广西大学—国家天文台天体物理与空间科学研究中心 China-VO and Astroinformatics 伽玛暴光学余辉光度函数 和60 cm 光学望远镜 王祥高 广西大学—国家天文台天体物理与空间科学研究中心 China-VO and Astroinformatics 2012·2012.11.28-12.02·三峡大学
Outline 1. GRB and it’s optical emission 2. Observed GRB Optical Brightness Distribution Function 3. MC simulation 4. Robotic 60-cm Telescopes of GXU-NAOC Center 5. Summary and Discussion
1.伽玛暴 伽玛射线暴(Gamma-Ray Burst,GRB)是宇宙学距离上的宇宙大爆炸以来的最强的能量爆发事件,它的主要特点是伽玛射线波段流量突然增强,以及具有的瞬时性,能量高,时标短,光变曲线复杂多变等特点。 伽玛暴是宇宙中除宇宙大爆炸之外最激烈的爆发现象,在短时标类能照亮整个宇宙。
科学意义 伽玛暴 引力物理 星系 恒星 物理 高能辐射过程 宇宙学 中心能源? 喷流形成和演化? 火球动能辐射? 各种成份的物理起源? …….
Shallow Decay Oneset 伽玛暴光变曲线 Distinct origins of various components ? luminosity functions (LF) at t<1h ? Oneset Li, Liang et al. 2012, arXiv1203.2332
Outline 1. GRB and it’s optical emission 2. Observed GRB Optical Brightness Distribution Function 3. MC simulation 4. Robotic 60-cm Telescopes of GXU-NAOC Center 5. Summary and Discussion
Data selection Sample: Corrections: k-correction, Galactic extinction Full sample of GRBs with optical afterglow detection from 1997-2012, 230 GRBs included 146 well-sampled LCs for our analysis. Most of them were observed in the R-band. Optical data, prompt gamma-ray dataand redshift. Corrections: k-correction, Galactic extinction (No correction for host galaxy extinction )
光度分布 Global lightcurves
光度分布 Onset
光度分布 shallow Decay
光度分布
Optical prompt emission of GRBs 目前已探测到伽玛暴~4000个; 但探测到爆发时光学辐射的<10个: GRB 990123, 041219, 050401, 050820A, 060111B, 061121, 080913B 其中仅仅 GRB 080913B有无时延观测! GRB 080913B
Summary for the observations: The observed distributions of R-band magnitude are roughly a Gaussian function. About 90% of GRBs in the above samples have R<20. This may be due to instrumental selection effect (only small robotic telescope can rapidly response to the GRB triggers). Prompt Optical Flares: More luminous, and the burst time is more early
Outline 1. A generic Optical Lightcurves of GRBs 2. Observed GRB Optical Brightness Distribution Function 3. MC simulation 4. Robotic 60-cm Telescopes of GXU-NAOC Center 5. Summary and Discussion
MC simulation Model (3)Extinction: (1)Optical luminosity function: (2)GRB rate: Free parameters in our models:
MC Result {α1=0.70, α2=1.9} Lb~ 1046 erg s-1 Our Monte Carlo (MC) simulations suggest that a intrinsic broken power-law luminosity function can well reproduced the observed magnitude distributions.
Outline 1. GRB and it’s optical emission 2. Observed GRB Optical Brightness Distribution Function 3. MC simulation 4. Robotic 60-cm Telescopes of GXU-NAOC Center (Robotic Autonomous Observatory) 5. Summary and Discussion
Space Multi-band Variable Objects Monitor GRM VT MXT CXG SVOM Space Multi-band Variable Objects Monitor GWAC GFTs GWAC, an array of ground wide angle cameras 450-900nm 2sr (90*90 deg)
GXU-NAOC Robotic Telescopes Diameter: 60cm FoV: 10arcmin Colors: g,r,i (z) CCDs: 1k1k EMCCD 600mm (24") Ritchey-Chrétien System f/3 primary mirror with f8 System focal ratio LOMO Ritchey Chrétien optical set Mirror material zero to low expansion Astro-Sital ceramics L/8 PtV wave, >95% Strehl Direct Drive Mount speed 15°/sec. ( 25°/sec. optional) Pointing :<3“ RMS with pointingfile Tracking precision: <0.15“ RMS in 5 minutes Encoder resolution: 0.007“ on the axis
EMCCD 增益可显著地改善这种极微弱信号的信噪比,由此在大吞吐量的分析研究中可实现更快的采样和更短的曝光时间。 快速读出, 半导体制冷型( -90 ℃ ).
Science goal of GXU-NAOC Robotic Telescopes Fast time resolution light curves Prompt emissions Early afterglow Confirming GWAC On: Sub-arcsecond localization Multi-color diagram
Swift SVOM 观测策略 伽玛暴坐标网络(GCN) 大型望远镜 GWAC 60 cm Robotic telescope
中心集群机硬件配置与软件环境 ►管理及IO节点:1个, 2颗8核CPU ►计算节点: 5个,每个节点有2颗8核CPU, 计算核心总数80核,每个计算 节点的内存容量:32G,共160G ►速度:双精度浮点运算峰值每秒0.64万亿次 ►容量:磁盘阵列存储空间裸容量32T。 ►系统峰值功耗:约为5kW
广西大学多功能计算平台网络拓扑图
广西大学多功能计算平台 采用混合式的集群(Cluster)架构,计算节点80个(1036核)包括: 刀片式计算节点:69个, 每节点2颗六核处器 ; GPU节点: 10个,每节点2颗八核处器 胖节点: 1个,每节点8颗六核处器 速度: 双精度浮点运算理论峰值每秒15万亿次 节点总内存容量:2.56TB 分配磁盘总容量: 135TB
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