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Chris Salter (NAIC – Arecibo)

GALFA & GALFACTS. GALFA-HI and GALFACTS (Courtesy: Steven Gibson). Chris Salter (NAIC – Arecibo). GALFA Sub-Consortia. H I Line ( GALFA-H I ) Continuum ( GALFA-CON = GALFACTS ) Radio Recombination Lines ( GALFA-RRL )

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Chris Salter (NAIC – Arecibo)

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  1. NAIC-AUSAC Meeting April 19 & 20, 2010 GALFA & GALFACTS GALFA-HI and GALFACTS (Courtesy: Steven Gibson) Chris Salter (NAIC – Arecibo)

  2. NAIC-AUSAC Meeting April 19 & 20, 2010 GALFA Sub-Consortia • H I Line (GALFA-HI) • 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.

  3. NAIC-AUSAC Meeting April 19 & 20, 2010 RRL Galactic-Plane Survey (PI: Yervant Terzian) • Galactic Structure • Chemical Abundances • Warm Diffuse ISM • HII Regions • Survey for |b| < 5o • 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 (Terzian & Lewis)

  4. NAIC-AUSAC Meeting April 19 & 20, 2010 GALFACTS (GALFA Continuum Transit Survey) (GALFACTS Pilot 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, Ip(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 (1h<RA<7h; 20°<δ<38°) observed Nov-Dec 2008. Now also observed at 327 MHz (Raja et al.) to provide finer resolution in RM for Faraday Tomography)

  5. NAIC-AUSAC Meeting April 19 & 20, 2010 Mapping Technique: ZA Nodding + AZ Wagging • 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 Tracks after several passes ALFA beams These are “woven” together to optimize zerolevels.

  6. NAIC-AUSAC Meeting April 19 & 20, 2010 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)

  7. NAIC-AUSAC Meeting April 19 & 20, 2010 GALFA-H I Observations GALFA-HI Pointing Record as of 2009 February 26 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

  8. NAIC-AUSAC Meeting April 19 & 20, 2010 GALFA H I Projects (Trms ~ 0.25 K)‏ PRECURSOR PERSEUS I-GALFA/ZOA/ GALFACTS2 a1943 HALO CLOUDS MBW/ZOA a2174/2294 DISK- HALO a2056/2051 a2186/2144/2390 OUTER HALO HIGH-LAT TURBULENCE a2034 a2060 WINGS TAURUS SHELL a2055 a2004 a2172 a2221 a2050 a2172 a2011 a2187 a2222 a2011 a2032 HIGH-LAT CLOUDS WATER FALL a2147 TRUE FIL TIP MAG STREAM GEM OB1 a2220 COLD CLOUD a2130/2124 a2010/2059 a2048/2059 GALFACTS/TOGS2 ALFALFA/TOGS1 AGES/TOGS1 (Trms ~ 0.35 K)‏ (Trms ~ 0.15 K)‏ (Trms ~ 0.04 K)‏

  9. NAIC-AUSAC Meeting April 19 & 20, 2010 I-GALFA Survey: 2008-9 I-GALFA Plane H I Survey VGPS SGPS CGPS 10 x IGPS sensitivity, 4 x velocity resolution

  10. NAIC-AUSAC Meeting April 19 & 20, 2010 I-GALFA (low-b Galactic Center Quadrant) (PI’s: Steven Gibson & Bon Chul Koo) Cold HI Absorption in Molecular Clouds Cold HI Emission at Higher Latitudes • Over 50% completed in 2008 • Full completion expected during 2009 • Commensal with GALFACTS2 Disc-Halo Interface

  11. NAIC-AUSAC Meeting April 19 & 20, 2010 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 108 Mo dark halo?

  12. NAIC-AUSAC Meeting April 19 & 20, 2010 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!

  13. NAIC-AUSAC Meeting April 19 & 20, 2010 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 TB ≈ 10K. • Upper limits on OH emission from Arecibo.

  14. NAIC-AUSAC Meeting April 19 & 20, 2010 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

  15. NAIC-AUSAC Meeting April 19 & 20, 2010 End

  16. NAIC-AUSAC Meeting April 19 & 20, 2010 GALFA - H I Projects 56% Mar 17 16% Mar 17 78% Mar 17 start ASAP start May 3

  17. NAIC-AUSAC Meeting April 19 & 20, 2010 Full-Stokes Multibeam CLEAN Stokes I Dirty Image Multibeam Clean Image (HPBW=3.5°) (S. Guram, MSc Thesis, U. Calgary) NVSS Comparison (HPBW=0.7°)

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