Diverse Phenomena Arise From a Single Engine: A History Lesson From AGN Unification Anna Ho Journal Club | 18 January 2019 1 Image Credit: Cosmovision (led by Dr. Wolfgang Steffen of the Instituto de Astronomia, UNAM, Ensenada, Mexico) for A. Marscher; NRAO/AUI/NSF 

2 Essential ingredients of an AGN Urry (2003) SMBH (106-10 Msol) 

3 Urry (2003) accretion disk Essential ingredients of an AGN 

4 Urry (2003) torus of gas and dust Essential ingredients of an AGN 

5 Urry (2003) high-velocity gas low-velocity gas Essential ingredients of an AGN 

6 Urry (2003) relativistic jet Essential ingredients of an AGN 

7 Urry (2003) Essential ingredients of an AGN —> zoo of phenomena Steep-spectrum quasar Seyfert II ULIRG Seyfert I QSO BL Lac Flat-spectrum quasar Fanaroff-Riley (FR) I radio galaxy FR II 

I. INTRODUCTION TO AGN 8 II. CONNECTING OPTICAL ACTIVE NUCLEI TO UNIDENTIFIED RADIO SOURCES (1900-1970) “the close correlation between the radio structure and the star with the jet is suggestive and intriguing” - Maarten Schmidt (1963) HST image, credit: ESA/Hubble & NASA 

9 Active optical sources 1) Seyfert (1943): small fraction of galaxies have bright nuclei with broad emission lines (Hβ) 4959, 5007 AA (OIII) 4860 AA Spectrum of NGC 1068 2) BL Lac: highly variable star 

10 (Hβ) 4959, 5007 AA (OIII) 4860 AA Pinning down radio sources Spectrum of NGC 1068 Active optical sources 1) Seyfert (1943): small fraction of galaxies have bright nuclei with broad emission lines 2) BL Lac: highly variable star 

11 Baade & Minkowski (1954): “[Cygnus A] is an extragalactic affair” (Hβ) 4959, 5007 AA (OIII) 4860 AA Pinning down radio sources Schmidt (1963): discovery of quasars (3C 273) Macleod (1968): discovery of radio source coincident with BL Lac Spectrum of NGC 1068 Active optical sources 1) Seyfert (1943): small fraction of galaxies have bright nuclei with broad emission lines 2) BL Lac: highly variable star 

I. INTRODUCTION TO AGN 12 II. CONNECTING OPTICAL ACTIVE NUCLEI TO UNIDENTIFIED RADIO SOURCES (1900-1970) “relativistic plasma can thus be collimated into two relativistic beams” - Blandford & Rees (1974) III. THE IDEA OF RELATIVISTIC JETS (1974) 

Hargrave & Ryle (1974): radio observations of Cygnus A contours of brightness temperature at 5 GHz 2500 K 2500 K 104 K HPBW 140 arcsec 80 arcsec 

Blandford & Rees (1974): these hot spots could represent the lobes of a jet • Active nucleus (engine) • Duration 106-107 years • < 10 pc • Surrounding “cloud” • High pressure (so, cloud size << galaxy size) Model ingredients: 

Blandford & Rees (1974): these hot spots could represent the lobes of a jet Perley (1984): “The jet and filaments in Cygnus A” image credit NRAO 

16 torus of gas and dust Essential ingredients —> zoo of observational classes engine presence of a relativistic jet no radio quiet yes radio loud 

I. INTRODUCTION TO AGN 17 II. CONNECTING OPTICAL ACTIVE NUCLEI TO UNIDENTIFIED RADIO SOURCES (1900-1970) “This scheme attributes the observed differences…to projection” - Orr & Browne (1982) III. THE IDEA OF RELATIVISTIC JETS (1974) IV. RADIO UNIFICATION: VIEWING ANGLE (1982) 

• Flat-spectrum (compact) • Steep-spectrum (diffuse) Observed classes of quasars 

Observed classes of quasars Browne (1982) 10 Jy 1 Jy 0.1 Jy 0.1 Frequency (GHz) 1 10 compact component (flat index) diffuse component (steep index) • Flat-spectrum (compact) • Steep-spectrum (diffuse) 

Unified by viewing angle w.r.t. jet axis (Orr & Browne 1982) Observed classes of quasars Browne (1982) 10 Jy 1 Jy 0.1 Jy 0.1 Frequency (GHz) 1 10 compact component (flat index) diffuse component (steep index) Steep- spectrum quasar BL Lac Flat-spectrum quasar • Flat-spectrum (compact) • Steep-spectrum (diffuse) • Lorentz factor = 5 (now 10) 

21 torus of gas and dust Essential ingredients —> zoo of observational classes engine viewing angle w.r.t. jet axis BL Lac flat-spectrum quasar steep-spectrum quasar on-axis off-axis presence of a relativistic jet no radio quiet yes radio loud 

I. INTRODUCTION TO AGN 22 II. CONNECTING OPTICAL ACTIVE NUCLEI TO UNIDENTIFIED RADIO SOURCES (1900-1970) “I would like to summarize for you…some things that might happen to the jets as they wend their way through the galaxy.” - Phinney (1982) III. THE IDEA OF RELATIVISTIC JETS (1974) IV. RADIO UNIFICATION: VIEWING ANGLE (1984) V. RADIO UNIFICATION: JET VELOCITY (1982-1995) 

Morphological classes of radio galaxies Fanaroff & Riley (1974) FR I (bright jet) 3C 31 (Laing 1996) FR II (bright disk) 3C 353 (Swain 1998) 

Morphological classes of radio galaxies Phinney (1982), Bicknell (1995) Fanaroff & Riley (1974) Differences due to jet deceleration Model ingredients • Relativistic jets on pc scale • FR I decelerate on kpc scale • Declaration due to entrainment FR I (bright jet) 3C 31 (Laing 1996) FR II (bright disk) 3C 353 (Swain 1998) 

25 torus of gas and dust Essential ingredients —> zoo of observational classes engine viewing angle w.r.t. jet axis steep-spectrum quasar on-axis off-axis presence of a relativistic jet no radio quiet yes radio loud successful jet choked (“dirty”) jet FR I FR II BL Lac flat-spectrum quasar 

26 Essential ingredients —> zoo of observational classes engine viewing angle w.r.t. jet axis steep-spectrum quasar on-axis off-axis radio unification scheme presence of a relativistic jet no radio quiet yes radio loud successful jet choked (“dirty”) jet FR I FR II BL Lac flat-spectrum quasar 

I. INTRODUCTION TO AGN 27 II. CONNECTING OPTICAL ACTIVE NUCLEI TO UNIDENTIFIED RADIO SOURCES (1900-1970) III. THE IDEA OF RELATIVISTIC JETS (1974) IV. RADIO UNIFICATION: VIEWING ANGLE (1984) V. RADIO UNIFICATION: JET VELOCITY (1982-1995) VI. OPTICAL UNIFICATION: VIEWING ANGLE (1985) “…the appearance of these figures is surprising. They look like the spectra of a Seyfert Type 1 object!” - Antonucci & Miller (1985) 

Classes of optical AGN Seyfert I BL > 1000 km/s (Hβ) (OIII) He I Hα, NII Wavelength (AA) Seyfert II NL < 1000 km/s 

Seyfert I (BL > 1000 km/s) (Hβ) (OIII) He I Hα, NII A surprise from spectropolarimetry Seyfert II in polarized light! Antonucci & Miller (1985) Wavelength (AA) NGC 1068 

Model ingredients (Antonucci & Miller 1985) Urry (2003) Seyfert II Seyfert I 

31 torus of gas and dust Essential ingredients —> zoo of observational classes engine viewing angle w.r.t. dusty torus Seyfert I Seyfert II on-axis off-axis viewing angle w.r.t. jet axis BL Lac flat-spectrum quasar steep-spectrum quasar on-axis off-axis radio unification scheme presence of a relativistic jet no radio quiet yes radio loud successful jet choked (“dirty”) jet FR I FR II 

32 torus of gas and dust Essential ingredients —> zoo of observational classes engine viewing angle w.r.t. dusty torus Seyfert I Seyfert II on-axis off-axis optical unification scheme viewing angle w.r.t. jet axis BL Lac flat-spectrum quasar steep-spectrum quasar on-axis off-axis radio unification scheme presence of a relativistic jet no radio quiet yes radio loud successful jet choked (“dirty”) jet FR I FR II 

I. INTRODUCTION TO AGN 33 II. CONNECTING OPTICAL ACTIVE NUCLEI TO UNIDENTIFIED RADIO SOURCES (1900-1970) III. THE IDEA OF RELATIVISTIC JETS (1974) IV. RADIO UNIFICATION: VIEWING ANGLE (1984) V. RADIO UNIFICATION: JET VELOCITY (1982-1995) VI. OPTICAL UNIFICATION: VIEWING ANGLE (1985) “[These IR sources] represent a class of extremely luminous galaxies, emitting as much energy as the most extreme Seyfert galaxies” - Houck et al. (1985) VII. IR UNIFICATION: VIEWING ANGLE (1989) 

IRAS sources IRAS Mrk 1014 IRAS 01003-2238 IRAS 08572+3915 IRAS 12071-0444 

IRAS sources IRAS Mrk 1014 IRAS 01003-2238 IRAS 08572+3915 IRAS 12071-0444 Model ingredients (Sanders 1989) • Insight: most quasars have similar IR properties • Dusty torus re-radiates emission from accretion disk Urry (2003) ULIRG 

36 Essential ingredients —> zoo of observational classes engine viewing angle w.r.t. dusty torus Seyfert I QSO Seyfert II on-axis off-axis ULIRG OIR unification scheme viewing angle w.r.t. jet axis BL Lac flat-spectrum quasar steep-spectrum quasar on-axis off-axis radio unification scheme presence of a relativistic jet no radio quiet yes radio loud successful jet choked (“dirty”) jet FR I FR II 

I. INTRODUCTION TO AGN 37 II. CONNECTING OPTICAL ACTIVE NUCLEI TO UNIDENTIFIED RADIO SOURCES (1900-1970) III. THE IDEA OF RELATIVISTIC JETS (1974) IV. RADIO UNIFICATION: VIEWING ANGLE (1984) V. RADIO UNIFICATION: JET VELOCITY (1982-1995) VI. OPTICAL UNIFICATION: VIEWING ANGLE (1985) VII. IR UNIFICATION: VIEWING ANGLE (1989) VIII. CONNECTION TO STELLAR EXPLOSIONS “…we demonstrate that the central engine responsible for long gamma-ray bursts can also trigger a SN Ic-BL” -Barnes et al. (2017) 

38 Urry (2003) Bill Saxton, NRAO/AUI/NSF AGN Stellar explosion • Jet —> radio loud • Jet —> radio loud 

39 Urry (2003) Bill Saxton, NRAO/AUI/NSF AGN Stellar explosion • Jet —> radio loud • Jet —> radio loud • Radio loud prefer elliptical galaxies, radio quiet prefer spiral galaxies • GRBs and Ic-BL SNe prefer dwarf starburst galaxies, regular Ic SN prefer disk galaxies 

40 Urry (2003) Bill Saxton, NRAO/AUI/NSF AGN Stellar explosion • Jet —> radio loud • Jet —> radio loud • No jet —> radio-quiet • No jet —> spherical engines? superluminous SN? • Radio loud prefer elliptical galaxies, radio quiet prefer spiral galaxies • GRBs and Ic-BL SNe prefer dwarf starburst galaxies, regular Ic SN prefer disk galaxies 

41 Urry (2003) Bill Saxton, NRAO/AUI/NSF AGN Stellar explosion • Jet —> radio loud • Jet —> radio loud • Successful/unsuccessful jets —> FR I/II • Successful/unsuccessful jets —> dirty fireballs??? • No jet —> radio-quiet • No jet —> spherical engines? superluminous SN? • Radio loud prefer elliptical galaxies, radio quiet prefer spiral galaxies • GRBs and Ic-BL SNe prefer dwarf starburst galaxies, regular Ic SN prefer disk galaxies 

42 Urry (2003) Bill Saxton, NRAO/AUI/NSF AGN Stellar explosion • Jet —> radio loud • Jet —> radio loud • Successful/unsuccessful jets —> FR I/II • No jet —> radio-quiet • No jet —> spherical engines? superluminous SN? • Radio loud prefer elliptical galaxies, radio quiet prefer spiral galaxies • GRBs and Ic-BL SNe prefer dwarf starburst galaxies, regular Ic SN prefer disk galaxies • On-axis jet —> BL Lac, flat-spectrum quasar • On-axis jet —> gamma-ray burst (GRB) • Successful/unsuccessful jets —> dirty fireballs??? 

43 Urry (2003) Bill Saxton, NRAO/AUI/NSF AGN Stellar explosion • Jet —> radio loud • Jet —> radio loud • Successful/unsuccessful jets —> FR I/II • No jet —> radio-quiet • No jet —> spherical engines? superluminous SN? • Radio loud prefer elliptical galaxies, radio quiet prefer spiral galaxies • GRBs and Ic-BL SNe prefer dwarf starburst galaxies, regular Ic SN prefer disk galaxies • On-axis jet —> BL Lac, flat-spectrum quasar • On-axis jet —> gamma-ray burst (GRB) • Off-axis jet —> steep-spectrum quasar • Off-axis jet —> ?? Ic-BL SN? • Successful/unsuccessful jets —> dirty fireballs??? 

44 Urry (2003) Bill Saxton, NRAO/AUI/NSF AGN Stellar explosion • Jet —> radio loud • Jet —> radio loud • Successful/unsuccessful jets —> FR I/II • No jet —> radio-quiet • No jet —> spherical engines? superluminous SN? • Radio loud prefer elliptical galaxies, radio quiet prefer spiral galaxies • GRBs and Ic-BL SNe prefer dwarf starburst galaxies, regular Ic SN prefer disk galaxies • On-axis jet —> BL Lac, flat-spectrum quasar • On-axis jet —> gamma-ray burst (GRB) • Off-axis jet —> steep-spectrum quasar • Off-axis jet —> ?? Ic-BL SN? • Obscuration by dense material —> Seyfert I/II, ULIRG • Obscuration by dense material —> AT2018cow?? • Successful/unsuccessful jets —> dirty fireballs??? 

45 Essential ingredients —> zoo of observational classes engine viewing angle w.r.t. dusty torus aspherical dense CSM on-axis? off-axis? viewing angle w.r.t. jet axis on-axis off-axis presence of a relativistic jet no yes radio loud successful jet choked (“dirty”) jet FR II GRB FR I LLGRB? Dirty fireball? radio quiet superluminous supernova? GRB BL Lac flat spectrum quasar Ic-BL SN steep-spectrum quasar optical unification scheme radio unification scheme ?? Seyfert I QSO oblique angle? AT2018cow?? ?? Seyfert II ULIRG 

46 NGC 1068 (M77) has an active galactic nucleus Imanishi (2018) Image Credit: ALMA (ESO/NAOJ/NRAO), Imanishi et al., NASA/ESA Hubble Space Telescope and A. van der Hoeven 46 

47 NGC 1068 (M77) has an active galactic nucleus 47 Credit: ALMA (ESO/NAOJ/NRAO), Imanishi et al. Imanishi (2018)