Multi-Colour Analysis of Galaxy Clusters with Radio Halos And/Or Relics
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
THE POLARIZATION of RADIO GALAXIES -Its Structure at Low Frequencies
STELLINGEN behorende bij het proefschrift THE POLARIZATION OF RADIO GALAXIES -its structure at low frequencies- 1. De structuur van de polarisatieverdelingen in uitgebreide extragalactische radiobronnen toont aan dat de veelgemaakte aanname van cilinder symmetrie voor de radiocomponenten onvolledig is (dit proefschrift). 2. Voor multispectrale vergelijkingen van radiokaarten van uitgebreide extragalactische stelsels ware het gewenst dat de Westerbork Synthese Radio Telescoop wordt uitgebreid met ontvangers bij een frequentie ergens tussen 610 MHz en 1400 MHz. 3. Het verloop van de spectrale index in zogenaamde edge-brightened double radio sources is slechts afhankelijk van de spectrale indices van de hot spots (dit proefschrift). 4. In de radiosterrenkunde blijft de theorie te ver achter bij de vele goede waarnemingen. 5. Om een goede astronoom te zijn moet men geloven dat het te bestuderen object de sleutel tot het heelal levert. 6. Bemande ruimtevaart moet waar mogelijk vermeden worden. 7. Sporters moeten zelf kunnen beslissen of zij een politiek omstreden evenement boycotten of niet. 8. Gelijktijdige pauze op alle Nederlandse astronomische instituten verhoogt de doelmatigheid. 9. De verwijzing private communication in wetenschappelijke literatuur is onacceptabel. 10. Het niet respecteren van Oost-Europese sportprestaties miskent het fenomeen topsport. 11. De huidige opzet van de dames tafeltennis competitie is nadelig voor het algehele dames spelniveau. W.J. Jagers Leiden, 2 december 1986 THE POLARIZATION OF RADIO GALAXIES its structure at low frequencies THE POLARIZATION OF RADIO GALAXIES its structure at low frequencies PROEFSCHRIFT ter verkrijging van de graad van Doctor in de Wiskunde en Natuurwetenschappen aan de Rijksuniversiteit te Leiden, op gezag van de Rector Magnificus Dr. -
Arxiv:2006.10868V2 [Astro-Ph.SR] 9 Apr 2021 Spain and Institut D’Estudis Espacials De Catalunya (IEEC), C/Gran Capit`A2-4, E-08034 2 Serenelli, Weiss, Aerts Et Al
Noname manuscript No. (will be inserted by the editor) Weighing stars from birth to death: mass determination methods across the HRD Aldo Serenelli · Achim Weiss · Conny Aerts · George C. Angelou · David Baroch · Nate Bastian · Paul G. Beck · Maria Bergemann · Joachim M. Bestenlehner · Ian Czekala · Nancy Elias-Rosa · Ana Escorza · Vincent Van Eylen · Diane K. Feuillet · Davide Gandolfi · Mark Gieles · L´eoGirardi · Yveline Lebreton · Nicolas Lodieu · Marie Martig · Marcelo M. Miller Bertolami · Joey S.G. Mombarg · Juan Carlos Morales · Andr´esMoya · Benard Nsamba · KreˇsimirPavlovski · May G. Pedersen · Ignasi Ribas · Fabian R.N. Schneider · Victor Silva Aguirre · Keivan G. Stassun · Eline Tolstoy · Pier-Emmanuel Tremblay · Konstanze Zwintz Received: date / Accepted: date A. Serenelli Institute of Space Sciences (ICE, CSIC), Carrer de Can Magrans S/N, Bellaterra, E- 08193, Spain and Institut d'Estudis Espacials de Catalunya (IEEC), Carrer Gran Capita 2, Barcelona, E-08034, Spain E-mail: [email protected] A. Weiss Max Planck Institute for Astrophysics, Karl Schwarzschild Str. 1, Garching bei M¨unchen, D-85741, Germany C. Aerts Institute of Astronomy, Department of Physics & Astronomy, KU Leuven, Celestijnenlaan 200 D, 3001 Leuven, Belgium and Department of Astrophysics, IMAPP, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands G.C. Angelou Max Planck Institute for Astrophysics, Karl Schwarzschild Str. 1, Garching bei M¨unchen, D-85741, Germany D. Baroch J. C. Morales I. Ribas Institute of· Space Sciences· (ICE, CSIC), Carrer de Can Magrans S/N, Bellaterra, E-08193, arXiv:2006.10868v2 [astro-ph.SR] 9 Apr 2021 Spain and Institut d'Estudis Espacials de Catalunya (IEEC), C/Gran Capit`a2-4, E-08034 2 Serenelli, Weiss, Aerts et al. -
The Radio Relic in Abell 2256: Overall Spectrum and Implications for Electron Acceleration
A&A 575, A45 (2015) Astronomy DOI: 10.1051/0004-6361/201423972 & c ESO 2015 Astrophysics The radio relic in Abell 2256: overall spectrum and implications for electron acceleration M. Trasatti1,H.Akamatsu2,L.Lovisari1, U. Klein1, A. Bonafede3, M. Brüggen3, D. Dallacasa4,5,andT.Clarke6 1 Argelander Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany e-mail: [email protected] 2 SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands 3 Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany 4 Dipartimento di Astronomia, Università di Bologna, via Ranzani 1, 40127 Bologna, Italy 5 INAF – Istituto di Radioastronomia, via Gobetti 101, 40129 Bologna, Italy 6 Naval Research Laboratory, 4555 Overlook Ave, SW, DC 20375 Washington, USA Received 10 April 2014 / Accepted 1 November 2014 ABSTRACT Context. Radio relics are extended synchrotron sources thought to be produced by shocks in the outskirts of merging galaxy clusters. The cluster Abell 2256 hosts one of the most intriguing examples in this class of sources. It has been found that this radio relic has a rather flat integrated spectrum at low frequencies that would imply an injection spectral index for the electrons that is inconsistent with the flattest allowed by the test particle diffusive shock acceleration (DSA). Aims. We aim at testing the origins of the radio relic in Abell 2256. Methods. We performed new high-frequency observations at 2273, 2640, and 4850 MHz. Combining these new observations with images available in the literature, we constrain the radio-integrated spectrum of the radio relic in Abell 2256 over the widest sampled frequency range collected so far for this class of objects (63−10 450 MHz). -
T-Ramisu: the Two-Meter Radio Mini Survey I. the Bootes Field
Astronomy & Astrophysics manuscript no. bootes˙wide˙field˙notable c ESO 2018 October 31, 2018 T-RaMiSu: The Two-meter Radio Mini Survey I. The Bootes¨ Field W. L. Williams1;2, H. T. Intema3;?, and H. J. A. Rottgering¨ 1 1 Leiden Observatory, Leiden University, P.O.Box 9513, NL-2300 RA, Leiden, The Netherlands e-mail: [email protected] 2 Netherlands Institute for Radio AStronomy (ASTRON), PO Box 2, 7990AA Dwingeloo, The Netherlands 3 National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475, USA Received / Accepted ABSTRACT We present wide area, deep, high-resolution 153 MHz GMRT observations of the NOAO Bootes¨ field, adding to the extensive, multi- wavelength data of this region. The observations, data reduction, and catalogue construction and description are described here. The seven pointings produced a final mosaic covering 30 square degrees with a resolution of 2500. The rms noise is 2 mJy beam−1 in the centre of the image, rising to 4−5 mJy beam−1 on the edges, with an average of 3 mJy beam−1. Seventy-five per cent of the area has an rms < 4 mJy beam−1. The extracted source catalogue contains 1289 sources detected at 5σ, of which 453 are resolved. We estimate the catalogue to be 92 per cent reliable and 95 per cent complete at an integrated flux density limit of 14 mJy. The flux densities and astrometry have been corrected for systematic errors. We calculate the differential source counts which are in good agreement with those in the literature and provide an important step forward in quantifying the source counts at these low frequencies and low flux densities. -
ORIGINS of QUASARS and GALAXY CLUSTERS 1 Inroduction
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by CERN Document Server ORIGINS OF QUASARS AND GALAXY CLUSTERS H. ARP Max-Planck-Institut f¨ur Astrophysik, 85741 Garching, Germany The distribution on the sky of clusters of galaxies shows significant association with relatively nearby, large, active galaxies. The pattern is that of clusters paired equidistant across a central galaxy with the apparent magnitudes and redshifts of their constituent galaxies being closely matched. The clusters and the galaxies in them tend to be strong X-ray and radio emitters and their redshifts occur at preferred redshift values. The central, low redshift galaxies often show evidence of ejection in the direction of these higher redshift clusters and the clusters often show elongation along these lines. In most of these respects the clusters resemble quasars which have been increasingly shown for the last 34 years to be similarly associated with active parent galaxies. It is argued here that, empirically, the quasars are ejected from active galaxies. They evolve to lower redshift with time, fragmenting at the end of their development into clusters of low luminosity galaxies. The cluster galaxies can be at the same distance as their lower redshift parents because they still retain a component of their earlier, quasar intrinsic redshift. 1 Inroduction The distribution on the sky of clusters of galaxies started to be catalogued about 40 years ago by George Abell and collaborators. The cores of these clusters were predominantly old stellar population E galaxies which were believed to be mostly gas free and inactive. -
To the Edge of the Universe Annual Report 2013
The Vatican Observatory To the Edge of the Universe Annual Report 2013 SPECOLAVatican Observatory VATICANA ANNUAL REPORT 2013 Vatican Observatory V-00120 Vatican City State Vatican Observatory Research Group Steward Observatory University of Arizona Tucson, Arizona 85721 USA http://vaticanobservatory.org Vatican Observatory Staff The following are permanent staff members of the Vatican Observatory, Pontifical Villas of Castel Gandolfo, Italy, and the Vatican Observatory Research Group (VORG), Tucson, Arizona, USA: • JOSÉ G. FUNES, S.J., Director • JÓZEF M. MAJ, S.J., Vice Director for Administration • PAVEL GABOR, S.J., Vice Director for VORG • RICHARD P. BOYLE, S.J. • DAVID A. BROWN, S.J. • GUY J. CONSOLMAGNO, S.J., Coordinator for Public Relations, Curator of the Vatican Meteorite Collection • CHRISTOPHER J. CORBALLY, S.J., President of the National Committee to International Astronomical Union • ALBERT J. DIULIO, S.J., President, Vatican Observatory Foundation • GABRIELE GIONTI, S.J. • JEAN-BAPTISTE KIKWAYA, S.J. • ROBERT J. MACKE, S.J. • SABINO MAFFEO, S.J., Emeritus staff Adjunct Scholars: • PAUL R. MUELLER, S.J., • LOUIS CARUANA, S.J. Coordinator for Science, Philosophy • ILEANA CHINNICI and Theology Studies • ROBERT JANUSZ, S.J. • ALESSANDRO OMIZZOLO • MICHAEL HELLER • WILLIAM R. STOEGER, S.J. • DANTE MINNITI Cover: Pope Francis visited the Vatican Observatory (VO) in July; he is seen here through a display case of antique astronomical globes and instruments, including a 16th century astrolabe and a hand- painted globe of Mars from 1915. (credit: L’Osservatore Romano) Editor: Emer McCarthy Design and layout: Antonio Coretti CONTENTS From the Director ............................................ 6 Science Priorities ............................................. 8 Research ........................................................ 14 Instrumentation & Technical Services ........... 25 Observatory and Staff Activities ................... -
Extragalactic Magnetic Fields
Rep. Pro& Phys. (1994) 325-382. Printed in lhe UK Extragalactic magnetic fields Philipp P Kronberg Department of Astronomy, University of Toronto, 60 St. George Street, Toronto, Canada M5S IA7 Abstract Recent advances in observational techniques reveal the widespread existence of magnetic fields in the Universe, and produce much firmer estimates of magnetic field strengths in interstellar and intergalactic space. Ordered, microgauss-level fields are common in spiral galaxy disks and halos, and appear to be a common property of the intra-cluster medium of clusters of galaces, indeed well beyond the cluster core regions. Strengths of ordered magnetic fields in the intracluster medium of cooling flow clusters exceed those which are typical of the interstellar medium of the Milky Way, suggesting that galaxy formation, and even cluster dynamics are, at least in some circumstances influ- enced by magnetic forces, which also could possibly affect the global dynamics in areas of some galaxies, especially dwarf galaxies, which are rich in interstellar gas and cosmic rays. Physical processes responsible for the regeneration of initial seed fields in galaxies, including mechanisms of magnetic diffusivity and dissipation which influence field amplification, are increasingly better, though far from completely, understood. We review the ‘conventional’, slow mean field a-w dynamo theory for disk galaxies, and more recent modifications to the theory. Fast-acting dynamo mechanisms appear to operate in galaxies, galaxy inflow and outflow, and in cooling flow clusters. Better understanding of the magnetic properties of extragalactic radio jets, including recent 3~ numerical simulations, has shown how fast dynamo processes associated with the radio jetilobe combination can effec!ivity magnetize large volumes of inlergalactic space. -
ING Technical Note No. 134 “ING Bibliography and Analysis 2002-2011” - Page 2
ING LA PALMA TECHNICAL NOTE NO. 134 ING Bibliography and Analysis 2002-2011 Javier Méndez (ING) May 2012 Contents 1. Introduction .................................................................................................................................................................... 3 2. Analysis. .......................................................................................................................................................................... 4 2.1. Paper counts. .......................................................................................................................................................... 4 2.2. Paper authorship. .................................................................................................................................................... 7 2.3. Paper instrument use. ............................................................................................................................................. 7 2.4. Paper count check. .................................................................................................................................................. 8 Appendix 1. “ING Bibliography 2002-2011”. ........................................................................................................................ 10 2002 .................................................................................................................................................................................. 10 2003 ................................................................................................................................................................................. -
The Radio Luminosity Function and Galaxy Evolution of Abell 2256
The Radio Luminosity Function and Galaxy Evolution of Abell 2256 A THESIS SUBMITTED TO THE FACULTY OF THE GRADUATE SCHOOL OF THE UNIVERSITY OF MINNESOTA BY Zahra Forootaninia IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE Lawrence Rudnick, Advisor January, 2015 c Zahra Forootaninia 2015 ALL RIGHTS RESERVED Acknowledgements I would like to express my special appreciation and thanks to my advisor Professor Lawrence Rudnick who has been a good mentor and gave me the unique opportunity and support. I appreciate his guidance, generous contribution of knowledge and experience and valuable comments in my search. I would also like to thank my committee members, Professor Terry Jones, Professor Robert Lysak and Professor Thomas Jones for serving as my committee members even at hardship. I would especially like to thank Professor Frazer Owen at National Radio Astronomy Observatory, for providing me with very fascinating data and his brilliant comments, suggestions and help. Next, I would like thank to Dr Kyle Willett for being so generous in sharing his knowledge and time with me. His recommendations always helped me find the correct path in my research. Also, I would like to thank Dr Reinout van Weeren for allowing me to use his Hubble Space Telescope data. A special thanks to my family. Words cannot express how grateful I am to my mother, father and my sister for all of the sacrifices that they have made on my behalf. I would also like to thank all of my friends who supported me in writing, and incited me to strive towards my goal. -
Publications of the Astronomical Society of the Pacific Vol. 107 1995
Publications of the Astronomical Society of the Pacific Vol. 107 1995 January No. 707 Publications of the Astronomical Society of the Pacific 107: 1-21, 1995 January Invited Review Paper Astrophysics in 1994 Virginia Trimble1 and Peter J. T. Leonard Department of Astronomy, University of Maryland, College Park, Maryland 20742 Received 1994 October 17; accepted 1994 November 3 ABSTRACT. 1994 was the year in which we saw the first images from the repaired Hubble Space Telescope', the probable detection of a diffuse intergalactic medium, a black hole in M87, and an enormous primordial deuterium abundance; the discovery of the first (and second) superluminal objects within our own galaxy; not to mention the demise of the Jovian dinosaurs. But, as always, most astronomers continued to work away on the projects that have interested them for years or decades, and we attempt also to report some progress in broader areas, including cooling flows, extragalactic globular cluster populations, disk instabilities, phases of the interstellar medium, and brown dwarfs among microlenses and other populations. Several sections of short items range from the obvious to the remarkable to the unbelievable. As in previous years, the ordering of the topics attempts to preserve the near-to-far custom of elementary astronomy textbooks. 1. INTRODUCTION Circulars, and (of course) Publications of the Astronomical Society of the Pacific. The proportions of cited papers com- Greetings, and welcome to the fourth annual roundup of 2 ing from the various journals are not very different from the beasts for the astrophysical zoo. It attempts, like its prede- cessors, to catch most of the obvious, newsworthy events, proportions they publish of the entire literature (apart from but also to highlight areas where less spectacular, yet hard over-representation of Nature, Science, and Letters sections). -
Jahresbericht 2012
Jahresbericht 2012 Argelander–Institut fur¨ Astronomie Rheinische Friedrich-Wilhelms-Universit¨at Bonn Auf dem Hugel¨ 71, 53121 Bonn Tel. (0228)73-3658, Telefax: (0228)73-1775 E-Mail: [email protected] WWW: http://www.astro.uni-bonn.de/ 1 Allgemeines Geschichte: Die Astronomie entfaltete sich in Bonn seit der Berufung Argelanders (1836). Er errichtete die Sternwarte an der Poppelsdorfer Allee, die 1845 in Betrieb genommen wurde. Ab 1952 wurden die Teleskope zum neuen Observatorium Hoher List in die Eifel umgesiedelt. Mit den Beobachtungsm¨oglichkeiten fur¨ die Radiostrahlung (Errichtung des Radioobservatoriums auf dem Stockert 1956) und mit der Raumfahrt entwickelten sich Fachrichtungen, die zur Grundung¨ des Radioastronomischen Instituts (1962), des Instituts fur¨ Astrophysik und Extraterrestrische Forschung (1964) und des Max-Planck-Instituts fur¨ Radioastronomie (1966) fuhrten.¨ 1973 bezogen die Institute gemeinsam das jetzt bestehen- de Geb¨aude. Am 1.1.2006 wurden die drei Universit¨atsinstitute zum Argelander-Institut fur¨ Astronomie zusammengefuhrt.¨ Das Observatorium Hoher List wurde am 30.06.2012 vom AIfA getrennt und geschlossen. Damit orientiert sich das AIfA weg von der beobach- tenden optischen Astronomie. Seit Oktober 2012 ist Kroupa Gesch¨aftsfuhrender¨ Direktor. Forschungsgruppen, welche 2012 am AIfA etabliert waren (Themengebiete werden in Eng- lisch angegeben): Mm/submm Astronomy: Star formation, galaxy evolution, ISM in galaxies, observational cosmology (Frank Bertoldi). Gravitational Lensing and Cosmology: Studying Galaxies, Galaxy Clusters, and Cosmo- logy with Weak Gravitational Lensing Magnification (Hendrik Hildebrandt: Emmy Noether Group). Stellar Astrophysics: The Evolution of Single and Binary Stars, Stellar Nucleosynthesis, Chemically peculiar stars, Globular clusters, Chemical evolution of the Galaxy, The progenitors of Gamma-Ray Bursts, Computational astrophysics (Robert Izzard). -
The Two-Meter Radio Mini Survey I
A&A 549, A55 (2013) Astronomy DOI: 10.1051/0004-6361/201220235 & c ESO 2012 Astrophysics T-RaMiSu: the Two-meter Radio Mini Survey I. The Boötes Field W. L. Williams1,2,H.T.Intema3,, and H. J. A. Röttgering1 1 Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands e-mail: [email protected] 2 Netherlands Institute for Radio AStronomy (ASTRON), PO Box 2, 7990 AA Dwingeloo, The Netherlands 3 National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475, USA Received 15 August 2012 / Accepted 31 October 2012 ABSTRACT We present wide area, deep, high-resolution 153 MHz GMRT observations of the NOAO Boötes field, adding to the extensive, multi- wavelength data of this region. The observations, data reduction, and catalogue construction and description are described here. The seven pointings produced a final mosaic covering 30 square degrees with a resolution of 25. The rms noise is 2 mJy beam−1 in the centre of the image, rising to 4–5 mJy beam−1 on the edges, with an average of 3 mJy beam−1. Seventy-five per cent of the area has an rms < 4 mJy beam−1. The extracted source catalogue contains 1289 sources detected at 5σ, of which 453 are resolved. We estimate the catalogue to be 92 per cent reliable and 95 per cent complete at an integrated flux density limit of 14 mJy. The flux densities and astrometry have been corrected for systematic errors. We calculate the differential source counts, which are in good agreement with those in the literature and provide an important step forward in quantifying the source counts at these low frequencies and low flux densities.