1 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
The µJy Sky and the Radio-FIR relation vs. z
2 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
Outline of Talk
1) µJy radio properties
2) Radio-FIR relation vs z
3) Implications, future directions
3 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
• G. Morrison (UH)• M. Pannella, V. Strazzullo, W-H. Wang (NRAO)• M. Polletta (Milan)• C. Lonsdale (NRAO)• A. Baker, Matt Klimek (Rutgers)• R. Ivison, A. Biggs (ROE)• D. Shupe (Herschel)• B. Wilkes (CFA)• R. Kilgard (Wesleyan)
Short List of Collaborators
4 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
SWIRE Deep Field: 1046+59
• Deepest existing radio survey at 20cm (rms 2.7µJy), also 50cm (10µJy), 90cm (70µJy)
• GALEX UV, ground-based optical, NIR, Spitzer IRAC, confusion-limited MIPS (24,70,160 µm),MAMBO 1.2mm, Chandra imaging, spectroscopy.
• XMM, SCUBA2, Herschel HerMES 100-500µm (1st priority) to come.
5 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
6 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
Radio Source Photo-z’s
Pannella/Strazzullo
UgrizJHK3.6µ4.5µ
7 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
Radio Luminosities vs. z
Majority of sources > 10^23 W/Hz, more luminous than Arp 220
8 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
1) µJysources are
resolvedmedian size ~ 1
arcsecor ~10 kpc,unlike local ULIRGs <
100pc.
9 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
Median Sizes from 1046+59
Large median size for sources continues down to bottom of the survey.
10 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
20cm Log N –Log S
Log N-log S
continues flat to bottom of survey.
6 sources/sq arcmin.
EVLA: 10X deeper: natural confusion ?
Huyng et al 2005
11 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
Radio SF or AGN ?
Both ~ galaxy size, but different relation to optical light.
M84: AGN (Mechanical Energy) M82: SF
12 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
Relation of Radio and Optical Brightness distributions (GOODS-N)
13 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
Radio SF vs. AGN
Condon et al 2002
Locally, AGN/SF luminosity functions cross at 10^23 W/Hz.
<10^23 SF>10^23 AGN
Frazer OwenNRAO
EVLA VisionDecember 17, 2008
14
Generic Radio/FIR Spectrum
15 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
Radio-FIR Relation
For SF q=2.3σ(q)~0.2
Condon et al 2002
Frazer OwenNRAO
EVLA VisionDecember 17, 2008
16
ULIRGs (Ultraluminous Infrared Galaxies)
L_FIR > 10^12 L_sun
Local examples have radio size < 100pc
(LIRGs > 10^11 L_sun)
Arp220 L_20cm=2.3x10^23 W/HzL_FIR=1.2x10^12 L_sun
Frazer OwenNRAO
EVLA VisionDecember 17, 2008
17
Radio-FIR Relation vs. z from Stacking Spitzer MIPS data
• 24, 70 and 160 µm sources stacked at the radio source positions in ranges of L_20cm and z.
• 160/70 µm ratio and error calculated.• Using redshifted templates with different dust
temperatures, rest-frame: T(dust), L_FIR and q=log(L_20cm/L_FIR) are calculated.
24µ 70µ 160µ
18 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
19 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
20 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
21 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
22 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
23 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
24 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
Best fit opt/NIRSEDs
Strazzullo et al
(2009)
25 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
5) X-rays
26 EVLA VisionDecember 17, 2008
Frazer OwenNRAO
Conclusions/Speculations• Star-formation and AGN activity go together: composites• Relation of AGN activity to evolutionary sequence still
unclear but probably not related by a simple, one-time event. Too many star-forming galaxies with AGN evidence.
• Deeper Herschel, XMM, EVLA data should make the picture clearer.
• Deep EVLA imaging will probably be dominated by more extreme star-forming objects. May reach natural confusion.
• Higher resolution radio observations from EVLA, eMerlin and SKA may be most productive path for more understanding.
• Need new imaging algorithms for EVLA /eMerlin to make deep, wide-field images.