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Imaging Bright Sources

Imaging Bright Sources. J1403-34. Taurus A. Pictor A. Hydra A. For A. 3C409 Cygnus A/X Gal Plane (Sun). Virgo A 3C273. 3C161. Cen A. J0408-65. J0444-28. X15 April 2011 : Bright Source Integration times (minutes). X15: Randall Wayth. CenA Left: MWA contours

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Imaging Bright Sources

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  1. Imaging Bright Sources

  2. J1403-34 Taurus A Pictor A Hydra A For A 3C409 Cygnus A/X Gal Plane (Sun) Virgo A 3C273 3C161 Cen A J0408-65 J0444-28

  3. X15 April 2011: Bright Source Integration times (minutes) X15: Randall Wayth

  4. CenA Left: MWA contours on ACTA+PKS image Right: MWA 115MHz image

  5. Centaurus A

  6. Pictor A Parkes Catalog

  7. Pictor A Parkes Catalog MWA Sources

  8. Briggs,… X11 data 2010

  9. Williams, Hewitt,… Dec 2010

  10. Confusion • 32T at low freq (~115MHz), Conf Lev ~ few tenths of Jy • Confusion Limit: no more than 1 Source in 20 Beams • is expected to be reliable • Confusion Level (rms): base fluctuation level • Rough scaling with Array Diameter and Frequency • ~ Fx Dy • with x ~ -1.4 to -2.1 (Ravi -1.4) • and y ~ -1 to -1.6 (Ravi -1) • infer “a few to 10’s” mJy for 3 km baselines @230 MHz

  11. LOFAR Continuum Imaging: sub-mJy noise, 105:1 dynamic range Region in 3C196 field Surface Brightness Sensitivity: for few arcsec Lofar Beam ~ same as for 32T beam w modest int-time (a beam which is matched to EoR study) ? To what extent is more resolution needed to isolate point source foregrounds ?

  12. Evolution and luminosity functions of sub-mJy radio sources Submitter: Colloquium Description: Speaker: Paolo Padovani (ESO-HQ) I present the evolutionary properties and luminosity functions of the radio sources belonging to the Chandra Deep Field South VLA survey, which reaches a flux density limit at 1.4 GHz of 42 microJy at the field center and redshift ~ 5. We use an unprecedented classification scheme based on radio, far- and near-IR, optical, and X-ray data to disentangle star-forming galaxies from active galactic nuclei (AGN) and radio-quiet from radio-loud AGN. We strengthen our previous result that star-forming galaxies become dominant only below 0.1 mJy. Radio-quiet AGN are confirmed to be an important class of sub-mJy sources, accounting for ~ 30% of the sample (and ~ 60% of all AGN). The sub-mJy radio sky turns out to be a complex mix of star-forming galaxies and radio-quiet AGN evolving at a similar, strong rate, non-evolving low-luminosity radio galaxies, and declining radio powerful (P > 3 x 10^24 W/Hz) AGN. Our results suggest that radio emission in radio-quiet AGN is closely related to star formation. In the plot are shown the number counts of the sub-mJy sources found in the VLA-CDFS observations. The total (black triangles) is split into the number counts for star-forming galaxies (green circles) and AGN (red squares). The latter are again split into radio-loud AGN (purple triangles) and radio-quiet AGN (blue circles).

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