Classifying GRB 170817A/GW170817 in a Fermi duration–hardness plane     

I. Horváth  B. G. Tóth  J. Hakkila  L. V. Tóth  L. G. Balázs  I. I. Rácz  S. Pintér  Z. Bagoly 《Astrophysics and Space Science》2018,363(3):53

GRB 170817A, associated with the LIGO-Virgo GW170817 neutron-star merger event, lacks the short duration and hard spectrum of a Short gamma-ray burst (GRB) expected from long-standing classification models. Correctly identifying the class to which this burst belongs requires comparison with other GRBs detected by the Fermi GBM. The aim of our analysis is to classify Fermi GRBs and to test whether or not GRB 170817A belongs—as suggested—to the Short GRB class. The Fermi GBM catalog provides a large database with many measured variables that can be used to explore gamma-ray burst classification. We use statistical techniques to look for clustering in a sample of 1298 gamma-ray bursts described by duration and spectral hardness. Classification of the detected bursts shows that GRB 170817A most likely belongs to the Intermediate, rather than the Short GRB class. We discuss this result in light of theoretical neutron-star merger models and existing GRB classification schemes. It appears that GRB classification schemes may not yet be linked to appropriate theoretical models, and that theoretical models may not yet adequately account for known GRB class properties. We conclude that GRB 170817A may not fit into a simple phenomenological classification scheme.  相似文献   

Filtration and Clogging Behavior of Geotextiles with Roorkee Soils     

Bal Krishna Maheshwari  Deepak A. Gunjagi 《Geotechnical and Geological Engineering》2008,26(1):101-107

Geotextile filters are rapidly replacing graded granular filters as the standard of practice in geotechnical design. The objective of the present study is to predict the behavior of the geotextile filter for the locally (Roorkee—India) available soils using three different geotextiles (two nonwoven and one woven). Nonwoven geotextiles are commonly used in filtration applications. This paper evaluates the long-term performance of two needle-punched nonwoven geotextiles and one woven geotextile. Filtration tests on soil–geotextile filter systems were conducted in the laboratory in order to evaluate the filtration and clogging behavior. Laboratory test program, include evaluation of performance of two different nonwoven and one woven geotextile filters in combination with locally available Solani River Sand and Clayey Soil. The paper describes the concept and details of the Fine Fraction Filtration (F³) test and presents data on three different geotextiles, which were evaluated using three different soil types. It is deduced that in all filtration applications, the non-woven geotextile would perform better than the woven geotextile.  相似文献   

Infinitesimal orbits around lagrange points in the elliptic,restricted three-body problem     

Dan Şelaru  Cătălin Cucu-Dumitrescu 《Celestial Mechanics and Dynamical Astronomy》1995,61(4):333-346

This study presents a method of obtaining asymptotic approximations for motions near a Lagrange point in the planar, elliptic, restricted three-body problem by using a von Zeipel-type method. The calculations are carried out for a second-order escape solution in the proximity of the equilateral Lagrange point, L ₄, where the primaries' orbital eccentricity is taken as the small parameter .  相似文献   

The multilevel fast multipole method for forward modelling the multiply scattered seismic surface waves   总被引：1，自引：0，他引：1  

Özcan Çakir 《Geophysical Journal International》2006,167(2):663-678

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Review on the macro-modeling alternatives and a proposal for modeling coupling beams in tall buildings   总被引：1，自引：1，他引：0  

A. Emre Toprak  İhsan Engin Bal  F. Gülten Gülay 《Bulletin of Earthquake Engineering》2015,13(8):2309-2326

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High Resolution Optical Spectroscopy of a B-type Abundance Standard Candidate in Ori OB1—HD 35039     

Şahin  Timur  Dervişoğlu  Ahmet 《Astronomy Letters》2019,45(8):528-545

Astronomy Letters - We present LTE analysis of high resolution optical spectra for the B-type abundance standard candidate HD 35039 (HR 1765, 22 Ori) with an ambigous binary nature. The spectra...  相似文献   

Application of landslide hazard scenarios at annual scale in the Niraj River basin (Transylvania Depression,Romania)     

Roşca Sanda  Bilaşco Ştefan  Petrea Dănuţ  Fodorean Ioan  Vescan Iuliu  Filip Sorin 《Natural Hazards》2015,77(3):1573-1592

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Salinity Distribution at Canal Istanbul and Its Possible Impacts on the Northern Marmara Sea     

Saçu  Şehriban  Erdik  Tarkan  Şen  Olgay 《中国海洋工程》2020,34(6):881-888

China Ocean Engineering - Turkey has announced its plan to construct a new waterway, Canal Istanbul, parallel to the Bosphorus. In this study, the influence of Canal Istanbul on salinity...  相似文献   

Erratum to: Climate change projections over India by a downscaling approach using PRECIS     

Prasanta Kumar Bal  Andimuthu Ramachandran  Kandasamy Palanivelu  Perumal Thirumurugan  Rajadurai Geetha  Balakrishnan Bhaskaran 《Asia-Pacific Journal of Atmospheric Sciences》2016,52(5):519-519

The author “Bhaski Bhaskaran” and his affiliation “Fujitsu Laboratory of Europe, Middlesex, UK” should be replaced by “Balakrishnan Bhaskaran”, “Fujitsu Laboratories of Europe Limited, Hayes Park, Middlesex, UK”, respectively.The corrected name and affiliation are shown in this erratum.  相似文献   

P–T–t evolution of eclogite/blueschist facies metamorphism in Alanya Massif: time and space relations with HP event in Bitlis Massif,Turkey     

Mete Çetinkaplan  Amaury Pourteau  Osman Candan  O. Ersin Koralay  Roland Oberhänsli  Aral I. Okay  Fukun Chen  Hüseyin Kozlu  Fırat Şengün 《International Journal of Earth Sciences》2016,105(1):247-281

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