Classification of BeppoSAX’s gamma-ray bursts

The BeppoSAX Catalog has been very recently published. In this paper we analyze—using the Maximum Likelihood (ML) method—the duration distribution of the 1003 GRBs listed in the catalog with duration. The ML method can identify the long and the intermediate duration groups. The short population of the bursts is identified only at a 96% significance level. MC simulation has been also applied and gives a similar significance level; 95%. However, the existence of the short bursts is not a scientific question after the Compton Gamma-Ray Observatory’s observation. Our minor result is this well-known fact that in the BeppoSAX data the short bursts are under-represented, mainly caused by the different triggering system. Our major result is the identification of the intermediate group in the BeppoSAX data. Therefore, four different satellites (CGRO, Swift, RHESSI and BeppoSAX) observed the intermediate type Gamma-Ray Burst.     

On the origin of the compact H ii regions around massive stellar clusters

The existence of compact H?ii regions around massive stellar clusters with ages exceeding several Myr challenges our understanding of the physical processes occurring inside such clusters, and their impact on the interstellar medium of the host galaxy. Here, we summarize our recent results dealing with the hydrodynamics of matter ejected by massive stars inside the cluster and show that compact H?ii regions found around some massive clusters may indicate that these are evolving in a bimodal hydrodynamic regime. The latter is characterized by the accumulation of the injected matter in the central, thermally unstable zone, and by the ejection of mass supplied by massive stars in the outer regions of the cluster.     

Gas kinematics in the halo of the warm ULIRG PKS1345+12

We use long-slit spectra taken with the William Herschel Telescope on La Palma and high-resolution Hubble Space Telescope imaging to study the gas kinematic in the halo of the ultraluminous infrared/radio galaxy PKS1345+12 (z=0.122). Our long-slit spectra show line splitting at the locations of massive star clusters ( $10^{6}<M_{\mathrm{SSC}}^{\mathrm{YSP}}<10^{7}$ M_⊙), indicating that they are moving at up to 450 km?s^?1 with respect to the local ambient gas. Given their kinematics, it is plausible that these super star clusters have been formed either in fast-moving gas streams or tidal tails that are falling back into the nuclear regions as part of the merger process, or as a consequence of jet-induced star formation linked to the extended, diffuse radio emission detected in the halo of the galaxy.     

Assessment of Raman spectroscopy as a tool for the non-destructive identification of organic minerals and biomolecules for Mars studies

Several characteristic geological features found on the surface of Mars by planetary rovers suggest that a possible extinct biosphere could exist based on similar sources of energy as occurred on Earth. For this reason, analytical instrumental protocols for the detection of biomarkers in suitable geological matrices unequivocally have to be elaborated for future unmanned explorations including the forthcoming ESA ExoMars mission. As part of the Pasteur suite of analytical instrumentation on ExoMars, the Raman/LIBS instrument will seek elemental and molecular information about geological, biological and biogeological markers in the Martian record. A key series of experiments on terrestrial Mars analogues, of which this paper addresses a particularly important series of compounds, is required to obtain the Raman spectra of key molecules and crystals, which are characteristic for each biomarker. Here, we present Raman spectra of several examples of organic compounds which have been recorded non-destructively—higher n-alkanes, polycyclic aromatic hydrocarbons, carotenoids, salts of organic acids, pure crystalline terpenes as well as oxygen-containing organic compounds. In addition, the lower limit of β-carotene detection in sulphate matrices using Raman microspectroscopy was estimated.     

An Estimation of Spatial Variations of Magnetic Field and Superthermal Electron Distribution in cm-Radio Burst Sources

The paper presents a new method of the estimation of spatial variations of the magnetic field and superthermal electron distribution in solar cm-radio burst sources. The method is based on minimization of the difference between the theoretical and observed radio fluxes and on the analysis of several burst spectra recorded in different moments of time. Several solar cm-radio bursts are analyzed by this method. It is found that the measure of the spatial variations of the superthermal electron distribution in the radio source is always larger than that for the magnetic field.     

A multiphysics and multiscale software environment for modeling astrophysical systems

We present MUSE, a software framework for combining existing computational tools for different astrophysical domains into a single multiphysics, multiscale application. MUSE facilitates the coupling of existing codes written in different languages by providing inter-language tools and by specifying an interface between each module and the framework that represents a balance between generality and computational efficiency. This approach allows scientists to use combinations of codes to solve highly coupled problems without the need to write new codes for other domains or significantly alter their existing codes. MUSE currently incorporates the domains of stellar dynamics, stellar evolution and stellar hydrodynamics for studying generalized stellar systems. We have now reached a “Noah’s Ark” milestone, with (at least) two available numerical solvers for each domain. MUSE can treat multiscale and multiphysics systems in which the time- and size-scales are well separated, like simulating the evolution of planetary systems, small stellar associations, dense stellar clusters, galaxies and galactic nuclei. In this paper we describe three examples calculated using MUSE: the merger of two galaxies, the merger of two evolving stars, and a hybrid N-body simulation. In addition, we demonstrate an implementation of MUSE on a distributed computer which may also include special-purpose hardware, such as GRAPEs or GPUs, to accelerate computations. The current MUSE code base is publicly available as open source at http://muse.li.     

Capture effects in carbonaceous material: A Stardust analogue study

Abstract— It is reasonable to expect that cometary samples returned to Earth by the Stardust space probe have been altered to some degree during capture in aerogel at 6.1 km/s. In order to help interpret the measured structure of these particles with respect to their original cometary nature, a series of coal samples of known structure and chemical composition was fired into aerogel at Stardust capture velocity. This portion of the study analyzed the surfaces of aerogel‐embedded particles using Raman spectroscopy. Results show that particle surfaces are largely homogenized during capture regardless of metamorphic grade or chemical composition, apparently to include a devolatilization step during capture processing. This provides a possible mechanism for alteration of some aliphatic compound‐rich phases through devolatilization of cometary carbonaceous material followed by re‐condensation within the particle. Results also show that the possibility of alteration must be considered for any particular Stardust grain, as examples of both graphitization and amorphization are found in the coal samples. It is evident that Raman G band (～1580 cm^?1) parameters provide a means of characterizing Stardust carbonaceous material to include identifying those grains which have been subjected to significant capture alteration.     

Do extrusion ages reflect magma generation processes at depth? An example from the Neogene Volcanic Province of SE Spain

The high-K calc-alkaline volcanic rocks along the Neogene Volcanic Province of SE Spain represent crustal anatectic melts mixed with mantle components during the opening of the Alborán Sea. Partially melted metapelitic enclaves, along with the geochemical signature, provide evidence of their crustal source. U–Pb SHRIMP geochronology on monazite and zircon from enclaves and their hosting lavas in the localities of El Hoyazo, Mazarrón and Mar Menor reveals variable delays between the melting at depth and the eruption of the volcanics. These data indicate that: (1) the most important event of anatexis in the Neogene spanned at least the 3 m.y. interval between 12 and 9 Ma; (2) there is no trend in age of crustal melting; and (3) the delay between magma generation and extrusion varies from more than 3 m.y. at El Hoyazo to ~0.5 m.y. and possibly 2.5 m.y. at Mar Menor, with no significant delay measurable at Mazarrón. The variable time delay between anatexis and lava extrusion indicates that radiometric ages of volcanics may provide misleading information on the timing of magma genesis occurring at depth. This highlights the pitfall of basing detailed geodynamic models on volcanic extrusion ages alone. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

The Mammoth Peak sheeted complex,Tuolumne batholith,Sierra Nevada,California: a record of initial growth or late thermal contraction in a magma chamber?

The Mammoth Peak sheeted intrusive complex formed in the interior of a ~7–10 km deep magma chamber, specifically in the Half Dome granodiorite of the Tuolumne batholith, central Sierra Nevada, CA (USA). The sheets consist of fractionated melts with accumulated hornblende, biotite, magnetite, titanite, apatite, and zircon. The accumulation, especially of titanite, had a profound effect on minor and trace elements (Nb, Ta, Ti, REE, U, Th, P, Zr, Hf, etc.), increasing their contents up to five to six times. Our thermal–mechanical modeling using the finite element method shows that cooling-generated tensile stresses resulted in the inward propagation of two perpendicular sets of dilational cracks in the host granodiorite. We interpret the sheeted complex to have formed by a crack-seal mechanism in a high strength, crystal-rich mush, whereby outward younging pulses of fractionated magma were injected into these syn-magmatic cracks at the margin of an active magma chamber. Thermal–mechanical instabilities developed after the assembly of the sheeted complex, which was then overprinted by late ~NW–SE magmatic foliation. This case example provides a cautionary note regarding the interpretation that sheeted zones in large granitoid plutons imply a diking mechanism of growth because the sheeted/dike complexes in plutons (1) may display inverse growth directions from the growth of the overall intrusive sequence; (2) need not record initial chamber construction and instead may reflect late pulsing of magma within an already constructed magma chamber; (3) have an overprinting magmatic fabric indicating the continued presence of melt after construction of sheeted complexes and thus a prolonged thermal history as compared to dikes; and (4) because the scale of the observed sheeted complexes may be small (<1%) in comparison to large homogenous parts of plutons, in which there is no evidence for sheeting or diking. Thus, where extensive dike complexes in plutons are absent, such as in much of the Tuolumne batholith, the application of an incremental diking model to explain chamber construction is at best speculative.