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The Chandra/SWIRE Survey: Radio Properties Of X-Ray Selected AGN

The Chandra/SWIRE Survey: Radio Properties Of X-Ray Selected AGN. Manuela Molina INAF/IASF Milano. In collaboration with: M. Polletta, L. Chiappetti, L. Paioro (INAF/IASF-Mi), G.Trinchieri (OA Brera), F. Owen (NRAO) and Chandra/SWIRE Team. . AGN9 – Ferrara, 24/27 May 2010. Talk Outline.

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The Chandra/SWIRE Survey: Radio Properties Of X-Ray Selected AGN

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  1. The Chandra/SWIRE Survey: Radio Properties Of X-Ray Selected AGN Manuela Molina INAF/IASF Milano In collaboration with: M. Polletta, L. Chiappetti, L. Paioro (INAF/IASF-Mi), G.Trinchieri (OA Brera), F. Owen (NRAO) and Chandra/SWIRE Team. AGN9 – Ferrara, 24/27 May 2010

  2. Talk Outline THE DATASET • The XMM-Chandra/SWIRE Survey • Description of the XMM Sample RADIO PROPERTIES OF THE XMM SAMPLE • Criteria for identifying AGN-driven radio activity • Some examples of peculiar sources X-RAY PROPERTIES OF THE XMM SAMPLE • X-Ray Variability (Chandra vs. XMM) • X-Ray Variability vs. Obscuration and X-Ray Absorption SUMMARY & CONCLUSIONS

  3. Open Questions & Objectives AGN FEEDBACK AGN Host Galaxy AGN Star Formation • AGN driven emission from sources close to Eddington limit • X-ray bright sources QUASAR or BRIGHT MODE (e.g. Di Matteo+05) • Mechanical Origin • Jets on small/large scales • Outflows and winds RADIO MODE (e.g. Croton+06) Signatures of AGN feedback Identify efficiently radiating AGN and radio-active AGN Study and comparison of their properties GOALS: Study of Radio and X-Ray Properties of an X-Ray Selected AGN Sample with deep multi-frequency radio coverage STRATEGY: AGN9 – Ferrara, 24/27 May 2010

  4. The XMM-Chandra/SWIRE Survey in the Deep SWIRE Field • The Deep SWIRE Field • Lockman Hole North • RA = 10h45m, DEC = 58o58′ • Area: 0.2 deg2 XMM-Newton • The Multi-l Data • VLA @ 90 and 20 cm (12mJy@5s) • GMRT @ 50 cm • MIPS @ 24, 70 and 160 mm • IRAC @ 3.6, 4.5, 5.8 and 8.0 mm • UH/UKIRT J, H, K • KPNO Ugriz • GALEX @ FUV (1500Å) and NUV (2500Å) • Chandra @ 0.3-8 keV (3 bands) • XMM @ 0.3-10 keV (5 bands) RED 0.5-2 keV GREEN 2-4.5 keV BLUE 4.5-10 keV AGN9 – Ferrara, 24/27 May 2010

  5. The Sample Selection: XMM Detected AGN (95) 38% UNOBSCURED 58% OBSCURED • 93 sources with Chandra counterpart • 71 with spectroscopic z • 24 with photometric z • All detected in Optical and/or Infrared (IR) • Count rates and fluxes in 5 bands • 3 Hardness Ratios • NH estimated from Xspec or HR FUV-Mid IR Spectral Energy Distribution (SED) AGN9 – Ferrara, 24/27 May 2010

  6. Criteria for identifying AGN–driven radio activity q24 parameter • q24<0.21: Radio Loud (RL)/ Radio Intermediate (RI) • 0.21<q24<1.45: Radio Quiet (RQ) • q24>1.45: Radio Weak (RW) q24=Log(F24μm/F20cm) <q24>=0.83±0.31 for RQ and SFGs (Appleton+04) Radio Spectral Index -1 inverted • α20,50<0.15: Inverted • 0.15≤α20,50≤0.5: Flat • 0.5<α20,50<1.1: Steep • α20,50≥1.1: Ultra Steep α20,50 (Sν∝ν-α) 1 ultra-steep 2 AGN9 – Ferrara, 24/27 May 2010 (Prandoni+09)

  7. Radio Properties of the X-Ray Sources • RW/RL with typical α (0.2-1) • Steep/Ultra-Steep are mostly RW and AGN1 • Flat spectrum are generally RQ/RI • Inverted spectrum are RQ • Inverted spectrum sources tend to be absorbed and obscured. • Steep/ultra-steep spectrum sources tend to be unabsorbed and unobscured. Opposite to UM expectations AGN9 – Ferrara, 24/27 May 2010

  8. Radio Semimajor Axis and z Distributions Semimajor Axis Distribution Redshift Distribution AGN9 – Ferrara, 24/27 May 2010

  9. A RW, Steep Spectrum Source AGN1 (Unobscured) • Radio: synchrotron • b=2.2 arcsec • Lobes/host? • Radio Weak: no SF? Absorbed α20,50=0.7 Central engine and SF can no longer accelerate electrons Fossil Synchrotron Emission? (e.g. Barvainis&Lonsdale 98) AGN9 – Ferrara, 24/27 May 2010

  10. Ultra Steep Spectrum Sources • Compact Source • Lobes/jets? • Radio Weak Unabsorbed α20,50=1.51 Synchrotron emission from electrons which are cooling down due to the lack of a reacceleration mechanism. (e.g. Barvainis&Lonsdale 98) AGN9 – Ferrara, 24/27 May 2010

  11. Inverted Spectrum Sources • Extended Source • AGN driven radio emission • Radio Weak SFG (Obscured) Absorbed α20,50=-0.07 Free-Free Absorption responsible for inverted spectrum? AGN9 – Ferrara, 24/27 May 2010

  12. A RL, Flat Spectrum Source • RL • Compact • Beamed QSO? • Obscuration from host galaxy? AGN2 (Obscured) α20,50=0.31 Absorbed Radio emission indicative of Synchro-Self Absorption

  13. X-Ray Absorption vs Dust Obscuration • UNOBSCURED: 52% • OBSCURED: 45% Almost half of the unabsorbed sources are obscured • UNOBSCURED: 27% • OBSCURED: 67% Most of the absorbed sources are also obscured (e.g. Tajer+08) AGN9 – Ferrara, 24/27 May 2010

  14. X-Ray Variability (Chandra vs XMM) Chandra (Sep. 2004) vs XMM (Oct. 2008/Apr. 2009) A source is variable if |FCXO-FXMM|>2x(ΔFCXO+ΔFXMM) i.e., more than 2σ flux variation in any band. 35% of the sources show variability, either in FLUX, SPECTRAL SHAPE or BOTH. AGN9 – Ferrara, 24/27 May 2010

  15. X-Ray Variability vs Obscuration and Absorption The fraction of unobscured and unabsorbed sources increases in the variable sub-sample AGN9 – Ferrara, 24/27 May 2010

  16. Summary • Radio properties and X-ray variability of a sample of 95 X-Ray detected AGN in the deep SWIRE field. • AGN-driven radio activity identified through q24parameter and radio spectral indexα20,50. • Examples of peculiar radio sources. • X-Ray Absorption vs. Dust Obscuration. • X-Ray Variability vs. X-Ray Absorption and Dust Obscuration. AGN9 – Ferrara, 24/27 May 2010

  17. Conclusions • Radio properties and X-ray variability of a sample of 95 X-Ray detected AGN in the deep SWIRE field. • Efficiently radiating (X-Ray Bright) AGN are mostly RQ with typical radio spectra and contain only a few sources (3%) with AGN-driven radio activity. • A certain number of X-Ray Bright AGN are RW, suggesting that any radio emission is the relic of a past AGN or SF activity. • Inverted spectrum sources tend to be absorbed and obscured. Steep/ultra-steep spectrum sources tend to be unabsorbed and unobscured (is this in contraddiction with UM predictions?). • AGN-driven radio emission is rare among X-Ray bright sources, suggesting that the quasar and radio feedback modes require different conditions and occur in AGN with intrinsic differences. • Evidence of dying activty (radio-weak) in some AGN 1 : last phase of evolution? AGN9 – Ferrara, 24/27 May 2010

  18. Conclusions • q24andα20,50provide good diagnostic tool for identifying “peculiar” sources • Different kinds of radio emission processes related to different evolutionary stages, ages and physical properties of sources. • Peculiarities observed in radio domain only • Almost half of the unabsorbed sources are obscured • Most of the absorbed sources are also obscured • The fraction of unobscured and unabsorbed sources increases in the variable sub-sample • Absorbed sources have flat/inverted radio spectra, while unabsorbed sources have steep/ultra-steep radio spectra, opposite to what expected from UM AGN9 – Ferrara, 24/27 May 2010

  19. X-Ray Variability Variability vs SED Class • 44% AGN1 • 9% SY 1.8 53% UNOBSCURED • 31% AGN2 • 12% SF 47% OBSCURED Variability is NOT related to SED Class • 10 Unobsc. AGN (36%) • 11 Obsc. AGN (64%) • 1 NA (4%) • 4 Unobsc. AGN (66%) • 2 Obsc. AGN (34%) Flux Variability Spec. Variability • 3 Unobscured AGN (83%) • 1 Obscured AGN (17%) Flux+Spec. Variability Variability vs X-ray Absorption • 76% Flux • 6% Spectrum • 18% Flux+Spec. • 60% Flux • 33% Spectrum • 7% Flux+Spec. Log(NH)<22 53% Log(NH)>22 47% As expected, unobscured sources tend, on average, to be more variable than obscured ones AGN9 – Ferrara, 24/27 May 2010

  20. Radio Properties of the X-Ray Sources Lx<1044 erg s-1 Lx>1044 erg s-1 unobsc. AGN unobsc. AGN obsc. AGN obsc. AGN • Median Obsc. = 0.58 • Median Unobsc = 0.85 • Unobsc. AGN have slightly flatter radio spec. indices • KS test suggests that the two subsets belong to different populations. • Median Obsc. = 0.76 • Median Unobsc = 0.73 • Unobsc. AGN have slightly flatter radio spec. indices. • KS test suggests subsets might belong to same population of sources. AGN9 – Ferrara, 24/27 May 2010

  21. Radio Properties of the X-Ray Sources Vir Lal & Ho (2010) find, in a radio-selected sample, a prevalence of sources with flat and highly inverted radio spectra. They also suggest that flat radio spectra are more frequent in type 2 quasars than in type 1, challenging UM. Is there a correlation between SED type and radio spectral index? • Bimodality in distributions • Unobscured AGN peaking at around 0.6 and 0.3 • Obscured AGN peaking at around 0.7 and 0.2 • Are Obscured and Unobscured AGN from the same population of sources? KS test hints at a different population • Obscured AGN also seem to have slightly flatter radio spectra than unobscured ones. AGN9 – Ferrara, 24/27 May 2010

  22. Multi-λAnalysis Are “peculiarities” observed only at radio frequencies? YES! Peculiar sources do not occupy any specific region in the plot AGN9 – Ferrara, 24/27 May 2010

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