Superluminal Motion and Relativistic Beaming in Blazar Jets
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Arxiv:2010.11303V2 [Astro-Ph.GA] 23 Feb 2021
DRAFT VERSION FEBRUARY 24, 2021 Preprint typeset using LATEX style emulateapj v. 01/23/15 RECONCILING EHT AND GAS DYNAMICS MEASUREMENTS IN M87: IS THE JET MISALIGNED AT PARSEC SCALES? BRITTON JETER1,2,3 ,AVERY E. BRODERICK1,2,3 , 1 Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada 2 Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, ON N2L 2Y5, Canada 3 Waterloo Centre for Astrophysics, University of Waterloo, Waterloo, ON N2L 3G1, Canada Draft version February 24, 2021 ABSTRACT The Event Horizon Telescope mass estimate for M87* is consistent with the stellar dynamics mass estimate and inconsistent with the gas-dynamics mass estimates by up to 2σ. We have previously explored a new gas-dynamics model that incorporated sub-Keplerian gas velocities and could, in principle, explain the discrepancy in the stellar and gas-dynamics mass estimate. In this paper, we extend this gas-dynamical model to also include non-trivial disk heights, which may also resolve the mass discrepancy independent of sub-Keplerian velocity components. By combining the existing velocity measurements and the Event Horizon Telescope mass estimate, we place con- straints on the gas disk inclination and sub-Keplerian fraction. These constraints require the parsec-scale ionized gas disk to be misaligned with the milliarcsecond radio jet by at least 11◦, and more typically 27◦. Modifications to the gas-dynamics model either by introducing sub-Keplerian velocities or thick disks produce further misalign- ment with the radio jet. If the jet is produced in a Blandford–Znajek-type process, the angular momentum of the black hole is decoupled with the angular momentum of the large-scale gas feeding M87*. -
Active Galactic Nuclei
Active Galactic Nuclei • Optical spectra, distance, line width • Varieties of AGN and unified scheme • Variability and lifetime • Black hole mass and growth • Geometry: disk, BLR, NLR • Reverberation mapping • Jets and blazars • AGN spectra Optical spectrum of an AGN • Variety of different emission lines • Each line has centroid, area, width • There is also continuum emission Emission lines • Shift of line centroid gives recession velocity v/c = Δλ/λ. • The width is usually characterized by the “Full Width at Half Maximum”. For a Gaussian FHWM = 2.35σ. • The line width is determined by the velocity distribution of the line emitting gas, Δv/c = σ/λ. • Area is proportional to the number of detected line photons or the line flux. • Usually characterized by “equivalent width” or range in wavelength over which integration of the continuum produces the same flux as the line. Early observations of AGN • Very wide emission lines have been known since 1908. • In 1959, Woltjer noted that if the profiles are due to Doppler motion and the gas is gravitationally bound then v2 ~ GM/r. For v ~ 2000 km/s, we have 10 r M ≥10 ( 100 pc ) M Sun • So AGN, known at the time as Seyfert galaxies, must either have a very compact and luminous nucleus or be very massive. Quasars • Early radio telescopes found radio emission from stars, nebulae, and some galaxies. • There were also point-like, or star-like, radio sources which varied rapidly these are the `quasi-stellar’ radio sources or quasars. • In visible light quasars appear as points, like stars. Quasar optical spectra Redshift of 3C273 is 0.16. -
Superluminal Motion of Gamma-Ray Blazars
High Energy Blazar Astronomy ASP Conference Series, Vol. 299, 2003 L.O. Takalo and E. Valtaoja Superluminal Motion of Gamma-Ray Blazars S.G. Jorstad Institute for Astrophysical Research, Boston University, 725 Commonwealth Ave., Boston, MA 02215-1401 Astronomical Institute of St. Petersburg State University, Universitetskij pr. 28, 198504 St. Petersburg, Russia A.P. Marscher Institute for Astrophysical Research, Boston University, 725 Commonwealth Ave., Boston, MA 02215-1401 Abstract. We have completed a program of monitoring of a sample of γ-ray blazars with the VLBA at 22 and 43 GHz. Analysis of the data allows us to conclude that the population of bright γ-ray blazars can be classified as highly superluminal, with apparent speeds as high as ∼40c. However, many of the blazars exhibit a wide range of apparent speeds from ∼4c to ∼20c in the same source. Comparison of brightness and polarization parameters with the jet velocities of moving components does not show significant correlation between these parameters. Intensive multifrequency VLBI monitoring is needed to reveal any patterns that might exist in the distribution of apparent speeds observed in the same object. 1. Introduction Apparent speed is one of the most important parameters for determining the physics of radio jets. The largest class of identified γ-ray sources (Hartman et al. 1999) consists of violently variable AGNs (blazars) characterized by one-sided superluminal radio jets. A popular model for the production of high-energy radiation in AGNs involves inverse-Compton scattering of low-energy photons by highly relativistic electrons in the jet. However, the seed photons for this process are uncertain: they might be from the accretion disk and/or nearby region (ECS-model; Sikora et al. -
On the Possibility of Faster-Than-Light Motions in Nonlinear Electrodynamics
Proceedings of Institute of Mathematics of NAS of Ukraine 2004, Vol. 50, Part 2, 835–842 On the Possibility of Faster-Than-Light Motions in Nonlinear Electrodynamics Gennadii KOTEL’NIKOV RRC Kurchatov Institute, 1 Kurchatov Sq., 123182 Moscow, Russia E-mail: [email protected] A version of electrodynamics is constructed in which faster-than-light motions of electro- magnetic fields and particles with real masses are possible. 1 Introduction For certainty, by faster-than-light motions we shall understand the motions with velocities v> 3 · 108 m/sec. The existence of such motions is the question discussed in modern physics. As already as in 1946–1948 Blokhintsev [1] paid attention to the possibility of formulating the field theory that allows propagation of faster-than-light (superluminal) interactions outside the light cone. Some time later he also noted the possibility of the existence of superluminal solutions in nonlinear equations of electrodynamics [2]. Kirzhnits [3] showed that a particle possessing the i tensor of mass M k =diag(m0,m1,m1,m1), i, k =0, 1, 2, 3, gab =diag(+, −, −, −)canmove faster-than-light, if m0 >m1. Terletsky [4] introduced into theoretical physics the particles with imaging rest masses moving faster-than-light. Feinberg [5] named these particles tachyons and described their main properties. Research on superluminal tachyon motions opened up additional opportunities which were studied by many authors, for example by Bilaniuk and Sudarshan [6], Recami [7], Mignani (see [7]), Kirzhnits and Sazonov [8], Corben (see [7]), Patty [9], Oleinik [10]. It has led to original scientific direction (several hundred publications). -
Radio Galaxies and Quasars
Published in "Galactic and Extragalactic Radio Astronomy", 1988, 2nd edition, eds. G.L. Verschuur and K.I. Kellerman. 13. RADIO GALAXIES AND QUASARS Kenneth I. Kellermann and Frazer N. Owen Table of Contents INTRODUCTION Optical Counterparts Radio Source Properties Radio Spectra Energy Considerations LOW-LUMINOSITY SOURCES Spiral, Seyfert, and Irregular Galaxies Elliptical Galaxies COMPACT SOURCES Self-Absorption Inverse Compton Radiation Polarization Structure Variability Source Dynamics and Superluminal Motion Relativistic Beaming EXTENDED SOURCES Jets, Lobes, and Hot Spots Jet Physics SUMMARY REFERENCES 13.1. INTRODUCTION All galaxies and quasars appear to be sources of radio emission at some level. Normal spiral galaxies such as our own galactic system are near the low end of the radio luminosity function and have radio luminosities near 1037 erg s-1. Some Seyfert galaxies, starburst galaxies, and the nuclei of active elliptical galaxies are 100 to 1000 times more luminous. Radio galaxies and some quasars are powerful radio sources at the high end of the luminosity function with luminosities up to 1045 erg s-1. For the more powerful sources, the radio emission often comes from regions well removed from the associated optical object, often hundreds of kiloparsecs or even megaparsecs away. In other cases, however, particularly in active galactic nuclei (AGN) or quasars, much of the radio emission comes from an extremely small region with measured dimensions of only a few parsecs. The form of the radio- frequency spectra implies that the radio emission is nonthermal in origin; it is presumed to be synchrotron radiation from ultra-relativistic electrons with energies of typically about 1 GeV moving in weak magnetic fields of about 10-4 gauss (see Section 1.1). -
Quasar Jet Emission Model Applied to the Microquasar GRS 1915+105
A&A 415, L35–L38 (2004) Astronomy DOI: 10.1051/0004-6361:20040010 & c ESO 2004 Astrophysics Quasar jet emission model applied to the microquasar GRS 1915+105 M. T¨urler1;2, T. J.-L. Courvoisier1;2,S.Chaty3;4,andY.Fuchs4 1 INTEGRAL Science Data Centre, ch. d’Ecogia 16, 1290 Versoix, Switzerland 2 Observatoire de Gen`eve, ch. des Maillettes 51, 1290 Sauverny, Switzerland Letter to the Editor 3 Universit´e Paris 7, 2 place Jussieu, 75005 Paris, France 4 Service d’Astrophysique, DSM/DAPNIA/SAp, CEA/Saclay, 91191 Gif-sur-Yvette, Cedex, France Received 18 December 2003 / Accepted 14 January 2004 Abstract. The true nature of the radio emitting material observed to be moving relativistically in quasars and microquasars is still unclear. The microquasar community usually interprets them as distinct clouds of plasma, while the extragalactic com- munity prefers a shock wave model. Here we show that the synchrotron variability pattern of the microquasar GRS 1915+105 observed on 15 May 1997 can be reproduced by the standard shock model for extragalactic jets, which describes well the long-term behaviour of the quasar 3C 273. This strengthens the analogy between the two classes of objects and suggests that the physics of relativistic jets is independent of the mass of the black hole. The model parameters we derive for GRS 1915+105 correspond to a rather dissipative jet flow, which is only mildly relativistic with a speed of 0:60 c. We can also estimate that the shock waves form in the jet at a distance of about 1 AU from the black hole. -
Bright Quasar 3C 273 Thierry J-L Courvoisier
eaa.iop.org DOI: 10.1888/0333750888/2368 Bright Quasar 3C 273 Thierry J-L Courvoisier From Encyclopedia of Astronomy & Astrophysics P. Murdin © IOP Publishing Ltd 2006 ISBN: 0333750888 Institute of Physics Publishing Bristol and Philadelphia Downloaded on Thu Mar 02 22:49:19 GMT 2006 [131.215.103.76] Terms and Conditions Bright Quasar 3C 273 E NCYCLOPEDIA OF A STRONOMY AND A STROPHYSICS Bright Quasar 3C 273 the objects are moving apart from one another (expansion) and thus are at very large distances. At a redshift of 0.158 QUASARS are the most luminous objects we know in the 3C 273 is thus found to be some 3 billion light years away. universe. 3C 273 is among the brightest quasars; it also In 1963 3C 273 was the most distant object known (see also happens to be one of the closest to the Earth. It is therefore HIGH-REDSHIFT QUASARS). bright in the night sky and hence has been the object of Being so far away and still easy to find on intense studies since its discovery in 1963. photographic plates, 3C 273 is an object of 13th magnitude; Quasars are found in the center of some galaxies 3C 273 is clearly a very luminous object indeed. Its light 14 (collections of some hundred billion stars; the MILKY output corresponds to 10 times that of the Sun. WAY is the galaxy in which our solar system is Most quasars do not radiate substantially in the radio embedded). Quasars are very peculiar celestial objects, part of the electromagnetic spectrum, and are called radio they outshine the galaxy that hosts them, although quiet quasars. -
Chapter 7 Causality in Superluminal Pulse Propagation
Chapter 7 Causality in Superluminal Pulse Propagation Robert W. Boyd, Daniel J. Gauthier, and Paul Narum 7.1 Introduction The theory of electromagnetism for wave propagation in vacuum, as embodied by Maxwell’s equations, contains physical constants that can be combined to arrive at the speed of light in vacuum c. As shown by Einstein, consideration of the space– time transformation properties of Maxwell’s equations leads to the special theory of relativity. One consequence of this theory is that no information can be transmitted between two parties in a time shorter than it would take light, propagating through vacuum, to travel between the parties. That is, the speed of information transfer is less than or equal to the speed of light in vacuum c and information related to an event stays within the so-called light cone associated with the event. Hypothetical faster-than-light (superluminal) communication is very intriguing because relativis- tic causality would be violated. Relativistic causality is a principle by which an event is linked to a previous cause as viewed from any inertial frame of reference; superluminal communication would allow us to change the outcome of an event after it has happened. Soon after Einstein published the theory of relativity, scientists began the search for examples where objects or entities travel faster than c. There are many known examples of superluminal motion [1]. One example arises when observing radio emission in certain expanding galaxies known as superluminal stellar objects. This motion can be explained by considering motions of particles whose speed is just below c (i.e., highly relativistic) and moving nearly along the axis connecting the object and the observer [2]. -
Relativistic Effects
Relativistic Effects 1 Introduction The radio-emitting plasma in AGN contains electrons with relativistic energies. The Lorentz factors of the emitting elec- trons are of order 1026– . We now know that the bulk motion of the plasma is also moving relativistically – at least in some regions although probably “only” with Lorentz factors about 10 or so. However, this has an important effect on the prop- erties of the emitted radiation – principally through the ef- fects of relativistic beaming and doppler shifts in frequency. This in turn affects the inferred parameters of the plasma. Relativistic Effects ©Geoffrey V. Bicknell 2 Summary of special relativity For a more complete summary of 4-vectors and Special Rel- ativity, see Rybicki and Lightman, Radiative Processes in As- trophysics, or Rindler, Special Relativity High Energy Astrophysics: Relativistic Effects 2/93 2.1 The Lorentz transformation y S y S V x x The primed frame is moving wrt to the unprimed frame with a velocity v in the x–direction. The coordinates in the primed frame are related to those in the unprimed frame by: High Energy Astrophysics: Relativistic Effects 3/93 Vx x= xvt– t= t – ------ c2 y = y z = z (1) v 1 = -- = ------------------- c 1 – 2 We put the space-time coordinates on an equal footing by putting x0 = ct. The the xt– part of the Lorentz transforma- tion can be written: x= x – x0 x0= x0 – x (2) The reverse transformation is: High Energy Astrophysics: Relativistic Effects 4/93 x = x + Vt yy= zz= Vx (3) t = t + -------- c2 i.e., x = x+ x0 x0 = x0+ x (4) High Energy Astrophysics: Relativistic Effects 5/93 2.2 Lorentz–Fitzgerald contraction 2.3 Time dilation y y V S S x x High Energy Astrophysics: Relativistic Effects 6/93 y y S S V L0 x x 2 1 x – x = L0 2 1 x – x = x2 – x1 – Vt2 – t1 –1 L0 = L L = L0 High Energy Astrophysics: Relativistic Effects 7/93 Consider a clock at a stationary position in the moving frame which registers a time interval T0. -
Astro-Ph/0009301
APJ IN PRESS; RECEIVED: 2000 SEPTEMBER 15; ACCEPTED 2000 OCTOBER 23 Preprint typeset using LATEX style emulateapj v. 21/08/00 PARSEC-SCALE BLAZAR MONITORING: PROPER MOTIONS DANIEL C. HOMAN1,ROOPESH OJHA2 , JOHN F. C. WARDLE1, AND DAVID H. ROBERTS1, Physics Department MS057, Brandeis University Waltham, MA 02454 MARGO F. ALLER3,HUGH D. ALLER3, AND PHILIP A. HUGHES3 Radio Astronomy Observatory, University of Michigan Ann Arbor, MI 48109 ApJ in Press; Received: 2000 September 15; Accepted 2000 October 23 ABSTRACT We present proper motions obtained from a dual frequency, six-epoch, VLBA polarization experiment moni- toring a sample of 12 blazars. The observations were made at 15 GHz and 22 GHz at bi-monthly intervals over 1996. Ten of the eleven sources for which proper motion could be reliably determined are superluminal. Only J2005+77 has no superluminal components. Three sources (OJ 287, J1224+21, and J1512−09) show motion faster −1 −1 −1 −1 than 10h c, requiring γpattern of at least 10h (H0 = 100h km s Mpc ). We compare our results to those in the literature and find motions outside the previously observed range for four sources. While some jet components exhibit significant non-radial motion, most motion is radial. In at least two sources there are components moving radially at significantly different structural position angles. In five of six sources (3C120, J1224+21, 3C273, 3C279, J1512−09, and J1927+73) that have multiple components with measurable proper motion, the innermost component is significantly slower than the others, suggesting that acceleration occurs in the jet. In the motions of individual components we observe at least one decelerating motion and two “bending” accelerations which tend to align their motions with larger scale structure. -
Analysis of Kepler Active Galactic Nuclei Using a Revised Kirk, Rieger, Mastichiadis (1998) Model Sarah M
Florida International University FIU Digital Commons FIU Electronic Theses and Dissertations University Graduate School 6-12-2014 Analysis of Kepler Active Galactic Nuclei Using A Revised Kirk, Rieger, Mastichiadis (1998) Model Sarah M. Dhalla Florida International University, [email protected] DOI: 10.25148/etd.FI14071133 Follow this and additional works at: https://digitalcommons.fiu.edu/etd Recommended Citation Dhalla, Sarah M., "Analysis of Kepler Active Galactic Nuclei Using A Revised Kirk, Rieger, Mastichiadis (1998) Model" (2014). FIU Electronic Theses and Dissertations. 1521. https://digitalcommons.fiu.edu/etd/1521 This work is brought to you for free and open access by the University Graduate School at FIU Digital Commons. It has been accepted for inclusion in FIU Electronic Theses and Dissertations by an authorized administrator of FIU Digital Commons. For more information, please contact [email protected]. FLORIDA INTERNATIONAL UNIVERSITY Miami, Florida ANALYSIS OF KEPLER ACTIVE GALACTIC NUCLEI USING A REVISED KIRK, RIEGER, MASTICHIADIS (1998) JET MODEL A thesis submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in PHYSICS by Sarah Mohammed Dhalla 2014 To: Interim Dean Michael R. Heithaus College of Arts and Sciences This thesis, written by Sarah Mohammed Dhalla, and entitled Analysis of Kepler Active Galactic Nuclei Using a Revised Kirk, Rieger, & Mastichiadis (1998) Jet Model, having been approved in respect to style and intellectual content, is referred to you for judgment. We have read this thesis and recommend that it be approved. Caroline Simpson Walter Van Hamme James R. Webb, Major Professor Date of Defense: June 12, 2014 The thesis of Sarah Mohammed Dhalla is approved. -
11 Jets and Gamma-Ray Burst Unification Schemes
11 Jets and Gamma-Ray Burst Unification Schemes Jonathan Granot1 and Enrico Ramirez-Ruiz2 (1) Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield, Herts, AL10 9AB, UK (2) Astronomy and Astrophysics Department, University of California, Santa Cruz, CA 95064, USA 11.1 Evidence for bulk relativistic motion in gamma-ray bursts The first line of evidence for ultra-relativistic bulk motion of the outflows that produce GRBs arises from the compactness argument. It relies on the observed short and intense pulses of gamma rays and their non-thermal en- ergy spectrum that often extends up to high photon energies. Together, these facts imply that the emitting region must be moving relativistically. In order to understand this better, let us first consider a source that is either at rest or moves at a Newtonian velocity, β v/c 1, corresponding to a ≡ ≪ bulk Lorentz factor Γ (1 β2)−1/2 1. For such a source the observed ≡ − ≈ variability timescale (e.g., the width of the observed pulses) ∆t, implies a typical source size or radius R < c∆t, due to light time travel effects (for sim- plicity we ignore here cosmological effects, such as redshift or time dilation). GRBs often show significant variability down to millisecond timescales, im- plying R< 3 107(∆t/ 1 ms) cm. At cosmological distances their isotropic × equivalent luminosity, L, is typically in the range of 1050 1053 ergs−1. − In addition, the (observed part of the) εFε GRB spectrum typically peaks around a dimensionless photon energy of ε E /m c2 1, so that (for ≡ ph e ∼ a Newtonian source) a good fraction of the total radiated energy is carried by photons that can pair produce with other photons of similar energy.