Discovery of Quasars
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The Global Jet Structure of the Archetypical Quasar 3C 273
galaxies Article The Global Jet Structure of the Archetypical Quasar 3C 273 Kazunori Akiyama 1,2,3,*, Keiichi Asada 4, Vincent L. Fish 2 ID , Masanori Nakamura 4, Kazuhiro Hada 3 ID , Hiroshi Nagai 3 and Colin J. Lonsdale 2 1 National Radio Astronomy Observatory, 520 Edgemont Rd, Charlottesville, VA 22903, USA 2 Massachusetts Institute of Technology, Haystack Observatory, 99 Millstone Rd, Westford, MA 01886, USA; vfi[email protected] (V.L.F.); [email protected] (C.J.L.) 3 National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; [email protected] (K.H.); [email protected] (H.N.) 4 Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan; [email protected] (K.A.); [email protected] (M.N.) * Correspondence: [email protected] Received: 16 September 2017; Accepted: 8 January 2018; Published: 24 January 2018 Abstract: A key question in the formation of the relativistic jets in active galactic nuclei (AGNs) is the collimation process of their energetic plasma flow launched from the central supermassive black hole (SMBH). Recent observations of nearby low-luminosity radio galaxies exhibit a clear picture of parabolic collimation inside the Bondi accretion radius. On the other hand, little is known of the observational properties of jet collimation in more luminous quasars, where the accretion flow may be significantly different due to much higher accretion rates. In this paper, we present preliminary results of multi-frequency observations of the archetypal quasar 3C 273 with the Very Long Baseline Array (VLBA) at 1.4, 15, and 43 GHz, and Multi-Element Radio Linked Interferometer Network (MERLIN) at 1.6 GHz. -
Star Maps: Where Are the Black Holes?
BLACK HOLE FAQ’s 1. What is a black hole? A black hole is a region of space that has so much mass concentrated in it that there is no way for a nearby object to escape its gravitational pull. There are three kinds of black hole that we have strong evidence for: a. Stellar-mass black holes are the remaining cores of massive stars after they die in a supernova explosion. b. Mid-mass black hole in the centers of dense star clusters Credit : ESA, NASA, and F. Mirabel c. Supermassive black hole are found in the centers of many (and maybe all) galaxies. 2. Can a black hole appear anywhere? No, you need an amount of matter more than 3 times the mass of the Sun before it can collapse to create a black hole. 3. If a star dies, does it always turn into a black hole? No, smaller stars like our Sun end their lives as dense hot stars called white dwarfs. Much more massive stars end their lives in a supernova explosion. The remaining cores of only the most massive stars will form black holes. 4. Will black holes suck up all the matter in the universe? No. A black hole has a very small region around it from which you can't escape, called the “event horizon”. If you (or other matter) cross the horizon, you will be pulled in. But as long as you stay outside of the horizon, you can avoid getting pulled in if you are orbiting fast enough. 5. What happens when a spaceship you are riding in falls into a black hole? Your spaceship, along with you, would be squeezed and stretched until it was torn completely apart as it approached the center of the black hole. -
The WSRT Zoa Perseus-Pisces Filament Wide-Field HI Imaging
MNRAS 000,1{29 (2016) Preprint 9 September 2021 Compiled using MNRAS LATEX style file v3.0 The WSRT ZoA Perseus-Pisces Filament wide-field HI imaging survey I. HI catalogue and atlas. M. Ramatsoku1;2;3?, M.A.W Verheijen1, R.C. Kraan-Korteweg2, G.I.G. J´ozsa4, A.C. Schr¨oder5, T.H. Jarrett2, E.C Elson2, W. van Driel6, W.J.G. de Blok3;2;1, P.A. Henning7. 1Kapteyn Astronomical Institute, University of Groningen, Landleven 12, 9747 AV Groningen, The Netherlands 2Astrophysics, Cosmology and Gravity Centre (ACGC), Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa 3ASTRON, Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA Dwingeloo, The Netherlands 4SKA South Africa, Radio Astronomy Research Group, 3rd Floor, The Park, Park Road, Pinelands 7405, South Africa 5South African Astronomical Observatory (SAAO), PO Box 9, 7935 Observatory, Cape Town, South Africa 6GEPI, Observatoire de Paris, CNRS, Universit´eParis Diderot, 5 place Jules Janssen, 92190 Meudon, France 7Department of Physics and Astronomy, University of New Mexico, 1919 Lomas Blvd. NE, MSC07 4220, Albuquerque NM 87131-0001, USA Accepted 2016 April 21. Received 2016 April 21; in original form 2015 November 24 ABSTRACT We present results of a blind 21cm H I-line imaging survey of a galaxy overdensity located behind the Milky Way at `;b ≈ 160◦, 0.5◦. The overdensity corresponds to a Zone-of-Avoidance crossing of the Perseus-Pisces Supercluster filament. Although it is known that this filament contains an X-ray galaxy cluster (3C 129) hosting two strong radio galaxies, little is known about galaxies associated with this potentially rich cluster because of the high Galactic dust extinction. -
Jet-Induced Star Formation in 3C 285 and Minkowski's Object⋆
A&A 574, A34 (2015) Astronomy DOI: 10.1051/0004-6361/201424932 & c ESO 2015 Astrophysics Jet-induced star formation in 3C 285 and Minkowski’s Object? Q. Salomé, P. Salomé, and F. Combes LERMA, Observatoire de Paris, CNRS UMR 8112, 61 avenue de l’Observatoire, 75014 Paris, France e-mail: [email protected] Received 5 September 2014 / Accepted 6 November 2014 ABSTRACT How efficiently star formation proceeds in galaxies is still an open question. Recent studies suggest that active galactic nucleus (AGN) can regulate the gas accretion and thus slow down star formation (negative feedback). However, evidence of AGN positive feedback has also been observed in a few radio galaxies (e.g. Centaurus A, Minkowski’s Object, 3C 285, and the higher redshift 4C 41.17). Here we present CO observations of 3C 285 and Minkowski’s Object, which are examples of jet-induced star formation. A spot (named 3C 285/09.6 in the present paper) aligned with the 3C 285 radio jet at a projected distance of ∼70 kpc from the galaxy centre shows star formation that is detected in optical emission. Minkowski’s Object is located along the jet of NGC 541 and also shows star formation. Knowing the distribution of molecular gas along the jets is a way to study the physical processes at play in the AGN interaction with the intergalactic medium. We observed CO lines in 3C 285, NGC 541, 3C 285/09.6, and Minkowski’s Object with the IRAM 30 m telescope. In the central galaxies, the spectra present a double-horn profile, typical of a rotation pattern, from which we are able to estimate the molecular gas density profile of the galaxy. -
Virgo the Virgin
Virgo the Virgin Virgo is one of the constellations of the zodiac, the group tion Virgo itself. There is also the connection here with of 12 constellations that lies on the ecliptic plane defined “The Scales of Justice” and the sign Libra which lies next by the planets orbital orientation around the Sun. Virgo is to Virgo in the Zodiac. The study of astronomy had a one of the original 48 constellations charted by Ptolemy. practical “time keeping” aspect in the cultures of ancient It is the largest constellation of the Zodiac and the sec- history and as the stars of Virgo appeared before sunrise ond - largest constellation after Hydra. Virgo is bordered by late in the northern summer, many cultures linked this the constellations of Bootes, Coma Berenices, Leo, Crater, asterism with crops, harvest and fecundity. Corvus, Hydra, Libra and Serpens Caput. The constella- tion of Virgo is highly populated with galaxies and there Virgo is usually depicted with angel - like wings, with an are several galaxy clusters located within its boundaries, ear of wheat in her left hand, marked by the bright star each of which is home to hundreds or even thousands of Spica, which is Latin for “ear of grain”, and a tall blade of galaxies. The accepted abbreviation when enumerating grass, or a palm frond, in her right hand. Spica will be objects within the constellation is Vir, the genitive form is important for us in navigating Virgo in the modern night Virginis and meteor showers that appear to originate from sky. Spica was most likely the star that helped the Greek Virgo are called Virginids. -
'-. 5 36 B6 19650268
-- '-. 5 36_B6 _ rr_nm O/ITEE I_ATUREOF THE QUASI-S_ OBJECTS F. HOYLE , University of Cambridge- C_m_ridge,Eng!and and G. R. BURBIDGE :University of California at San Diego La Jolla, California ) 19650268 1965026885-002 ON _ NA_NJEE OF THE QUASI-STELLAR OBJECTS F. HOYLE Uni,_ersity of Cambridge Cambridge, England and G. R. BURBIDGE University of California at San Diego - La Jolla, California Received July 1965 1985028885-003 ABST_ACT In this paper we discuss the origin of the quasi-stellar objects from , two different points of view: (i) that they are objects al;cosmological distances as has been commonly supposed, and (ii) that they are local obje:ts situated at distance _ 1 - l0 Mpc. In the introductory section the optical properties of the quasi-stellar objects ar_:compared with the optical properties of galaxies associated with strong radio courses and Syefert nuclei from both points of view. Section II is devoted to a d.Lscussion of (i) and on this basis it is argue_ that they are most probably the nuclei of galaxies which have reached a high density phase at which time the formation of me_sive objects and their subsequent evolution has occurred. Apart from the suggestion of Terrell little atr.entionhas been paid until now to the possibility that they are local objects and so we have considered this in considerable detail. A plausible case can now be made for supposing that they are coherent objects which have been ejected at relativistic speeds L from the nuclei of galaxies at times when they erupt to give rise to strong radio source_ and other phenomena. -
The Faint X-Ray Source Population Near 3C 295 V
Outskirts of Galaxy Clusters: Intense Life in the Suburbs Proceedings IAU Colloquium No. 195, 2004 c 2004 International Astronomical Union A. Diaferio, ed. DOI: 10.1017/S1743921304000109 The faint X-ray source population near 3C 295 V. D’Elia1,F.Fiore,M.Elvis,M.Cappi,S.Mathur,P.Mazzotta, E. Falco and F. Cocchia 1INAF - Osservatorio Astronomico di Roma - Via di Frascati, 33 I-00040 Monteporzio Catone (Rome), Italy email: [email protected] Abstract. We present a statistical analysis of the Chandra observation of the source field around the 3C 295 galaxy cluster (z =0.46). Three different methods of analysis, namely a chip by chip LogN-LogS, a two-dimentional Kolmogorov-Smirnov (KS) test, and the angular correlation function (ACF) show a strong overdensity of sources in the North-East of the field, that may indicate a filament of the large scale structure of the universe towards 3C 295. 1. Introduction N-body and hydrodynamical simulations show that high redshift clusters of galaxies lie at the nexus of several filaments of galaxies (see e.g. Peacock 1999). Such filaments map out the “cosmic web” of voids and filaments of the large scale structure of the universe. Thus, rich clusters represent good indicators of regions of sky where several filaments converge. The filaments themselves could be mapped out by Active Galactic Nuclei (AGNs), assuming that AGNs trace galaxies. Cappi et al. (2001) studied the distribution of the X-ray sources around 3C 295 (z = 0.46). The cluster was observed with the ACIS-S CCD array for a short exposure time (18 ks). -
Globular Clusters 20
From; http://www.reciprocalsystem.com/um/index.htm The Universe of Motion DEWEY B. LARSON Volume III of a revised and enlarged edition of The Structure of the Physical Universe Preface 17. Pulsars 1. Introduction 18. Radiative Processes 2. Galaxies 19. X-ray Emission 3. Globular Clusters 20. The Quasar Situation 4. The Giant Star Cycle 21. Quasar Theory 5. The Later Cycles 22. Verification 6. The Dwarf Star Cycle 23. Quasar Redshifts 7. Binary and Multiple Stars 24. Evolution of Quasars 8. Evolution–Globular Cluster Stars 25. The Quasar Populations 9. Gas and Dust Clouds 26. Radio Galaxies 10. Evolution–Galactic Stars 27. Pre-Quasar Phenomena 11. Planetary Nebulae 28. Inter-Sector Relations 12. Ordinary White Dwarfs 29. The Non-Existent Universe 13. The Cataclysmic Variables 30. Cosmology 14. Limits 31. Implications 15. The Intermediate Region References 16. Type II Supernovae Preface This volume applies the physical laws and principles of the universe of motion to a consideration of the large-scale structure and properties of that universe, the realm of astronomy. Inasmuch as it presupposes nothing but a familiarity with physical laws and principles, it is self-contained in the same sense as any other publication in the astronomical field. However, the laws and principles applicable to the universe of motion differ in many respects from those of the conventional physical science. For the convenience of those who may wish to follow the development of thought all the way from the fundamentals, and are not familiar with the theory of the universe of motion, I am collecting the most significant portions of the previously published books and articles dealing with that theory, and incorporating them, together with the results of some further studies, into a series of volumes with the general title The Structure of the Physical Universe. -
9303350505 Instruction Manual • Manuel D
INSTRUCTION MANUAL • MANUEL D’INSTRUCTIONS MANUAL DE INSTRUCCIONES • BEDIENUNGSANLEITUNG MANUALE DI ISTRUZIONI • MANUAL DE INSTRUÇÕES LIT.#: 9303350505 1 6/1/05 10:58:03 AM CONTENTS ENGLISH ....................................................................... 2 FRANÇAIS .....................................................................35 ESPAÑOL ......................................................................69 DEUTSCH ....................................................................103 ITALIANO ...................................................................137 PORTUGUÊS ...............................................................171 2 6/1/05 10:58:03 AM WHERE DO I START? Congratulations on the purchase of your Tasco SpaceStation Goto Telescope! It is our sincere hope Your Tasco telescope can bring the wonders of the universe to your eye. While this manual that you will enjoy this telescope for years to come! is intended to assist you in the set-up and basic use of this instrument, it does not cover everything you might like to know about astronomy. Although SpaceStation will give a respectable tour of the night sky, it is recommended you get a very simple star chart and a flashlight with a red bulb or red cellophane over the end. For objects other than stars and constellations, a basic guide to astronomy is a must. Some recommended sources appear on our website at www.Tasco.com. Also on our website will be current events in the sky for suggested viewing. But, some of the standbys that you can see are: The Moon—a wonderful view of our lunar neighbor can be enjoyed with any magnification. Try viewing at different phases of the moon. Lunar highlands, lunar maria (lowlands called “seas” for their dark coloration), craters, ridges and mountains will astound you. Saturn—even at the lowest power you should be able to see Saturn’s rings and moons. -
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). -
Active Galactic Nuclei - Suzy Collin, Bożena Czerny
ASTRONOMY AND ASTROPHYSICS - Active Galactic Nuclei - Suzy Collin, Bożena Czerny ACTIVE GALACTIC NUCLEI Suzy Collin LUTH, Observatoire de Paris, CNRS, Université Paris Diderot; 5 Place Jules Janssen, 92190 Meudon, France Bożena Czerny N. Copernicus Astronomical Centre, Bartycka 18, 00-716 Warsaw, Poland Keywords: quasars, Active Galactic Nuclei, Black holes, galaxies, evolution Content 1. Historical aspects 1.1. Prehistory 1.2. After the Discovery of Quasars 1.3. Accretion Onto Supermassive Black Holes: Why It Works So Well? 2. The emission properties of radio-quiet quasars and AGN 2.1. The Broad Band Spectrum: The “Accretion Emission" 2.2. Optical, Ultraviolet, and X-Ray Emission Lines 2.3. Ultraviolet and X-Ray Absorption Lines: The Wind 2.4. Variability 3. Related objects and Unification Scheme 3.1. The “zoo" of AGN 3.2. The “Line of View" Unification: Radio Galaxies and Radio-Loud Quasars, Blazars, Seyfert 1 and 2 3.2.1. Radio Loud Quasars and AGN: The Jet and the Gamma Ray Emission 3.3. Towards Unification of Radio-Loud and Radio-Quiet Objects? 3.4. The “Accretion Rate" Unification: Low and High Luminosity AGN 4. Evolution of black holes 4.1. Supermassive Black Holes in Quasars and AGN 4.2. Supermassive Black Holes in Quiescent Galaxies 5. Linking the growth of black holes to galaxy evolution 6. Conclusions Acknowledgements GlossaryUNESCO – EOLSS Bibliography Biographical Sketches SAMPLE CHAPTERS Summary We recall the discovery of quasars and the long time it took (about 15 years) to build a theoretical framework for these objects, as well as for their local less luminous counterparts, Active Galactic Nuclei (AGN). -
A Kinematic Study of the Irregular Dwarf Galaxy NGC 4861 Using HI
Astronomy & Astrophysics manuscript no. 11766.bw c ESO 2021 September 10, 2021 A kinematic study of the irregular dwarf galaxy NGC 4861 using H i and Hα observations J. van Eymeren1;2;3, M. Marcelin4, B. S. Koribalski3, R.-J. Dettmar2, D. J. Bomans2, J.-L. Gach4, and P. Balard4 1 Jodrell Bank Centre for Astrophysics, School of Physics & Astronomy, The University of Manchester, Alan Turing Building, Oxford Road, Manchester, M13 9PL, UK e-mail: [email protected] 2 Astronomisches Institut der Ruhr-Universitat¨ Bochum, Universitatsstraße¨ 150, 44780 Bochum, Germany 3 Australia Telescope National Facility, CSIRO, P.O. Box 76, Epping, NSW 1710, Australia 4 Laboratoire d’Astrophysique de Marseille, OAMP, Universite´ Aix-Marseille & CNRS, 38 rue Fred´ eric´ Joliot-Curie, 13013 Marseille, France Accepted 20 July 2009 ABSTRACT Context. Outflows powered by the injection of kinetic energy from massive stars can strongly affect the chemical evolution of galaxies, in particular of dwarf galaxies, as their lower gravitational potentials enhance the chance of a galactic wind. Aims. We therefore performed a detailed kinematic analysis of the neutral and ionised gas components in the nearby star-forming irregular dwarf galaxy NGC 4861. Similar to a recently published study of NGC 2366, we want to make predictions about the fate of the gas and to discuss some general issues about this galaxy. Methods. Fabry-Perot interferometric data centred on the Hα line were obtained with the 1.93m telescope at the Observatoire de Haute-Provence. They were complemented by H i synthesis data from the VLA. We performed a Gaussian decomposition of both the Hα and the H i emission lines in order to search for multiple components indicating outflowing gas.