1. Continuo Infrarosso
IR puo’ essere non termico (sincrotrone) o termico. Importante
slope del cut off submm
Se sincrotrone auto-assorbimento a = -2.5
Il minimo a 1 micro suggerisce termico
Variabilita’ (dimensioni) da indicazioni discordanti
Recenti dati ISO suggeriscono IR termico in radio quieti QSO
mentre flat spectrum radio QSO hanno emissione non termica
dominante

2. Recent result: Baldi et al. arXiv:1010.5277
Usando HST osservazioni di 100 3C sources si ricava che:
FR I: The correlation among near IR, optical, and radio nuclear
luminosity  non thermal origin (IR)
FR II con righe di emissione deboli (low-ionization galaxies LIG):
sono indistinguibili da FR I  stesse proprieta’
FR II con righe allargate (BLO): unresolved near IR nucleus +
large near IR excess dominant  hot circumnuclear dust
(confermato da spettro e SED)
FR II con righe strette ma luminose (high-ionization galaxies HIG)
simili ma fainter di BLO  substantial obscuration + reflection

3. What do AGN look like? Mass not well known 10 years ago…
Big! So disc peak somewhere in unobservable UV/EUV !!
Spectra generally not dominated by the disc – hard tail often carries a large fraction of Lbol and puzzling soft excess also can carry large fraction of Lbol
Richards et al 2006, Elvis et al 2004

4. Effetti con z e/o Luminosita’
Spettri in ottico e UV non mostrano dipendenza da luminosita’ o
redshift in QSS ma αox mostra una chiara dipendenza con z o L
Intrinseco o effetti di selezione?
Piu’ recenti risultati a favore di reale dipendenza da L e non da z
anche se difficile separare L da z che si correlano in flux-limited
samples.
In ogni caso la dispersione e’ molto larga in QSS e probabilmente
una fondamentale proprieta’ in parte dovuta anche alla
sovrapposizione di star formation effects

5. Scale di grandezza
SMBH ≈ AU
Accretion Disk mpc
Compact radio VLBI core pc
BLR pc
Toro molecolare pc
NLR
Host Galaxy
Radio Lobi Mpc

6. Storchi-Bergmann et al. (2003)
Disk Signatures
A relatively small subset of AGNs have double-peaked profiles that are characteristic of rotation.
Disks are not simple; non-axisymmetric.
Sometimes also seen in difference or rms spectra.
Disks can’t explain everything…
NGC 1097
Storchi-Bergmann et al. (2003)

7. Continuo Banda Radio
Importante storicamente e non, ma in Lbolometrica contribuisce
poco a causa della sua bassa energia
Temperatura di Brillanza: intensita’ di sorgente radio dipende da
flusso e diametro angolare da cui proviene. Con Tb intendo la
temperatura che dovrebbe avere un CN per irradiare lo stesso
flusso.
I = F/πθ2 = B = 2kTb/2
F = flusso osservato monocromatico; θ diametro angolare della
sorgente. Si ottiene T ≈ 1011 – 1012 K che chiaramente indica
una origine non termica

8. Esiste una Tb massima dell’ordine di 1012 K in quanto
densita’ energia del campo magnetico:
Umag = B2/8π controlla rate delle perdite di sincrotrone
Con densita’ di energia Urad = 4πJ/c
Quando Urad e’ al punto che supera Umag inizia ad essere rilevante
l’interazione di Compton inverso.
Poiche’ non vediamo una intensa radiazione in banda gamma significa
che:
Urad/Umag < 1 che corrisponde a Tmax ≈ 1012 K (catastrofe Compton)
Nuclei radio: sorgenti compatte su risoluzione angolare arcsecond
con alta Tb e spettro piatto (piccole dimensioni angolari).
Ma spettro piatto + alta variabilita’ indicano presenza di strutture
su piccola scala quindi con T tale da dare catastrofe Compton
Vedremo la soluzione grazie a alta risoluzione  VLBI

9. Risoluzione angolare: R = 1.22 lambda/D in radianti
Lambda e D stessa unita’ di misura!
occhio D= 8 mm R = 17.3” ma retina degrada a 1’
Telescopio 4 m puo’ arrivare a 0.035” ma seeing….
Radio non ha grossi problemi con atmosfera a frequenze
fino a 22 GHz per cui R meglio di 1 mas

10. Accuratezza Specchio  0.1 
ISTITUTO DI RADIOASTRONOMIA, INAF - ITALY
Il Radiotelescopio
Sub-riflettore
Simile a telescopio ottico!
Il radiotelescopio funziona allo stesso modo di un telescopio ottico. Notare pero’ che in banda radio sono consentite discontinuità dell’ordine del mm e cm mentre in ottico le discontinuita’ devono essere dell’ordine del centesimo di micron.
Schema: specchio riflettente + sub-riflettore + ricevitori al fuoco secondario. Esempio di ricevitore a 20 cm.
Sostegno
Ricevitori
Accuratezza Specchio  0.1 
RADIOASTRONOMY

11. Importanti caratteristiche del telescopio
ISTITUTO DI RADIOASTRONOMIA, INAF - ITALY
Importanti caratteristiche del telescopio
Sensibilità  D2
Potere Risolutore  /D
D= 30 m
30’
Banda radio:
 = 20 cm
10’
D= 80 m
D=700 m 1’
Caratteristiche principali dei telescopi. Sensibilita’ e potere risolutivo. I radiotelescopi non riescono a risolvere bene i dettagli.
I radio telescopi sono un po’ miopi!
Pupilla:  ~ mm
D = 5 mm 1’
RADIOASTRONOMY

12. Arecibo 300 m Effelsberg (Bonn) 100 m Parkes (Australia) 64 m
Green Bank (WEST VIRGINIA) 100x110 m
(Agosto 2000)
Arecibo
(Portorico)
300 m
Effelsberg
(Bonn)
100 m
Parkes
(Australia)
64 m
Jodrell Bank
(Manchester)
75 m
La necessita’ di aumentare il potere risolutivo fa si’ che i radiotelescopi siano molto grandi. Ecco i piu’ grandi del mondo!
Parkes: 64 m dal 1961
Jodrell Bank 75 m
Effelsberg 100 m (anni 60)
Nuovo Green Bank 100x Agosto 2000
Arecibo 300 m (stesso dettaglio dell’occhio umano)

13. L’ INTERFEROMETRO d Potere Risolutore: ~ /d Sensibilità: ~ N x D2
ISTITUTO DI RADIOASTRONOMIA, INAF - ITALY
L’ INTERFEROMETRO
Potere Risolutore: ~ /d
(d = distanza antenne)
Sensibilità: ~ N x D2
(N=numero antenne) d
La radiointerferometria sfrutta un principio dell’ottica che dice che il potere risolutore e’ definito dai 2 punti diametralmente opposti dello specchio. Si puo’ quindi immaginare uno specchio virtuale di diametro d=distanza tra le due antenne, di cui le due antenne sono I due punti diametralmente opposti.
RADIOASTRONOMY

14. Very Large Array (New Mexico)
ISTITUTO DI RADIOASTRONOMIA, INAF - ITALY
Very Large Array (New Mexico)
27 antenne di 25 m
Dmax ~ 30 km
Westerbork (Olanda)
14 antenne di 25 m
Dmax ~ 3 km
Esempi di interferometri:
Westerbork (Olanda): 14 antenne di 25 metri. Dmax = 3 km
ATCA (Australia): 6 antenne di 22 m. Dmax = 6 km
VLA (New Mexico): 27 antenne di 25 m. Dmax = 30 km (1” a 20 cm)
ATCA (Australia)
6 antenne di 22 m
Dmax ~ 6 km
1” a 20 cm
RADIOASTRONOMY

15. European VLBI Network – EVN
ISTITUTO DI RADIOASTRONOMIA, INAF - ITALY
European VLBI Network – EVN
L’EVN. 18 Antenne di cui 2 in Cina, 1 in Sud Africa e 1 negli Stati Uniti (Arecibo). E’ mostrato anche il correlatore EVN situato Dwingeloo (Olanda). Cl
18 Antenne
RADIOASTRONOMY

16. Very Long Baseline Array (VLBA)
ISTITUTO DI RADIOASTRONOMIA, INAF - ITALY
Very Long Baseline Array (VLBA)
Dal 1993
10 antenne da 25-m sparse tra USA e Canada
Correlatore a
Socorro
RADIOASTRONOMY

17. Very Long Baseline Interferometry : VLBI EVN
Spatial VLBI

20. 3C 264

21. z 1” 1 mas 0.06 1.6 kpc 1.6 pc 0.16 3.6 kpc 3.6 pc 0.5 7.1 kpc 7.1 pc
Cyg A
3C 273
3C 48
Resolving Power
radians  = 20 cm, D = 1000 km   = 0.04”

22. VLBI studies of radio galaxy nuclei : one of the most important results is the detection of proper superluminal motion
Expansion of about
6 pc in 3.5 years:
 velocity  6c

23. QUASAR
z = 0.75
The southernmost feature is moving at about 9c (Venturi et al. 1997)

24. Observation performed with the space VLBI at 5 GHz
QUASAR
z = 0.302
Aug Sep 01
Observation performed with the space VLBI at 5 GHz
(Murphy et al. 2003)

25. For example :  = 10o and v = 0.999c then : v(OBS) = 10.7 c
By the time that light leaves from position
(2), light emitted from position (1) will have
travelled a distance AC
The difference in arrival time for the
observer is :
SUPERLUMINAL MOTION
The apparent velocity as seen by the
observer is
For example :  = 10o and v = 0.999c
then : v(OBS) = 10.7 c

26. The detection of superluminal motions and
of one-sided jets in the majority of both
low power and high power radio galaxies
indicates that the jets at their basis are
all strongly relativistic

27. Effetto Doppler e boosting relativistico
Se una sorgente si muove con v = βc in una direzione che forma
angolo θ con la linea di vista abbiamo
o = e/((1-βcosθo)) = e D
Dove  e’ il fattore di Lorentz e
D = 1/((1-βcosθo)) e’ il Doppler factor (velocita’ positiva in
avvicinamento D > 1 quando β > 0 e o > e
Se velocita’ bassa  ≈ 1 e D  (1 + β cosθo) Doppler classico
Consideriamo sorgente con Luminosita’ totale Le e luminosita’
monocromatica L(e)
La potenza irradiata in banda e sara’ ricevuta in banda
o = e D

28. Consideriamo come varia luminosita’ – essendo radiazione per unita’
di tempo teniamo conto
trasformazione energia fotoni
o = e x D
Trasformazione dei tempi
dto = dte - dte  v cosθ/c = dte(1 – β cosθ) = dte/D
sorgente si e’ avvicinata tra tempo emissione 2 fotoni
La radiazione ricevuta in superficie unitaria compresa in cono angolo
solido do che sara’ diverso da de
do = de/D2
si ottiene da aberrazione relativistica ricordando che do ≈ π dθo2

29. In conclusione
Lo = Le x D4
Boosting relativistico o Doppler boosting o relativistic beaming
Se lavoriamo con luminosita’ monocromatiche
Lo(o)do = Le(e)de x D4
da cui
Lo(o) = Le(e) x D3
Se lo spettro e’ di sincrotrone L()  - possiamo scrivere
Lo(o) = Le(o) x D3+ = Le(o) x D4 D-(1-)
Il termine D-(1-) e’ noto come correzione K

31. JET RELATIVISTIC EFFECTS (DOPPLER BOOSTING) :
Doppler factor
Jet pointing toward the observer is AMPLIFIED

32. From the ratio between the approaching and the receding jet,
the jet velocity and orientation can be constrained
JET SIDEDNESS RATIO
Ma se parliamo di getti o plasmoidi quasi continui si parla di
brillanza: la lunghezza della struttura nella direzione
del moto e’ influenzato da D ma lo spessore della struttura no
(moto unidimensionale) ne segue che:

33. Jet sidedness
Se  = 5 (β = 0.98) e  = 0.7 e θ = 0 risulta Ba/Br = R = 2 x 104
Ne consegue che dati 2 getti intrinsecamente uguali vedo solo
quello che si muove verso di me e non l’altro
From the jet to cj brightness ratio R we derive:
Main problem: low luminosity radio jets do not give strong
constraints: in 3C264 the highest j/cj ratio is > 37
corresponding to θ < 52o and β > 0.62

34. FR I - 3C 449
FR II - 3C 47

35. Radio image of the FR II radio galaxy Cygnus A.
~1 Mpc
This galaxy also has HUGE radio lobes.
The thin line through the galaxy is a jet ejected from the nucleus.
The lobes occur where the jets plow into intracluster gas.

36. FR I radio galaxy: most of the energy comes from a small nucleus with a halo of weaker emission in a halo around the nucleus.
Visible image of the core-halo (FR I) radio galaxy M87.
This giant elliptical (E1) galaxy is ~100 Kpc across.
It has a “jet” of material coming from the nucleus.

37. Close-up view of the jet in M87 at radio wavelengths.
~2 kpc
galaxy nucleus, i.e. the radio core
The jet is apparently a series of distinct “blobs”, ejected by the galaxy nucleus, and moving at up to half the speed of light.
The jet and nucleus are clearly non-stellar.

38. Quasar
BL Lac
MK 501
Radio Galaxy
BL Lac

39. Radio core dominance
Given the existence of a general correlation between the core
and total radio power we can derive the expected intrinsic core
radio power from the unboosted total radio power at low
frequency.
Pc = observed core radio power at 5 GHz
Ptot = observed total radio power at 408 MHz
La potenza del core e’ legata alla presenza del jet relativistico
la potenza totale NO – a bassa frequenza cosi core non pesa
essendo auto-assorbito

40. Alta e bassa Potenza: Relativistici Su scala piccola
The comparison of the expected intrinsic and observed core radio power will
constrain β and θ.
A large dispersion of the core radio power is expected because of the
dependance of the observed core radio power with θ.
From the data dispersion we derive that Г has to be > 2 and < 10

41. Pc = Pi D(2+ )
Pbest-fit = P(60) = Pi D(2+ ) = Pi/2+(1-β cosθ)2+ = con θ = 60
Pi/2+(1-β/2)2+
Pi = P(60)/D(2+ ) da cui Pi = P(60) 2+(1-β/2)2+
e Pc = P(60) (1-β/2)2+ / (1-β cosθ)2+
Assumendo  = 0 (nucleo)
Pc = P(60) (1-β/2)2 / (1-β cosθ)2
(Pc/P(60))0.5 = (1-β/2)/ (1-β cosθ) Pc da osservazioni
P(60) da Ptot e best fit
Possiamo assumere tutti i getti circa stessa velocita  posizione
punti solo legati a orientazione MA dispersione dipende da velocita’
dei getti
Problema: variabilita’ !!!!

42. Conseguenze di tempi diversi
Getto relativistico in avvicinamento insegue suoi fotoni per cui
intervalli di tempo non si conservano
Se emesso segnale a tempo t=0 e segnale successivo a intervallo
tempo ta, osservatore riceve segnale a t2 = ta+(d – vta cosθ)/c
Osservatore vede 2 segnali a t = t2 – t1 = ta(1 – v/c cosθ) =
ta(1 – β cosθ)
Se 2 getti o lobi intrinsecamente simmetrici si muovono relativist.
appariranno diversi perche li vediamo a t intrinseco diverso
a = approaching ed r receading
ta = t /(1-β cosθ) tr = t /(1+β cosθ)
Essendo L’a = La sinθ = vta sinθ e L’r = Lr sinθ = vtr sinθ
L = Lunghezza (size)

43. Arm length ratio risulta che:
By comparison of the size of the approaching (La)
and receding (Lr) jet we derive:
o anche La/Lr = L’a/L’r = θa/θr = Da/Dr

44. Lobi radio: Mediano asimmetria flussi = 1.6
se dovuto a moto relativistico ne derivo β cosθ ≈ 0.06
da cui β < 0.1
Inoltre risulta che
Sa/Sr = (θa/θr)3+ da cui lobo piu’ lontano dal nucleo dovrebbe
essere piu’ luminoso, ma cio’ non verificato anzi contrario
Tutto porta a derivare velocita’ espansione lobi < 0.1c
Tale velocita’ e’ anche in accordo con diametro e stima eta’ della
radio sorgente

45. THE MEASUREMENT OF THE JET VELOCITY
Proper Motion
In some sources proper motion has been detected allowing
a direct measure of the jet apparent pattern velocity.
The observed distribution of the apparent velocity shows a
large range (e.g. Kellerman et al. 2000)

46. From the measure of the apparent velocity we can derive
constraints on β and θ:
But are bulk and pattern velocity correlated????
In a few cases where proper motion is well defined there is a
general agreement between the highest pattern velocity and
the bulk velocity:
Ghisellini et al. 1993
Cotton et al for NGC 315
Giovannini et al for
However in the same source we can have different pattern
velocities as well as standing and high velocity moving
structures

47. In some well studied sources the jets show a smooth and uniform
surface brightness  no proper motion visible
e.g. Mkn 501 (Giroletti et al. 2003, ApJ)
βamax = β ≈  per v ≈ c
Il massimo si ha per cos θ = β ossia sen θ = 1/
(θ ≈ 1/ per  grandi)

48. Se il redshift e’ molto elevato occorre inserire correzione
relativistica perche’ tutto si sta allontanando da noi con
moto relativistico
Sempre: v = βc e’ la velocita’ del blob rispetto al nucleo
della sorgente
Vedi astro-ph/ ,

49. On the parsec scale it shows a core, a strong extended jet and
a short cj
counterjet
flat spectrum core
main jet

50. Superluminal motion
Well defined components – 11 epochs from 1991 to 2002
Only high quality data:
jet: 5 and 8.4 GHz data
cj 8.4 GHz only
Jet: βapp = 2.7 constant
All components constant
velocity
cj side βapp = 0.3

51. Since we know the j and cj proper motion according to
Mirabel et al we can derive the jet orientation:
μa = β senθ/(1 – β cosθ) c/D
μr = β senθ/(1 + β cosθ) c/D
che diventano
β cosθ = (μa – μr) /(μa + μr) = 0.8
cgs e moti propri in radianti s-1
Da cui D <= c/(μaμr)0.5 (velocita’ massima e’ c)
(distance of the superluminal galactic source) .

52. From the j-cj arm ratio ( about 10) we derive
β cosθ = 0.8
in agreement with the measured pattern velocity

53. Shear-layer δ = 2.4 - boosted If the inner spine is moving with e.g.
Г = 15 the corresponding Doppler
factor is 0.7 – deboosted.
A fast spine and a lower velocity
shear layer can explain the limb
brightened structure.
core
If the external region started with the same velocity of the
inner spine, its velocity decreased from to 0.88c in less than
100 pc. This suggest a velocity structure already present at the
jet beginning.

54. Results From our study on sources from the B2 and 3CR catalogues
and from literature data we found that:
- In all sources pc scale jets move at high velocity. No correlation
has been found with core or total radio power
- We used the jet velocity and the corresponding orientation to
derive the Doppler factor for each source:
and the corresponding intrinsic core radio power:
 = 0

55. The line is the general correlation between the core and total
M87
3C192
The line is the general correlation between the core and total
radio power. Points in the left side (observed data) show the
expected dispersion because of different orientation. Note
that we started to observe sources with brighter core.
In the right figure we plotted the derived intrinsic core radio
power. We have here a small dispersion since we removed the
spread due to different orientation angles.

56. Struttura dei nuclei radio
Strutture compatte auto assorbite
Non vediamo ‘core’ ma base del getto
Autoassorbimento: Tb simile a temperatura cinetica elettroni
relativistici
Spettro a campana radiosorgente opaca a se stessa
in regime opaco flusso cresce come 2.5,
dove la sorgente e’ trasparente flusso cala come -
Indicando con max ed Smax la frequenza dove lo spettro
raggiunge il massimo e con Smax il flusso corrispondente
abbiamo
H(gauss) ≈ (θ(mas))4(max(GHz))5(Smax(Jy))-2 D/(1+z)
con D = fattore Doppler

57. Dove θ e’ il diametro angolare nella zona di transizione
quindi abbiamo stima del campo magnetico
viceversa assumendo il campo magnetico di equipartizione
possiamo stimare diametro angolare della rs
Spettro = somma spettri di singole componenti da cui spettro piatto
3C 338 a FR I radio galaxy
3C 452 a NL FR II radio galaxy

58. Variabilita’
Compatte mostrano variabilita’ piu’ o meno marcata in tutte le
bande
A frequenze < 1 GHz scintillazione interstellare
Variabilita’ a lungo periodo
ad alta frequenza intrinseco: modello nube inizialmente opaco
che espande e diventa trasparente a frequenze sempre piu’
basse e con flussi sempre minori (perdite adiabatiche)
La variabilita’ avviene a tempi diversi a diverse frequenze
Variabilita’ a corto periodo
Assumendo che dimensioni lineari sorgente siano < cTv dove Tv
e’ il tempo della variabilita’, ne derivano dimensioni angolari
< arcsec

59. Tbo = Tbi x D Da dimensioni angolari cosi piccole risulta che
I = F/πθ2 = B = 2kTb/2
Se e’ θ piccolo e/o  e’ grande possiamo ottenere Tb() > 1012 K
Per cui 1) emissione coerente – difficile per regioni cosi grandi
2) diametri sottostimati
Infatti T alta implica radiazione alta energia non osservata e vita
breve della rs
Possibile soluzione nube in espansione in moto relativistico verso
di noi
Tbo = Tbi x D

60. History The present status
AGN Unification
History
The present status

61. What’s all this Unification?
Historically it is attempt to explain as much as the spread of observational properties as possible in terms of orientation effects.
Assume some axis; i.e. rotation
More generally, it is an attempt to explain the diversity of observational properties in terms of a simple model

62. The AGN Paradigm

63. Introduction
AGN are not spherically symmetric and thus what you see depends on from where you view them. This is the basis of most unification models.
It was the discovery of superluminal motion and the interpretation in terms of bulk relativistic motion of the emitter that first made people realize that orientation in AGN was important.
I will outline the consequences of Doppler boosting, describe the historical development of schemes and then review the modern evidence.
N.B. Relativistic beaming is not the only mechanism that can make AGN emission anisotropic

64. Doppler boosting
When an emitting body is moving relativistically the radiation received by an observer is a very strong function of the angle between the line of sight and the direction of motion.
The Doppler effect changes the energy and frequency of arrival of the photons.
Relativistic aberration changes the angular distribution of the radiation.

66. Parent populations
To every beamed source there will be many unbeamed sources – the parent population.
How to identify the parent population?
Look at some emission that’s isotropic; e.g. radio lobe emission, far infrared emission, narrow-line emission, etc in the beamed population and look for another population having the same luminosity function for the isotropic emission.

67. History of Unification
Rowan-Robinson (1976, ApJ, 213,635) tried to unify Seyfert galaxies and radio sources.
Mostly wrong – no beaming
But the importance of dust and IR emission correct.
Blandford and Rees (Pittsburgh BL Lac meeting 1978) laid the foundations for beaming unification. (Radio loud only).

68. History continued
Scheuer and Readhead (1979, Nature,277,182) proposed that radio core-dominated quasars and radio quiet quasars could be unified – the former being beamed versions of the latter.
Orr and Browne (1982,MNRAS,200,1067 ) realized that the Scheuer and Readhead scheme could not work because MERLIN and VLA had shown that most of the core-dominated quasars had extended (isotropic) radio emission and thus their parent population could not be radio quiet. We looked for a non-radio quiet parent population
Proposed core-dominated/lobe-dominated unification for quasars

69. Radio Galaxy/Quasar Unification (Both are FR2s)
Widely discussed before, but first published by Barthel (1989, ApJ, 336,606) – an extension of core-dominated/lobe-dominated quasar unification.
Quasars have strong continuum and broad lines and radio galaxies (FR2s) have little continuum (other than starlight) and no broad lines.
How could they be the same thing? Only if one could hide the quasar nucleus with something optically thick (a molecular torus).
N.B. In a parallel line of development Antonucci and Miller had discovered polarized broad lines in the Seyfert 2 NGC1068 which they interpreted as being scattered nuclear radiation from a hidden BLR.

70. The AGN Paradigm

72. BL Lacs and FR1 RGs
Similar arguments apply to these intrinsically lower luminosity objects; BL Lacs are the beamed cores of FR1 RGs. (Note FR1 RGs generally have only weak and narrow emission lines and BLLacs are almost lineless.)
Blandford and Rees (1978)
Browne (1983, MNRAS,204,23)
Antonucci and Ulvestad (1985,ApJ,294,158)
Padovani and Urry (1991, ApJ,368,373)

73. Evidence for BL Lac/FR1 unification
The statistics look ok (Browne; Padovani and Urry) for reasonable Lorentz factors
The required relativistic jets are seen in a few FR1s, most notably in M87 (Biretta AJ,520,621).
The strength of optical cores in FR1s seems to correlate with the strength of the radio core consistent with both being beamed (Capetti &Celotti,1999,MNRAS,303,434, Chiaberge et al. 2000,A&A,358,104)
=> No hidden BLR in FR1s (but BL Lac itself has a broad line)

74. HST Image of jet in M87 M87 is an FR1 radio galaxy
Superluminal motion has been detected in both radio and optical

75. Evidence for superluminal motion in M87

76. Correlation between optical nuclear and radio core luminosities (Chiaberge et al,A&A,358,104)

77. NGC6251 HST image of the optical core.
Despite dust lane (dark band) the core is clearly visible
The strength of cores correlated with that of radio core

78. Optical nuclei are very
common.

79. Parent Population intrinsic observed
Low frequency  no beaming effects
Nuclear properties different since are affected
by beaming but in agreement if we compare intrinsic
values.

80. The correlation between the optical and radio nuclear flux density in FR I implies common synchrotron origin and no dust torus
BL Lacs show the same correlation in agreement with Unified Models. The shift is due to the different boosting
BL Lacs
Chiaberge et al. 1999
FR I

81. BL Lacs
Chiaberge et al. 1999
FR I
Our sample
Corrected for the Doppler factor
BL Lacs observed

82. A correlation between X-ray and radio is expected if there is a fundamental
connection between accretion flows and jets. Merloni et al showed that
the sources define a FP in the three-dimensional space: log LR, log LX, log MBH.
They used AGN and X-ray binaries (SMBH and BH) but not BL Lacs because
of beaming

83. observed
intrinsic
FP relation
FP relation
Observed BL Lacs properties do not follow the FP, but if we plot intrinsic
properties we note a general agreement even if the large data dispersion
and the separation between HBL and LBL suggest secondary effects (velocity
structures and/or correlation between jet velocity and source properties)

84. The Chandra view of the 3C/FRI sample. I
X-ray cores are ubiquitous in FR I,
just like the optical cores.

85. The Chandra view of the 3C/FRI sample. II
A very strong correlation emerges between the radio/optical and the
X-ray cores in FRI radio-galaxies.

86. Summarizing:
Chandra observations of FR I radio-galaxies provide further support for the jet scenario and not only based on the strong radio/optical/X-ray correlations.
Spectral indices have values similar to proper counterpart of jet dominated sources (LBL). They also show the evolution expected from beaming and the same luminosity evolution of BL Lac.
Measurements of radio/optical and X-ray nuclei represents a unique
tool to explore the properties of AGN.

87. Tests of radio galaxy/quasar unification
The relative numbers of FR2 RGs and Qs (about 2:1 => half-cone angle of ~45 degrees) should be related to the size of the un-obscured cone angle hence can calculate by what factor the radio sizes of Qs should be smaller than RGs.
The results are mixed but do not rule anything out.
If the quasar nucleus is hidden by dust the intercepted energy should be re-radiated in the FIR. Qs and RGs should have same FIR luminosity.
Seems just about ok

88. Tests continued
Broad lines should be detectable in narrow line RGs – either in scattered polarized light or in the IR.
Some examples of both are seen as well as some UV broad lines (e.g. Cygnus A)
Narrow emission lines well away from the torus should have the same luminosity in RGs and Qs of intrinsically the same power.
[OIII] is stronger in Qs (Jackson and Browne)
[OII] is the same (Hes et al.)
The Q luminosity function should be a “beamed” version of the RG one (Urry and Padovani)

89. Correlations -- Radio
If jets are relativistic, some “unification” is inevitable. What’s the evidence for relativistic jets?
Superluminal motion (rarely measurable in RGs)
Jet asymmetry (X-ray jets seen with Chandra need relativistic motion to give enough IC emission)
Laing– Garrington effect
Even in radio galaxies, the side of the source with the jet is less depolarized
=> Jet asymmetry arises from orientation and hence they are relativistic.

90. Radio map of 3C175

91. CHANDRA X-Ray Jet in Pictor-A

92. Unification across the FR1/FR2 boundary?
There does seem to be a real distinction between FR1s and FR2s:
Radio structure
Radio luminosity
Optical emission line properties
Cosmological evolution
But the non-thermal emission is similar in both
Also FR2s could possibly evolve into FR1s
There is no strong evidence against this (Unification by time?)

93. FR2s evolving into FR1s? Assume:
FR2s are objects with relativistic jets that reach the full extent of the radio source
That the distance that jets can travel at relativistic speeds depends on jet power; high power jets make it further out.
Then young small sources of a given jet power will be FR2s, but as they grow and get older they will become FR1s
Some crossing of the FR boundary with time for lower-power objects.
(N.B. There are some FR2s with weak emission lines which when beamed may become BL Lacs)

94. Wider Unification
Stimulated by the discovery of polarized broad lines in a Seyfert 2 (narrow-line Seyfert) by Antonucci and Miller (1985,ApJ,297,621), in the mid 1980s the optical community realized that AGN were not spherically symmetric and that orientation effects were important.
There emerged the standard model the key ingredient of which is the “obscuring torus” which hides the inner part of all AGN (BLR plus disk emission), both radio-quiet and radio-loud

95. Accretion Disk+Black Hole
The Structure of AGN
Seyfert 1
Narrow Line Region
Torus
Central Engine:
Accretion Disk+Black Hole
Seyfert 2
Broad Line Region

96. Apparenza AGN dipende da angolo rispetto a linea di vista
Toro oscurante – nasconde AGN e BLR in type 2 AGN
Jet relativistico: doppler boosting
Esistenza toro:
Ionization cones
BLR polarizzate in oggetti tipo 2
Emissione continua visto da oggetti tipo 2 puo’ non essere
sufficiente a ionizzare NLR
Soft X-ray absorption in oggetti tipo 2
Radio free-free absorption
Non esistenza toro: correlazione Pcore e nucleo ottico in FR I
In accordo con assenza righe Bl-Lacs

97. Seyfert 1 – Seyfert 2 Intrinsically same except for obscuration ?
So now take only unobscured objects!

98. Seyfert 1 - Quasars Similar spectra and line ratios,
strong UV flux to excite lines,
probably similar L/LEdd ~
Increasing L
Increasing M

99. Evidence for the standard model
More hidden BLR seen in scattered (polarized) light.
Ionization cones.
Though many claimed not many are convincing
Photoionization considerations – some Seyfert 2s do not have enough ionization photons seen to give the NLR luminosity
Molecular disks, particularly NGC4258

100. Ionization cone in NGC 5728
If ionizing photons are blocked by the torus then one expects to see cones delineating the boundary.

106. In S2 vediamo continuo e BLR solo se riflesse, da nubi, materiale
ionizzato o altro S1
BLR riflessa S2

108. X-ray ionization cones
Seyfert 2 galaxy NGC5252
OIII ionization cones
X-ray ionization cones
Tadhunter & Tsvetanov, Nature, 1989
Wilson & Tsvetanov, 1994
Camilla Boschieri, tesi di laurea

109. Young radio sources Powerful in radio band (P1.4 GHz > 1025 W/Hz);
1. Introduction
Young radio sources
Powerful in radio band (P1.4 GHz > 1025 W/Hz);
Compact size (LS < 15 – 20 kpc):
Spectral peak  ~ 100 MHz to a few GHz;
Heavily depolarized;
High fraction in flux-density limited catalogues (15% – 30% )

110. The spectral peak Their main property is the optically-thin
1. Introduction
The spectral peak
Optically thin
Optically
thick nb
n-a
Log 
Log S()
Their main property
is the optically-thin
steep spectrum that
turns over at low
frequencies.
(D=1!)

111. Turnover frequency versus linear size
Implica campi magn.
simili

112. 1. Introduction
The peak frequency
Turnover

113. Linear size - turnover CSS GPS HFP LLS < 15 - 20 kpc
1. Introduction
Linear size - turnover
HFP
GPS
CSS
LLS < kpc
t ~ 50 – 100 MHz
CSS
LLS < 1 kpc
t ~ 1 GHz
GPS
LLS ~ 10 pc
t  4 GHz
HFP
The smaller the source, the higher the turnover frequency

114. Linear size The radio sources completely resides within the
1. Introduction
Linear size
The radio sources completely resides within the
Insterstellar medium (ISM) of the host galaxy
Compact Symmetric Objects (CSO)
LS < 1 kpc (<0.1”), within the NLR;
Medium Symmetric Objects (MSO)
LS < 15 – 20 kpc (<1”)

115. High resolution observations!
1. Introduction
High resolution observations!
MSO: VLA  21 cm; 3.6 cm

116. High resolution observations!
1. Introduction
High resolution observations!
CSO: VLBI  21 cm; 3.6 cm
VLBA
EVN

117. 1. Introduction
Morphology
Scaled-down version of the classical Extended Doubles: they should represent the young stage in radio source evolution
Hot spots
Core
150 kpc
7 pc
350 pc
Core HS HS
Core
4.5 kpc HS
Core

118. Why are they so compact? Youth scenario: Frustration scenario: Compact
1. Introduction
Why are they so compact?
Youth scenario:
Frustration scenario:
Compact
Young
Baldwin 82, Fanti+ 95, Readhead+ 96, Snellen+ 00…..
Compact
Frustrated
van Breugel+ 84, Baum+ 90

119. Youth: Proper motion B0710+439 LS tkin ~ ~ 103 yr!! vsep vsep= 0.3c
1. Introduction
Youth: Proper motion B
Polatidis&Conway 03
vsep= 0.3c
Young
Hot spots
Core LS
vsep
~ 103 yr!!
tkin ~

120. Youth: Proper motion B2352+495 vsep = 0.12c tkin ~ 3·103 yr
1. Introduction
Youth: Proper motion B
Core
Hot-Spot
vsep = 0.12c
tkin ~ 3·103 yr
Owsianik et al. 1998

121. Kinematic age Polatidis&Conway 03
1. Introduction
Kinematic age
Polatidis&Conway 03
The kinematic ages derived for a dozen of the most compact (≤100 pc) CSOs are in the range of 103 – 104 yr, much shorter than the ages estimated for the largest (up to a few Mpc) radio galaxies.

122. Youth: Spectral analysis
1. Introduction
Youth: Spectral analysis
B , Murgia 2003
From the break frequency br we can derive the radiative age, once the magnetic field is known!
trad  br-1/2 H-3/2
From br in the lobes:
trad ~ 103 yr

123. Youth: spectral analysis
1. Introduction
Youth: spectral analysis B

124. 1. Introduction
Youth: radiative age
trad ~ 103 yr

125. The “frustration” scenario
1. Introduction
The “frustration” scenario
Compact
Frustrated
Observations from IR to X-ray searching for an excess of dust,
and cold, warm and hot gas did not provide evidence of a
particularly dense environment.
Fanti+ 00, Siemiginowska+ 05
Indirect support to the youth scenario

126. 1. Introduction
Sample selection
The selection of young sources cannot be based on the morphological properties.
Samples are selected on the basis of the spectral shape and the peak frequency
This implies the selection of both galaxies and quasars, with different proportion depending on the peak frequency and luminosity.

127. Sample selection High frequency/luminosity selected sample
1. Introduction
Sample selection
High frequency/luminosity selected sample
Higher fraction of quasars
Low frequency/luminosity selected sample
Higher fraction of galaxies

128. 2. Radio properties Introduction 3. Source evolution
4. Physical properties
5. The ambient medium

129. Radio properties Flux density and spectral variability;
Radio morphology;
Polarization.

130. 2. Radio properties
Variability
Young radio sources should not possess significant amount of variability because they should be intrinsically compact.
No beaming effects!!

131. Variability…..galaxies
2. Radio properties
Variability…..galaxies
Simultaneous multifrequency observations at various epochs do not show remarkable changes in young radio sources identified with GALAXIES

132. Variability…..galaxies
2. Radio properties
Variability…..galaxies
Simultaneous multifrequency observations at various epochs do not show remarkable changes in young radio sources identified with GALAXIES

133. 2. Radio properties
Variability….quasars
A significant fraction of compact sources identified with QUASARS high level of variability are present.

134. 2. Radio properties
Variability….quasars
A significant fraction of compact sources identified with QUASARS high level of variability are present.

135. 2. Radio properties
Morphology…galaxies
GALAXIES have a “symmetric” structure, where symmetric means “two-sided”
500 pc
Core HS

136. 2. Radio properties
Morphology…quasars
A large fraction of QUASARS have a Core-Jet or a Complex structure.
Complex
Core-Jet
Rossetti et al. 2005

137. Polarization properties
2. Radio properties
Polarization properties
LS < 6 kpc
Fanti et al. 2004
Unpolarized at 1.4 GHz
Cotton et al. 2003
LS < 3 kpc
Unpolarized at 8.4 GHz

138. 2. Radio properties
Faraday screen

139. 2. Radio properties
Rotation Measure
CSS with LLS > 5 kpc are polarized with H // to the jet axis
CSS with LLS < 5 kpc have high RM
GPS and HFP galaxies are usually unpolarized
HFP quasars are strongly polarized

140. Galaxies vs quasars The different characteristics shown by GPS/HFP
2. Radio properties
Galaxies vs quasars
The different characteristics shown by GPS/HFP
with different optical identification are consistent
with the idea that GPS/HFP galaxies and quasars
represent two different radio source populations:
Galaxies Compact sources
Quasars Beamed objects

141. …with some exceptions J0650+6001 Quasar z=0.45 vsep = 0.39c±0.18c
2. Radio properties
…with some exceptions J
Quasar z=0.45
vsep = 0.39c±0.18c
tkin = 360±170 yr

142. The quasar J0650+6001 vi=0.43c±0.04c 12 < θ < 28
2. Radio properties
The quasar J
From the source expansion:
From the flux density ratio:
vi=0.43c±0.04c
12 < θ < 28

143. The quasar J1459+3337 t ~ 50 yr Rapid evolution of radio emission
2. Radio properties
The quasar J
Rapid evolution of radio emission
peak moves to low frequency
- from 24 to 12 GHz in 7 yr
variability of the spectrum
- in the optically-thick part of the spectrum the flux density increases as the source expands
t ~ 50 yr

144. 3. Source evolution Introduction 2. Radio properties
4. Physical properties
5. The ambient medium

145. Evolutionary stages Higher peak frequency Smaller linear size
3. Source evolution
Evolutionary stages
Murgia 2003
Higher peak frequency
Smaller linear size
Younger the source

146. ? Evolutionary stages HFP GPS CSS FR I/II HFP GPS CSS
3. Source evolution
Evolutionary stages
HFP
GPS
CSS ?
HFP
GPS
CSS
FR I/II

147. Too many young radio sources!
3. Source evolution
Too many young radio sources!
Young radio sources represent 15% - 30% of the
objects in flux density-limited catalogues.
The fraction expected on the basis of the source
age is much smaller!!
Young
Old
103-4 yr
107-8 yr ~
0.01%

148. 3. Source evolution
Luminosity evolution
The radio sources should decrease in luminosity by an order of magnitude as they evolve (Fanti et al. 1995).
The ambient medium enshrouding the radio source should play a role in the source evolution (Baldwin 1982)

149. Luminosity evolution…
3. Source evolution
Luminosity evolution…
If the thrust of each relativistic jet is balanced by the ram-pressure of the surrounding medium:
Velocity:
Assuming equipartition, the luminosity is:
1/2 Pj
v 
nextmpcA
L 
Pj t
V3/7
7/4
Energy density:
u 
Pj t V

150. …in a King-like density profile
3. Source evolution
…in a King-like density profile
- /2 r2
next  n0
1 +
r02
r < r0 (like CSO)
r > r0 (like MSO)
v  t
2 - 
4 - 
v 
t-1/2
2 + 
L 
t5/8
L  t
16 - 4

151. 3. Source evolution
Luminosity evolution
L  t 5/8
L  t -1/2

152. CSS evolvono in radio sorgenti piu’ deboli, questo risolve
il problema del loro numero apparentemente troppo elevato
FR II
FR I
limite osserv. per giganti

153. A survey of low‐luminosity compact sources and its implication for the evolution of radio‐loud active galactic nuclei – I. Radio data
(a) Luminosity–size diagram for AGNs. (b) Luminosity–redshift diagram for AGNs. Squares indicate CSS sources from the samples: grey squares, Fanti et al. (2001); black squares, Marecki et al. (2003a); empty squares, Laing et al. (1983). The diamonds indicate GPS objects and small black squares indicate HFP objects from the sample of Labiano et al. (2007). The filled circles indicate FR I objects and open circles indicate FR IIs from the sample of Laing et al. (1983). The crosses indicate the current sample of LLC sources, except for the source with the redshift indicated as ‘d’.
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153

154. A survey of low‐luminosity compact sources and its implication for the evolution of radio‐loud active galactic nuclei – I. Radio data
Evolutionary scheme of radio‐loud AGNs.
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Monthly Notices of the Royal Astronomical Society Volume 408, Issue 4, pages , 30 SEP 2010 DOI: /j x
154

155. Fading radio sources Young but fading objects?
3. Source evolution
Fading radio sources
Despite the luminosity evolution, young objects are still too many
Gugliucci et al. 2005
The age distribution sharply peaks below 500 yr
Young but fading objects?

156. PKS 1518+047: a study case tsyn = 2700±600 yr
3. Source evolution
PKS : a study case
tsyn = 2700±600 yr
Neither injection nor acceleration of new particles!
tOFF = 550±100 yr

157. Recurrent activity? Low accretion rate: 103 yr
3. Source evolution
Recurrent activity?
The large fraction of young radio sources may be explained assuming the existence of short-lived objects with intermittent activity.
Recurrent activity may be caused by radiation pressure instability within the accretion disk (Czerny et al. 2009).
Low accretion rate: 103 yr
Eddington accretion rate: 108 yr

158. FIRST 33Myr 0836+29B 4C29.30 100Myr A galaxy merger >200Myr
Jamrozy et al.
2007
FIRST
33Myr
25 kpc
Van Breugel et al. 1986
VLA A+B at 20cm
B 4C29.30
A galaxy merger
100Myr
Jamrozy et al. 2007

159. only flat spectrum component
Core – most compact
only flat spectrum component 4
10 yrs
1 kpc
VLA – A array at 6 cm

160. core 15 yrs 70 yrs Strong outburst after 1990 Jamrozy et al. 2007
2005.8
core
15 yrs
5 pc
1 kpc
70 yrs
Strong outburst after 1990
Jamrozy et al. 2007

161. Fossils from the past On kpc scales: J0111+3906: 128 kpc
3. Source evolution
Fossils from the past
On kpc scales:
J : 128 kpc
trelic ~ 107–108 yr
On pc-scales:
J : 50 pc
OQ208: 43 pc
trelic ~ 103 – 104 yr

162. 4. Physical properties Introduction 2. Radio properties
3. Source evolution
4. Physical properties
5. The ambient medium

163. Physical properties The knowledge of the physical properties
occurring during the first stages of the radio
emission is fundamental in order to determine
the initial conditions to be used in the
development of the evolutionary models!!

164. Spectral peak SSA in a homogeneous component: β = 2.5
4. Physical properties
Spectral peak
Optically thin
Optically
thick


Radiative
losses
Log 
Log S()
SSA in a homogeneous component:
β = 2.5
SSA is present BY DEFAULT!

165. Magnetic field In the presence of SSA from homogeneous component:
4. Physical properties
Magnetic field
In the presence of SSA from homogeneous component:
HSSA =
f()5 S2p (1+z)
max min 5p
Kellermann&Pauliny-Toth 81

166. Are young objects in equipartition?
4. Physical properties
Are young objects in equipartition?
In case of equipartition:
Heq  (1+k)2/7 -2/7 P2/7 V-2/7
Pacholczyk 1970
Heq  HSSA
Orienti&Dallacasa 08

167. Are young objects in equipartition?
4. Physical properties
Are young objects in equipartition?
In case of equipartition:
Heq  (1+k)2/7 -2/7 P2/7 V-2/7
Pacholczyk 1970
Heq  HSSA
Orienti&Dallacasa 08
with some exceptions…

168. SSA or Free-Free Absorption?
4. Physical properties
SSA or Free-Free Absorption?
Optically-thick part of the spectrum is too steep to be described by SSA only. Addition of FFA is needed!!!
HSSA cannot be derived

169. Inhonogeneous ambient medium!
4. Physical properties
SSA or FFA?
FFA
SSA
Inhonogeneous ambient medium!

170. 5. The ambient medium Introduction 2. Radio properties
3. Source evolution
4. Physical properties
5. The ambient medium

171. The ambient medium The onset of radio 4C 31.04 activity is currently
thought to be related to
merger/accretion
events occurring in the
host galaxy and which
fill the central region of
fuel for the AGN
4C 31.04

172. 4C31.04: a CSO z = 0.06 S1.4 GHz = 2.5 Jy P1.4 GHz = 2.4 x 1025 W/Hz
MH=-23.6 (Perlman et al. 2001)
1 mas/yr = 5.4 c
(H0 = 50 km sec-1 Mpc-1)

173. VLBA @ 5 GHz, epoch July 2000 (10 mas = 15 pc)

174. Expansion... results. DE ~ 0.4 mas DW ~ 0.5 mas DT = 5 yr v ~ 0.5 c
age ~ 500 yr

175. Rich environment High incidence of ionized gas (FFA);
5. The ambient medium
Rich environment
As a consequence of the merger, the medium
enshrouding the radio source should be rich
and dense of gas
High incidence of ionized gas (FFA);
Highly depolarized sources;
High detection rate (~40%)of molecular gas (CO) in emission (Mack+ 09);

176. 5. The ambient medium
The ambient medium
The jet is piercing its way through the dense medium left by the merger
4C 31.04, Conway 03

177. The HI in young radio sources
5. The ambient medium
The HI in young radio sources
Larger incidence than what found in extended galaxies (~10%, Morganti et al. 2001)

178. The HI in young radio sources
5. The ambient medium
The HI in young radio sources
Anti-correlation between linear size LS and the column density NHI (Pihlström et al. 2003, Gupta et al. 2006)

179. The HI in young radio sources
5. The ambient medium
The HI in young radio sources
Circumnuclear disk/torus with a radiaclly decreasing density profile
Mundell et al. 2003

180. The molecular gas Disk structure Symmetric Doubled-peak profile
5. The ambient medium
The molecular gas
Symmetric Doubled-peak profile
Disk structure
Mdisk ~ 1.4·1010 M○
Ocaña-Flaquer et al 2010

181. The molecular gas HCO+ (1-0) CO (2-1) Unsettled disk?
5. The ambient medium
The molecular gas
HCO+ (1-0)
CO (2-1)
Asymmetric doubled-peak profiles
Unsettled disk?
Mdisk ~ 5·109 M○
…and the absorption?
Garcia-Burillo+ 08

182. VLBI observations Central disk HI detected against the whole source
5. The ambient medium
VLBI observations
, Peck+ 99
HI detected against the whole source
Central disk
v = 350 km/s
NH  2x1023 cm –2 (Ts = 8000 K)

183. VLBI observations Off-nuclear cloud
5. The ambient medium
VLBI observations
, Maness+04
HI detected only against the southern hot spot
Off-nuclear cloud
v = 540 km/s
NH  2x1020 cm –2 (Ts = 100 K)

184. VLBI observations Off-nuclear cloud
5. The ambient medium
VLBI observations
4C 12.50
HI located ~100 pc from the core, where the jet bends
Morganti+ 04
Off-nuclear cloud
v = 150 km/s
NH  1022 cm –2 (Ts = 100 K)
Mcl ~ 106 M○

185. Jet-cloud interaction?
5. The ambient medium
Jet-cloud interaction?
Jet-cloud interaction may influence the source growth, for example slowing down the jet expansion and enhancing its luminosity!
Labiano+ 06

186. Jet-cloud interaction
5. The ambient medium
Jet-cloud interaction
4C 12.50
Shallow, broad and blue-shifted component
Morganti+ 04
Outflow!
v  2000 km/s
NH  2.6x1021 cm –2 (Ts = 1000 K)

187. Outflows Δv ~ 2000 km/s τ ~ 0.005 NHI ~ 8·1020 cm-2
5. The ambient medium
Outflows
OQ 208, Orienti+ 06
Δv ~ 2000 km/s
τ ~ 0.005
NHI ~ 8·1020 cm-2
Amounts of gas are expelled from the host galaxy!!

188. Fast outflows of atomic gas
5. The ambient medium
Fast outflows of atomic gas
Large receiver WSRT
7 CSOs detected
Mrate ~50 M○/yr
Morganti+05

189. Fast outflows of ionized gas
5. The ambient medium
Fast outflows of ionized gas
Giant outflows of ionized gas detected only in galaxies hosting a young radio source
Complex line profile O[III]
v ~ 2000 km/s
Blueshift
Holt+ 08

190. 5. The ambient medium
Outflows
Jet-cloud interaction may influence both the source growth and the properties of the ISM.
Outflows of ionized and atomic gas found only in galaxies hosting a young radio sources, implying a higher probability that jet-ISM interaction takes place in such objects!!