Using the MSX mid-infrared observations,we reveal a 100pc-scale superbubble surrounding the giant HII region NGC3603.We suggest that the diffuse surrounding infrared emission in bands A,C,and D is dominated by that of...Using the MSX mid-infrared observations,we reveal a 100pc-scale superbubble surrounding the giant HII region NGC3603.We suggest that the diffuse surrounding infrared emission in bands A,C,and D is dominated by that of PAH and the emission in band E is dominated by that of dust grains.The fitted dust temperature is consistent with heating by the central cluster's UV photons.The derived gas-to-dust mass ratio for the bubble shell is of order 102.展开更多
In this paper,we study nonthermal high energy radiation from old rotation-powered pulsars with ages greater than 106 yr based on the revised outer gap model.In this model,the inclination angle and geometry of the magn...In this paper,we study nonthermal high energy radiation from old rotation-powered pulsars with ages greater than 106 yr based on the revised outer gap model.In this model,the inclination angle and geometry of the magnetic field have been taken into account,and the fractional size f of the outer gap is determined by the electron/positron pair production process.The cascade process caused by the back-flowing particles moving from the outer gap to the star will produce the observed nonthermal X-ray emission,and the relativistic particles accelerated in the outer gap will produce gamma-rays via curvature radiation.For nine old pulsars which have been detected to have nonthermal X-rays,we first use the observed nonthermal X-ray emission to estimate reasonable inclination angles,and then estimate their gamma-ray emissions.We also study the possibilities of gamma-ray emissions from other old rotation-powered pulsars.We compare our predicted gamma-ray flux with the sensitivities of AGILE and Fermi.展开更多
基金support by the National Basic Research Program of China (Grant No. 2009CB824800)the National Natural Science Foundation of China (Grant Nos. 10725312 and 10673003)
文摘Using the MSX mid-infrared observations,we reveal a 100pc-scale superbubble surrounding the giant HII region NGC3603.We suggest that the diffuse surrounding infrared emission in bands A,C,and D is dominated by that of PAH and the emission in band E is dominated by that of dust grains.The fitted dust temperature is consistent with heating by the central cluster's UV photons.The derived gas-to-dust mass ratio for the bubble shell is of order 102.
基金supported by the National Basic Research Program of China (Grant No. 2009CB824800)the National Natural Science Foundation of China (Grant Nos. 10778702 and 10803005)the Foundation of Yunnan Province of China (Grant No. 2006A0001Q)
文摘In this paper,we study nonthermal high energy radiation from old rotation-powered pulsars with ages greater than 106 yr based on the revised outer gap model.In this model,the inclination angle and geometry of the magnetic field have been taken into account,and the fractional size f of the outer gap is determined by the electron/positron pair production process.The cascade process caused by the back-flowing particles moving from the outer gap to the star will produce the observed nonthermal X-ray emission,and the relativistic particles accelerated in the outer gap will produce gamma-rays via curvature radiation.For nine old pulsars which have been detected to have nonthermal X-rays,we first use the observed nonthermal X-ray emission to estimate reasonable inclination angles,and then estimate their gamma-ray emissions.We also study the possibilities of gamma-ray emissions from other old rotation-powered pulsars.We compare our predicted gamma-ray flux with the sensitivities of AGILE and Fermi.
