The Messenger
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Observational Evidence of AGN Feedback
Observational Evidence of AGN Feedback A.C Fabian Institute of Astronomy, Madingley Road Cambridge CB3 0HA, UK Abstract Radiation, winds and jets from the active nucleus of a massive galaxy can interact with its interstellar medium leading to ejection or heating of the gas. This can terminate star formation in the galaxy and stifle accretion onto the black hole. Such Active Galactic Nucleus (AGN) feedback can account for the observed proportionality between central black hole and host galaxy mass. Direct observational evidence for the radiative or quasar mode of feedback, which occurs when the AGN is very luminous, has been difficult to obtain but is accumulating from a few exceptional objects. Feedback from the kinetic or radio mode, which uses the mechanical energy of radio-emitting jets often seen when the AGN is operating at a lower level, is common in massive elliptical galaxies. This mode is well observed directly through X-ray observations of the central galaxies of cool core clusters in the form of bubbles in the hot surrounding medium. The energy flow, which is roughly continuous, heats the hot intracluster gas and reduces radiative cooling and subsequent star formation by an order of magnitude. Feedback appears to maintain a long-lived heating/cooling balance. Powerful, jetted radio outbursts may represent a further mode of energy feedback which affect the cores of groups and subclusters. New telescopes and instruments from the radio to X-ray bands will come into operation over the next few years and lead to a rapid expansion in observational data on all modes of AGN feedback. -
A Basic Requirement for Studying the Heavens Is Determining Where In
Abasic requirement for studying the heavens is determining where in the sky things are. To specify sky positions, astronomers have developed several coordinate systems. Each uses a coordinate grid projected on to the celestial sphere, in analogy to the geographic coordinate system used on the surface of the Earth. The coordinate systems differ only in their choice of the fundamental plane, which divides the sky into two equal hemispheres along a great circle (the fundamental plane of the geographic system is the Earth's equator) . Each coordinate system is named for its choice of fundamental plane. The equatorial coordinate system is probably the most widely used celestial coordinate system. It is also the one most closely related to the geographic coordinate system, because they use the same fun damental plane and the same poles. The projection of the Earth's equator onto the celestial sphere is called the celestial equator. Similarly, projecting the geographic poles on to the celest ial sphere defines the north and south celestial poles. However, there is an important difference between the equatorial and geographic coordinate systems: the geographic system is fixed to the Earth; it rotates as the Earth does . The equatorial system is fixed to the stars, so it appears to rotate across the sky with the stars, but of course it's really the Earth rotating under the fixed sky. The latitudinal (latitude-like) angle of the equatorial system is called declination (Dec for short) . It measures the angle of an object above or below the celestial equator. The longitud inal angle is called the right ascension (RA for short). -
A Deep Spectroscopic Study of the Filamentary Nebulosity in NGC 4696, the Brightest Cluster Galaxy in the Centaurus Cluster R
University of Kentucky UKnowledge Physics and Astronomy Faculty Publications Physics and Astronomy 2011 A Deep Spectroscopic Study of the Filamentary Nebulosity in NGC 4696, the Brightest Cluster Galaxy in the Centaurus Cluster R. E. A. Canning University of Cambridge, UK A. C. Fabian University of Cambridge, UK R. M. Johnstone University of Cambridge, UK J. S. Sanders University of Cambridge, UK C. S. Crawford University of Cambridge, UK See next page for additional authors Right click to open a feedback form in a new tab to let us know how this document benefits oy u. Follow this and additional works at: https://uknowledge.uky.edu/physastron_facpub Part of the Astrophysics and Astronomy Commons, and the Physics Commons Repository Citation Canning, R. E. A.; Fabian, A. C.; Johnstone, R. M.; Sanders, J. S.; Crawford, C. S.; Ferland, Gary J.; and Hatch, N. A., "A Deep Spectroscopic Study of the Filamentary Nebulosity in NGC 4696, the Brightest Cluster Galaxy in the Centaurus Cluster" (2011). Physics and Astronomy Faculty Publications. 36. https://uknowledge.uky.edu/physastron_facpub/36 This Article is brought to you for free and open access by the Physics and Astronomy at UKnowledge. It has been accepted for inclusion in Physics and Astronomy Faculty Publications by an authorized administrator of UKnowledge. For more information, please contact [email protected]. Authors R. E. A. Canning, A. C. Fabian, R. M. Johnstone, J. S. Sanders, C. S. Crawford, Gary J. Ferland, and N. A. Hatch A Deep Spectroscopic Study of the Filamentary Nebulosity in NGC 4696, the Brightest Cluster Galaxy in the Centaurus Cluster Notes/Citation Information Published in Monthly Notices of the Royal Astronomical Society, v. -
Molecular Gas Content of Galaxies in the Hydra-Centaurus Supercluster
MOLECULAR GAS CONTENT OF GALAXIES IN THE HYDRA-CENTAURUS SUPERCLUSTER W.K. Huchtmeier ™ ** <$ '"" & ^ O Max-Planck-Institut fiir Radioastronomie Auf dem Hugel 69 , 5300 Bonn 1 , W. Germany • Abstract A survey of bright spiral galaxies in the Hydra-Centaurus supercluster for the CO(l-O) transition at 115 GHz was performed with the 15m Swedish-ESO submillimeter telescope (SEST). A total of 30 galaxies have been detected in the CO(l-O) transition out of 47 observed, which is a detection rate over 60%. Global physical parameters of these galaxies derived from optical, CO, HI, and IR measurements compare very well with properties of galaxies in the Virgo cluster. The Hydra I cluster (Abell 1060) is one of the nearest clusters and very similar to the Virgo cluster in many global parameters like type, population, size, and shape. Both clusters have comparable velocity dispersions (i.e. total mass) and are spiral rich. Hydra is well isolated in velocity space and appears more circular (Kwast 1966), and might be dynamically more relaxed, although the center may contain significant substructures (Fitchett and Meritt 1988) or projected foreground groups. Both clusters contain low luminosity central X-ray sources. We assume a distance of 68.4 Mpc for Hydra I in order to allow direct comparison with some (nearly) complete galaxy samples. The Centaurus cluster provides a valuable contrast to Virgo and Coma. It is intermediate in distance and in galaxy population type with a relatively well defined SO-dominated core and an extensive S-rich halo. Its richness class in the Abell scale is 1 or 2 which is richer than Virgo and poorer than Coma. -
The Messenger
THE MESSENGER No, 40 - June 1985 Radial Veloeities of Stars in Globular Clusters: a Look into CD Cen and 47 Tue M. Mayor and G. Meylan, Geneva Observatory, Switzerland Subjected to dynamical investigations since the beginning photometry of several clusters reveals a cusp in the luminosity of the century, globular clusters still provide astrophysicists function of the central region, which could be the first evidence with theoretical and observational problems, wh ich so far have for collapsed cores. only been partly solved. The development of photoelectric cross-corelation tech If for a long time the star density projected on the sky was niques for the determination of stellar radial velocities opened fairly weil represented by simple dynamical models, recent the door to kinematical investigations (Gunn and Griffin, 1979, N .~- .", '. '.'., .' 1 '&307 w E ,. 1~ S Fig. 1: Left: 47 Tue (NGC 104) from the Deep Blue Survey - SRC-(J). Right: Centre of 47 Tue from a near-infrared photometrie study of Lioyd Evans. The diameter ofthe large eirele eorresponds to the disk ofthe left photograph. The maximum ofthe rotation appears inside the eircle; the linear part of the rotation eurve (solid-body rotation) affeets only stars inside one areminute of the eentre. 1 Rlre J 250r;.' .;r2' -i4.:...__.....;6;.;.. .;rB. ,;.;10::....--. Tentative Time-table of Council Sessions (J lkm/5] and Committee Meetings in 1985 (.) Gen x =2. November 12 Scientific Technical Committee November 13-14 Finance Committee December 11 -12 Observing Programmes Committee December 16 Committee of Council December 17 Council 10. All meetings will take place at ESO in Garching. -
The Giant That Turned out to Be a Dwarf 7 March 2007
The giant that turned out to be a dwarf 7 March 2007 New data obtained on the apparent celestial have very different redshifts, with NGC 5011C couple, NGC 5011 B and C, taken with the 3.6-m moving away from us five times slower than its ESO telescope, reveal that the two galaxies are companion on the sky. "This indicates they are at not at the same distance, as was believed for the different distances and not at all associated", says past 23 years. The observations show that NGC Jerjen. "Clearly, NGC 5011C belongs to the close 5011C is not a giant but a dwarf galaxy, an group of galaxies centred around Centaurus A, overlooked member of a group of galaxies in the while NGC 5011B is part of the much farther vicinity of the Milky Way. Centaurus cluster." The galaxy NGC 5011C is located towards the The astronomers also established that the two Centaurus constellation, in the direction of the galaxies have very different intrinsic properties. Centaurus A group of galaxies and the Centaurus NGC 5011B contains for example more heavy cluster of galaxies. The former is about 13 million chemical elements than NGC 5011C, and the latter light-years from our Milky Way, while the latter is seems to contain only about 10 million times the about 12 times farther away. mass of the Sun in stars and is therefore a true dwarf galaxy. For comparison, our Milky Way The appearance of NGC 5011C, with its low contains thousands of times more stars. density of stars and absence of distinctive features, would normally lead astronomers to "Our new observations with the 3.6-m ESO classify it as a nearby dwarf elliptical galaxy. -
Multiplicity of Late-Type B Stars with Hgmn Peculiarity
Astronomy & Astrophysics manuscript no. 14246 c ESO 2018 November 20, 2018 Multiplicity of late-type B stars with HgMn peculiarity⋆ M. Sch¨oller1, S. Correia2, S. Hubrig2, and N. Ageorges3 1 European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany e-mail: [email protected] 2 Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany 3 Max-Planck-Institut f¨ur extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany Received September 15, 1996; accepted March 16, 1997 ABSTRACT Context. Observations at various wavelengths of late B-type stars exhibiting strong overabundances of the chemical elements Hg and Mn in their atmospheres indicate that these stars are frequently found in binary and multiple systems. Aims. We intend to study the multiplicity of this type of chemically peculiar stars, looking for visual companions in ′′ ′′ the range of angular separation between 0. 05 and 8 . Methods. We carried out a survey of 56 stars using diffraction-limited near-infrared imaging with NAOS-CONICA at the VLT. Results. Thirty-three companion candidates in 24 binaries, three triples, and one quadruple system were detected. Nine companion candidates were found for the first time in this study. Five objects are likely chance projections. The detected companion candidates have K magnitudes between 5m. 95 and 18m. 07 and angular separations ranging from ′′ ′′ <0. 05 to 7. 8, corresponding to linear projected separations of 13.5–1700 AU. Conclusions. Our study clearly confirms that HgMn stars are frequently members of binary and multiple systems. Taking into account companions found by other techniques, the multiplicity fraction in our sample may be as high as 91%. -
CRIRES High-Resolution Infrared Spectroscopy of the Long-Period Cepheid L Carinae N
CRIRES high-resolution infrared spectroscopy of the long-period Cepheid l Carinae N. Nardetto, E. Poretti, A. Gallenne, M. Rainer, R. Anderson, P. Fouque, W. Gieren, D. Graczyk, P. Kervella, P. Mathias, et al. To cite this version: N. Nardetto, E. Poretti, A. Gallenne, M. Rainer, R. Anderson, et al.. CRIRES high-resolution infrared spectroscopy of the long-period Cepheid l Carinae. Astronomy and Astrophysics - A&A, EDP Sciences, 2018, 616, pp.A92. 10.1051/0004-6361/201833210. hal-02302126 HAL Id: hal-02302126 https://hal.archives-ouvertes.fr/hal-02302126 Submitted on 17 Nov 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. A&A 616, A92 (2018) Astronomy https://doi.org/10.1051/0004-6361/201832991 & c ESO 2018 Astrophysics CRIRES high-resolution infrared spectroscopy of the long-period Cepheid l Carinae? N. Nardetto1, E. Poretti2,3, A. Gallenne4, M. Rainer2, R. I. Anderson5, P. Fouqué6, W. Gieren7,8, D. Graczyk7,8,9 , P. Kervella10,11,12 , P. Mathias13,14, A. Mérand5, D. Mourard1, H. Neilson15, G. Pietrzynski9, B. Pilecki9, J. Storm16, S. Borgniet10, A. Chiavassa1, V. Hocdé1, and B. Trahin10 1 Université Côte d’Azur, OCA, CNRS, Lagrange, France e-mail: [email protected] 2 INAF – Osservatorio Astronomico di Brera, Via E. -
FY 2015 Annual Report
REPORT OF RESEARCH ACTIVITIES Fiscal Year 2014-2015 USF Research & Innovation University of South Florida USF Research & Innovation University of South Florida 3702 Spectrum Blvd, Suite 165 Tampa, Florida 33612-9445 Phone: 813-974-5570 Fax: 813-974-4962 Email: [email protected] This document is also available on the USF Office of Research Web site at www.research.usf.edu UNIVERSITY OF SOUTH FLORIDA RESEARCH & INNOVATION REPORT OF RESEARCH ACTIVITIES FISCAL YEAR 2014/2015 SECTION 1 CONTACTS 1 2 CONTACT INFORMATION USF Research & Innovation USF System Office of the Senior Vice President Fiscal Year 2014-2015 Sanberg, Paul R. [email protected] (813) 974-5570 USF System Senior Vice President for Research, Innovation & Economic Development Sarkar, Sudeep [email protected] (813) 974-5570 Associate Vice President for Research & Innovation Steele, Martin [email protected] (813) 974-2343 Associate Vice President for Veterans Research Hendrix, Rhonda [email protected] (813) 974-5554 Chief Operating Officer & Director Central Services McLaughlin, Mark [email protected] (813) 974-8124 Assistant Budget Director Lowry, Judy [email protected] (813) 974-3181 Director Outreach & Engagement Sponsored Research and Research Financial Management Puig, Rebecca [email protected] (813) 974-5465 Associate Vice President for Research & Innovation Anderson, Keith [email protected] (813) 974-6329 Director Sponsored Research 3 Research Technologies Skinner, Rick [email protected] (813) 974-5569 Director Shaheen, Omar [email protected] (813) 974-1303 Assistant Director -
Large Peculiar Velocities in the Hydra Centaurus Supercluster
LARGE PECULIAR VELOCITIES IN THE HYDRA CENTAURUS SUPERCLUSTER M. Aaronson1*, G.D. Bothun2, K.G. Budge3, JA. Dawe4, R.J. Dickens5, RJ. Hall6, J.R. Lucey7, J.R. Mould3, J.D. Murray6, R.A. Schommer8, A.E. Wright6. 1 Steward Observatory, University of Arizona 2 University of Michigan 3 California Institute of Technology 4 Australian National University 5Rutherford Appleton Laboratory 6 Australian National Radio Astronomy Observatory 7Anglo Australian Observatory 8 Rutgers University ABSTRACT Six clusters forming part of the Hydra-Cen Supercluster and its ex- tension on the opposite side of the galactic plane are under study at 21 cm with the Parkes radiotélescope. The infrared Tully-Fisher relation is used to determine the relative distances of the clusters. These clusters exhibit significant and generally positive peculiar velocities ranging from essentially zero for the Hydra cluster to as much as 1000 km/sec for the Pavo and Centaurus clusters. An upper limit of 500 km/sec was previously found in the study of clusters accessible from Arecibo. Data collection is not yet complete, however, and is further subject to unstud- ied systematic errors due to present reliance on photographic galaxy diameters. Nevertheless, these preliminary results support the notion of a large scale (and pre- sumably gravit at ionally) disturbed velocity field in the second and third quadrants of the supergalactic plane. 1. INTRODUCTION Comparison of the ratios of distances of galaxies with the ratios of their recession velocities allows one to learn something about the "noise" in the Hubble flow on various scales. One is subject to the limitation, however, that distance indicators are imprecise, and the 0.4 mag scatter in the infrared Tully-Fisher (IRTF) relation translates to an uncertainty of 1000 km/sec in an individual galaxy at cz = 5000 km/sec. -
Gas and Dust in the Magellanic Clouds
Gas and dust in the Magellanic clouds A Thesis Submitted for the Award of the Degree of Doctor of Philosophy in Physics To Mangalore University by Ananta Charan Pradhan Under the Supervision of Prof. Jayant Murthy Indian Institute of Astrophysics Bangalore - 560 034 India April 2011 Declaration of Authorship I hereby declare that the matter contained in this thesis is the result of the inves- tigations carried out by me at Indian Institute of Astrophysics, Bangalore, under the supervision of Professor Jayant Murthy. This work has not been submitted for the award of any degree, diploma, associateship, fellowship, etc. of any university or institute. Signed: Date: ii Certificate This is to certify that the thesis entitled ‘Gas and Dust in the Magellanic clouds’ submitted to the Mangalore University by Mr. Ananta Charan Pradhan for the award of the degree of Doctor of Philosophy in the faculty of Science, is based on the results of the investigations carried out by him under my supervi- sion and guidance, at Indian Institute of Astrophysics. This thesis has not been submitted for the award of any degree, diploma, associateship, fellowship, etc. of any university or institute. Signed: Date: iii Dedicated to my parents ========================================= Sri. Pandab Pradhan and Smt. Kanak Pradhan ========================================= Acknowledgements It has been a pleasure to work under Prof. Jayant Murthy. I am grateful to him for giving me full freedom in research and for his guidance and attention throughout my doctoral work inspite of his hectic schedules. I am indebted to him for his patience in countless reviews and for his contribution of time and energy as my guide in this project. -
7.5 X 11.5.Threelines.P65
Cambridge University Press 978-0-521-19267-5 - Observing and Cataloguing Nebulae and Star Clusters: From Herschel to Dreyer’s New General Catalogue Wolfgang Steinicke Index More information Name index The dates of birth and death, if available, for all 545 people (astronomers, telescope makers etc.) listed here are given. The data are mainly taken from the standard work Biographischer Index der Astronomie (Dick, Brüggenthies 2005). Some information has been added by the author (this especially concerns living twentieth-century astronomers). Members of the families of Dreyer, Lord Rosse and other astronomers (as mentioned in the text) are not listed. For obituaries see the references; compare also the compilations presented by Newcomb–Engelmann (Kempf 1911), Mädler (1873), Bode (1813) and Rudolf Wolf (1890). Markings: bold = portrait; underline = short biography. Abbe, Cleveland (1838–1916), 222–23, As-Sufi, Abd-al-Rahman (903–986), 164, 183, 229, 256, 271, 295, 338–42, 466 15–16, 167, 441–42, 446, 449–50, 455, 344, 346, 348, 360, 364, 367, 369, 393, Abell, George Ogden (1927–1983), 47, 475, 516 395, 395, 396–404, 406, 410, 415, 248 Austin, Edward P. (1843–1906), 6, 82, 423–24, 436, 441, 446, 448, 450, 455, Abbott, Francis Preserved (1799–1883), 335, 337, 446, 450 458–59, 461–63, 470, 477, 481, 483, 517–19 Auwers, Georg Friedrich Julius Arthur v. 505–11, 513–14, 517, 520, 526, 533, Abney, William (1843–1920), 360 (1838–1915), 7, 10, 12, 14–15, 26–27, 540–42, 548–61 Adams, John Couch (1819–1892), 122, 47, 50–51, 61, 65, 68–69, 88, 92–93,