CE-1伽马能谱测量中4种月球岩石的能谱特征分析

从CE-1 γ能谱测量获得的数据出发,对原始数据进行处理,将原始谱线按每5°×5°网格内平均而获得月表上的γ能谱数据。选取了12条不同位置分别代表玄武岩、斜长岩、富镁岩和KREEP岩的能谱曲线进行分析,发现同一岩性的谱线具有相似性。通过对每种岩性选择的一条谱线进行分析可知,不同的岩性能谱曲线有一定的差别,表现为不同岩性在元素特征能谱峰的变化不同,玄武岩的能谱曲线特征峰主要的元素为Th、K、Si、Ca、C、Fe和Ti;斜长岩的能谱曲线特征峰主要元素为U、Ca、C、Mg、Al和Mn。KREEP岩的能谱曲线特征峰主要为K、Th、U、Si、Ca和Fe,而低C和Al;富镁岩能谱曲线表现为低U、Si、Ca和Cl而高K、Mg、Th和Fe含量特征。文中给出了能较好区分不同岩性的元素特征峰能量,可为月表γ能谱的定量分析奠定基础。     

Optical identification of the hard X-ray source IGR J18257-0707

We present the results of our optical identification of the hard X-ray source IGR J18257-0707 through its spectrophotometric observations with the optical RTT-150 telescope. The accurate position of the X-ray source determined using Chandra observations has allowed this source to be confidently associatedwith a faint optical object (m _R ≈ 20.4) whose optical spectrumexhibits a broad H _α emission line at redshift z = 0.037. Thus, the source IGR J18257-0707 is a type-1 Seyfert galaxy at redshift z = 0.037.     

Variability of radiation from the Crab Nebula

We consider variations of the radiation from the Crab Nebula in two energy ranges: X-rays (2–10 keV) and very-high-energy (>1 TeV) gamma rays. We demonstrate the presence of sine-shaped quasi-periodic variations in the X-ray range, with the period P = 862 d. A positive correlation was detected between variations of X-rays and gamma rays (the HEGRA data) with time.     

The Master Mobile Astronomical System. Optical Observations of Gamma-Ray Bursts

The operating principles of the telescope-robot system MASTER (Mobile Astronomical System of Telescopes-Robots, http://observ.pereplet.ru), designed to search for fast transient phenomena in the optical range, are described. The robot-telescope includes the following: a Richter-Slefogt telescope with D=355 mm, F/D=2.4, a Richter-Slefogt telescope with D=200 mm, F/D=2.4, a Flugge telescope with D=280 mm, F/D=2.5, a TV camera with a field of 20x40 degrees, and three CCD cameras. A German mount with a slew rate of 8 deg/s is used. MASTER obtains images down to 19^m in a field of 6 square degrees in a 1.5 minute exposure. We present some observations of the optical afterglow of cosmic gamma-ray bursts. MASTER was the first system in Europe to record optical emission from GRB030329.__________Translated from Astrofizika, Vol. 48, No. 3, pp. 463–475 (August 2005).     

The first hours of the optical afterglow from the cosmic gamma-ray burst 030329

We describe the first results of our observations of the exceptionally bright optical afterglow from the cosmic gamma-ray burst (GRB) of March 29, 2003 (030329), with the 1.5-m Russian-Turkish telescope (RTT150) installed at the TUBITAK National Observatory (Turkey) at Mount Bakyrlytepe. RTT150 was one of the first medium-class telescopes pointed at the afterglow. The observations began as early as about six hours after the GRB. During the first five hours of our observations, the BV RI flux fell off exactly as a power law with the same slope ?1.19±0.01. Subsequently, in all of the BV RI bands, we observed the same increase in the power-law slope of the light curve to a value that was later recorded during the observations at observatories in the western hemisphere. The break in the power-law light curve occurs at t ? t ₀ ≈ 0.57 days (13.5 h) and lasts for about 0.2 days. Apart from this smooth decrease in the flux, the afterglow exhibited no flux variability. The upper limits on the variability are 10–1% on time scales of 0.1–1000 s, respectively. The BV RI spectral flux distribution during the first night of our observations closely corresponds to a power-law spectrum with a spectral index α=0.66±0.01. The change in the power-law slope of the light curve at the end of our observations is probably attributable to the deceleration of the ultrarelativistic jet to a gamma factor when its structural features begin to show up in the light curve. The radio, optical, and X-ray broadband spectrum is consistent with the assumption about the synchrotron radiation of the ultrarelativistic jet. This unique object continues to be observed with RTT150.     

Delay of emission from extragalactic gamma-ray burst sources as a test for selecting a model of the universe

We obtained an order-of-magnitude estimate for the dispersion of light caused by the effect of quantum fluctuations on the propagation of electromagnetic waves in four-dimensional spacetime. We calculated the delay of the photons from cosmological gamma-ray bursts (GRBs) for the flat, open, and closed cosmological models. This delay is attributable to the effect of expansion of the Universe on the propagation of a dispersive light wave in space. Analysis shows that the delay of GRB photons contains a regular component related to the expansion of the Universe. We conclude that cosmological models of the Universe can be selected by the delay of emission of various energies from GRBs; the accuracy of measuring the parameter Δt/ΔE _γ must be no lower than 10^?6 s MeV^?1.     

地面γ能谱测量影响因素初探

由于地面γ能谱测量所反映的是表层土壤中的情况，因此地表影响因素，如介质的粒度、湿度及环境温度等成为不可忽视的干扰因素。经试验的数据曲线分析表明，介质粒度越大，其γ场降低，衰减率高；而介质的湿度越大，介质对射线的吸收量增高，衰减率增高。选择适当的季节，进行γ能谱测量也是很重要的。     

航空物探技术在1:25万区域地质调查中的应用

介绍了国内外物探技术在区域地质调查中的应用现状,航空物探技术在1:25万北京市幅区域地质调查中的应用,认为航空物探方法在火山岩、侵入岩和变质岩的岩性填图,以及划分断裂构造和圈定火山机构等方面具有重要作用,特别是在挖掘地下隐伏信息方面的作用尤为明显,能提高区域地质调查的高科技含量与效率.