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AUSAC Meeting · March 9 & 10, 2009 Chris Salter (NAIC – Arecibo) G A L F A.

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Presentation on theme: "AUSAC Meeting · March 9 & 10, 2009 Chris Salter (NAIC – Arecibo) G A L F A."— Presentation transcript:

1 AUSAC Meeting · March 9 & 10, 2009 Chris Salter (NAIC – Arecibo) G A L F A

2 AUSAC Meeting · March 9 & 10, 2009 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. All GALFA data will be made public through the National Virtual Observatory.

3 AUSAC Meeting · March 9 & 10, 2009 RRL Plane Survey Galactic Structure Chemical Abundances Warm Diffuse ISM Survey |b| < 5 o, 2000 h 300s int; co-add lines Start June, PALFA/ZOA Terzian et al. a2064 PI: Yervant Terzian

4 AUSAC Meeting · March 9 & 10, 2009 RRL  -Lines in 300 MHz ALFA Bandpass

5 AUSAC Meeting · March 9 & 10, 2009 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  -lines in band & combine for S/N 4.6min/pointing; 3 points at same (AZ, ZA) for ON-OFF comparison (RA sep: 1.15 o cos  )‏ Sparse PALFA pointing grid (figure); fill in later PALFA has already done most of |b| < 1 o sparsely; do 2 nd pass on wider alt. grid points for RRL/ZOA

6 AUSAC Meeting · March 9 & 10, 2009 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

7 AUSAC Meeting · March 9 & 10, 2009 The G-ALFA Continuum Transit Survey (GALFACTS)‏ Spectropolarimetric survey of entire Arecibo Sky (-0.8 o <  < +37.8 o = 12,734 deg 2 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 )‏

8 AUSAC Meeting · March 9 & 10, 2009 Mapping Technique: ZA Nodding + AZ Wagging ALFA beams Tracks after several passes These are woven together to form a map.

9 AUSAC Meeting · March 9 & 10, 2009 Full Stokes Multibeam CLEAN S. Guram MSc Thesis U. Calgary Stokes I Dirty Image Multibeam Clean Image NVSS Comparison (1/4 beam)‏

10 AUSAC Meeting · March 9 & 10, 2009 Perseus ISM: Polarized Intensity Taylor, Salter, et al.

11 AUSAC Meeting · March 9 & 10, 2009 Magnetic Fields from Polarimetry A foreground magnetized plasma changes the polarization position angle  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 Faraday screen C. Bredeson (from diffuse or compact source)‏

12 AUSAC Meeting · March 9 & 10, 2009 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 ~10 4 sightlines; SKA will get ~10 7 )‏ 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 M51 (Fletcher & Beck 2004)‏ Milky Way (J. Brown)‏

13 AUSAC Meeting · March 9 & 10, 2009 ISM Magnetic Field Structure Diffuse Faraday Screens Turbulence + Power Spectra Discrete Objects –SNRs –HII Regions –Molecular Clouds & PDRs Haverkorn et al. (2003)‏ Gaensler et al. (2001)‏ A. R. Taylor

14 AUSAC Meeting · March 9 & 10, 2009 Polarized Cosmic Background 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. COBE Planck

15 AUSAC Meeting · March 9 & 10, 2009 GALFACTS Precursor vs. Effelsberg Stokes Q Stokes I ALFA beam0 Effelsberg ALFA beam0 Rotation Measure: RM = dPA / 2 Position Angle: PA = 0.5 * atan (U/Q)‏ Effelsberg

16 AUSAC Meeting · March 9 & 10, 2009 Multi- wavelength portrait of the Perseus Molecular Cloud region. ~1% of the GALFACTS + TOGS2 survey area! Knee et al. Taylor et al.

17 AUSAC Meeting · March 9 & 10, 2009 Arecibo Sky Coverage (i.e. GALFACTS/TOGS2 Area)‏ I-GALFA

18 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

19 AUSAC Meeting · March 9 & 10, 2009 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 GALFA H I Observations

20 AUSAC Meeting · March 9 & 10, 2009 GALFA H I Projects a2186/2144/2390 a2048/2059 a2010/2059 a2130/2124 a2056/2051 a2060 a2055 a2034 a1943 a2004 a2174/2294 a2221 ALFALFA/TOGS1AGES/TOGS1GALFACTS/TOGS2 IGALFA/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 (78%)‏ (56%)‏(16%)‏ (start May 3)‏ (start ASAP)‏ (T rms ~ 0.25 K)‏ (T rms ~ 0.15 K)‏(T rms ~ 0.04 K)‏(T rms ~ 0.35 K)‏

21 AUSAC Meeting · March 9 & 10, 2009 GALFA H I : 8.5 o Atlas Tile Cubes Width = 512 pixels * 1.0' = 8.53 o = 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)‏

22 AUSAC Meeting · March 9 & 10, 2009 TOGS H I (in progress)‏ Right Ascension Declination Fall Data from 2005 + 2006

23 AUSAC Meeting · March 9 & 10, 2009 IRAS 100  m dust emission Right Ascension Declination Similar structure as HI!

24 AUSAC Meeting · March 9 & 10, 2009 MBM 53-55 H I “Shell” IRIS Dust + CO ContoursGALFA HI + Velocity Colors HI gives IRAS velocities; study HI-H 2 transition (Gibson et al.)‏ 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 AUSAC Meeting · March 9 & 10, 2009 TOGS H I (in progress)‏ Right Ascension Declination Spring Data from 2005 + 2006

26 AUSAC Meeting · March 9 & 10, 2009 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.

27 AUSAC Meeting · March 9 & 10, 2009 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.

28 AUSAC Meeting · March 9 & 10, 2009 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.

29 AUSAC Meeting · March 9 & 10, 2009 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.

30 AUSAC Meeting · March 9 & 10, 2009 M33: Optical Photo by David Malin (Isaac Newton Telescope, IAC/RGO)‏ 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.

31 AUSAC Meeting · March 9 & 10, 2009 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

32 AUSAC Meeting · March 9 & 10, 2009 End

33 AUSAC Meeting · March 9 & 10, 2009 GALFA - H I Projects 56% Mar 17 16% Mar 17 78% Mar 17 start ASAP start May 3

34 AUSAC Meeting · March 9 & 10, 2009 Data products will be made public through the NVO. GALFACTS Data Pipeline

35 AUSAC Meeting · March 9 & 10, 2009 Polarized Continuum Intensity: DRAO ST + Effelsberg 100m + DRAO 26m This is ``Faraday screen’’ structure in the Magneto-Ionic Medium. K R. Kothes GALFA-CON

36 AUSAC Meeting · March 9 & 10, 2009

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40 GALFA-H I – E Pluribus Unum [Josh Peek]

41 AUSAC Meeting · March 9 & 10, 2009 Fine Structure in Perseus H I Lewis Knee et al.

42 AUSAC Meeting · March 9 & 10, 2009 Fine Structure in Perseus H I Lewis Knee et al.

43 AUSAC Meeting · March 9 & 10, 2009 Fine Structure in Perseus H I Lewis Knee et al.

44 AUSAC Meeting · March 9 & 10, 2009 High-Velocity Clouds in the Galactic Halo Josh Peek

45 AUSAC Meeting · March 9 & 10, 2009 Forbidden-Velocity Line Wings in the Galactic Disk Bon-Chul Koo

46 AUSAC Meeting · March 9 & 10, 2009 Narrow-Line H I Absorption and Molecular Clouds Marko Krco

47 AUSAC Meeting · March 9 & 10, 2009 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

48 AUSAC Meeting · March 9 & 10, 2009 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

49 AUSAC Meeting · March 9 & 10, 2009 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


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