50 Years of Understanding Galactic Atomic Hydrogen with Parkes. Naomi McClure-Griffiths CSIRO Astronomy & Space Science

Transcription

1 50 Years of Understanding Galactic Atomic Hydrogen with Parkes Naomi McClure-Griffiths CSIRO Astronomy & Space Science

2 Outline Parkes surveys of Galactic HI Large-scale distribution of HI in the Milky Way Spiral structure: Then & Now Disk-halo interaction From the disk From the halo Galactic Centre: Then & Now Summary

3 Parkes Galactic HI surveys Galactic Plane Surveys: Galactic Centre: Kerr (1964, AJ, 69, 547) Galactic HI survey: Kerr & Vallak (1967), Kerr (1969), Kerr & Lindman (1970), Kerr & Knapp (1970), Lindman & Kerr (1970) Radhakrishnan, Goss, et al. (1972 various) HI absorption with interferometer Strong et al (1982) McClure-Griffiths et al (2005) All Sky Surveys HIPASS HVCs (Putman et al 2002) GASS (McClure-Griffiths et al 2009, Kalberla et al 2010) Frank Kerr ( )

4 Parkes role in the Galactic HI renaissance Putman et al (1998) H I studies of the Galaxy had reached a plateau by the 1970 s Limited by resolution with single dishes (~ ¼ deg GP - ½ deg all-sky) Interferometric focus Parkes to the rescue! Multibeam enabled fast sky coverage Techniques for combining ATCA + Parkes data for high angular resolution McClure-Griffiths et al (2003) McClure-Griffiths et al (2009)

5 All-Sky Surveys The multibeam receiver enabled all-sky surveys: HIPASS (HVCs) Velocity range: km/s to km/s Velocity resolution: 18 km/s GASS south of δ=+1º Velocity range: -400 km/ s to 500 km/s Velocity resolution: 1 km/s McClure-Griffiths et al., 2009, ApJS, 181, 398

6 The IGPS era of Galactic Plane HI data NH from LAB (Kalberla et al 2006) CGPS: Taylor et al (2003) VGPS: Stil et al (2006) SGPS: McClure-Grffiths et al (2005) International Galactic Plane Survey: ~1 K rms, 1 km/s spectral res, 2 arcmin angular res

7 Parkes 10 deg

8 ATCA Parkes 10 deg

9 ATCA Parkes 10 deg ATCA+Parkes

10 Galactic warps and flares Kerr (1969) from Kerr (1969), Hindman(1969), Henderson(1968) Levine, Blitz & Heiles (2006)

11 Galactic warps and flares Kerr (1969) from Kerr (1969), Hindman(1969), Henderson(1968) Levine, Blitz & Heiles (2006) Picture largely unchanged: Southern warp goes ~1 kpc below disk at R~15 kpc before rising back up

12 Measuring the rotation curve R = R0 sin(l) R = R0 sin(l) Image credit: NASA/JPL-Caltech/R. Hurt (SSC)

13 Measuring the rotation curve R = R0 sin(l) R = R0 sin(l) Image credit: NASA/JPL-Caltech/R. Hurt (SSC)

14 Measuring the rotation curve Inner Galaxy intensity Outer Galaxy R = R0 sin(l) terminal velocity velocity R = R0 sin(l) Image credit: NASA/JPL-Caltech/R. Hurt (SSC)

15 Wiggles & Bumps in Rotation Curves Kwee et al (1954): rotation curve of the inner Galaxy had bumps and wiggles Shane & Bieger-Smith (1966) showed that the HI profiles are dominated by kinematic effects Lin et al (1969) and many others showed that density wave theory could explain the bumps and wiggles Kwee, Muller & Westerhout (1954)

16 Wiggles & Bumps in Rotation Curves Kwee et al (1954): rotation curve of the inner Galaxy had bumps and wiggles Shane & Bieger-Smith (1966) showed that the HI profiles are dominated by kinematic effects Lin et al (1969) and many others showed that density wave theory could explain the bumps and wiggles Kerr (1964)

17 Rotation Curves McClure-Griffiths & Dickey (2007, 2012 in prep) Kerr (1964)

18 Rotation Θ/Θ0 = (R/R0) Curves McClure-Griffiths & Dickey (2007, 2012 in prep) Kerr (1964)

19 Rotation Θ/Θ0 = (R/R0) Curves McClure-Griffiths & Dickey (2007, 2012 in prep) Kerr (1964) Rotation curve traced with ~5 pc resolution, limits on peak-to-peak streaming motions of 10 km/s

20 Spiral Maps: Then Kerr 1969 Oort, Kerr, Westerhout (1958)

21 Spiral Maps: Then Assembled from: Kerr (1969a), Kerr et al (1976), Kerr 1969 Simonson et al (1976)

22 Spiral Maps: Now

23 Spiral Maps: Now A new spiral arm from Parkes + ATCA data HI is not the best way to map Milky Way spiral structure

24 Spiral Maps: Now A new spiral arm from Parkes + ATCA data HI is not the best way to map Milky Way spiral structure

25 Spiral Maps: Now A new spiral arm from Parkes + ATCA data HI is not the best way to map Milky Way spiral structure McClure- Griffiths et al (2004)

26 A view of GASS GASS movie -290 km/s to +360 km/s CSIRO. The Evolution of the Milky Way scale Tb=-0.1 to 20 K

27 Going up or coming down? Lower halo scattered with parsec scale HI clouds Discovered with GBT by Lockman (2002) Co-rotating with the disk gas up to ~1.5 kpc May contain up to 50% of the mass of the lower halo

28 The bits going up... ~2 kpc ~3.4 kpc Ophiucus superbubble (Pidopryhora et al. 2007) HI (purple), Ha (green) McClure-Griffiths et al. (2006)

29 Clouds, Cloudlets and Galactic Structure Halo much more structured near active parts of the Galaxy 3:1 clouds in 1st vs 4th quadrants 2:1 scale height of clouds 1st vs 4th quadrants Ford, Lockman & McClure-Griffiths (2010)

30 Clouds, Cloudlets and Galactic Structure Halo much more structured near active parts of the Galaxy 3:1 clouds in 1st vs 4th quadrants 2:1 scale height of clouds 1st vs 4th quadrants Lower halo HI is populated by star formation activity in the disk Ford, Lockman & McClure-Griffiths (2010)

31 Galactic All Sky Survey GASS: McClure-Griffiths et al. (2009)

32 Parkes and High Velocity Clouds Positive velocities Negative velocities Putman et al (2002)

33 Parkes and High Velocity Clouds Positive velocities Negative velocities Putman et al (2002) HVCs both Galactic and extragalactic, Southern HVC sky dominated by Magellanic gas

34 Galactic Centre McClure-Griffiths et al (2011) Kerr & Vallek (1967)

35 Galactic Centre McClure-Griffiths et al (2011) Kerr & Vallek (1967)

36 McClure- Griffiths et al (2011)

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38 Summary Parkes has had a non-stop ride with Galactic HI Kerr and collaborators led the way from 1961 Rotation curves Maps of spiral structure Description of the Galactic warp Galactic Centre maps Parkes multibeam gave all-sky coverage from 1997 onwards High velocity gas (including Magellanic) Outflowing gas Parkes combined with the ATCA from 1999 onwards New spiral arm New rotation curves New images of the Galactic Centre It s not over yet - stay tuned for Parkes + ASKAP!

39 Happy 50th Birthday Parkes!