Supported by the National Natural Science Foundation of China.Acknowledgements We thank our partner group in the Max-Planck-Intitut fur Radioastronomie for the 6cm system mounted at the Nanshan 25 m t
In this second paper of our. series, we estimate the age of 41 star clusters,which were detected by Melnick & D'odorico in the nearby spiral galaxy M33, by
Intraday polarization angle swings of ~180° observed in two sources (QSO 0917+624 and QSO 1150+812) are discussed in the framework of refractive interstella
The observations with Swift X-ray telescope (XRT) challenge the conventional gamma-ray burst model in many aspects. The XRT light curves are generally composed