I. Belakovskiy I. V. Pekov V. V. Gurzhiy W. Schüller B. Ternes 《Geology of Ore Deposits》2015,57(8):721-731
A new mineral, mendigite (IMA no. 2014-007), isostructural with bustamite, has been found in the In den Dellen pumice quarry near Mendig, Laacher Lake area, Eifel Mountains, Rhineland-Palatinate (Rheinland-Pfalz), Germany. Associated minerals are sanidine, nosean, rhodonite, tephroite, magnetite, and a pyrochlore-group mineral. Mendigite occurs as clusters of long-prismatic crystals (up to 0.1 × 0.2 × 2.5 mm in size) in cavities within sanidinite. The color is dark brown with a brown streak. Perfect cleavage is parallel to (001). D calc = 3.56 g/cm3. The IR spectrum shows the absence of H2O and OH groups. Mendigite is biaxial (–), α = 1.722 (calc), β = 1.782(5), γ = 1.796(5), 2V meas = 50(10)°. The chemical composition (electron microprobe, mean of 4 point analyses, the Mn2+/Mn3+ ratio determined from structural data and charge-balance constraints) is as follows (wt %): 0.36 MgO, 10.78 CaO, 37.47 MnO, 2.91 Mn2O3, 4.42 Fe2O3, 1.08 Al2O3, 43.80 SiO2, total 100.82. The empirical formula is Mn2.00(Mn1.33Ca0.67) (Mn0.50 2+ Mn0.28 3+ Fe0.15 3+ Mg0.07)(Ca0.80 (Mn0.20 2+)(Si5.57 Fe0.27 3+ Al0.16O18). The idealized formula is Mn2Mn2MnCa(Si3O9)2. The crystal structure has been refined for a single crystal. Mendigite is triclinic, space group \(P\bar 1\); the unit-cell parameters are a = 7.0993(4), b = 7.6370(5), c = 7.7037(4) Å, α = 79.58(1)°, β = 62.62(1)°, γ = 76.47(1)°; V = 359.29(4) Å3, Z = 1. The strongest reflections on the X-ray powder diffraction pattern [d, Å (I, %) (hkl)] are: 3.72 (32) (020), 3.40 (20) (002, 021), 3.199 (25) (012), 3.000 (26), (\(01\bar 2\), \(1\bar 20\)), 2.885 (100) (221, \(2\bar 11\), \(1\bar 21\)), 2.691 (21) (222, \(2\bar 10\)), 2.397 (21) (\(02\bar 2\), \(21\bar 1\), 203, 031), 1.774 (37) (412, \(3\bar 21\)). The type specimen is deposited in the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow, registration number 4420/1. 相似文献