The Rapidly Flaring Afterglow of the Very Bright and Energetic GRB 070125

We report on multi-wavelength observations, ranging from the X-ray to radio wave bands, of the IPN-localized gamma-ray burst GRB 070125. Spectroscopic observations reveal the presence of absorption lines due to O I, Si II, and C IV, implying a likely redshift of z = 1.547. The well-sampled light curves, in particular from 0.5 to 4 days after the burst, suggest a jet break at 3.7 days, corresponding to a jet opening angle of ~7.0 degrees, and implying an intrinsic GRB energy in the 1 - 10,000 keV band of around E = (6.3 - 6.9)x 10^(51) erg (based on the fluences measured by the gamma-ray detectors of the IPN network). GRB 070125 is among the brightest afterglows observed to date. The spectral energy distribution implies a host extinction of Av < 0.9 mag. Two rebrightening episodes are observed, one with excellent time coverage, showing an increase in flux of 56% in ~8000 seconds. The evolution of the afterglow light curve is achromatic at all times. Late-time observations of the afterglow do not show evidence for emission from an underlying host galaxy or supernova. Any host galaxy would be subluminous, consistent with current GRB host-galaxy samples. Evidence for strong Mg II absorption features is not found, which is perhaps surprising in view of the relatively high redshift of this burst and the high likelihood for such features along GRB-selected lines of sight.Comment: 50 pages, 9 figures, 5 tables Accepted to the Astrophysical Journa

A pre-research on GWAC massive catalog data storage and processing system

GWAC (Ground Wide Angle Camera) poses huge challenges in large-scale catalogue storage and real-time processing of quick search of transients among wide field-of-view time-series data. Firstly, this paper proposes the concept of using databases’ capabilities of fast data processing and parallelism, which will improve system performance and availability through the integration of data storage and computing platform. To understand the feasibility of Column-store MonetDB in vast catalogue management, we carry out a variety of pilot experiments of key technologies. We conduct TPC-H benchmark, data loading benchmark and optimization, and key algorithm testing of astronomical source association, all compared with the traditional row store database. Then, we use MonetDB to realize cross-match Zone algorithm. UDF function is developed for customizable data loading. Tests results show t MonetDB database has a remarkable performance in large amounts of data management and is efficient in real-time data process, thus has the ability to deal with 2.5T catalog data. In the end we propose a wide field of view massive time serial observation data processing solution using the in-memory column store database MonetDB. The experimental results show that the feasibility of the scheme. The design plan of MonetDB-based massive catalogue data processing solution, is an efficient astronomical database solution that combines data processing and data management

SNS application programming plan.

The plan for Spallation Neutron Source accelerator physics application programs is presented. These high level applications involve processing and managing information from the diagnostic instruments, the machine control system, models and static databases and will be used to investigate and control beam behavior. Primary components include an SNS global database and Java-based XAL Application Toolkit. A key element in the SNS application programs is time synchronization of data used in these applications, due to the short pulse (1 ms), pulsed (60 Hz) nature of the device. The data synchronization progress is also presented