Cosmic Rays in Star-Forming Galaxies
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Quasistellar Objects: Overview ENCYCLOPEDIA of ASTRONOMY and ASTROPHYSICS
eaa.iop.org DOI: 10.1888/0333750888/1585 Quasistellar Objects: Overview Patrick Osmer 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 22:43:08 GMT 2006 [131.215.103.76] Terms and Conditions Quasistellar Objects: Overview ENCYCLOPEDIA OF ASTRONOMY AND ASTROPHYSICS Quasistellar Objects: Overview Quasistellar objects, or quasars, were defined originally as star-like objects of large redshift. Quasars are believed to be powered by the accretion of matter onto massive black holes at the centers of galaxies, a process that emits more energy than thermonuclear reactions. Today, quasars are considered to be the most luminous members of the general class of objects called active galactic nuclei, or AGNs. Quasars are the most luminous objects in the universe. This article begins with a brief history of the discovery of quasars. Next it describes their main properties and the concepts that have been developed to explain them. It continues with a description of their nature and theoretical models. Then additional properties and topics are considered: absorption lines, host galaxies, Figure 1. Optical image of 3C273. The object looks stellar in and luminosity functions and evolution. this image except that it is accompanied by a jet of radiation extending to the lower right. (Credit National Optical Astronomy Observatories/National Science Foundation. History Copyright Association of Universities for Research in In 1960 Mathews and Sandage identified the radio source Astronomy Inc (AURA), all rights reserved.) 3C 48 (the 48th object in the 3rd Cambridge catalog of radio sources) with a star-like object of 16th magnitude. -
Pos(Westerbork)006 S 4.0 International License (CC BY-NC-ND 4.0)
Exploring the time-varying Universe PoS(Westerbork)006 Richard Strom ASTRON Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands E-mail: [email protected] Lodie Voûte ASTRON, Anton Pannekoek Inst. Of Astronomy, University of Amsterdam, Postbus 94249, 1090 GE Amsterdam, The Netherlands E-mail: [email protected] Benjamin Stappers School of Phys. & Astron., Alan Turing Bldg., University of Manchester, Oxford Road, Manchester M13 9PL, UK E-mail: [email protected] Gemma Janssen ASTRON Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands E-mail: [email protected] Jason Hessels ASTRON Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands E-mail: [email protected] 50 Years Westerbork Radio Observatory, A Continuing Journey to Discoveries and Innovations Richard Strom, Arnold van Ardenne, Steve Torchinsky (eds) Published with permission of the Netherlands Institute for Radio Astronomy (ASTRON) under the terms of the Creative CommonsAttribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0). Exploring the time-varying Universe Chapter 5.1 The earliest start Richard Strom* Introduction The WSRT interferometrically measures Fourier components of the sky bright- ness distribution from a region set by the primary beam of the telescope ele- ments, at a radio frequency determined by the receiver. This information is used to construct a two-dimensional image of radio emission from the piece of sky observed. Because it is an east-west interferometer array, the information obtained at any instant of time can only be used to construct a one-dimensional map (the telescope so synthesized has the response of a fan beam – narrow in one direction, but orthogonally very elongated). -
Stsci Newsletter: 1991 Volume 008 Issue 03
SPACE 'fEIFSCOPE SOENCE ...______._.INSTITUIE Operated for NASA by AURA November 1991 Vol. 8No. 3 HIGHLIGHTS OF THIS ISSUE: HSTSCIENCE HIGHLIGHTS WF/PC OBSERVATIONS OF THE STELLAR O NEW SCIENCE RESULTS ON M87, CRAB PULSAR CUSP IN M87 O COSTAR PROGRESSING WELL The photograph on the left shows one of a set of images of the central regions of the giant ellipti O ANSWERS TO YOUR QUESTIONS ABOUT HST DATA cal galaxy M87, obtained in June 1991 withHSI's Wide Field and Planetary Camera {WF/PC). 0 CYCLE 2 PEER REVIEW UNDERWAY Analysis of these images has revealed a stellar cusp in the core of M87, consistent with the pres ence of a massive black hole in its nucleus. A combined approach of image deconvolution and modelling has made it possible to investigate the starlight distribution in M87 down to a limiting radius of about 0'.'04 from the nucleus (or about 3 pc from the nucleus if the Virgo cluster is at 16 Mpc). The results show that the central struc ture of M87 can be described by three compo nents: a power-law starlight profile with an r·114 slope which continues unabated into the center, an unresolved central point source, and optical coun terparts of the jet knots identified by VLBI obser vations. In both the V- and /-band Planetary Camera images, the stellar cusp is consistent with the black-hole model proposed for M87 by Young et al. in 1978; in this model, there is a central mas sive object of about 3 x 109 Me. -
A Thin Diffuse Component of the Galactic Ridge X-Ray Emission and Heating of the Interstellar Medium Contributed by the Radiation of Galactic X-Ray Binaries
A&A 564, A107 (2014) Astronomy DOI: 10.1051/0004-6361/201323332 & c ESO 2014 Astrophysics A thin diffuse component of the Galactic ridge X-ray emission and heating of the interstellar medium contributed by the radiation of Galactic X-ray binaries Margherita Molaro1, Rishi Khatri1, and Rashid A. Sunyaev1,2 1 Max Planck Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching, Germany e-mail: [email protected] 2 Space Research Institute, Russian Academy of Sciences, Profsoyuznaya 84/32, 117997 Moscow, Russia Received 23 December 2013 / Accepted 14 January 2014 ABSTRACT We predict athindiffuse component of the Galactic ridge X-ray emission (GRXE) arising from the scattering of the radiation of bright X-ray binaries (XBs) by the interstellar medium. This scattered component has the same scale height as that of the gaseous disk (∼80 pc) and is therefore thinner than the GRXE of stellar origin (scale height ∼130 pc). The morphology of the scattered component is furthermore expected to trace the clumpy molecular and HI clouds. We calculate this contribution to the GRXE from known Galactic XBs assuming that they are all persistent. The known XBs sample is incomplete, however, because it is flux limited and spans the lifetime of X-ray astronomy (∼50 years), which is very short compared with the characteristic time of 1000−10 000 years that would have contributed to the diffuse emission observed today due to time delays. We therefore also use a simulated sample of sources, to estimate the diffuse emission we should expect in an optimistic case assuming that the X-ray luminosity of our Galaxy is on average similar to that of other galaxies. -
Distant Arm - NGC772
29 September 2016, Zeiss Cas 150/2250 Distant Arm - NGC772 Telescope: Zeiss Cassegrain 150/2250 Eyepieces: ATC53P - ATC Plossl, f=53mm, (42×, 530) ATC20K - ATC Kellner, f=20mm, (113×, 220) A-16 - Zeiss Abbe Ortho, f=16mm, (141×, 200) O-12.5 - CZJ Ortho, f=12.5mm, (180×, 140) Time: 2016/09/29 19:30-21:40UT Location: R´ıˇcanyˇ Weather: Clear sky with slight haze and decaying small thin clouds. Mount: Zeiss 1b Accessories: Baader/Zeiss T2 prism This was my typical backyard session. I could go out only for a short time after I put all three kids in to their beds. The night was still warm. Normally, I would try to take an advantage of it and go to some darker place. As I was alone with the kids for the whole week I was bound to stay in our backyard. During last couple of years, I have learnt to live with this handicap. There is always something interesting to look at, even with small refractors. Recently, I was explor- ing the capability of my largest telescope, 150mm Cassegrain. For this night, the main targets were two galaxies, NGC 660 and NGC 772, which I had troubles to locate two days before in 80mm refractor. I was curios how much of help the larger telescope would be. I did not jump to these two galaxies im- mediately. They were still low in the slight haze enhanced by the street lamps. I started a little bit higher in Andromeda with beau- tiful edge-on galaxy NGC 891 (V=10.0, 13:50 ×2:50, PA22◦). -
From Dust to Dust: Protoplanetary Disk Accretion, Hot Jupiter Climates, and the Evaporation of Rocky Planets
UC Berkeley UC Berkeley Electronic Theses and Dissertations Title From Dust to Dust: Protoplanetary Disk Accretion, Hot Jupiter Climates, and the Evaporation of Rocky Planets Permalink https://escholarship.org/uc/item/9jq3136f Author Perez-Becker, Daniel Alonso Publication Date 2013 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California From Dust to Dust: Protoplanetary Disk Accretion, Hot Jupiter Climates, and the Evaporation of Rocky Planets By Daniel Alonso Perez-Becker A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Physics in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Eugene Chiang, Co-chair Professor Christopher McKee, Co-chair Professor Eliot Quataert Professor Geoffrey Marcy Fall 2013 From Dust to Dust: Protoplanetary Disk Accretion, Hot Jupiter Climates, and the Evaporation of Rocky Planets Copyright 2013 by Daniel Alonso Perez-Becker 1 Abstract From Dust to Dust: Protoplanetary Disk Accretion, Hot Jupiter Climates, and the Evaporation of Rocky Planets by Daniel Alonso Perez-Becker Doctor of Philosophy in Physics University of California, Berkeley Professor Eugene Chiang, Co-chair Professor Christopher McKee, Co-chair This dissertation is composed of three independent projects in astrophysics concerning phenomena that are concurrent with the birth, life, and death of planets. In Chapters 1 & 2, we study surface layer accretion in protoplanetary disks driven stellar X-ray and far-ultraviolet (FUV) radiation. In Chapter 3, we identify the dynamical mechanisms that control atmospheric heat redistribution on hot Jupiters. Finally, in Chapter 4, we characterize the death of low-mass, short-period rocky planets by their evaporation into a dusty wind. -
Nasa's Next Four Large Telescopes Hearing Committee on Science, Space, and Technology House of Representatives
NASA’S NEXT FOUR LARGE TELESCOPES HEARING BEFORE THE SUBCOMMITTEE ON SPACE COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY HOUSE OF REPRESENTATIVES ONE HUNDRED FIFTEENTH CONGRESS FIRST SESSION DECEMBER 6, 2017 Serial No. 115–41 Printed for the use of the Committee on Science, Space, and Technology ( Available via the World Wide Web: http://science.house.gov U.S. GOVERNMENT PUBLISHING OFFICE 27–680PDF WASHINGTON : 2018 COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY HON. LAMAR S. SMITH, Texas, Chair FRANK D. LUCAS, Oklahoma EDDIE BERNICE JOHNSON, Texas DANA ROHRABACHER, California ZOE LOFGREN, California MO BROOKS, Alabama DANIEL LIPINSKI, Illinois RANDY HULTGREN, Illinois SUZANNE BONAMICI, Oregon BILL POSEY, Florida AMI BERA, California THOMAS MASSIE, Kentucky ELIZABETH H. ESTY, Connecticut JIM BRIDENSTINE, Oklahoma MARC A. VEASEY, Texas RANDY K. WEBER, Texas DONALD S. BEYER, JR., Virginia STEPHEN KNIGHT, California JACKY ROSEN, Nevada BRIAN BABIN, Texas JERRY MCNERNEY, California BARBARA COMSTOCK, Virginia ED PERLMUTTER, Colorado BARRY LOUDERMILK, Georgia PAUL TONKO, New York RALPH LEE ABRAHAM, Louisiana BILL FOSTER, Illinois DRAIN LAHOOD, Illinois MARK TAKANO, California DANIEL WEBSTER, Florida COLLEEN HANABUSA, Hawaii JIM BANKS, Indiana CHARLIE CRIST, Florida ANDY BIGGS, Arizona ROGER W. MARSHALL, Kansas NEAL P. DUNN, Florida CLAY HIGGINS, Louisiana RALPH NORMAN, South Carolina SUBCOMMITTEE ON SPACE HON. BRIAN BABIN, Texas, Chair DANA ROHRABACHER, California AMI BERA, California, Ranking Member FRANK D. LUCAS, Oklahoma ZOE LOFGREN, California MO BROOKS, Alabama DONALD S. BEYER, JR., Virginia BILL POSEY, Florida MARC A. VEASEY, Texas JIM BRIDENSTINE, Oklahoma DANIEL LIPINSKI, Illinois STEPHEN KNIGHT, California ED PERLMUTTER, Colorado BARBARA COMSTOCK, Virginia CHARLIE CRIST, Florida RALPH LEE ABRAHAM, Louisiana BILL FOSTER, Illinois DANIEL WEBSTER, Florida EDDIE BERNICE JOHNSON, Texas JIM BANKS, Indiana ANDY BIGGS, Arizona NEAL P. -
Making a Sky Atlas
Appendix A Making a Sky Atlas Although a number of very advanced sky atlases are now available in print, none is likely to be ideal for any given task. Published atlases will probably have too few or too many guide stars, too few or too many deep-sky objects plotted in them, wrong- size charts, etc. I found that with MegaStar I could design and make, specifically for my survey, a “just right” personalized atlas. My atlas consists of 108 charts, each about twenty square degrees in size, with guide stars down to magnitude 8.9. I used only the northernmost 78 charts, since I observed the sky only down to –35°. On the charts I plotted only the objects I wanted to observe. In addition I made enlargements of small, overcrowded areas (“quad charts”) as well as separate large-scale charts for the Virgo Galaxy Cluster, the latter with guide stars down to magnitude 11.4. I put the charts in plastic sheet protectors in a three-ring binder, taking them out and plac- ing them on my telescope mount’s clipboard as needed. To find an object I would use the 35 mm finder (except in the Virgo Cluster, where I used the 60 mm as the finder) to point the ensemble of telescopes at the indicated spot among the guide stars. If the object was not seen in the 35 mm, as it usually was not, I would then look in the larger telescopes. If the object was not immediately visible even in the primary telescope – a not uncommon occur- rence due to inexact initial pointing – I would then scan around for it. -
Numerical Models of Galaxy Evolution: Black Hole Feedback and Disk Heating by Jackson Eugene Debuhr
Numerical Models of Galaxy Evolution: Black Hole Feedback and Disk Heating by Jackson Eugene DeBuhr A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Physics in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Chung-Pei Ma, Co-Chair Professor Eliot Quataert, Co-Chair Professor Christopher McKee Professor Leo Blitz Spring 2012 Numerical Models of Galaxy Evolution: Black Hole Feedback and Disk Heating Copyright 2012 by Jackson Eugene DeBuhr 1 Abstract Numerical Models of Galaxy Evolution: Black Hole Feedback and Disk Heating by Jackson Eugene DeBuhr Doctor of Philosophy in Physics University of California, Berkeley Professor Chung-Pei Ma, Co-Chair Professor Eliot Quataert, Co-Chair This thesis explores two topics in contemporary galaxy evolution using numerical models and N-body simulation: feedback in active galactic nuclei and the heating of stellar disks. Two numerical models of feedback from active galactic nuclei are developed and applied to the case of a major merger between two disk galaxies. Accretion into central black holes is modeled via a subgrid prescription based on angular momentum transport on unresolved scales. Feedback from black holes is modeled in two ways, both of which deposit a momentum τL=c into the surroundings, where L is the luminosity of radiation produced by the galactic nucleus. In the first model, the momentum is divided equally among the nearby gas particles to model processes like the absorption of ultraviolet light by dust grains. The second model deposits the same amount of momentum into the surroundings, but it does so by launching a wind with a fixed speed, which only has a direct effect on a small fraction of the gas in the black hole's vicinity. -
Understanding the Bizarre Shapes of Radio Supernova Remnants
Barrels, jets and smoke-rings: Understanding the bizarre shapes of radio supernova remnants Bryan Malcolm Gaensler A thesis submitted for the degree of Doctor of Philosophy at the University of Sydney February 1999 To Dr Michael Bishop, For showing me where to start 1 Abstract This thesis considers the various morphologies of radio supernova remnants (SNRs), and attempts to determine whether their appearance results from the properties of the progenitor star and its supernova explosion, or from the structure of the inter- stellar medium (ISM) and ambient magnetic field into which a SNR consequently expands. High-resolution observations of Supernova 1987A show a young remnant whose appearance and evolution are completely dominated by the structure of its progenitor wind. A statistical study of the Galactic population of bilateral SNRs demonstrates that the symmetry axes of these remnants run parallel to the Galac- tic Plane. This result can be explained by the interaction of main sequence stellar wind-bubbles with the ambient magnetic field; expansion of SNRs into the resulting elongated cavities results in a bilateral appearance with the observed alignment. Radio observations of SNR G296.8{00.3 show a double-ringed morphology which is best explained by expansion either into an anisotropic main-sequence progenitor wind or into multiple cavities in the ISM. Data on SNRs G309.2{00.6 and G320.4{ 01.2 (MSH 15{52) make a strong case that the appearance of both remnants is significantly affected by collimated outflows from a central source; for G309.2{00.6 the source itself is not detected, but for G320.4{01.2 there is now compelling evi- dence that the remnant is associated with and is interacting with the young pulsar PSR B1509{58. -
A Guide to Hubble Space Telescope Objects
James L. Chen A Guide to Hubble Space Telescope Objects Their Selection, Location, and Signifi cance Graphics by Adam Chen The Patrick Moore The Patrick Moore Practical Astronomy Series More information about this series at http://www.springer.com/series/3192 A Guide to Hubble Space Telescope Objects Their Selection, Location, and Signifi cance James L. Chen Graphics by Adam Chen Author Graphics Designer James L. Chen Adam Chen Gore , VA , USA Baltimore , MD , USA ISSN 1431-9756 ISSN 2197-6562 (electronic) The Patrick Moore Practical Astronomy Series ISBN 978-3-319-18871-3 ISBN 978-3-319-18872-0 (eBook) DOI 10.1007/978-3-319-18872-0 Library of Congress Control Number: 2015940538 Springer Cham Heidelberg New York Dordrecht London © Springer International Publishing Switzerland 2015 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifi cally the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfi lms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specifi c statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. -
RADIO STARS and THEIR LIVES in the GALAXY Lynn D
Accepted to PASP A Preprint typeset using LTEX style emulateapj v. 12/16/11 RADIO STARS AND THEIR LIVES IN THE GALAXY Lynn D. Matthews1 Accepted to PASP ABSTRACT This paper summarizes the three-day international workshop Radio Stars and Their Lives in the Galaxy, held at the Massachusetts Institute of Technology Haystack Observatory on 2012 October 3-5. The workshop was organized to provide a forum for the presentation and discussion of advances in stellar and solar astrophysics recently (or soon to be) enabled by the latest generation of state-of-the- art observational facilities operating from meter to submillimeter wavelengths. The meeting brought together both observers and theorists to discuss how radio wavelength observations are providing new and unique insights into the workings of stars and their role in the Galactic ecosystem. Topics covered included radio emission from hot and cool stars (from the pre- to post-main-sequence), the Sun as a radio star, circumstellar chemistry, planetary nebulae, white dwarf binaries and novae, supernova progenitors, and radio stars as probes of the Galaxy. Subject headings: meeting summary, Stars — stars: AGB and post-AGB – stars: winds, outflows – circumstellar matter – radio lines: stars 1. BACKGROUND AND MOTIVATION FOR THE precision astrometry, and the routine study of sources at WORKSHOP a level of a few tens of µJy. We also heard how develop- Radio emission has now been detected from stars ments in theory, modeling, and laboratory astrophysics across the entire Hertzsprung-Russell (H-R) diagram, are improving our ability to interpret results. This paper spanning virtually every stage of stellar evolution.