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AUSAC Meeting · March 9 & 10, 2009 Chris Salter (NAIC – Arecibo) The GALFA Consortium GALFA-HI and GALFACTS (Courtesy: Steven Gibson)
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AUSAC Meeting · March 9 & 10, 2009 GALFA Sub-Consortia H I Line (GALFA-H I ) Continuum (GALFA-CON = GALFACTS) Radio Recombination Lines (GALFA-RRL) Each GALFA sub-consortium has its own membership and internal organization. All GALFA data will be made public through the National Virtual Observatory.
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AUSAC Meeting · March 9 & 10, 2009 RRL Galactic-Plane Survey Galactic Structure Chemical Abundances Warm Diffuse ISM HII Regions Survey for |b| < 5 o Integration time of 300s Commensal with PALFA & ZoA projects Share a “Mock spectrometer” database with ZoA (Δv≈4 kms -1 ) Record H163α − H174α, plus He & C α-lines and H β-lines Co-add transitions to increase signal-to-noise “Leap-Frog” Pointing to provide ON/OFFs (PI: Yervant Terzian) (Terzian & Lewis)
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AUSAC Meeting · March 9 & 10, 2009 GALFACTS (GALFA Continuum Transit Survey) Full-Stokes, all-Arecibo-sky, continuum survey. Employs meridian NODding scans with subsequent “multi-beam” basket- weaving to optimize zero-levels. Bandwidth = 300 MHz → Faraday tomography, I p (x, y, RM). Use “winking cal” for best possible calibration. Use of an original multi-beam CLEAN. Calibration run in Oct 2008 was first scheduled observations with Mock spectrometers. First GALFACTS region (1 h <RA<7 h ; 20°<δ<38°) observed Nov-Dec 2008. (GALFACTS Pilot Survey) Now also observed at 327 MHz (Raja et al.) to provide finer resolution in RM for Faraday Tomography)
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AUSAC Meeting · March 9 & 10, 2009 Mapping Technique: ZA Nodding + AZ Wagging ALFA beams Tracks after several passes These are “woven” together to optimize zerolevels. P.I.: Russ Taylor Web Page: www.ucalgary.ca/ras/GALFACTS 14400 channels over 300-MHz bandwidth with “Mock spectrometer” Brightness sensitivity: rms~100 μJy/bm Meridian scanning speed ~1.5° per sec CIMA “Smart Basket-weaving” used
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AUSAC Meeting · March 9 & 10, 2009 GALFACTS (continued) Catalog of Poln. Percentage, Position Angle & RM for 50,000 sources → Galactic Magnetic Field Studies. Thermal-nonthermal separation of low- b Galactic continuum emission. Provide thermal brightnesses for use by GALFA-RRL. Studies of discrete Galactic radio sources (e.g. SNRs & HII regions). Studies of high-b Galactic Loops. Foreground removal for EoR and Planck full-Stokes CMB studies. GALFA-HI TOG2 commensal project. First GALFACTS look at the Galactic Center quadrant via commensal observations with I-GALFA. (GALFACTS precursor imaging of the Perseus Molecular Cloud region)
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AUSAC Meeting · March 9 & 10, 2009 GALFA-HI Pointing Record as of 2008 March 14 GALSPECT has 8192 channels over 7.14 MHz → 0.18 km/s/channel, and ± 750 km/s total coverage GALFA-H I Observations GALFA-HI Pointing Record as of 2009 February 26
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AUSAC Meeting · March 9 & 10, 2009 GALFA H I Projects a2186/2144/2390 a2048/2059a2010/2059 a2130/2124 a2056/2051 a2060 a2055 a2034 a1943 a2004 a2174/2294 a2221 ALFALFA/TOGS1AGES/TOGS1 GALFACTS/TOGS2 I-GALFA/ZOA/ GALFACTS2 DISK- HALO MBW/ZOA PERSEUS TAURUS HALO CLOUDS WINGS a2220 a2222a2187 a2050 a2011 a2172 a2147 a2032 TIP MAG STREAM GEM OB1 TRUE FIL SHELL HIGH-LAT CLOUDS HIGH-LAT TURBULENCE WATER FALL OUTER HALO PRECURSOR COLD CLOUD (T rms ~ 0.25 K) (T rms ~ 0.15 K)(T rms ~ 0.04 K) (T rms ~ 0.35 K)
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AUSAC Meeting · March 9 & 10, 2009 CGPS VGPS SGPS I-GALFA Plane H I Survey 10 x IGPS sensitivity, 4 x velocity resolution I-GALFA Survey: 2008-9
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AUSAC Meeting · March 9 & 10, 2009 I-GALFA (low-b Galactic Center Quadrant) (PI’s: Steven Gibson & Bon Chul Koo) Over 50% completed in 2008 Full completion expected during 2009 Commensal with GALFACTS2 Cold HI Absorption in Molecular Clouds Cold HI Emission at Higher Latitudes Disc-Halo Interface
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AUSAC Meeting · March 9 & 10, 2009 HI near Globular Cluster, Pal 4 (PI: Jacco van Loon) Earlier LBW study detected HI in metal-poor cluster, M15 (van Loon et al, 2006). New stringent HI upper limits placed on clusters M3, NGC 5466 & Pal 13. Pal 4 is the 2nd most distant known globular cluster (D = 109 kpc). Large HI HVC discovered near Pal 4. Is it coincidence, gas stripped from the cluster by interaction with halo gas, or could both be situated in a 10 8 M o dark halo?
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AUSAC Meeting · March 9 & 10, 2009 An IVC Towards Abell 1367 (PI: Kevin Douglas) Commensal GALFA-HI observations with EALFA-AGES of 10 fields. The Abell 1367 field is at b ≈ 70°−75°, and reveals possibly cometary IVCs. Brightness temperatures of the features are only 1K or less!
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AUSAC Meeting · March 9 & 10, 2009 The Three Little Pigs (and a Friend) (PI: Josh Goldston Peek) Tiny clouds found at b ≈ 85°; Δθ ≈ 1'. VLA follow-up shows condensed cores, optically-thick, with T B ≈ 10K. Upper limits on OH emission from Arecibo.
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AUSAC Meeting · March 9 & 10, 2009 GALFA Summary Small GALFA-H I projects completed 3 Sub-Consortia (GALFA-H I, -CON, -RRL) TOGS1&2 in progress; data analysis on-going I-GALFA and GALFACTS in progress GALFA-RRL/ZOA/PALFA starting soon All final GALFA datasets will be on NVO GALFA website: www.naic.edu/alfa/galfa
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AUSAC Meeting · March 9 & 10, 2009 End
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AUSAC Meeting · March 9 & 10, 2009 GALFA - H I Projects 56% Mar 17 16% Mar 17 78% Mar 17 start ASAP start May 3
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AUSAC Meeting · March 9 & 10, 2009 Full-Stokes Multibeam CLEAN (S. Guram, MSc Thesis, U. Calgary) Stokes I Dirty Image Multibeam Clean Image (HPBW=3.5°) NVSS Comparison (HPBW=0.7°)
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