We present near-infrared spectroscopic and photometric observations of nova V5584 Sgr taken during the first 12 d following its discovery on Oct. 26.439 UT2009. The evolution of the spectra is shown from the initial P...We present near-infrared spectroscopic and photometric observations of nova V5584 Sgr taken during the first 12 d following its discovery on Oct. 26.439 UT2009. The evolution of the spectra is shown from the initial P Cygni phase to an emission line phase. The prominent carbon lines seen in the JHK spectra closely match those observed in an Fe II class nova outburst. The spectra show first-overtone CO bands in emission between 2.29-2.40 μm. By examining WISE and other publicly available data, we show that the nova underwent a pronounced dust formation phase between February- April 2010.展开更多
SGR J1745-2900 is a magnetar near the Galactic center. X-ray observations of this source found a decreasing X-ray luminosity accompanied by an enhanced spindown rate. This negative correlation between X-ray luminosity...SGR J1745-2900 is a magnetar near the Galactic center. X-ray observations of this source found a decreasing X-ray luminosity accompanied by an enhanced spindown rate. This negative correlation between X-ray luminosity and spindown rate is hard to understand. The wind braking model of magnetars is employed to explain this puzzling spindown behavior. During the release of magnetic energy of magnetars, a system of particles may be generated. Some of these particles remain trapped in the magnetosphere and may contribute to the X-ray luminosity. The rest of the particles can flow out and take away the rotational energy of the central neutron star. A smaller polar cap angle will cause the decrease of X-ray luminosity and enhanced spindown rate of SGR J1745-2900. This magnetar is shortly expected to have a maximum spindown rate.展开更多
Tanzania is one of the countries in Africa that has engaged in the projects for construction of the electrified Standard Gauge Railway (SGR). However, lack of integration of transportation and land-use planning threat...Tanzania is one of the countries in Africa that has engaged in the projects for construction of the electrified Standard Gauge Railway (SGR). However, lack of integration of transportation and land-use planning threatens economic sustainability of the SGR project. This study was carried out for the purpose of finding-out how transportation can be integrated with land-use planning for economic sustainability of the project. The study was carried-out by using qualitative research approach through demonstration as case study. Findings show that construction of the SGR is not integrated with land-use planning around the stations and along the SGR corridor. It is concluded that economic sustainability of the SGR projects can be achieved by integration of transport and land-use planning. As demonstrated, it is recommended to deliberate for integration of transportation and land-use planning in the SGR projects of which the prime land within Transit Stations can be efficiently used by using Transit Oriented Development and secure more land for production activities around the Transit Stations and along the SGR corridor.展开更多
基金funded by the Department of Space, Government of India
文摘We present near-infrared spectroscopic and photometric observations of nova V5584 Sgr taken during the first 12 d following its discovery on Oct. 26.439 UT2009. The evolution of the spectra is shown from the initial P Cygni phase to an emission line phase. The prominent carbon lines seen in the JHK spectra closely match those observed in an Fe II class nova outburst. The spectra show first-overtone CO bands in emission between 2.29-2.40 μm. By examining WISE and other publicly available data, we show that the nova underwent a pronounced dust formation phase between February- April 2010.
基金supported by the Xinjiang Bairen projectthe National Natural Science Foundation of China (NSFC, 11103021)+2 种基金West Light Foundation of CAS (LHXZ201201)Youth Innovation Promotion Association of CASthe National Basic Research Program of China (973 Program, 2015CB857100)
文摘SGR J1745-2900 is a magnetar near the Galactic center. X-ray observations of this source found a decreasing X-ray luminosity accompanied by an enhanced spindown rate. This negative correlation between X-ray luminosity and spindown rate is hard to understand. The wind braking model of magnetars is employed to explain this puzzling spindown behavior. During the release of magnetic energy of magnetars, a system of particles may be generated. Some of these particles remain trapped in the magnetosphere and may contribute to the X-ray luminosity. The rest of the particles can flow out and take away the rotational energy of the central neutron star. A smaller polar cap angle will cause the decrease of X-ray luminosity and enhanced spindown rate of SGR J1745-2900. This magnetar is shortly expected to have a maximum spindown rate.
文摘Tanzania is one of the countries in Africa that has engaged in the projects for construction of the electrified Standard Gauge Railway (SGR). However, lack of integration of transportation and land-use planning threatens economic sustainability of the SGR project. This study was carried out for the purpose of finding-out how transportation can be integrated with land-use planning for economic sustainability of the project. The study was carried-out by using qualitative research approach through demonstration as case study. Findings show that construction of the SGR is not integrated with land-use planning around the stations and along the SGR corridor. It is concluded that economic sustainability of the SGR projects can be achieved by integration of transport and land-use planning. As demonstrated, it is recommended to deliberate for integration of transportation and land-use planning in the SGR projects of which the prime land within Transit Stations can be efficiently used by using Transit Oriented Development and secure more land for production activities around the Transit Stations and along the SGR corridor.
