1 / 23

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.

vashon
Download Presentation

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

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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

More Related