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Broadband Spectral Modelling of Bent Jets of Active Galactic Nuclei Arxiv
Broadband spectral modelling of bent jets of Active Galactic Nuclei A Thesis submitted to the University of Mumbai for the Ph. D. (SCIENCE) Degree in PHYSICS Submitted By B. Sunder Sahayanathan Under the Guidance of Dr. A. K. Mitra Astrophysical Sciences Division arXiv:1109.0618v2 [astro-ph.HE] 7 Sep 2011 Bhabha Atomic Research Centre Trombay, Mumbai - 400085 October 2010 In memory of my beloved grandma Josephine... Abstract The understanding of the physics of relativistic jets from active galactic nuclei (AGN) is still incomplete. A way to understand the different features of the AGN jets is to study it broadband spectra. In general, within the limits of present observations, AGN jets are observed in radio-to-X-ray energy band and they exhibit various intrinsic features such as knots. Particularly, the blazar jets which are pointed towards the observer, are observed in radio-to-γ-ray and their radio maps exhibit internal jet structures. Moreover, the high energy emission from blazars show rapid variability. In this thesis, models have been developed to study the radiation emission processes from the knots of AGN jets as well as for blazar jets. A continuous injection plasma model is devel- oped to study the X-ray emission from the knots of sources 1136-135, 1150+497, 1354+195 and 3C 371. The knot dynamics is then studied within the framework of internal shock model. In such a scenario, knots are formed due to the collision of two successive matter blobs emitted sporadically from the central engine of AGN. Shocks, generated in such col- lisions, accelerate electrons to relativistic energies. -
Extragalactic Astronomy: the U Nivcre Bey Nd Our Galaxy
U1IJT RESUPE EU 1J3 199 021 775 dacon Eenneth Char TITLE Extragalactic Astronomy: The U nivcre Bey nd Our Galaxy. American Astronomical Society, Princeton, N.J. SFONS AGENCY National Aeronautics and Space Administra ashingtonl D.C.; National Science Foundation, Washington, D.C. REPOBT NO NASA-i:T-129 PUB DATE Sep 76 NOTE 44p.; FOF ltEd aocunents, _e SE 021 773-776 AVAII,AULE Superintendent of Documents, U.S. G-vernment Prin ing Office, Washington, D.C. 20402(5 ock Number 033-000-00657-8, $1.30) E.-RS PE10E 1F-$0.03 HC-$2.06 Plus Postige. DESCilIPTORS *Astronomy; Curriculum; *Instructional Materials; Science Education; *Scientific iesearch; Secondary Education; *Secondary School Science; *Space Sciences TIF NASA; National Aeronautics and Space Administration BSTRACT This booklet is part of an American Astronomical Society curriculum project designed to provide teaching materials to teachers or secondary school chemistry, physics, and earth science. The material is presented in three parts: one section provides the fundamental content of extragalactic astronomy, another section discusses modern discoveries in detail, and the last section summarizes the earlier discussions within the structure of the Big Bang Theory of Evolution. Each of the three sections is followed by student exercises and activities, laboratory projects, and questions and answers. The glossary contains unfamiliar terms used in the text and a collection of teacher aids such as literature references and audiovisual materials. (111) ***** *** * ** ** ***************** ********** Document., acquired by IC include many informal unpublished aterials not available from other sources. ERIC makes every effort * * to obtain the best copy available. Nevertheless, items of marginal * * reproducibility are often encountered and tbis affects the quality * * of the microfiche and hardcopy reproductions ERIC makes available * * via the ERIC Document Reproduction Service (EDRS). -
An Optical Spectroscopic Survey of the 3CR
A&A 560, A81 (2013) Astronomy DOI: 10.1051/0004-6361/201322842 & c ESO 2013 Astrophysics An optical spectroscopic survey of the 3CR sample of radio galaxies with z < 0.3 V. Implications for the unified model for FR IIs Ranieri D. Baldi1, Alessandro Capetti2, Sara Buttiglione3, Marco Chiaberge4,5,6, and Annalisa Celotti1,7,8 1 SISSA-ISAS, via Bonomea 265, 34136 Trieste, Italy e-mail: [email protected] 2 INAF − Osservatorio Astrofisico di Torino, Strada Osservatorio 20, 10025 Pino Torinese, Italy 3 INAF − Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, 35122 Padova, Italy 4 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA 5 INAF − Istituto di Radio Astronomia, via P. Gobetti 101, 40129 Bologna, Italy 6 Center for Astrophysical Sciences, Johns Hopkins University, 3400 N. Charles Street Baltimore, MD 21218, USA 7 INAF − Osservatorio Astronomico di Brera, via E. Bianchi 46, 23807 Merate, Italy 8 INFN − Sezione di Trieste, via Valerio 2, 34127 Trieste, Italy Received 14 October 2013 / Accepted 30 October 2013 ABSTRACT We explore the implications of our optical spectroscopic survey of 3CR radio sources with z < 0.3 for the unified model (UM) for radio-loud AGN, focusing on objects with a “edge-brightened” (FR II) radio morphology. The sample contains 33 high ionization galaxies (HIGs) and 18 broad line objects (BLOs). According to the UM, HIGs, the narrow line sources, are the nuclearly obscured counterparts of BLOs. The fraction of HIGs indicates a covering factor of the circumnuclear matter of 65% that corresponds, adopting a torus geometry, to an opening angle of 50◦ ± 5. -
The Jets in Radio Galaxies
The jets in radio galaxies Martin John Hardcastle Churchill College September 1996 A dissertation submitted in candidature for the degree of Doctor of Philosophy in the University of Cambridge i `Glaucon: ª...But how did you mean the study of astronomy to be reformed, so as to serve our pur- poses?º Socrates: ªIn this way. These intricate traceries on the sky are, no doubt, the loveliest and most perfect of material things, but still part of the visibleworld, and therefore they fall far short of the true realities Ð the real relativevelocities,in theworld of purenumber and all geometrical ®gures, of the movements which carry round the bodies involved in them. These, you will agree, can be conceived by reason and thought, not by the eye.º Glaucon: ªExactly.º Socrates: ªAccordingly, we must use the embroidered heaven as a model to illustrateour study of these realities, just as one might use diagrams exquisitely drawn by some consummate artist like Daedalus. An expert in geometry, meeting with such designs, would admire their ®nished workmanship, but he wouldthink it absurd to studythem in all earnest with the expectation of ®nding in their proportionsthe exact ratio of any one number to another...º ' Ð Plato (429±347 BC), The Republic, trans. F.M. Cornford. ii Contents 1 Introduction 1 1.1 Thisthesis...................................... ... 1 1.2 Abriefhistory................................... .... 2 1.3 Synchrotronphysics........ ........... ........... ...... 4 1.4 Currentobservationalknowledgeintheradio . ............. 5 1.4.1 Jets ........................................ 6 1.4.2 Coresornuclei ................................. 6 1.4.3 Hotspots ..................................... 7 1.4.4 Largescalestructure . .... 7 1.4.5 Theradiosourcemenagerie . .... 8 1.4.6 Observationaltrends . -
Extragalactic Radio Jets
Annual Reviews www.annualreviews.org/aronline Ann. Rev. Astron.Astrophys. 1984. 22 : 319-58 Copyright© 1984 by AnnualReviews Inc. All rights reserved EXTRAGALACTIC RADIO JETS Alan H. Bridle National Radio AstronomyObservatory, 1 Charlottesville, Virginia 22901 Richard A. Perley National Radio Astronomy Observatory, Socorro, New Mexico 87801 1. INTRODUCTION Powerful extended extragalactic radio sources pose two vexing astro- physical problems [reviewed in (147) and (157)]. First, from what energy reservoir do they draw their large radio luminosities (as muchas 10a8 W between 10 MHzand 100 GHz)?Second, how does the active center in the parent galaxy or QSOsupply as muchas 10~4 J in relativistic particles and fields to radio "lobes" up to several hundredkiloparsecs outside the optical object? Newaperture synthesis arrays (68, 250) and new image-processing algorithms (66, 101, 202, 231) have recently allowed radio imaging subarcsecond resolution with high sensitivity and high dynamicrange; as a result, the complexityof the brighter sources has been revealed clearly for the first time. Manycontain radio jets, i.e. narrow radio features between compact central "cores" and more extended "lobe" emission. This review examinesthe systematic properties of such jets and the dues they give to the by PURDUE UNIVERSITY LIBRARY on 01/16/07. For personal use only. physics of energy transfer in extragalactic sources. Wedo not directly consider the jet production mechanism,which is intimately related to the Annu. Rev. Astro. Astrophys. 1984.22:319-358. Downloaded from arjournals.annualreviews.org first problemnoted above--for reviews, see (207) and (251). 1. i Why "’Jets"? Baade & Minkowski(3) first used the term jet in an extragalactic context, describing the train of optical knots extending ,-~ 20" from the nucleus of M87; the knots resemble a fluid jet breaking into droplets. -
Jet-Powered Molecular Hydrogen Emission from Radio Galaxies
JET-POWERED MOLECULAR HYDROGEN EMISSION FROM RADIO GALAXIES The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Ogle, Patrick, Francois Boulanger, Pierre Guillard, Daniel A. Evans, Robert Antonucci, P. N. Appleton, Nicole Nesvadba, and Christian Leipski. “JET-POWERED MOLECULAR HYDROGEN EMISSION FROM RADIO GALAXIES.” The Astrophysical Journal 724, no. 2 (November 11, 2010): 1193–1217. © 2010 The American Astronomical Society As Published http://dx.doi.org/10.1088/0004-637x/724/2/1193 Publisher IOP Publishing Version Final published version Citable link http://hdl.handle.net/1721.1/95698 Terms of Use Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The Astrophysical Journal, 724:1193–1217, 2010 December 1 doi:10.1088/0004-637X/724/2/1193 C 2010. The American Astronomical Society. All rights reserved. Printed in the U.S.A. JET-POWERED MOLECULAR HYDROGEN EMISSION FROM RADIO GALAXIES Patrick Ogle1, Francois Boulanger2, Pierre Guillard1, Daniel A. Evans3, Robert Antonucci4, P. N. Appleton5, Nicole Nesvadba2, and Christian Leipski6 1 Spitzer Science Center, California Institute of Technology, Mail Code 220-6, Pasadena, CA 91125, USA; [email protected] 2 Institut d’Astrophysique Spatiale, Universite Paris-Sud 11, Bat. 121, 91405 Orsay Cedex, France 3 MIT Center for Space Research, Cambridge, MA 02139, USA 4 Physics Department, University of California, Santa Barbara, CA 93106, USA 5 NASA Herschel Science Center, California Institute of Technology, Mail Code 100-22, Pasadena, CA 91125, USA 6 Max-Planck Institut fur¨ Astronomie (MPIA), Konigstuhl¨ 17, D-69117 Heidelberg, Germany Received 2009 November 10; accepted 2010 September 22; published 2010 November 11 ABSTRACT H2 pure-rotational emission lines are detected from warm (100–1500 K) molecular gas in 17/55 (31% of) radio galaxies at redshift z<0.22 observed with the Spitzer IR Spectrograph. -
Pos(AASKA14)109
Giant radio galaxies as probes of ambient WHIM in PoS(AASKA14)109 the era of the SKA Bo Peng1;2, Ru-Rong Chen1, and Richard Strom1;3 1NAOC; 2JLRAT; 3ASTRON E-mail: [email protected] The missing baryons are usually thought to reside in galaxy filaments as warm-hot intergalactic medium (WHIM). From previous studies, giant radio galaxies are usually associated with galaxy groups, which normally trace the WHIM. We propose observations with the powerful SKA1 to make a census of giant radio galaxies in the southern hemisphere, which will probe the ambient WHIM. The radio galaxies discovered will also be investigated to search for dying radio sources. With the highly improved sensitivity and resolution of SKA1, more than 6,000 giant radio sources will be discovered within 250 hours. Advancing Astrophysics with the Square Kilometre Array, June 8-13, 2014 Giardini Naxos, Sicily, Italy c Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. http://pos.sissa.it/ GRGs as probes of ambient WHIM Bo Peng 1. The WHIM Baryonic matter - protons, neutrons, and electrons - belongs to a class of massive elementary particles which make up the atoms of all materials on Earth and in the stars. From the Big Bang theory and the results of WMAP, baryonic matter contributes no more than 5 percent of the cosmos, though it remains not completely accounted for. From a census of the observable baryonic density in the current Universe (e.g. Shull, Smith & Danforth (2012)), all the stars, dust and gas within galaxies constitute less than 50 percent of baryons predicted by the theory. -
Fueling the Central Engine of Radio Galaxies II
A&A 549, A58 (2013) Astronomy DOI: 10.1051/0004-6361/201220118 & c ESO 2012 Astrophysics Fueling the central engine of radio galaxies II. The footprints of AGN feedback on the ISM of 3C 236, A. Labiano1, S. García-Burillo2,F.Combes3, A. Usero2, R. Soria-Ruiz2, G. Tremblay4,R.Neri5,A.Fuente2, R. Morganti6,7, and T. Oosterloo6,7 1 Centro de Astrobiología, CSIC-INTA, Carretera de Ajalvir km. 4, 28850 Torrejón de Ardoz, Madrid, Spain e-mail: [email protected] 2 Observatorio Astronómico Nacional, Alfonso XII, 3, 28014 Madrid, Spain 3 Observatoire de Paris, LERMA, CNRS, UMR 8112, 61 Av. de l’Observatoire, 75014 Paris, France 4 European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany 5 IRAM, 300 rue de la Piscine, Domaine Universitaire, 38406 Saint-Martin d’Hères Cedex, France 6 Netherlands Foundation for Research in Astronomy, Postbus 2, 7990 AA Dwingeloo, The Netherlands 7 Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands Received 27 July 2012 / Accepted 30 October 2012 ABSTRACT Context. There is growing observational evidence of active galactic nuclei (AGN) feedback on the interstellar medium (ISM) of radio-quiet and radio-loud galaxies. While AGN feedback is expected to be more common at high-redshift objects, studying local universe galaxies helps to better characterize the different manifestations of AGN feedback. Aims. Molecular line observations can be used to quantify the mass and energy budget of the gas affected by AGN feedback. We study the emission of molecular gas in 3C 236, a Faranoff-Riley type 2 (FR II) radio source at z∼0.1, and search for the footprints of AGN feedback. -
Arxiv:1804.09969V1
Research in Astron. Astrophys. Vol.0 (20xx) No.0, 000–000 Research in http://www.raa-journal.org http://www.iop.org/journals/raa Astronomy and (LATEX: sample.tex; printed on November 9, 2018; 22:51) Astrophysics The pc-scale radio structure of MIR-observed radio galaxies Ye Yuan1,2,3, Minfeng Gu1,2 and Yongjun Chen1,4 1 Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, China; [email protected] 2 Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai, 200030, China 3 Uinversity of Chinese Academy of Sciences,19A Yuquan Road, Beijing 10049, China 4 Key Laboratory of Radio Astronomy, Chinese Academy of Sciences, 2 West Beijing Road, Nanjing, JiangSu 210008, China Abstract We investigated the relationship between the accretion process and jet proper- ties by ultilizing the VLBA and mid-infrared (MIR) data for a sample of 45 3CRR radio galaxies selected with a flux density at 178 MHz > 16.4 Jy, 5 GHz VLA core flux den- sity 7 mJy, and MIR observations. The pc-scale radio structure at 5 GHz are presented by using≥ our VLBA observations for 21 sources in February, 2016, the analysis on the archival data for 16 objects, and directly taking the measurements for 8 radio galaxies available in literatures. The accretion mode is constrained from the Eddington ratio with a dividing value of 0.01, which is estimated from the MIR-based bolometric luminosity and the black hole masses. While most FRII radio galaxies have higher Eddington ratio than FRIs, we found that there is indeed no single correspondence between the FR morphol- ogy and accretion mode with eight FRIIs at low accretion and two FRIs at high accretion rate. -
Radio Galaxies Dominate the High-Energy Diffuse Gamma-Ray
FERMILAB-PUB-16-128-A Prepared for submission to JCAP Radio Galaxies Dominate the High-Energy Diffuse Gamma-Ray Background Dan Hoopera;b;c Tim Lindend and Alejandro Lopeze;a aFermi National Accelerator Laboratory, Center for Particle Astrophysics, Batavia, IL 60510 bUniversity of Chicago, Department of Astronomy and Astrophysics, Chicago, IL 60637 cUniversity of Chicago, Kavli Institute for Cosmological Physics, Chicago, IL 60637 dOhio State University, Center for Cosmology and AstroParticle Physcis (CCAPP), Colum- bus, OH 43210 eMichigan Center for Theoretical Physics, Department of Physics, University of Michigan, Ann Arbor, MI 48109 E-mail: [email protected], [email protected], [email protected] Abstract. It has been suggested that unresolved radio galaxies and radio quasars (sometimes referred to as misaligned active galactic nuclei) could be responsible for a significant fraction of the observed diffuse gamma-ray background. In this study, we use the latest data from the Fermi Gamma-Ray Space Telescope to characterize the gamma-ray emission from a sample of 51 radio galaxies. In addition to those sources that had previously been detected using Fermi data, we report here the first statistically significant detection of gamma-ray emission from the radio galaxies 3C 212, 3C 411, and B3 0309+411B. Combining this information with the radio fluxes, radio luminosity function, and redshift distribution of this source class, we +25:4 find that radio galaxies dominate the diffuse gamma-ray background, generating 77:2−9:4 % of this emission at energies above 1 GeV. We discuss the implications of this result and point out that it provides support for∼ scenarios in which IceCube's high-energy astrophysical arXiv:1604.08505v2 [astro-ph.HE] 8 Aug 2016 neutrinos also originate from the same population of radio galaxies. -
Annual Report 2013 E.Indd
2013 ANNUAL REPORT NATIONAL RADIO ASTRONOMY OBSERVATORY 1 NRAO SCIENCE NRAO SCIENCE NRAO SCIENCE NRAO SCIENCE NRAO SCIENCE NRAO SCIENCE NRAO SCIENCE 493 EMPLOYEES 40 PRESS RELEASES 462 REFEREED SCIENCE PUBLICATIONS NRAO OPERATIONS $56.5 M 2,100+ ALMA OPERATIONS SCIENTIFIC USERS $31.7 M ALMA CONSTRUCTION $11.9 M EVLA CONSTRUCTION A SUITE OF FOUR WORLDCLASS $0.7 M ASTRONOMICAL OBSERVATORIES EXTERNAL GRANTS $3.8 M NRAO FACTS & FIGURES $ 2 Contents DIRECTOR’S REPORT. 5 NRAO IN BRIEF . 6 SCIENCE HIGHLIGHTS . 8 ALMA CONSTRUCTION. 26 OPERATIONS & DEVELOPMENT . 30 SCIENCE SUPPORT & RESEARCH . 58 TECHNOLOGY . 74 EDUCATION & PUBLIC OUTREACH. 80 MANAGEMENT TEAM & ORGANIZATION. 84 PERFORMANCE METRICS . 90 APPENDICES A. PUBLICATIONS . 94 B. EVENTS & MILESTONES . 118 C. ADVISORY COMMITTEES . .120 D. FINANCIAL SUMMARY . .124 E. MEDIA RELEASES . .126 F. ACRONYMS . .136 COVER: The National Radio Astronomy Observatory Karl G. Jansky Very Large Array, located near Socorro, New Mexico, is a radio telescope of unprecedented sensitivity, frequency coverage, and imaging capability that was created by extensively modernizing the original Very Large Array that was dedicated in 1980. This major upgrade was completed on schedule and within budget in December 2012, and the Jansky Very Large Array entered full science operations in January 2013. The upgrade project was funded by the US National Science Foundation, with additional contributions from the National Research Council in Canada, and the Consejo Nacional de Ciencia y Tecnologia in Mexico. Credit: NRAO/AUI/NSF. LEFT: An international partnership between North America, Europe, East Asia, and the Republic of Chile, the Atacama Large Millimeter/submillimeter Array (ALMA) is the largest and highest priority project for the National Radio Astronomy Observatory, its parent organization, Associated Universities, Inc., and the National Science Foundation – Division of Astronomical Sciences. -
SRG/ART-XC All-Sky X-Ray Survey: Catalog of Sources Detected During the first Year M
Astronomy & Astrophysics manuscript no. art_allsky ©ESO 2021 July 14, 2021 SRG/ART-XC all-sky X-ray survey: catalog of sources detected during the first year M. Pavlinsky1, S. Sazonov1?, R. Burenin1, E. Filippova1, R. Krivonos1, V. Arefiev1, M. Buntov1, C.-T. Chen2, S. Ehlert3, I. Lapshov1, V. Levin1, A. Lutovinov1, A. Lyapin1, I. Mereminskiy1, S. Molkov1, B. D. Ramsey3, A. Semena1, N. Semena1, A. Shtykovsky1, R. Sunyaev1, A. Tkachenko1, D. A. Swartz2, and A. Vikhlinin1, 4 1 Space Research Institute, 84/32 Profsouznaya str., Moscow 117997, Russian Federation 2 Universities Space Research Association, Huntsville, AL 35805, USA 3 NASA/Marshall Space Flight Center, Huntsville, AL 35812 USA 4 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA July 14, 2021 ABSTRACT We present a first catalog of sources detected by the Mikhail Pavlinsky ART-XC telescope aboard the SRG observatory in the 4–12 keV energy band during its on-going all-sky survey. The catalog comprises 867 sources detected on the combined map of the first two 6-month scans of the sky (Dec. 2019 – Dec. 2020) – ART-XC sky surveys 1 and 2, or ARTSS12. The achieved sensitivity to point sources varies between ∼ 5 × 10−12 erg s−1 cm−2 near the Ecliptic plane and better than 10−12 erg s−1 cm−2 (4–12 keV) near the Ecliptic poles, and the typical localization accuracy is ∼ 1500. Among the 750 sources of known or suspected origin in the catalog, 56% are extragalactic (mostly active galactic nuclei (AGN) and clusters of galaxies) and the rest are Galactic (mostly cataclysmic variables (CVs) and low- and high-mass X-ray binaries).