A maximum entropy map of the 511 keV positron annihilation line emission distribution near the galactic center

被引:32
作者
Cheng, LX
Leventhal, M
Smith, DM
Purcell, WR
Tueller, J
Connors, A
Dixon, D
Kinzer, RL
Skibo, JG
机构
[1] NORTHWESTERN UNIV,DEPT PHYS & ASTRON,EVANSTON,IL 60208
[2] NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771
[3] UNIV NEW HAMPSHIRE,DURHAM,NH 03824
[4] UNIV CALIF RIVERSIDE,INST GEOPHYS & PLANETARY PHYS,RIVERSIDE,CA 92521
[5] USN,RES LAB,WASHINGTON,DC 20375
关键词
galaxy; general; gamma rays; observations;
D O I
10.1086/310638
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We have applied the maximum entropy method to a large data set based on Compton Gamma Ray Observatory (CGRO)/OSSE, Solar Maximum Mission, Transient Gamma-Ray Spectrometer, Gamma-Ray Imaging Spectrometer, HEXAGONE, and FIGARO observational results of the Galactic center 511 keV radiation in order to produce a map of the 511 keV line emission. This map suggests two components: a central bulge with a flux of 5.7 +/- 0.29 x 10(-4) photons cm(-2)s(-1) and a Galactic plane (GP) component with a flux of 2.2 +/- 0.4 x 10(-4) photons cm(-2) s(-1). The central bulge is located at l = -0.degrees 47 +/- 0.degrees 24, b = 0.degrees 1 +/- 0.degrees 18, and FWHM = 5.degrees 28 +/- 0.degrees 48. We note that the position of the GP component coincides with a strong hot spot in the COMPTEL map of 1.8 MeV Al-26 line emission. A comparison between CGRO/OSSE and other instruments with larger field of view suggests an extended diffuse 511 keV emission. An interesting hot spot at l = -4 degrees, b = 7 degrees with a flux of similar to 2 x 10(-4)photons cm(-2)s(-1) is shown on our map. A bootstrap test indicates that the significance level of this feature is 3.5 sigma.
引用
收藏
页码:L43 / L46
页数:4
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