Extragalactic radio sources : proceedings of the 175th Symposium of the International Astronomical Union, held in Bologna, Italy, 10-14 October 1995

On the 100th anniversary of Marconi's successful experiment on radio broadcasting, 250 astronomers from all over the world met in Bologna (Italy) for five days, to update their knowledge of the physics and statistical properties of powerful extragalactic radio sources. Since their discovery in the fifties enormous progress has been made. The existence of superluminal motions in the cores of radio sources, the presence there of a black hole surrounded by an absorbing dust torus, as inferred mostly from studies at other wavelengths, are now accepted ideas. Nevertheless, in spite of these efforts, there are many questions still unanswered. For instance we do not know which mechanism produces the huge amount of energy supplied to radio sources, how the jets connecting the `engine' to the lobes are formed and collimated, which of the differences observed among the various classes of radio sources are apparent and which are real. These and other related topics are discussed in this book. Front Matter....Pages i-xl Guglielmo Marconi and Radioastronomy....Pages 1-4 Parsec-Scale Structure of Compact Radio Sources....Pages 5-10 The Sub-Parsec Scale Jets of AGN....Pages 11-13 Radio Observations of the γ-Ray Blazar 0528+134....Pages 14-16 A Dramatic (and Invisible!) Flare in NRAO 530....Pages 17-18 VLBI Observations of Southern EGRET Identifications....Pages 19-20 Monitoring the Jet in Centaurus a at 0.1 Parsec Resolution....Pages 21-22 A Counterjet in the Nucleus of Centaurus A....Pages 23-24 High Frequency Radio Observations of the Nucleus of Cen A....Pages 25-26 Simultaneous Multi-Frequency Imaging of the Nucleus of NGC 1275....Pages 27-29 Constraints on the Accretion Region in NGC 1275 from VLBA Observations of the Counterjet....Pages 30-32 Continuum VLBI Polarimetry of 3C454.3 at 43 GHZ....Pages 33-34 Multi-Frequency VLBI Observations of 3C390.3....Pages 35-37 Structural Changes in CTA102....Pages 39-40 VLBA Studies of BL Lac....Pages 41-42 Helical Motion in the BL Lac Object OJ287 ?....Pages 43-44 Variability Characteristics of Blazar OJ 287....Pages 45-46 The Environment of OJ 287: Nearby Galaxies and a Long Optical Jet?....Pages 47-48 New Results from VLBI Polarization Observations of BL Lacertae Objects....Pages 49-50 3.6 cm VLBI Total Intensity and Polarization Images of BL Lacertae Objects....Pages 51-52 Back Matter....Pages 187-194 Extended Emission in BL Lac Objects....Pages 53-54 Arcsecond Scale Polarization of BL Lac Objects....Pages 55-56 Superluminal Motions: The First 100 Sources....Pages 57-62 CSS Versus Large Size Sources....Pages 63-66 A VLBI Study of GHZ-Peaked-Spectrum Radio Sources....Pages 67-68 2.23 and 8.29 GHZ Observations of CSS-GPS Candidates....Pages 69-70 Large Bent Jets in the Inner Region of CSS....Pages 71-72 High-Resolution Structure of Southern Compact Steep Spectrum Sources....Pages 73-74 A Single Baseline VLBI Survey of Southern Peaked Spectrum Sources....Pages 75-76 Extreme Depolarization in Compact Steep Spectrum Sources....Pages 77-78 Large Rotation Measures in CSS Sources....Pages 79-80 NLR Kinematics in CSS Radio Sources....Pages 81-82 A World Array VLBI Image of 3C216 at 1.6GHZ....Pages 83-84 5 GHZ Evn Polarization of 3C286....Pages 85-87 The Evolution of Extragalactic Radio Sources....Pages 88-89 PKS 1413+135: A Very Young Radio Galaxy....Pages 90-91 A Circumnuclear Hi Disk in the Compact Symmetric Object 4C31.04?....Pages 92-94 Multifrequency Study of VLBI—Compact Sources: 1–22 GHZ Spectra Observations and Model Fits....Pages 95-96 Statistical Analysis of Observations of a Complete Sample of Compact Extragalactic Radio Sources....Pages 97-98 High Radio Frequency Studies of Equatorial and Southern AGN....Pages 99-100 Back Matter....Pages 187-194 A Simple Method to Analyze Radio Frequency Outbursts of Quasars....Pages 101-102 Long-Term Variability of Extragalactic Sources at 843 MHZ....Pages 103-104 Gravitational Lenses....Pages 105-110 Scintillating Lenses....Pages 111-112 A VLA Study of Ooty Small Diameter Sources....Pages 113-114 Multi-Frequency VLBI Observations of the Gravitational Lens B0218+357....Pages 115-117 PKS 1117+146: Gravitational Lens or Micro Lobes....Pages 118-119 High Precision Astrometry Over Large Angular Scales with Closure Constraints: The Triplet 1803+784/1928+738/2007+777....Pages 120-121 EVN Phase-Referenced Observations of 1308+328....Pages 122-123 VLBI Observations of FRI Radio Galaxies....Pages 124-126 Parsec Scale Properties of Low Power Radio Galaxies....Pages 127-128 VLBI Observations of Low-Redshift Radio Galaxies....Pages 129-130 The Relativistic Jet in M84....Pages 131-132 The Parsec-Scale Nucleus and Jets of Hydra A....Pages 133-135 Low Luminosity Radio Galaxies....Pages 137-142 FR I Jets in Southern Radio Galaxies....Pages 143-144 High-Frequency Study of Low and Intermediate Luminosity Radio Galaxies....Pages 145-146 Large-Scale Structure: Jets on Kiloparsec Scales....Pages 147-152 The Jets in FRII Radio Galaxies with Z < 0.3....Pages 153-154 Low-Luminosity Radio QSOs: The B2 Sample....Pages 155-156 Back Matter....Pages 187-194 An Atlas of Extragalactic Radio Sources....Pages 157-158 Extreme Rotation Measure Radio Galaxies....Pages 159-162 Radio Polarisation Studies of Galaxies at Z > 2....Pages 163-165 Cygnus A: Some Topics from the Workshop....Pages 167-174 First Millimeter Mapping of the Jet and Nucleus of M87....Pages 175-176 Unusual Radio Structures in Markarian 6....Pages 177-178 IRAS 0421+0400: A Curious Spiral with Flaring Jets....Pages 179-180 Analysis Of VLBI Spot Map of H 2 O Masers for the HII Region Complex IC133 of Spiral Galaxy M33....Pages 181-182 A Search for HI in Strong Radio Galaxies....Pages 183-184 A Multi-Radio-Frequency Study of a RQQ....Pages 185-186 Back Matter....Pages 187-194 Hubble Space Telescope Observations of Extragalactic Jets....Pages 195-200 HST Observations of Jets and Radio Lobes....Pages 201-202 Merlin and HST Observations of the Jet in 3C273....Pages 203-204 Circumnuclear Disks in Radio-Quiet Active Galaxies....Pages 205-210 Probing AGN with Water Masers....Pages 211-214 What Powers Ultra-Luminous IRAS Galaxies?....Pages 215-216 Optical-Radio Connections....Pages 217-222 Optical Polarization of 3C 265....Pages 223-226 A Powerful Jet/Cloud Interaction in the Radio Galaxy PKS 2250-41....Pages 227-229 Radio Outflows and the Origin of the Narrow Line Region in Seyfert Galaxies....Pages 230-231 Back Matter....Pages 297-304 Matter-Bounded Photoionized Clouds....Pages 232-233 Is the UV Alignment Effect Present in Low Redshift Radio Galaxies?....Pages 234-235 Weak Radio Galaxies: Narrow-Band Optical Imaging....Pages 236-237 Optical Properties of FR I Radio Galaxies....Pages 238-239 Optical Properties of B2 Radio Galaxies....Pages 240-241 Nearly Simultaneous Optical and VLBI Polarization Observations of BL Lac Objects....Pages 242-243 Can BL Lac Nuclei and Broad Line Regions Coexist or when is an Object a BL Lac?....Pages 244-245 Intraday Variability Statistics in Radio-Selected and X-Ray Selected BL Lac Objects....Pages 246-247 Host Galaxies of Radio-Loud & Radio-Quiet AGN....Pages 248-249 A Possible Fundamental Difference Between Radio Loud and Radio Quiet AGN....Pages 250-251 The Radio and Optical Properties of Quasars....Pages 252-253 Optical Properties of the Radio Source B2 0828+32....Pages 254-255 Inverse Compton X-Rays from Giant Radio Galaxies....Pages 256-258 Rosat Studies of Extragalactic Radio Sources....Pages 259-262 Soft X-Ray Properties of a Complete Sample of Radio Sources....Pages 263-264 X-Ray Spectra of BL Lacertae Objects from the Rosat Archive....Pages 265-266 The Rosat X-Ray Spectra of BL Lacertae Objects....Pages 267-268 The Search for a New BL Lac Sample....Pages 269-270 Optical Identifications for a Sample of Rexs: Search for BL Lac Objects....Pages 271-272 X-Ray Spectral Properties of Radio Galaxies....Pages 273-276 Back Matter....Pages 297-304 Gamma-Ray Emission from Extragalactic Radio Sources: Egret Observations of Active Galactic Nuclei....Pages 277-280 The Big Picture from Radio Waves to Gamma Rays....Pages 281-282 The Radio-Gamma-Ray Connection: The Radio Properties of Gamma-Ray-Bright Blazars....Pages 283-284 AGN Statistics of Simultaneous Radio and Gamma Ray Observations....Pages 285-286 Optical Monitoring of Gamma-Ray Loud Blazars....Pages 287-288 Optical Monitoring of the Gamma-Ray Loud BL Lac Object S5 0716+714....Pages 289-290 The Highest Energy Cosmic Rays....Pages 291-296 Back Matter....Pages 297-304 Radio Sources in Clusters of Galaxies....Pages 305-310 General Properties of Giant Radio Galaxies....Pages 311-312 Morphologies in Mpc-Size Radio Galaxies....Pages 313-314 Towards a Complete Sample of Giant Radio Galaxies at Z > 0.4....Pages 315-316 Spectral Indices and Particle Ageing Studies on the Giant Radio Galaxy NGC6251....Pages 317-318 Evolution of Powerful Extended Radio Sources....Pages 319-320 Radio Source Environments at Redshifts > 0.5....Pages 321-322 The Environments of Radio Galaxies....Pages 323-324 Clusters of Galaxies at Intermediate Redshifts: A Sample Selected at Radio Wavelenghts....Pages 325-326 Quasar Radio Morphology and Environment at Z ~ 1/2....Pages 327-328 Quasar Radio Structure in Cluster Environments....Pages 329-330 Radio-Optical Alignments in Nearby Cooling Flow Cluster Central Galaxies....Pages 331-332 Diffuse Cluster Radio Sources....Pages 333-338 Back Matter....Pages 367-372 Electron Transport in the Coma Cluster....Pages 339-340 Coma Cluster: CR Acceleration and Gamma-Ray Production....Pages 341-342 The Radio Lobes of Virgo A....Pages 343-344 The Relic Radio Source B2 0924+30....Pages 345-346 Radio Spectra and Particle Ages of the Head-Tail Radio Galaxy NGC1265....Pages 347-348 Observations of Straight-Angle Tailed Radio Galaxies in Rich Clusters of Galaxies....Pages 349-350 The Environment of Hercules A....Pages 351-352 Multi-Wavelength Study of Rosat Clusters of Galaxies....Pages 353-354 Atca 13 and 20 CM Observations of A3556....Pages 355-356 The X-Ray Intracluster Medium....Pages 357-360 A2241: Clusters with Head-Tails at X-Rays....Pages 361-362 ASCA Observations of Clusters of Galaxies....Pages 363-366 Back Matter....Pages 367-372 Unified Schemes for Extragalactic Radio Sources....Pages 373-378 The Unification of Radio-Loud AGN....Pages 379-380 Orientation Effects and Seyfert Cores....Pages 381-384 New Observations of BL Lacertae Objects....Pages 385-388 The Unification of Quasars and Radio Galaxies....Pages 389-390 The Evolutionary Unified Scheme, Jet Asymmetry, and Superluminal Motion....Pages 391-392 Radio Structures of the MRC 1-JY Sources and the Unification of Radio Galaxies and Quasars....Pages 393-394 Spectral Index Asymmetries in Low-Z Radio Galaxies....Pages 395-396 Back Matter....Pages 409-412 Depolarization Studies of Radio Sources and the Unified Scheme....Pages 397-399 The UV/Radio Correlation of Quasars and its Implications for Unified Schemes....Pages 400-401 KECK Spectropolarimetry of High Redshift Radio Galaxies....Pages 402-404 Composite Optical Spectra of Radio quasars....Pages 405-406 On the X-Ray Emission from the Powerful Radio Galaxies....Pages 407-408 Back Matter....Pages 409-412 X-Ray and Gamma-Ray Emission in Blazars....Pages 413-416 Cooling-Flow Models of the X-Ray Emission and Temperature Profiles of Elliptical Galaxies....Pages 417-418 High-Energy Gamma and Radio Variability of Blazars in the Model of Non-Stationary Jets....Pages 419-420 Comptonization as Blazar High Energy Emission....Pages 421-422 The Nature of Flat Spectrum Sources....Pages 423-426 Energy Transport in Radio Galaxies and Quasars: A Workshop Theory Review....Pages 427-432 The Production of Jets from Magnetized Accretion Disks: Simulation of the Blandford-Payne Mechanism....Pages 433-434 A Numerical Study of Relativistic Jets....Pages 435-436 Viewing Angle and the Appearance of Superluminal Jets....Pages 437-438 Simulations of Superluminal Radio Sources....Pages 439-440 Physics of the M87 Jet....Pages 441-442 Relativistic Electron-Positron Clouds in VLBI Jets....Pages 443-444 The Cosmic Nozzle....Pages 445-446 Intrinsic Kinematics of Moving Components in Curved Relativistic Jets....Pages 447-448 Supersonic Jets and Lobe Morphologies....Pages 449-452 Back Matter....Pages 491-494 3-D Simulations of Kelvin-Helmholtz Instabilities in Supersonic Jets....Pages 453-454 MHD Self-Similar Solutions for Collimated Jets....Pages 455-456 MHD Equilibria of Helical Jets....Pages 457-458 A New Analytical Jet Model....Pages 459-460 Boundary Layers in Extragalactic Jets....Pages 461-462 Fractal Properties of Extragalactic Jets: Evidence of Turbulence?....Pages 463-464 ISM/Radio Material Interaction Modeling....Pages 465-466 Numerical Simulations of Extragalactic Jets in an Inhomogeneous Environment....Pages 467-468 Shock Excitation of Emission Lines and the Relation to GPS Sources....Pages 469-470 Dynamical Models of Emission-Line Gas in Radio Galaxies....Pages 471-472 Shock Excitation of Emission Lines in Radio Galaxies....Pages 473-474 Comparative Study of Extragalactic Radio Sources from “Double Jet” Models....Pages 475-476 Distortion Effects in BL Lac Radio Jets....Pages 477-478 Describing the Asymmetries in Extragalactic Radio Sources....Pages 479-480 Analytical Modelling of Linear Size Evolution of Powerful Radio Sources....Pages 481-482 How Radio Sources Stay Young....Pages 483-484 A Cocoon Transparency and the 3C 345 Low Frequency Variability....Pages 485-486 Simulation of the Variable Multifrequency Radio Emission and Structure of the Quasar 2145+067....Pages 487-488 The Spectral and Spatial Decomposition of Extragalactic Radio Sources....Pages 489-490 Back Matter....Pages 491-494 The Westerbork Northern Sky Survey....Pages 495-498 Back Matter....Pages 533-534 First Results from the VLA First Survey....Pages 499-502 The NRAO VLA D-Array Sky Survey (NVSS)....Pages 503-506 The Parkes-MIT-NRAO Radio Surveys....Pages 507-512 The Distant Dragns Survey....Pages 513-514 2-JY Sample of Southern Radio Sources....Pages 515-516 The MRC 1-JY Sample of Radio Galaxies....Pages 517-518 The B3-VLA Sample....Pages 519-521 A Deep 20 CM Radio Mosaic of the ESO Key-Project Galaxy Redshift Survey....Pages 523-524 Radio Observations of the Marano Field: Sub-Millijansky Source Counts and Spectral Index Studies....Pages 525-526 The VLBA Calibrator Survey....Pages 527-528 The VSOP Mission for Extragalactic Radio Sources....Pages 529-530 Imaging of Extragalactic Radio Sources with the VSOP Space VLBI Mission....Pages 531-532 Back Matter....Pages 533-534 Radio Luminosity Functions....Pages 535-540 A Nuclear Luminosity Function for Seyferts....Pages 541-542 VLA Observations of the Cambridge-Cambridge Rosat Survey....Pages 543-544 On the Cosmological Evolution of Radio Quiet and Radio Loud Quasars....Pages 545-546 Space Distribution of Radio-Source Populations....Pages 547-552 Space Densities for Powerful Radio Sources in the Light of Unification....Pages 553-554 The Radio Sky at Micro-JY Levels....Pages 555-558 Redshift Distribution & Nature of μ -JY Radio Sources....Pages 559-560 Back Matter....Pages 597-602 The Space Density of High-Redshift Quasars....Pages 561-562 Cosmological Size Evolution of Extragalactic Radio Sources....Pages 563-566 New Results from Complete Samples of Faint Radio Galaxies and Quasars....Pages 567-568 Spectral Index - Redshift Relation for Radio Galaxies and Quasars....Pages 569-570 High Redshift Radio Galaxies....Pages 571-576 HST and Keck Observations of High Redshift Radio Galaxies....Pages 577-580 High-Redshift Milli-Jansky Radio Galaxies....Pages 581-582 Distant Radio Galaxies: The Strong Link between the Radio and Optical Emission....Pages 583-584 The R-Band Hubble Diagram for GPS Galaxies....Pages 585-587 Stellar Population Models of Distant Radio Galaxies....Pages 588-590 The RATAN-600 - VLA - 6M Russian Telescope: Early Universe Project....Pages 591-592 Faint Radio Sources and the Cosmic Microwave Background....Pages 593-594 FSRQ and the Gamma-Ray Background....Pages 595-596 Conclusions....Pages 603-608 Back Matter....Pages 597-602 Back Matter....Pages 609-631