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A view of the sub-mJy radio population: The AGN component LOFAR perspectives

A view of the sub-mJy radio population: The AGN component LOFAR perspectives. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – Sept. 2008. Isabella Prandoni (INAF-IRA, Italy).

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A view of the sub-mJy radio population: The AGN component LOFAR perspectives

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  1. A view of the sub-mJy radio population: The AGN componentLOFAR perspectives INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – Sept. 2008 Isabella Prandoni (INAF-IRA, Italy)

  2. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – Sept. 2008 EMERGENCE OF NEW POPULATION(S) I – Modelingthe sub-mJy population EXCESS @ S<1 mJy: To qualitatively reproduce counts: 1. SF galaxies 2. Classical RL-AGNs steep/flat or FRI/FRII Mainly steep FRI RGs [logP<24] 3. RQ-AGN(Jarvis & Rawlings 04) RScompact & steep (<<10 kpc) 22 < logP<24 em. line spectrum  Type 1/Type 2

  3. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – Sept. 2008 II – Obs. properties of sub-mJy sources ATESP-DEEP1 Sample:115 RS with S>0.4 mJy in 1 sq. degr. • Radio Power Distribution:(DEEP1abc) • ETS 1023-25 W Hz-1 • Low-intermediate power AGNs • QSO  P < 1025-26 WHz-1 • RI-QSOs[RQ-QSOs: 22<logP<24] • LTS  2/3 P < 1024 W Hz-1 • Star-forming gals 64 % 14 % 19 % (Mignano,IP+ 08) • Sample largely dominated (78%) by AGN activity AGNs: mostly FRI-like (No evidence of RQ-AGNs)

  4. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – Sept. 2008 • AGN • ETS • LTS/SB flat flat steep steep II – Flat spectrum ETS (Mignano, IP+ 08) Upper limits Double/Extended RS • In DEEP1abc: • 24/39 ETS are flat/inverted: • - P 5 GHz~ 1022-24 W Hz-1(+ ETS spectra) • - Typically compact(<10-20 kpc) (+ flat)  • ADAF - ADAF+jet systems?(local LLAGNs) eg. Falcke & Biermann 99 FRI larger & steep core-dominated FRI? [base-jet emission]  Multi-freq. (0.1 –100 GHz) high-res. radio obs. needed

  5. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – Sept. 2008 pure ADAF candidates αhigh<0.2 Jet-dominated systems Jet+ADAF II – ETS: High frequency follow-up Flux-limited sub-set of 15 ATESP-DEEP1 ETS with S>0.6 mJy ATCA: Simultaneous Multi-freq. obs. [5, 8, 20 GHz] (14 in 2008 to be added) most RS consistent with jet dominated systems (α<0.2) Base jet componentsor Jet+ADAF (α>=0) systems 2 RS still consistent with pure ADAF systems (α>0.2) Prandoni, Ricci+ in prep [8 - 20 GHz] [1.4 - 5 GHz]

  6. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – Sept. 2008 flat steep II – Radio-quiet AGNs in FLS • First Look Survey (FLS) • S>0.115 mJy • Multi-band information: • opt. Spectra  MMT Hectospec • MIR 24 mm  Spitzer MIPS • 1.4 GHz  VLA/WSRT • 0.61 GHz  GMRT •  MIR-Radio correlation: • q24=log(S24/S1.4)=0.83±0.31 •  Spectral index: a(1.4-0.61) • 3 RQ-AGN with • S(1.4 GHz) > 0.115 mJy • [area=1 sq. degr.] RQ AGNs RL AGNs SFGs RQ AGNs RL AGNs SFGs Prandoni, Morganti+ in prep

  7. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – Sept. 2008 S>10 microJy 0 1 2 3 III – Benefits of LOFAR 1. Large FoV  Large deep samples to probe evolution of low-P AGNs  constraints to AGN models for P< 1024 W/Hz @ z<4 (RL-AGN + RQ-AGN component) 240 MHz:2 104 RS in PB [1.5 sq.deg.] @ 100-km LOFAR conf. limit of S>14 mJy Low frequencies  steep sources (RQ-AGN)  Radio spectra in poorly explored freq. range NB:Not only steep LLAGNs For flat AGNs LOFAR 240 MHz deep fields as faint as current VLA deep fields

  8. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – Sept. 2008 III- Benefits of E-LOFAR • International bs increase resolution: • High spatial resolution important Max Freq. Angular Confusion Baseline resol. Limit (3s) (km) (MHz) (“) (Jy) 150 240 2.4 13 500 240 0.6 5 1000 240 0.3 1  separate SB and AGN NB: sub-arcsec resolution  AGN/SF morphology on kpc scales  embedded AGNs in SFGs(cfr. eMERLIN  0.15” @ 1.5 GHz)  Lower confusion limit(sensitivity limited surveys) Slim~1 Jyfactor 10 lower P @ same z

  9. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – Sept. 2008 Summary • General agreement between obs. data and models (PLE/LDE) More quantitative LLAGN modeling larger deep radio samples (All-sky/degree scale LOFAR 240 MHz deep surveys) • At S>0.4 mJy & I<23.5 no evidence of a RQ-AGN component Probing the steep RQ-AGN component  deeper AGN surveys and/or lower frequency ( LOFAR) • (base-)Jet/Jet+ADAF scheme most plausible for compact flat-spectrum ETS Probing Accretion schemes Obs. Follow-up e.g. multi-freq./high-res. radio obs. over large freq. range (for low freq. range  E-LOFAR) [Slim100 mJy]

  10. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – Sept. 2008

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