The z=5.8 Quasar SDSSp J1044-0125: A Peek at Quasar Evolution?

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-law slope, with an absorber partially covering the continuum. This may be X-ray evidence to support the argument of Mathur (2000) that narrow line Seyfert 1 galaxies, which show steep power-law slopes, might be the low redshift, low luminosity analogues of the high redshift quasars. Heavily shrouded and steep X-ray spectrum quasars may indeed represent the early stages of quasar evolution (Mathur 2000, Fabian 1999) and SDSSp J104433.04-012502.2 is possibly giving us a first glimpse of the physical evolution of quasar properties.Comment: To appear in A

Estimating commitment in a digital market place environment

The future generation of mobile communication shall be a convergence of mobile telephony and information systems which promises to change people's lives by enabling them to access information when, where and how they want. It presents opportunities to offer multimedia applications and services that meet end-toend service requirements. The Digital Marketplace framework will enable users to have separate contracts for different services on a per call basis. In order for such a framework to function appropriately, there has to be some means for the network operator to know in advance if its network will be able to support the user requirements. This paper discusses the methods by which the network operator will be able to determine if the system will be able to support another user of a certain service class and therefore negotiate parameters like commitment, QoS and the associated cost for providing the service, thus making the Digital Marketplace wor