1. Group meeting @ Nov. 01, USTC
4/18/2019
Group Nov. 01, USTC
AGN-dominated
SFG-dominated

2. Discovery of quasar in 1963 - famous 3C 273
quasar, QSO, quasi-stellar object, ...
starlike
extremely luminous
broad lines
jet
Greenstein & Schmidt 64; optical
3C 273
Bahcall+95
HST (~ B,V) + MERLIN (18 cm)

3. Discovery of quasar in 1963 - famous 3C 273 - SED
quasar, QSO, quasi-stellar object, ...
starlike
extremely luminous
broad lines
jet
UV/optical - near-IR
panchromatic
Courvoisier 98

4. Active Galactic Nuclei (AGNs) family
AGN, quasar, QSO, quasi-stellar object, ..
high or low luminosity
Broad line or narrow line
Type I or II
Seyfert 1, ..., 1.5, ..., 2
FR I or II
LINERs: Low-Ionization Nuclear Emission-line Regions
blazars: BL Lac and Optically Violent Variables (OVVs)
...

5. BH + Accretion power and AGN structures
more or less ...
Beckmann & Shrader 2012

6. Radio-loud (RL) and radio-quiet (RQ) in AGN UM
RL: radio-loud
how and when does jet emerge?
jet
Elvis+94
RQ: radio-quiet
Beckmann & Shrader 2012

7. Radio emissions synchrotron (relativistic e-)
4/18/2019
Radio emissions
synchrotron (relativistic e-)
supernova remnants ~ SF (Condon+13)
shocks in outflows (Zakamska & Greene 14)
AGN’s corona & jet
free-free (bremsstrahlung)
HII regions ~ SF
From Vernesa Smolčić

8. Radio emissions and the radio-IR correlation
4/18/2019
Radio emissions and the radio-IR correlation
for normal galaxies
L1.4GHz
LTIR ~ SFR
From Vernesa Smolčić

9. the same mechanism for the radio emission?
Are RL quasar the same population as RQ quasar?
RL: radio-loud
the same mechanism for the radio emission?
jet
Elvis+94
RQ: radio-quiet
weak AGN?
SF?
Beckmann & Shrader 2012

10. What matters: RL vs RQ quasars?
single vs two population(s)
Why is only a small fraction, 10-15% of quasars RL?

11. Single population - all related to SMBH/AGN?
4/18/2019
Single population - all related to SMBH/AGN?
BH mass, Accretion rate, magnetic field, BH spin (jet > RL)
no evidence for BH spin powering jets in X-ray binaries? (Fender+10)
the role of BH spin in powering quasar radio jets remains uncertain? (Heckman & Best 14)
Intermittent activity (active > RL)
characteristic timescales of months to years, amplitude <~ 1 mag
Absorption (few absorption > RL)
suppressed by synchrotron self absorption and/or free-free absorption
Host galaxy properties (no host difference?)
a mixture of early- and late-type galaxies for the host of QSOs? (...)
the hosts of both RL and RQ quasars with Mi < are all massive ellipticals? (Dunlop+03)
Relativistic Doppler beaming (view along the jet > RL)
radiation is beamed into a solid angle ~ 1/γ2, with typical γ ~ 10 (Scheuer & Readhead 79)

12. 4/18/2019
Two populations?
SMBH/AGN RL RQ
Kellermann+89 SF

13. A volume-limited sample observed by VLA @ ~ 6 GHz
4/18/2019
A volume-limited sample observed by ~ 6 GHz
to compare the radio properties of optical-selected QSOs ...
178 optical color-selected QSOs:
“radio-unbiased”: QSO selected using SDSS colors
exclude only 1.4 GHz FIRST detection
real AGN: more than one broad line with FWHM > 1000 km s-1
bright enough: Mi < -23 (or mi < 19 for z < 0.3)
exclude Seyfert and low-luminosity AGNs
0.2 < z < 0.3
see also, Kimball+11, Condon+13, Kellermann+16, ...

14. Source properties (VLA beam width ~ 3.5″ FWHM @ ~ 6 GHz)
4/18/2019
Source properties (VLA beam width ~ 3.5″ ~ 6 GHz)
Stotal
Speak RL RQ
L6 ≳ W Hz-1 or
S ~ 0.6 mJy beam-1 for z ~ 0.3
34 RL Quasars: ~ 20%
L6 ≳ W Hz-1
~ 100 kpc
13 extended
144 RQ Quasars: ~ 80%
1021 ≲ L6 ≲ W Hz-1
SFR ~ M☉ yr-1
radio size ≲ 10 kpc
1 extended (maybe unreal)

15. (a) 5 extended RL quasars with asymmetry - must be AGN power!
4/18/2019
(a) 5 extended RL quasars with asymmetry - must be AGN power!
relativistic Doppler boosting

16. (a) 8 extended RL quasars with symmetry - not AGN alone!
4/18/2019
(a) 8 extended RL quasars with symmetry - not AGN alone!
litter or no differential Doppler boosting

17. (b) Bimodal distributions?
4/18/2019
(b) Bimodal distributions?
the presence of two populations
the radio-loud population cannot result from the extended emission alone
Stotal
Speak

18. (c) 6 GHz radio luminosity function @ z ~ 0.2-0.3
4/18/2019
(c) 6 GHz radio luminosity z ~
RLQs: ~ 20%
L6 ≳ W Hz-1
flat LF
RQQs: ~ 80%
bump at L6 ~ W Hz-1, or SFR ~ 20 M☉ yr-1
evidence for SF in QSO host galaxies
two separate populations whose radio emission is dominated by distinctly different energy sources.

19. 4/18/2019
Summary
VLA observations of a sample of 178 SDSS QSOs with Mi < -23 and 0.2 < z < 0.3
QSO radio emission (suggested)
most luminous objects ~ SMBHs
less luminous objects ~ SFs
relevant measure of radio loudness (more physical)
radio luminosity, instead of the radio-optical flux density ratio
RL: AGN > SF; RQ: SF > AGN
symmetrical extended structures and flux density distribution of RL quasars
relativistic beaming is no enough
FAST ? & future SKA, ngVLA, ...

20. Existing and planned surveys @ 1.4 GHz
4/18/2019
Existing and planned 1.4 GHz
Norris+13

21. 4/18/2019
radio future