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Extragalactic Science

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Extragalactic Science. Jim Condon. Why Synthesis Imaging?. Angular resolution can be specified by the observer (to reduce “confusion,” match angular scales of the source or multiwavelength data -- but trade off surface-brightness sensitivity) Extremely accurate absolute astrometry - PowerPoint PPT Presentation
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Eleventh Synthesis Imaging Workshop Socorro, June 10-17, 2008 Extragalactic Science Jim Condon
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Page 1: Extragalactic Science

Eleventh Synthesis Imaging WorkshopSocorro, June 10-17, 2008

Extragalactic Science

Jim Condon

Page 2: Extragalactic Science

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

Why Synthesis Imaging?

Angular resolution can be specified by the observer (to reduce “confusion,” match angular scales of the source or multiwavelength data -- but trade off surface-brightness sensitivity)

Extremely accurate absolute astrometry (high angular resolution, clocks instead of rulers, no plane-parallel refraction)

High dynamic range via deconvolution and self-calibration “fixing” telescope

High sensitivity via long integrations, suppression of “baseline” errors and RFI

(Figures from Brunthaler et al. 2005, Science, 307, 1440)

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

Extragalactic Science: The radio continuum sky at 45 arcsec resolution Where’s our Galaxy?

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

“It’s turtles all the way down”

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

Flux density versus luminosity of radio sources

• Evolution 10X in luminosity few nearby sources, <z> ~ 1

• “shell” L S• AGNs at high L, S• Star-forming galaxies

at low L, S

Page 6: Extragalactic Science

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

High Luminosity: Relativistic Jets and Lobes from AGN

Centaurus A atradio (purple), optical, and X-ray wavelengths

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

Jet Energy via Radio Bubbles in Hot Cluster Gas

6 X 1061 ergs ~ 3 X 107 solar masses X c2 (McNamara et al. 2005, Nature, 433, 45)

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

Resolution and Surface-brightness Sensitivity

Page 9: Extragalactic Science

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

Superluminal Motion in Compact Jets

Page 10: Extragalactic Science

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

Resolving the circumnuclear disk in NGC 4258 and directly measuring the black-hole mass

NGC 4258

r

NGC 4258

Page 11: Extragalactic Science

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

Beating Confusion

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

NVSS (45 arcsec) grayscale under GB 300-ft (12 arcmin) contours

“RMS” confusionc 0.2 -0.7 2

where is in mJy/beam, is in GHz, and is in arcmin

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

Low Luminosity: AGN+Starbursts

= 5 arcsec = 23 mJy/beam(c ~ 1 mJy/beam)

Page 14: Extragalactic Science

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

Low Luminosity: Star-forming Galaxies

free-free

synchrotron

dust

Page 15: Extragalactic Science

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

SNe and GRBs

3-o

50o

cm 1nerg 105 E

≈×≈

Page 16: Extragalactic Science

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

VLBA/HSA Image of the Starburst Nuclei in Arp 220

Page 17: Extragalactic Science

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

Evolution of star formation

• Radio “Madau diagram”

• Free from dust extinction

Page 18: Extragalactic Science

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

Star Formation at High Redshift

Page 19: Extragalactic Science

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

Primordial Starbursts

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

Radio Spectral Lines: Cold Gas

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

Crash Forensics

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

EVLA and ALMA

• Continuous frequency coverage from 1 GHz to 50 GHz

• Detect CO at almost any redshift

• Study excitation of star-forming gas in distant galaxies

Page 23: Extragalactic Science

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

The Most Distant Quasar

• VLA image of CO (4-3) from the first known star formation– Redshifted

to 46 GHz

• Optical Image

• Artist’s conception of disk of molecules and dust

Walter et al. 2003

Page 24: Extragalactic Science

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

Geometric Distances, H0, and Dark Energy

PreliminaryProperties of UGC 3789 Maser Disk

R ~ 0.09 - 0.20 pc (0.40 - 0.87 mas)V ~ 750 - 450 km/sMbh ~ 1.2 x 107 Msun

a ~ 3.6 km s-1 yr-1 (mean value)

D ~ 51 Mpc (15%)H0 ~ 64 km s-1 Mpc-1

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Eleventh Synthesis Imaging Workshop, June 10-17, 2008

The End...

...NOT!


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