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Steven Gibson

G A L F A. Steven Gibson. GALFA Survey Family. 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.

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Steven Gibson

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  1. G A L F A Steven Gibson AUSAC Meeting · March 17&18, 2008

  2. GALFA Survey Family • 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. AUSAC Meeting · March 17&18, 2008

  3. Galactic Structure Chemical Abundances Warm Diffuse ISM Survey |b| < 5o, 2000 h 300s int; co-add lines Start June, PALFA/ZOA RRL Plane Survey a2064 PI: Yervant Terzian Terzian et al. AUSAC Meeting · March 17&18, 2008

  4. RRL a-Lines in 300 MHz ALFA Bandpass AUSAC Meeting · March 17&18, 2008

  5. RRL Observing Strategy • Commensal with PALFA + ZOA • Share 300 MHz pDev spectrum with ZOA; 5 km/s channels (H + He lines; narrower C in followup) • Observe 12 a-lines in band & combine for S/N • 4.6min/pointing; 3 points at same (AZ, ZA) for ON-OFF comparison (RA sep: 1.15o cos d) • Sparse PALFA pointing grid (figure); fill in later • PALFA has already done most of |b| < 1o sparsely; do 2nd pass on wider alt. grid points for RRL/ZOA AUSAC Meeting · March 17&18, 2008

  6. RRL (PALFA) Pointing Grid • 5min/point • sparse grid; fill in later • ½ S/N in white points • each color observed on different night; OFF pos on same P. Freire AUSAC Meeting · March 17&18, 2008

  7. The G-ALFAContinuum Transit Survey (GALFACTS) • Spectropolarimetric survey of entire Arecibo Sky (-0.8o < d < +37.8o = 12,734 deg2 in 1500 h) • 8192 channels over a bandwidth of 300 MHz for RM coverage and RFI excision (spectrometer being built) • 500 μJy ~ 5σ polarized flux sensitivity • fast meridian scanning : 2 degrees / min • awaiting pDev data translation software, airport radar RFI solution (signal path filter or other fix) • PI: Russ Taylor (www.ras.ucalgary.ca/GALFACTS) AUSAC Meeting · March 17&18, 2008

  8. Mapping Technique: ZA Nodding + AZ Wagging Tracks after several passes ALFA beams These are woven together to form a map. AUSAC Meeting · March 17&18, 2008

  9. Full Stokes Multibeam CLEAN Stokes I Dirty Image Multibeam Clean Image S. Guram MSc Thesis U. Calgary NVSS Comparison (1/4 beam) AUSAC Meeting · March 17&18, 2008

  10. Perseus ISM: Polarized Intensity Taylor, Salter, et al. AUSAC Meeting · March 17&18, 2008

  11. Magnetic Fields from Polarimetry • A foreground magnetized plasma changes the • polarization position angle Q of background • polarized emission via Faraday Rotation: • where the Rotation Measure is given by PSR B1154-62 (Gaensler et al 1998) background synchrotron emission observer (from diffuse or compact source) Faraday screen C. Bredeson AUSAC Meeting · March 17&18, 2008

  12. Global Galactic B-Field Structure • Faraday Rotation Measures toward point sources • Pathfinder project for SKA ``origin and evolution of cosmic magnetism’’ initiative (GALFA can probe ~104 sightlines; SKA will get ~107) • Milky Way – thorough sampling of arm pattern in plane and at higher latitudes, where role of field is largely unknown • Nearby Galaxies – map global field, determine open vs. closed geometry Milky Way (J. Brown) M51 (Fletcher & Beck 2004) AUSAC Meeting · March 17&18, 2008

  13. ISM Magnetic Field Structure • Diffuse Faraday Screens • Turbulence + Power Spectra • Discrete Objects • SNRs • HII Regions • Molecular Clouds & PDRs Gaensler et al. (2001) Haverkorn et al. (2003) A. R. Taylor AUSAC Meeting · March 17&18, 2008

  14. Polarized Cosmic Background COBE • Planck requires low-frequency constraints on Galactic synchrotron foreground to measure polarized cosmic background correctly. High frequency resolution is needed to unwrap and remove Faraday rotations in the foreground for an accurate polarization measurement. • Planck will provide dust polarization maps to compare with ISM B-field radio data. These trace orthogonal field components and are thus highly complementary. Planck AUSAC Meeting · March 17&18, 2008

  15. GALFACTS Precursor vs. Effelsberg ALFA beam0 Stokes I Effelsberg ALFA beam0 Stokes Q Effelsberg Position Angle: PA = 0.5 * atan (U/Q) Rotation Measure: RM = dPA / l2 AUSAC Meeting · March 17&18, 2008

  16. Taylor et al. Multi- wavelength portrait of the Perseus Molecular Cloud region. ~1% of the GALFACTS+ TOGS2 survey area! Knee et al. AUSAC Meeting · March 17&18, 2008

  17. I-GALFA Arecibo Sky Coverage (i.e. GALFACTS/TOGS2 Area) AUSAC Meeting · March 17&18, 2008

  18. I-GALFA Survey: 2008-9 I-GALFA Plane H I Survey VGPS SGPS CGPS 10 x IGPS sensitivity, 4 x velocity resolution AUSAC Meeting · March 17&18, 2008

  19. GALFA H I Observations GALSPECT Pointing Record as of 2008 March 14 GALSPECT has 8192 channels over 7.14 MHz => 0.18 km/s per channel, +/- 750 km/s coverage AUSAC Meeting · March 17&18, 2008

  20. GALFA H I Projects (Trms ~ 0.25 K) (start May 3) PRECURSOR IGALFA/ZOA/ GALFACTS2 (78%) PERSEUS 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 a2048/2059 a2130/2124 a2010/2059 ALFALFA/TOGS1 AGES/TOGS1 GALFACTS/TOGS2 (56%) (16%) (start ASAP) (Trms ~ 0.15 K) (Trms ~ 0.04 K) (Trms ~ 0.35 K) AUSAC Meeting · March 17&18, 2008

  21. GALFA H I : 8.5o Atlas Tile Cubes Width = 512 pixels * 1.0' = 8.53o = 152.84 * 3.35' beam; 32’ overlaps 4 bytes/pix * 8192 chan = 8 GB/tile cube; grid of 45 x 5 tiles = 1.8 TB (prelim: 2 bytes/pix * 2048 chan = 1 GB/tile cube * 2 (narrow & wide) AUSAC Meeting · March 17&18, 2008

  22. TOGS H I (in progress) Fall Data from 2005 + 2006 Declination Right Ascension AUSAC Meeting · March 17&18, 2008

  23. IRAS 100mm dust emission Similar structure as HI! Declination Right Ascension AUSAC Meeting · March 17&18, 2008

  24. MBM 53-55 H I “Shell” IRIS Dust + CO Contours GALFA HI + Velocity Colors HI gives IRAS velocities; study HI-H2 transition (Gibson et al.) AUSAC Meeting · March 17&18, 2008 Galactic Shells: GALFA peak brightness temperature HI map (left) and IRIS 100 micron thermal dust emission (right) from the nearby molecular cloud complex MBM 53-55 (e.g., Magnani et al. 1985; Yamamoto et al. 2003), which is thought to be part of an expanding shell (Gir et al. 1994). The rich detail provided by GALFA enables direct comparisons between the datasets and provides information on the HI content, environment and kinematics of the shell. This work is to be published by S. J. Gibson et al.

  25. TOGS H I (in progress) Spring Data from 2005 + 2006 Declination Right Ascension AUSAC Meeting · March 17&18, 2008

  26. Leo Cold Cloud: GALFA HI image of an extremely cold (17 K) and nearby (< 40 pc) CNM cloud in our Galaxy's ISM (Meyer et al. 2006). Color rep-resents LSR velocity and bright-ness represents hydrogen column density. Because of its location within the local hot bubble, this cloud makes a very interesting laboratory for the study of the CNM and the CNM/HIM interface. A program comparing the 21-cm observations to infrared dust emission and optical and UV stellar absorption is underway. This work is to be published by J. E. G. Peek et al. AUSAC Meeting · March 17&18, 2008

  27. Needles: This image shows bundles of very fine (~5’) filamentary features at high galactic latitude (b > 80). These features, discovered by GALFA, are highly correlated to starlight polarization (red lines), indicating magnetic fields along their length. In addition, the angle of both the magnetic fields and the filament bundles is coincident with the angle of the local spiral arm. We find these 'filament bundles' throughout the diffuse ISM, indicating a new technique for finding the orientation of magnetic fields. This work is to be published by J. E. G. Peek et al. AUSAC Meeting · March 17&18, 2008

  28. Very High-Velocity Clouds (VHVCs): GALFA reveals the detailed structure of VHVCs in the halo and can be used to probe the diffuse halo medium through fingers extending off the sides of the cloud and head-tail clouds (e.g. Peek et al. 2007; Stanimirovic et al. 2006). This work is to be published by J. Peek et al. and J. Grcevich et al. AUSAC Meeting · March 17&18, 2008

  29. Magellanic Stream: The HI velocity field of the Magellanic System from the Parkes telescope (left; 15.5’ resolution; Putman et al. 2003) and the tip of the Magellanic Stream as observed by GALFA (right). The GALFA data reveal four coherent 10-15 degree long filaments that differ in morphology and velocity structure and may have different origins/ages. Numerous small clouds with high negative velocities are also evident. Some of these clouds show evidence for a multiphase medium and may result from spatial fragmentation of the Stream due to thermal instability. This work is to be published by S. Stanimirovic et al. AUSAC Meeting · March 17&18, 2008

  30. M33: A Local Group galaxy as revealed by GALFA. What was traditionally thought to be a quiescent galaxy shows clear evidence for either tidal/ram pressure disruption and/or gas cloud accretion. This work is to be published by M. E. Putman et al. M33: Optical Photo by David Malin (Isaac Newton Telescope, IAC/RGO) AUSAC Meeting · March 17&18, 2008

  31. GALFA Summary • 3 Sub-Consortia (H I, CON, RRL) • Small GALFA-H I projects done. TOGS1 in progress; initial data cubes made; I-GALFA/ GALFACTS start in May. • GALFA-RRL/ZOA/PALFA start in June • Main GALFACTS start ASAP • All final GALFA datasets will be on NVO. • GALFA website:www.naic.edu/alfa/galfa AUSAC Meeting · March 17&18, 2008

  32. End AUSAC Meeting · March 17&18, 2008

  33. GALFA - H I Projects 56% Mar 17 16% Mar 17 78% Mar 17 start ASAP start May 3 AUSAC Meeting · March 17&18, 2008

  34. GALFACTS Data Pipeline Data products will be made public through the NVO. AUSAC Meeting · March 17&18, 2008

  35. GALFA-CON K R. Kothes Polarized Continuum Intensity: DRAO ST + Effelsberg 100m + DRAO 26m This is ``Faraday screen’’ structure in the Magneto-Ionic Medium. AUSAC Meeting · March 17&18, 2008

  36. AUSAC Meeting · March 17&18, 2008

  37. AUSAC Meeting · March 17&18, 2008

  38. AUSAC Meeting · March 17&18, 2008

  39. AUSAC Meeting · March 17&18, 2008

  40. GALFA-H I – E Pluribus Unum [Josh Peek] AUSAC Meeting · March 17&18, 2008

  41. Fine Structure in Perseus H I Lewis Knee et al. AUSAC Meeting · March 17&18, 2008

  42. Fine Structure in Perseus H I Lewis Knee et al. AUSAC Meeting · March 17&18, 2008

  43. Fine Structure in Perseus H I Lewis Knee et al. AUSAC Meeting · March 17&18, 2008

  44. High-Velocity Clouds in the Galactic Halo Josh Peek AUSAC Meeting · March 17&18, 2008

  45. Forbidden-Velocity Line Wings in the Galactic Disk Bon-Chul Koo AUSAC Meeting · March 17&18, 2008

  46. Narrow-Line H I Absorption and Molecular Clouds Marko Krco AUSAC Meeting · March 17&18, 2008

  47. Stuff to Talk About • GALFA Survey Groups (HI, CON, RRL) • Status of Survey Projects • HI • TOGS • Disk-Halo & other completed projects • I-GALFA • CON • GALFACTS Main + I-GALFA commensal (radar RFI) • RRL : PALFA/ZOA commensal (PDEV) • Science Results, Presentations, & Publications AUSAC Meeting · March 17&18, 2008

  48. New Images to Show • Partial Lambda & turnaround stuff? • GALFACTS newsletter figs – multibeam clean, Per map • RRL figure Yervant emailed in Dec/Jan? • TOGS tile layout and specifications • TOGS fall and spring local & HVC maps • TOGS poster images • Magellanic streamlets • M33 • Leo Cloud • MBM 53-55 • blah AUSAC Meeting · March 17&18, 2008

  49. Other RRL Figures • Sample 4’ continuum map of survey area? (indicate sensitivity if possible; whitepaper says H line in sources down to 0.5 Jy, but is this for actual PALFA survey this summer? Not clear – whitepaper says 300s in one place and 20m in another!) • Arecibo RRL Spectra (RRL whitepaper Figure 4, from 1978?? Is this useful?) • PALFA pointing grid with description of visit & ON-OFF strategy (RRL whitepaper Figure 9) • Note somewhere that high-res C obs will be followup rather than part of main survey AUSAC Meeting · March 17&18, 2008

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