1. 2006 AUSAC Meeting VLBI/eVLBI with the 305-m Arecibo Radio Telescope Arecibo VLBI Group Chris Salter Tapasi Ghosh Emmanuel Momjian Arun Venkataraman (Jon Hagen)

2. 2006 AUSAC Meeting VLBI Operations 2005-6 Telescope proposals: 28 (10 HSA, 15 Global/EVN, 3 e-VLBI) Observing Runs : 40 (14 HSA, 18 Global/EVN, 5 eVLBI, 3 NME) Standard Operations at 1Gbit/s from Feb-2005 Operations at 327 MHz, L-, C-, and X-bands No. of VLBI runs: 2001=12, 2002=15, 2003=16, 2004=24, 2005=36. eVLBI in 2005-6 eVLBI continuum demonstrator on March 05 Sustained operations at 32 Mb/s (occasional fringes at 64Mb/s) Joined EXPReS Consortium (funded Oct. 05) Demonstration of eVLBI to E.C. Science Commissioner, July 05

3. 2006 AUSAC Meeting eVLBI Advantages No need for disks/tapes. Speed at which results are obtained. Target of Opportunity. Real-time monitor of Station reliability. Reduced manpower at VLBI station. No longer observing blind. Disadvantages Fear of single point failure. No multi-pass correlation. Loss of low bandwidth stations. Presently lower max bit rate than disks. Capital and recurring costs of links.

4. 2006 AUSAC Meeting Data Path to JIVE  PRISANET (PR) of the Arecibo Obs./UPR.  AMPATH (US) of Florida Intl. Univ.  Abilene (US) of Internet 2.  SURFnet (NL) of SURFnet BV. Data rate: 32 Mbps. DAR/Formatter MK5 JIVE in2net

5. 2006 AUSAC Meeting EXPReS Objectives: 1) Create production-level e-VLBI service. 2) Reliable telescope connection to the JIVE correlator via Internet. 3) Data flow of up to 16 Gb/s into correlator via infrastructure of trans-continental dimensions and capability of generating real-time cosmic radio source images. 4) Design and prototype hardware, software and data transport services to support future e-VLBI facilities with net data flows of hundreds of Gb/s.

6. 2006 AUSAC Meeting e-VLBI Plans & Possibilities Need to upgrade Mark-5 system (~$5k). –Faster CPU –Gb/s ethernet Present link from AO is shared OC-3 (155 Mb/s) –Cannot sustain > 32 Mb/s to JIVE In near term focus on optimizing OC-3 link –Reserve bandwidth (at a cost) –More efficient protocols (TCP variants) Update observatory switch to be OC-12 (655 MB/s) compatible (~$20k). If available, OC-12 may cost $200k/month at present. Cheaper fiber expected after communication link to St. Croix established.

7. 2006 AUSAC Meeting High-SensitivityVLBI Science - I D. Hough (Trinity U. Tx.) & C. Aars (Angelo State U, Tx) Search for pc-scale jets in extremely faint FRII Radio Galaxy Nuclei. RMS noise =10  Jy/beam Peak flux=1.5 mJy (3C34), 4 mJy (3C132)

8. 2006 AUSAC Meeting High-Sensitivity VLBI Science - II Extragalactic Supernova Remnants SN2001em 18-cm eVLBI; Garrett et al. 3.5-cm HAS; Bietenholz & Bartel Odd SN thought possibly to be an off-axis GRB. VLBI shows this to be unlikely as source is not Expanding relativistically. SN1979C 6-cm HAS; Bartel & Beitenholz Shell structure revealed in this SNR for The first time. Peak brightness = 230  Jy/beam

9. 2006 AUSAC Meeting High-Sensitivity VLBI Science - III Nuclei of ARP 220 18-cm Global; Lonsdale et al. RMS=5.5  Jy /beam; Linear resolution ~ 1 pc Detect 49 point sources with 60  Jy < S < 1.2 mJy. Four of the sources are new, implying an SN- rate of 4  2 per year in ARP220. 6-cm 1Gbps EVN; Parra & Conway Observed Arp220 for 10 min (rms=30  Jy/beam) as part of 100 source ULIRG sample. First two 5-GHz detections in Arp220, neither coincident with 18-cm compact sources. Western detection confirmed with VLBA archive data & 18-cm ToO data, believed to be ultra-luminous SNs similar to SN1986J.

10. 2006 AUSAC Meeting Current & Near-Future Activities Continue support of HSA and Global/EVN arrays. For 2005, five e-VLBI tests scheduled, starting 16 March. Purchase more Mark-5 disc packs. Offer has been made to host the next EVN Technical Operation Group (TOG) meeting of EVN at Arecibo. When available, upgrade to Mark-5B. Explore options for a supplementary antenna to improve efficiency of phase-referenced VLBI, etc.

11. 2006 AUSAC Meeting Timeline The post-upgrade 305 m Arecibo radio telescope became a part of the VLBI network in late 1990s for the HALCA mission of the Japanese VSOP project (S2 recorder). In 2001, Arecibo acquired its hybrid tape-based VLBA-Mark IV (VLBA4) recording system. In 2004, the Observatory procured its Mark 5A disk-based recording system, enabling the largest telescope in the world to become electronically connected to other radio telescopes in the world in real time via eVLBI observations.