Arecibo Station Report to EVN CBD Nov. 3-4, 2008 -------------------------------------------------- 1. Hardware Update: In June 2008, a cryogenically-cooled 327-MHz receiver was installedon the 305-m telescope, replacing the existing room-temperature receiver at that band. This is a native dual-linear polarization receiver with an average Tsys of ~ 95 K (for the colder part of the sky). The new receiver represents about a 30 K improvement in Tsys compared to the old receiver. The current system has two front-end filters of 50- and 30-MHz bandwidths centered at 327 MHz. 2. Personnel Update: In September 2007, Dr. Emmanuel Momjian moved from Arecibo to the EVLA of NRAO at Socorro. 3. EVN General Sessions : Arecibo participated in both the June and the October 2008 sessions of the EVN. Arecibo has also participated in HSA, eVLBI, Ultra-wide band VLBI, and single-dish baseband pulsar data recording (using the MK5A system). Details of some of these and other VLBI observations in the recent past follows: 1) On Monday, May 5th 2008, e-VLBI iwas performed with an array including Hartebeesthoek Radio Astronomy Observatory in S. Africa. Fringes were obtained at 32 Mbps, limited by HRAO's available data rate. This used the old ATM fibers in Puerto Rico. This was the first US-Africa e-VLBI. 2) Friday, May 9th, e-VLBI with the 6-m TIGO dish at Conception, Chile. This also used the old ATM fibers. This was the first North-South American e-VLBI fringes. 3) Ultra Wideband VLBI (UW-VLBI) test on Thursday, May 15th, between the GBT and AO, at 4 Gbps. Disc recording using DBE (Digital Backend) and 2 x Mk5B+ recorders on loan from Haystack. Ten seconds of data transferred via ftp to Haystack, and correlated there. In 10 sec, 1700:1 SNR fringe was obtained on a 122 mJy source, the most sensitive interferometric baseline yet obtained anywhere! 4) Saturday - Sunday, 17-18th May, "production" disc-recording VLBI at 4 Gbps. Data recorded for complete transits at AO of a number of gravitationally-lensed radio sources to search for the presence of weak central images to the total lensed images. Data successfully recorded, and was correlated at Haystack. The DBE and Mk5B+ systems have been returned to Haystack. 5) Tuesday, 20th May, e-VLBI test session with Westerbork, Onsala, Medicina, Cambridge, Torun, and Jodrell Bank, with the data correlated in real time at JIVE in the Netherlands. Successful sustained fringes at 128 and 256 Mbps from Arecibo. (Previous best was 105 Mbps.) Fringes were briefly obtained at 512 Mbps, but technical development seem needed to sustain this data rate. First usage of the new Centennial de PR fibers. (6) On Thursday, May 22nd, the 305-m Arecibo telescope of the National Astronomy & Ionosphere Center joined with other members of the EXPReS (Express Production Real-time e-VLBI Service) project in a live demonstration of the first ever real-time, electronic Very Long Baseline Interferometry (e-VLBI) observations that simultaneously used telescopes in North America, South America, Europe and Africa. This simulates a telescope almost 11,000 kilometers in diameter. The results were immediately transmitted to Bruges, Belgium, as part of a live demonstration at the TERENA (Trans-European Research and Education Networking Association) Networking Conference 2008. These observation of the quasar 3C454.3 and other targets marked a major milestone for Arecibo in its e-VLBI participation; the 256 Mega-bits per second (Mbps) rate at which the data was streamed from Puerto Rico to the central signal processor at JIVE (Joint Institute for VLBI in Europe) in the Netherlands was four times higher than Arecibo had previously achieved, and the Arecibo team believe that they have a further factor of two in hand given the new gigabit optical fiber links that were being used at the Observatory for the first time. Bandwidth was reserved via a Virtual Local Area Network (VLAN), with transcontinental coordination achieved between link providers and institutions along the signal path to JIVE. (7) On the 9th of September, we were able to demonstrate real-time fringes between Arecibo and several European EVN telescopes at a rate of 512Mb/s. This was made possible by improvements in the network connectivity from Puerto Rico to the mainland USA via the PRISANET gigabit infrastructure jointly developed by the University of Puerto Rico, Centennial of PR, and the AO, and a dedicated network path all the way from Arecibo to JIVE in The Netherlands.