1. The GALFA Consortium Chris Salter (NAIC – Arecibo)
GALFA-HI and GALFACTS
(Courtesy: Steven Gibson)
Chris Salter (NAIC – Arecibo)
AUSAC Meeting · March 9 & 10, 2009

2. 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.
AUSAC Meeting · March 9 & 10, 2009

3. RRL Galactic-Plane Survey
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
(PI: Yervant Terzian)
Galactic Structure
Chemical Abundances
Warm Diffuse ISM
HII Regions
(Terzian & Lewis)
AUSAC Meeting · March 9 & 10, 2009

4. 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)
AUSAC Meeting · March 9 & 10, 2009

5. Mapping Technique: ZA Nodding + AZ Wagging
P.I.: Russ Taylor
Web Page:
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.
AUSAC Meeting · March 9 & 10, 2009

6. 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)
AUSAC Meeting · March 9 & 10, 2009

7. 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
AUSAC Meeting · March 9 & 10, 2009

8. GALFA H I Projects (Trms ~ 0.25 K)‏ PRECURSOR I-GALFA/ZOA/ GALFACTS2
PERSEUS
a1943
HALO
CLOUDS
DISK-
HALO
MBW/ZOA
a2174/2294
a2056/2051
a2186/2144/2390
a2034
OUTER
HALO
HIGH-LAT
TURBULENCE
a2060
WINGS
TAURUS
SHELL
a2055
a2004
a2172
a2221
a2050
a2172
a2011
a2187
a2011
a2222
a2032
HIGH-LAT
CLOUDS
TRUE
FIL
a2147
WATER
FALL
TIP MAG
STREAM
a2220
GEM
OB1
COLD
CLOUD
a2130/2124
a2010/2059
a2048/2059
GALFACTS/TOGS2
ALFALFA/TOGS1
AGES/TOGS1
(Trms ~ 0.15 K)‏
(Trms ~ 0.04 K)‏
(Trms ~ 0.35 K)‏
AUSAC Meeting · March 9 & 10, 2009

9. 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 9 & 10, 2009

10. 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
AUSAC Meeting · March 9 & 10, 2009

11. 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?
AUSAC Meeting · March 9 & 10, 2009

12. 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!
AUSAC Meeting · March 9 & 10, 2009

13. 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.
AUSAC Meeting · March 9 & 10, 2009

14. 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:
AUSAC Meeting · March 9 & 10, 2009

15. End
AUSAC Meeting · March 9 & 10, 2009

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

17. 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°)
AUSAC Meeting · March 9 & 10, 2009