The newly discovered z=5.8 quasar SDSSp J104433.04-012502.2 was recently detected in X-rays and found to be extremely X-ray weak. Here we present the hardness ratio analysis of the XMM-Newton observation. We consider various models to explain the detection in the soft X-ray band and non-detection in the hard band, together with its X-ray weakness. We show that the source may have a steep power-...

We present a result of the quasar CO(J = 6− 5) observations of SDSSp J104433.04−012502.2 at z = 5.8. Ten-days observations with the Nobeyama Millimeter Array yielded an rms noise level of ∼ 2.1 mJy beam in a frequency range from 101.28 GHz to 101.99 GHz at a velocity resolution of 120 km s. No significant clear emission line was detected in the observed field and frequency range. Three sigma up...

The survivable network design problem (SNDP) is to construct a minimum-cost subgraph satisfying certain given edge-connectivity requirements. The first polynomial-t ime approximation algorithm was given by Williamson et al. (Combinatorica 15 (1995) 435454) . This paper gives an improved version that is more efficient. Consider a graph of n vertices and connectivity requirements that are at most...

We present new images of the Supernova Remnant (SNR) G127.1+0.5 (R5), based on the 408 MHz and 1420 MHz continuum emission and the HI-line emission data of the Canadian Galactic Plane Survey (CGPS). The radio spectrum of the central compact source (0125+628) is analyzed in the range 178 MHz–8.7 GHz, indicating a flat spectrum with synchrotron self-absorption below 800 MHz. The SNR’s flux densit...