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Radio Surveys Radio Counts Luminosity Function Evolution Modeling the faint radio sky

INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007. Radio Emitting AGNs: Statistical Studies I. Prandoni. Radio Surveys Radio Counts Luminosity Function Evolution Modeling the faint radio sky.

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Radio Surveys Radio Counts Luminosity Function Evolution Modeling the faint radio sky

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  1. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Radio Emitting AGNs: Statistical Studies I. Prandoni • Radio Surveys • Radio Counts • Luminosity Function • Evolution • Modeling the faint radio sky

  2. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Statistical Studies: Surveys • Various source populations  average properties- Cosmological evolution  average properties vs. z[ev. of single objects not possible]- Rare objects- Serendipitous discoveries  new classes of objs- Source catalogues  ad hoc samples

  3. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Why Radio Surveys? Advantages of radio band feasible from the ground(like optical) observing day and night scarsely sensitive to atmospheric variations complete samples[no dust/IGM extinction and/or gas obscuration]

  4. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 VLA (New Mexico) 27 dishes (25 m) dmax ~ 30 km dmax Why Radio Surveys? Advantages of radio observing techniquesFOV  /D: small aperture  larger FOV  interferometry /dhigh resolution  lower confusion limit good position accuracy  ND2: large N  better rms mosaicing (>’90s)efficient technique to cover large areas of sky with uniform rms (mainly at radio s) Nobeyama Millimeter Array

  5. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Mosaicing Technique: theory Mosaicingcombination ofregularly spacedmultiple pointings linearly combined to produce an image larger than telescope’s primary beam (FOV) • Intensity distr. (or Brightness) in final mosaic I(l,m) •  weighted average of pixels in individual pointings • Weights  primary beam response + expected noise • If same obs. param. and cond.  pointingPi (l,m)  i 2=  2 • I(l,m)modulated only by primary beam response: Sault & Killeen 1995 Ii(l,m) Brightness of i-th pointing

  6. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Mosaicing Technique: theory Mosaicing experiment Main Issue: pointing grid pattern (geometry & spacings) Limit on spacings from Nyquist theorem: To recover full information:  srett D  shex 2  D To get uniform noise over the mosaic I:  (I)= /( Pi2) = const. (I)/ = 1/( Pi2) = const. [i = ]

  7. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 =1 P1(0) P2(s) -s 0 s r Mosaicing Technique: theory A SIMPLE CASE:  Two Pointings: P1(0), P2 (s)  Circular Gaussian Primary Beams: Pi(r) = exp[-4 ln2 (r/FWHM)2] Pi2(r) = exp[-4 ln2 (r/FWHM/2)2 ]  Pi'(r) with FWHM’= FWHM/2 =s/FWHM’ (P'1 + P‘2)

  8. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Mosaicing Technique: simulations ATCA:D=22 m =20 cm FWHM = 33 arcmin FWHM’= FWHM/2 = 23.33 arcmin Sensitivity over 1 sq.deg. (I)/ = 1/( Pi2)  Contours: 5%, 10%, 20%, … Rectangular Grid: 4x4 pointings s=23.33 arcmin

  9. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Rectangular Grid of 4x4 pointings with spacing s=20 arcmin Mosaicing Technique: simulations (I)/i = 1/( Pi2)  Contours: 5%, 10%, 20%, … Sensitivity over 1 sq.deg. Hexagonal Grid: 22 pointings s=20 arcmin For comparison Nyquist @ ATCA:  shex 19.6 arcmin

  10. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Mosaicing Technique: simulations (I)/i = 1/( Pi2)  Contours: 5%, 10%, 20%, … Sensitivity over 1 sq.deg. Rectangular Grid: 4x4 pointings s=20 arcmin For comparison Nyquist @ ATCA:  srett 17 arcmin s=20’ only for point source det. experiments

  11. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Major Large Scale Radio Surveys Slim > 100 mJy : 3CR (Bennett et al. 1962, Laing et al. 1983)  =178 MHz Area=6 srSlim 9 Jy N  3504C (Pilkington & Scott1965, Gower et al. 1967)  =178 MHz Area=6 srSlim 2 Jy N  10008C (Rees 1990)  =151 MHz Area=0.8 srSlim 1 Jy N  5000MOLONGLO(Large et al. 1981)  =408 MHz Area=8 srSlim 700 mJy N  12000B2 (Colla et al. 1970, 1972, 1973, Fanti et al. 1974)  =408 MHz Area=2 srSlim 200 mJy N  10000PKS (Wall et al. 1971 and following papers)  =2.7 GHz Area=7 srSlim 200 mJy N  17000B3 (Ficarra et al. 1985)  =408 MHz Area=1 srSlim 100 mJy N  13000

  12. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Major Large Scale Radio Surveys 1 mJy < Slim < 100 mJy : 87GB (Gregory & Condon 1991)  =5.0 GHz Area=6 srSlim 30 mJy N  55000GB6 (Gregory et al. 1996)  =5.0 GHz Area=6 srSlim 18 mJy N  75000WENSS (Rengelink et al. 1997)  =325 MHz Area=3 srSlim 15 mJy N  2x105SUMSS(Mauch et al. 2003)  =0.8 GHz Area=7900 deg2Slim 6-10 mJ N2x105NVSS (Condon et al. 1993, 1998)  Area=10 srSlim 2.5 mJy N  2x106FIRST (Becker et al. 1993, White et al. 1997)  Area=3 srSlim 1 mJy N  9x105 MOSAICS

  13. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Best Studied Deep Radio Fields Slim < 1 mJy @ 1.4 GHz Marano Field:(Gruppioni et al. 1997) Slim = 0.2 mJy; Area = 0.36 deg2 LBDS:(Windhorst et al. 1984) Slim = 0.1-0.2 mJy; Area = 5.5 deg2 Lockman Hole:(de Ruiter et al. 1997) Slim = 0.12 mJy; Area = 0.35 deg2 Lynx 3A:(Oort 1987) Slim = 0.1 mJy; Area = 0.8 deg2 0852+17:(Condon & Mitchell 1984) Slim = 0.08 mJy; Area = 0.32 deg2 1300+30:(Mitchell & Condon 1985) Slim = 0.08 mJy; Area = 0.25 deg2 HDF North:(Richards 1999) Slim = 0.04 mJy; Area = 0.3 deg2 Typically N<100 RS

  14. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Source Counts Survey catalogue of sources  source counts vs.S (or mag) logN – logS or logN – log m Integral counts N(>S): num. of sources per area unit (sr or deg2) with flux >S Differential counts N(S): num. of sources per area unit with flux between S and S+dS Source counts  simplest cosmological tool to constrain a) source cosmological evolution; b) contribution of different galaxy types to global population; c) Universe geometry (in principle) Comparison between Observed & Modeled source counts

  15. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Theory of Source Counts • Simplest source count model  non-ev. static Euclidean Universe • L  N(>S) = (L) V • (L)=uniform volume density of sources with luminosity L • V= 4/3 d3 =volume over which the sources have flux >S • NB: d=d(L) • L S=L/(4d2 )or d=[L/(4S)]1/2 • N(L,>S) = 4/3 d3 = 4/3 [L/(4S)]3/2  (L) L3/2 S-3/2 NB: If (L) L-3/2 [Critical LF]  N(L,>S) = N(>S)  S-3/2 only Summing over L:Ntot(>S) [L (L) L3/2] S-3/2 and N(S) = d N(>S) /dS  S-5/2 N(>S) S-3/2 & N(S) S-5/2

  16. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Theory of Source Counts Beyond Local Universe  relativistic expanding Universe a) expansion:dmax  luminosity distance dL In a E-dS, =0, =1  dL = dc (1+z) [dc =comoving distance]  S=L/[4dc2(1+z)2 ]  For given S & L  dc2 < static Eucl. b) geometry:curved space-time (Robertson-Walker metric)  dVsr = r2dr/ [(1-kr2)]1/2 where k = 0,1,-1 NB: only when k=0 (flat Universe)  V=sphere (Euclidean case) For any standard cosmological models: N(>S)  S-(S)where <3/2 and  3/2 for S  Counts flatter than for static Eucl. case at decreasing S

  17. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 No S -5/2 =0 L1 log [N(S)] =1 L2 L1<L2 N/No = 1 log [S 5/2N(S)] log S (Jy) =0 L1 =1 L1<L2 L2 log S (Jy) Theory of Source Counts (L) uniform NB: Total N(S) dictated by (L) [(L) defines the proportion in which curves for each L added to total]

  18. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 S -5/2 =0 log [n(S)] =1 log S (Jy) Introducing Evolution Only assuming comoving source density not constant we can get N(S) steeper than Euclidean  (L)=0 r where  N(L,>S) = 0rdN  0rr + dr  S –(++1) If evolution dominates the counts shape  Universe geometry cannot be determined

  19. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Observed Radio Source Counts Normalized Counts @ 1.4 GHz log [S 5/2 N(S)] III II I IV V I - Euclidean Region  Local bright RS II - Steep Rise  N(>S)  S–(1.8-1.9) (AGN LF ev.) III - Euclidean Region  differential LF evolution IV - Convergence Region  N(>S)  S–(0.5-0.8) to 1% of Eucl.value (cutoff @ z~2-3) V - Euclidean Region  new population of RS (SFG) log S (Jy)

  20. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Evolutionary Source Counts Models To build source count models  4 main ingredients: 1) cosmology; 2) LF 3) SED; 4) evolution Two basic types of source count model: “forward” & “backward” Forwards method (ab initio) statistically follows the growth of dark matter halos forwards in time by accretion and mergers, in a given galaxy formation paradigm and evolutionary framework Backwards methodlocal F(L) evolved backwards in time, assuming arbitrary form of evolution Radio Source Counts traditionally backwards method (closely tied to obs., few free parameters, but no physical meaning) [NB: not clear why only 10% of AGNs are radio-loud]

  21. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Radio Luminosity Function F(L)dL or F(P)dP  density of sources (per Mpc3) with radio power between P and P+dP To get F(P)dP  RS identification and redshift measurement Not easy  only 3CR complete id. and z (Bright Es at z1-2) S-z relation does not hold for radio-AGNs Redshift distribution peaks at z=1-2 Backwards approach  Local LF + evolution

  22. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 SFG AGN Sadler et al. 2002 Local Radio Luminosity Function Two components: Classical Radio-Loud AGN: - flat LF over 5 orders of mag (close to critical LF  any DS samples same DL) - knee at log P  24.5 (W/Hz) (FRI vs FRII/QSO) - LF  Double Power Law Star Forming Galaxies: -steep LF - log P < 24.5 (W/Hz) - overcome AGNs at log P < 23 (W/Hz) -LF  Power Law + Exp. Power Law + Gaussian Exp. Recent Determination of F(P)dP at 1.4 GHz (Schechter et al. 1976) (Saunders et al. 1990)

  23. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 SED  K correction Spectral Energy Distribution for Arp220 Radio frequency range Barger et al. 2000 Steep RS a  -0.7 (FRI/FRII) Flat RS 0< a < -0.5 (BLLac/QSO) Effect of z on observed spectrum

  24. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 PDE log [F(L)] PLE Local LF log L (W/Hz) Evolution of RLF Two possible scenarios: PLE  horizontaltranslation of local LF PDE  verticaltranslation of local LF • Narrow peak of N(S)/No • +wide AGN LF • both PLE & PDE rejected • LDDE(Longair 1966) only brightest sources evolve 3CR  high-P QSO/FRII stronger DE(Spinrad et al. 85) • 3C  FRI no or little ev.(Laing et al. 83)but questioned!

  25. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Evolution of RLF Evolution Functions for Radio-AGNs (99% @ S>60 mJy): typically LE + two sub-populations: a)steep & flat RS (Dunlop & Peackock 1990) b)FRI & FRII RS (Jackson & Wall 1999) a) D&P90  LD Double Power Law F(P,z) = dexp {-k [ (P/Pc)+(P/Pc)β ] } where Pc=Pc(z) log Pc (z)= az2 + bz + c , β, a,b,c differ for steep & flat Can reproduce N(z) at mJy level & decline between 2<z<5

  26. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Evolution of RLF b) J&W99  LD Exp. function + redshift cut-off F(P,z) = exp[M(P)t(z)] where t(z)  look-back time M(P)  LD factor = 0 for P<P1 = Mmaxfor P1P P2 = Mmax for P>P2 redshift cut-off F = F(P,z) for z < zc F = F(P, zc-z) for zc/2 < z < zc F = 0 for z> zc P1,P2,Mmax,zc  differ for FRI & FRII FRII strong ev.FRI no ev.  dramatic decline of BL-FRII at S 1 mJy (but evidence of sub-mJy QSO)

  27. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Evolution of RLF Evolution Functions for SFGs: two sub-populations: not ev. normal Spirals  local RLF strongly ev. Starburst gals for SB ev.:F(P,z)=g(z) x F(P/f(z),z=0) where g(z)  density ev. f(z)  luminosity ev. typically ev. functions of the form: f(z) (1+z)Q and g(z)  (1+z)P PLE preferred: Q  3; P0 (but see P=6.7 Rowan-Robinson 93)

  28. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Evolution of RLF • Non parametric approach: 2 arbitrary ev. functions • F(P,z) = g(z) x F(P/f(z),z=0)where g(z)  density ev. • f(z)  luminosity ev. • (Condon et al. 1984) • No distinction between bright and faint sources • Can be used for any type of source (applied to both AGN and Star Forming Galaxies) • NB: for SFGs Local LF  Radio or FIR LF • (see Saunders et al. 90) • thanks to Radio/FIR corr

  29. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Radio/FIR Correlation SDSS SFG: Remarkably tight FIR/radio correlation radio luminosity  nearly proportional to SFR  nearly independent of B and other parameters. Yun et al. 2002

  30. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Radio/FIR Correlation SFG: Remarkably tight FIR/radio correlation rescaled FIR (dashed curve) and radio (solid curve) local LFs of SFGs coincide. FIR and radio imply the same recent SFRD..

  31. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Radio/FIR Correlation Holds up to z=1 SDSS, Yun et al. 2002 Local Sample Spitzer FLS, Appleton et. al. 2004

  32. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 ρSFR (z) vs. z Hopkins et al. 2004 The Promise of Deep Radio Fields • If sub-mJy sources are mainly SFGs • Deep Radio Samples can be used to derive SFH of the universe Advantages: higher res. than FIR complete unbiased view (no dust extinction) Dust enshrouded SFH up to high z

  33. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Largest Deep Radio Mosaics ATESP:(Prandoni et al. 2000a,b) Slim = 0.47 mJy; Area = 26 deg2 N  3000 ELAIS S:(Gruppioni et al. 1999) Slim = 0.4 mJy; Area = 4.0 deg2 PDF:(Hopkins et al. 1998, 2003) Slim = 0.06 mJy; Area = 4.6 deg2 N  2000 ELAIS N:(Ciliegi et al. 1999) Slim = 0.135 - 1.15 mJy; Area = 0.12 - 4.22 deg2 VLA-VVDS:(Bondi et al. 2003) Slim = 0.08 mJy; Area = 1.0 deg2 N  1000 VLA-COSMOS:(Schinnerer et al. 2007) Slim = 0.05 mJy; Area = 2.0 deg2 N  3500 FIRST LOOK Survey:(Condon et al. 2003, Morganti et al 2004) Slim = 0.04-0.1 mJy; Area = 1-5 deg2 N  1000-3500

  34. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 A New Look at Radio Counts NATURE/EVOLUTION of sub-mJy RS Low L/high z AGN, SB, Ell. Fractions? F(L) ? N(z) ? SHARP STEEPENING @ S<1 mJy SF dominates at Jy fluxes ETS important at sub-mJy & mJy fluxes e.g.Richards et al. 99, Gruppioni et al. 99, Haarsma et al. 00, Prandoni et al. 01b, 02,Gruppioni et al. 03, Sullivan et al. 04, Ciliegi et al. 05, Fomalont et al. 06 No Change in slope down to 10 μJy

  35. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Prandoni et al. 2002 Composition of the sub-mJY population Prandoni et al. 2001b Radio to Optical Ratio: R= S x 100.4[mag-12.5] (Condon 80) R>100 AGN/ETS R<100  SFGs SF dominates @ low R AGN/ETS dominate @ high R ATESP-EIS • Early-type gals important at sub-mJy fluxes • Selection effects explain discrepancies among sub-mJy samples

  36. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Composition of sub-mJY population SB+Sp CONTRIBUTION TO 1.4 GHz COUNTS ELAIS S SB + Spirals: a) L15 ~ k L1.4 GHz b) mod.ev.per n(S15 )  n(S15 )  n(S1.4GHz) Gruppioni et al. 2003 Contribution of MIR SB+Sp to n(S1.4 GHz ): ~10% @ S~0.5-1 mJy >60% @ S<0.05-0.1 mJy • Nuclear processes dominate @ S>0.5 mJy?

  37. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 A New Look to Radio Count Models A - Classical RL-AGNs lum. ev. steep/flat(e.g. D&P90) FRI/FRII(e.g. J&W99) B - SF gals. PLE  local F(L) + L ~ (1+z)p p~3 up to zmax then L=L(zmax) (e.g.Condon 89,Saunders et al. 90, Machalski & Godlowski 00, Yun et. al 01, Sadler et al. 02) C – Radio-Quiet AGNs R<1-10 (Jarvis & Rawlings 2004) 1.4 GHz Source Counts

  38. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Jarvis & Rawlings 2004 z=2 RQQ FRI FRII dN/dz z=0 Lum. Function Jarvis 2007 A Radio-quiet AGN Component hard X-ray LDDE LF Ueda et al 2003 log(Lx)=-4.57 + 1.012 log(L1.4GHz) Brinkmann et al. 2000 RQQ Radio 1.4 GHz LF

  39. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 A Radio-quiet AGN Component Observational characterization: RQ-QSO: Kukula et al. 1998  radio em. from optically selected RQQ (Mv<-23) RScompact & steep (<<10 kpc, α1.48.4~ -0.7); 22< log(L1.4GHz)<24 host galaxy disk/spheroidal (em. line spectrum) LDDE (Jarvis & Rawlings 2004):  largest component at z<1 • Ideal Samples 0.5<S<5 mJyideal to study the low-luminosity AGN component and infer its physical properties & evolution: • low/high accretion rates? (FRI vs. RQQ) • lower L AGNs peak at lower z? [NB:LDDE recently found for opt/X-ray AGNsBongiorno et al. 07; Ueda et al. 03; Hasinger et al. 05] see also Vigotti et al. 03; Cirasuolo et al. 06 for radio AGNs

  40. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 The New Promise of sub-mJy Samples Assessing Low-Power AGNs Physical properties and Evolution • Ideal samples  S>0.5 mJy • low/high accretion rates? (FRI vs. RQQ) lower L AGNs peak at lower z?Type I & II AGNs [NB:LDDE recently found for opt/X-ray AGNs Bongiorno et al. 07; Ueda et al. 03; Hasinger et al. 05] see also Vigotti et al. 03; Cirasuolo et al. 06 for radio AGNs Connection between SFH & MBH accretion

  41. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 The Issue of Optical Identifications Sub-mJy population very ELUSIVE! Updated to 2003 Prandoni et al. 2004 INCOMPLETE OPT. ID. (tipically 50-60%) More severe for OPT. SPECTROSCOPY

  42. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Salvato 2005 - www.mpe.mpg.de/~mara/surveys The Issue of Optical Identifications • … but in the last years, evolving picture: • developement of photometric techniques • deep spectroscopy surveys • coordinated multi-λ observational efforts (e.g. PDS, VVDS, COSMOS, DPS, etc )

  43. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 The ATESP-DEEP1 Sample • 5 GHz follow-up: • 2x0.5 sq. deg. at d = -40 • 2 radio mosaics with uniform rms flux  70 Jy • 111 sources with S > 0.4 mJy • Spatial resolutions: •  10”  radio spectra •  2”  radio morphology • 1.4 GHz ATESP Survey: • 26x1 sq. deg. at d = -40 • 16 radio mosaics with uniform rms flux  80 Jy • 2967 sources with S > 0.4 mJy Spatial resolution:  10” (Prandoni et al. 2000a,b; 2001) • UBVRIJK imaging from DPS • 2x0.5 sq. deg. at d = -40 • 4 WFI fields (DEEP1a,b,c,d) + SOFI • UAB~ 25.7, BAB~ 25.5, VAB~ 25.2, • RAB~ 24.8, IAB ~24.1 • JAB≤ 23.4 and 21.3 <Ks AB≤ 22.7 (Prandoni et al. 2006) DEEP 1 a b c d Mignano et al. 07a, Olsen et al 06

  44. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Assessing the Low-P AGN Component • Redshift Distribution: • ETS up to z = 2 (peak at z = 0.5) • QSO  1.5<z <2.5 • LTS  z<1 • Radio Power Distribution: • ETS 1023-25 W Hz-1 • (triggered by low-intermediate luminosity AGNs) • QSO  P < 1025-26 WHz-1 • RI-QSOs • lower than usually found for classical radio-loud QSOs • LTS  2/3 P < 1024 W Hz-1 • (SF) ATESP-DEEP1, Mignano et al. 2007b 67 % 12 % 16 %  Sample largely dominated (78%) by AGN activity

  45. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Assessing the Low-P AGN Component 5 GHz: 111 ATESP RS 1.4 GHz: 109 ATESP RS NB: double/ext RS (Prandoni et al. 2006) SIGNIFICANT FLATTENING WITH DECREASING FLUX S > 4 mJy steep spectrum (αmed ~ -0.7, S ~να) S < 4 mJy large fraction of flat spectra (α > -0.5) + significant #of inverted spectra (α >0 ) 46% at 1.4 GHz [αmed~-0.53] 63% at 5 GHz [αmed~-0.29] 29% at 5 GHz

  46. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 • AGN • ETS • LTS/SB Assessing the Low-P AGN Component Radio spectral index vs R - most α > –0.5 sources  high R [R>1000  powerful RG and QS0] - α > –0.5 & low R  ETS [RS probably triggered by AGN] - LTS/SB  steep sources [as expected for synchrotron em. in gal. disks or in nuclear SB] Mignano et al. 2007b

  47. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 • AGN • ETS • LTS/SB Assessing the Low-P AGN Component Mignano et al. 2007b Upper limits Double/Extended RS • DEEP1abc: • 39 ETS 24 with flat/inverted spectra • Typically compact (<10-20 kpc) • P 5 GHz~ 1022-24 W Hz-1(+ ETS spectra) FRI class? • BUT:FRI larger and steep

  48. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Assessing the Low-P AGN Component • compactness + flat/inverted spectrum •  Sinchrotron/free-free self-absorption • similar to so-called Low Power Compact (LPC) RS? • (P408 MHz<1025.5 WHz-1, see Giroletti et al. 2005) • composite sub-class of FRI: • Low-P BL Lac; jet instability; frustration • young sources? But GPS  P 1.4 GHz > 1025 W Hz-1 • low accr./radiative efficiency(ADAF/ADIOS)LLAGN? • But typicallyP 5 GHz < 1021 W Hz-1 (eg.Doi et al. 05) • unless ADAF+jet  higher P and still flat/inverted spectra • (eg. Falcke & Biermann 99)  further analysis needed

  49. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Assessing the Low-P AGN Component  Multi-freq simultaneous obs. needed to confirm spectra NB:high freq. data (>10 GHz) needed to discriminate ADAF from more conventional accretion schemes Jet-dominated sources: -0.7< α < 0.2depending on relative contr. of extended (opt-thin) and base (self-abs.) jet components ADAF: 0.2< α < 1.1up to mm-λ (Nagar et al. 01) with α varying with accr. rate (α~0.4 if L ~ 10-4 LEdd ; α ~ 1 if L ~ 10-7 LEdd) NB: Coexistent outflows may flatten the spectra (but α>0) Strong outflows may shift the peak to cm λ (Quataert & Narayan 99)

  50. INAF - ISTITUTO DI RADIOASTRONOMIA I. Prandoni – 14/06/2007 Comparison with Models • Models: • RG & QSO (Steep + Flat) • Ev. SB & normal Sp. • All • Datasets: • ETS+QSO LTS/SB All General agreement between data and models At S>0.4 mJy & I<23.5 no evidence of a RQAGN component Low-accr./radiative efficiency most plausible scheme for flat-spectrum ETS

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