Studying Dark Matter with Cosmic Supercolliders (Pdf)
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Galaxy Clusters: Waking Perseus
PUBLISHED: 2 JUNE 2017 | VOLUME: 1 | ARTICLE NUMBER: 164 news & views GALAXY CLUSTERS Waking Perseus The Perseus cluster contains over 1,000 a Kelvin–Helmholtz instability, which galaxies packed into a region ~3,500 kpc propagates in the wave direction and in extent. It is inevitable that such close- causes the dark area indicated in the packed galaxies will interact, and the image. This dark ‘bay-like’ feature is Chandra X-ray Observatory has observed approximately the size of the Milky Way, the beautiful result of that interaction and may be the result of a cold front in (pictured). This is no snapshot — the cluster gas: an interface where the Chandra observed the galaxy cluster temperature drops dramatically on scales for over 16 days in order to capture this much smaller than the mean free path. image. Stephen Walker and colleagues An advantage of this comparison of have retrieved the archival data and observations and simulations is that processed it to enhance the edges of (unmeasurable) physical quantities the surface brightness distribution. This can be estimated. In this case, the bay analysis, reported last year (Sanders et al., 50 kpc feature only appears in this form when Mon. Not. R. Astron. Soc. 460, 1898–1911; the ratio of the thermal pressure to the ROYAL ASTRONOMICAL SOCIETY ASTRONOMICAL ROYAL 2016), highlighted two features in the magnetic pressure is ~200, and this X-ray emission that are discussed by determination in turn allows the authors Walker et al. (Mon. Not. R. Astron. Soc. pattern seen in the image could have been to obtain an order-of-magnitude estimate 468, 2506–2516; 2017): the swirling wave generated by a passing galaxy cluster about of the magnetic field. -
The Dynamical State of the Coma Cluster with XMM-Newton?
A&A 400, 811–821 (2003) Astronomy DOI: 10.1051/0004-6361:20021911 & c ESO 2003 Astrophysics The dynamical state of the Coma cluster with XMM-Newton? D. M. Neumann1,D.H.Lumb2,G.W.Pratt1, and U. G. Briel3 1 CEA/DSM/DAPNIA Saclay, Service d’Astrophysique, L’Orme des Merisiers, Bˆat. 709, 91191 Gif-sur-Yvette, France 2 Science Payloads Technology Division, Research and Science Support Dept., ESTEC, Postbus 299 Keplerlaan 1, 2200AG Noordwijk, The Netherlands 3 Max-Planck Institut f¨ur extraterrestrische Physik, Giessenbachstr., 85740 Garching, Germany Received 19 June 2002 / Accepted 13 December 2002 Abstract. We present in this paper a substructure and spectroimaging study of the Coma cluster of galaxies based on XMM- Newton data. XMM-Newton performed a mosaic of observations of Coma to ensure a large coverage of the cluster. We add the different pointings together and fit elliptical beta-models to the data. We subtract the cluster models from the data and look for residuals, which can be interpreted as substructure. We find several significant structures: the well-known subgroup connected to NGC 4839 in the South-West of the cluster, and another substructure located between NGC 4839 and the centre of the Coma cluster. Constructing a hardness ratio image, which can be used as a temperature map, we see that in front of this new structure the temperature is significantly increased (higher or equal 10 keV). We interpret this temperature enhancement as the result of heating as this structure falls onto the Coma cluster. We furthermore reconfirm the filament-like structure South-East of the cluster centre. -
MC^ 2: Galaxy Imaging and Redshift Analysis of the Merging Cluster CIZA J2242. 8+ 5301
LLNL-DOC-661846-DRAFT A Preprint typeset using LTEX style emulateapj v. 8/13/10 MC2: GALAXY IMAGING AND REDSHIFT ANALYSIS OF THE MERGING CLUSTER CIZA J2242.8+5301 William A. Dawson1, M. James Jee2, Andra Stroe3, Y. Karen Ng2, Nathan Golovich2, David Wittman2, David Sobral3,4,5, M. Bruggen¨ 6, H. J. A. Rottgering¨ 3, R. J. van Weeren7 (Dated: Draft June 21, 2021) LLNL-DOC-661846-DRAFT ABSTRACT X-ray and radio observations of CIZA J2242.8+5301 suggest that it is a major cluster merger. Despite being well studied in the X-ray, and radio, little has been presented on the cluster structure and dynamics inferred from its galaxy population. We carried out a deep (i< 25) broad band imaging survey of the system with Subaru SuprimeCam (g & i bands) and the Canada France Hawaii Telescope (r band) as well as a comprehensive spectroscopic survey of the cluster area (505 redshifts) using Keck DEIMOS. We use this data to perform a comprehensive galaxy/redshift analysis of the system, which is the first step to a proper understanding the geometry and dynamics of the merger, as well as using the merger to constrain self-interacting dark matter. We find that the system is dominated by two ′+0.7 +0.13 subclusters of comparable richness with a projected separation of6.9 −0.5 (1.3−0.10 Mpc). We find that the north and south subclusters have similar redshifts of z 0.188 with a relative line-of-sight velocity difference of 69 190kms−1. We also find that north and south≈ subclusters have velocity dispersions of +100 −±1 +100 −1 +4.6 14 1160−90 kms and 1080−70 kms , respectively. -
Size and Scale Attendance Quiz II
Size and Scale Attendance Quiz II Are you here today? Here! (a) yes (b) no (c) are we still here? Today’s Topics • “How do we know?” exercise • Size and Scale • What is the Universe made of? • How big are these things? • How do they compare to each other? • How can we organize objects to make sense of them? What is the Universe made of? Stars • Stars make up the vast majority of the visible mass of the Universe • A star is a large, glowing ball of gas that generates heat and light through nuclear fusion • Our Sun is a star Planets • According to the IAU, a planet is an object that 1. orbits a star 2. has sufficient self-gravity to make it round 3. has a mass below the minimum mass to trigger nuclear fusion 4. has cleared the neighborhood around its orbit • A dwarf planet (such as Pluto) fulfills all these definitions except 4 • Planets shine by reflected light • Planets may be rocky, icy, or gaseous in composition. Moons, Asteroids, and Comets • Moons (or satellites) are objects that orbit a planet • An asteroid is a relatively small and rocky object that orbits a star • A comet is a relatively small and icy object that orbits a star Solar (Star) System • A solar (star) system consists of a star and all the material that orbits it, including its planets and their moons Star Clusters • Most stars are found in clusters; there are two main types • Open clusters consist of a few thousand stars and are young (1-10 million years old) • Globular clusters are denser collections of 10s-100s of thousand stars, and are older (10-14 billion years -
Constraining Cosmic Rays and Magnetic Fields in the Perseus
A&A 541, A99 (2012) Astronomy DOI: 10.1051/0004-6361/201118502 & c ESO 2012 Astrophysics Constraining cosmic rays and magnetic fields in the Perseus galaxy cluster with TeV observations by the MAGIC telescopes J. Aleksic´1,E.A.Alvarez2, L. A. Antonelli3, P. Antoranz4, M. Asensio2, M. Backes5, U. Barres de Almeida6, J. A. Barrio2, D. Bastieri7, J. Becerra González8,9, W. Bednarek10, A. Berdyugin11,K.Berger8,9,E.Bernardini12, A. Biland13,O.Blanch1,R.K.Bock6, A. Boller13, G. Bonnoli3, D. Borla Tridon6,I.Braun13, T. Bretz14,26, A. Cañellas15,E.Carmona6,28,A.Carosi3,P.Colin6,, E. Colombo8, J. L. Contreras2, J. Cortina1, L. Cossio16, S. Covino3, F. Dazzi16,27,A.DeAngelis16,G.DeCaneva12, E. De Cea del Pozo17,B.DeLotto16, C. Delgado Mendez8,28, A. Diago Ortega8,9,M.Doert5, A. Domínguez18, D. Dominis Prester19,D.Dorner13, M. Doro20, D. Eisenacher14, D. Elsaesser14,D.Ferenc19, M. V. Fonseca2, L. Font20,C.Fruck6,R.J.GarcíaLópez8,9, M. Garczarczyk8, D. Garrido20, G. Giavitto1, N. Godinovic´19,S.R.Gozzini12, D. Hadasch17,D.Häfner6, A. Herrero8,9, D. Hildebrand13, D. Höhne-Mönch14,J.Hose6, D. Hrupec19,T.Jogler6, H. Kellermann6,S.Klepser1, T. Krähenbühl13,J.Krause6, J. Kushida6,A.LaBarbera3,D.Lelas19,E.Leonardo4, N. Lewandowska14, E. Lindfors11, S. Lombardi7,, M. López2, R. López1, A. López-Oramas1,E.Lorenz13,6, M. Makariev21,G.Maneva21, N. Mankuzhiyil16, K. Mannheim14, L. Maraschi3, M. Mariotti7, M. Martínez1,D.Mazin1,6, M. Meucci4, J. M. Miranda4,R.Mirzoyan6, J. Moldón15,A.Moralejo1,P.Munar-Adrover15,A.Niedzwiecki10, D. Nieto2, K. Nilsson11,29,N.Nowak6, R. -
Clusters of Galaxy Hierarchical Structure the Universe Shows Range of Patterns of Structures on Decidedly Different Scales
Astronomy 218 Clusters of Galaxy Hierarchical Structure The Universe shows range of patterns of structures on decidedly different scales. Stars (typical diameter of d ~ 106 km) are found in gravitationally bound systems called star clusters (≲ 106 stars) and galaxies (106 ‒ 1012 stars). Galaxies (d ~ 10 kpc), composed of stars, star clusters, gas, dust and dark matter, are found in gravitationally bound systems called groups (< 50 galaxies) and clusters (50 ‒ 104 galaxies). Clusters (d ~ 1 Mpc), composed of galaxies, gas, and dark matter, are found in currently collapsing systems called superclusters. Superclusters (d ≲ 100 Mpc) are the largest known structures. The Local Group Three large spirals, the Milky Way Galaxy, Andromeda Galaxy(M31), and Triangulum Galaxy (M33) and their satellites make up the Local Group of galaxies. At least 45 galaxies are members of the Local Group, all within about 1 Mpc of the Milky Way. The mass of the Local Group is dominated by 11 11 10 M31 (7 × 10 M☉), MW (6 × 10 M☉), M33 (5 × 10 M☉) Virgo Cluster The nearest large cluster to the Local Group is the Virgo Cluster at a distance of 16 Mpc, has a width of ~2 Mpc though it is far from spherical. It covers 7° of the sky in the Constellations Virgo and Coma Berenices. Even these The 4 brightest very bright galaxies are giant galaxies are elliptical galaxies invisible to (M49, M60, M86 & the unaided M87). eye, mV ~ 9. Virgo Census The Virgo Cluster is loosely concentrated and irregularly shaped, making it fairly M88 M99 representative of the most M100 common class of clusters. -
Arxiv:1705.02358V2 [Hep-Ph] 24 Nov 2017
Dark Matter Self-interactions and Small Scale Structure Sean Tulin1, ∗ and Hai-Bo Yu2, y 1Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3, Canada 2Department of Physics and Astronomy, University of California, Riverside, California 92521, USA (Dated: November 28, 2017) Abstract We review theories of dark matter (DM) beyond the collisionless paradigm, known as self-interacting dark matter (SIDM), and their observable implications for astrophysical structure in the Universe. Self- interactions are motivated, in part, due to the potential to explain long-standing (and more recent) small scale structure observations that are in tension with collisionless cold DM (CDM) predictions. Simple particle physics models for SIDM can provide a universal explanation for these observations across a wide range of mass scales spanning dwarf galaxies, low and high surface brightness spiral galaxies, and clusters of galaxies. At the same time, SIDM leaves intact the success of ΛCDM cosmology on large scales. This report covers the following topics: (1) small scale structure issues, including the core-cusp problem, the diversity problem for rotation curves, the missing satellites problem, and the too-big-to-fail problem, as well as recent progress in hydrodynamical simulations of galaxy formation; (2) N-body simulations for SIDM, including implications for density profiles, halo shapes, substructure, and the interplay between baryons and self- interactions; (3) semi-analytic Jeans-based methods that provide a complementary approach for connecting particle models with observations; (4) merging systems, such as cluster mergers (e.g., the Bullet Cluster) and minor infalls, along with recent simulation results for mergers; (5) particle physics models, including light mediator models and composite DM models; and (6) complementary probes for SIDM, including indirect and direct detection experiments, particle collider searches, and cosmological observations. -
Astronomy Magazine 2011 Index Subject Index
Astronomy Magazine 2011 Index Subject Index A AAVSO (American Association of Variable Star Observers), 6:18, 44–47, 7:58, 10:11 Abell 35 (Sharpless 2-313) (planetary nebula), 10:70 Abell 85 (supernova remnant), 8:70 Abell 1656 (Coma galaxy cluster), 11:56 Abell 1689 (galaxy cluster), 3:23 Abell 2218 (galaxy cluster), 11:68 Abell 2744 (Pandora's Cluster) (galaxy cluster), 10:20 Abell catalog planetary nebulae, 6:50–53 Acheron Fossae (feature on Mars), 11:36 Adirondack Astronomy Retreat, 5:16 Adobe Photoshop software, 6:64 AKATSUKI orbiter, 4:19 AL (Astronomical League), 7:17, 8:50–51 albedo, 8:12 Alexhelios (moon of 216 Kleopatra), 6:18 Altair (star), 9:15 amateur astronomy change in construction of portable telescopes, 1:70–73 discovery of asteroids, 12:56–60 ten tips for, 1:68–69 American Association of Variable Star Observers (AAVSO), 6:18, 44–47, 7:58, 10:11 American Astronomical Society decadal survey recommendations, 7:16 Lancelot M. Berkeley-New York Community Trust Prize for Meritorious Work in Astronomy, 3:19 Andromeda Galaxy (M31) image of, 11:26 stellar disks, 6:19 Antarctica, astronomical research in, 10:44–48 Antennae galaxies (NGC 4038 and NGC 4039), 11:32, 56 antimatter, 8:24–29 Antu Telescope, 11:37 APM 08279+5255 (quasar), 11:18 arcminutes, 10:51 arcseconds, 10:51 Arp 147 (galaxy pair), 6:19 Arp 188 (Tadpole Galaxy), 11:30 Arp 273 (galaxy pair), 11:65 Arp 299 (NGC 3690) (galaxy pair), 10:55–57 ARTEMIS spacecraft, 11:17 asteroid belt, origin of, 8:55 asteroids See also names of specific asteroids amateur discovery of, 12:62–63 -
Annual Report 2013 Cover Photo: the International LOFAR Telescope (ILT) & Big Data, Danielle Futselaar © ASTRON
Annual report 2013 Cover photo: The International LOFAR Telescope (ILT) & Big Data, Danielle Futselaar © ASTRON. Photo on this page: prototype for the Apertif phased array feed. The Westerbork Synthesis Radio Telescope (WSRT) will be upgraded with Phased Array Feeds (PAFs), which will allow scientists to perform much faster observations with the telescope with a wider field of view. More information is available on the ASTRON/ JIVE daily image: http://www.astron.nl/ dailyimage/main.php?date=20130624. 2 ASTRON Annual report 2013 Facts and figures of 2013 8 Awards or grants 163 employees 162 refereed articles Funding: € 17,420,955 Expenditure: € 17,091,022 Balance: € 329.33 25 press releases 3 ASTRON Annual report 2013 Contents Facts and figures 2013 3 Director’s report 5 ASTRON Board and Management Team 7 ASTRON in brief 8 Contribution to top sectors 11 Performance indicators 12 Astronomy Group 17 Radio Observatory 22 R&D Laboratory 30 Connected legal entities 36 NOVA Optical/ Infrared Instrumentation Group 38 Joint Institute for VLBI in Europe 41 Outreach and education 43 Appendices 58 Appendix 1: financial summary 59 Appendix 2: personnel highlights 60 Appendix 3: WSRT & LOFAR proposals in 2013 62 Appendix 4: board, committees & staff in 2013 65 Appendix 5: publications 67 4 ASTRON Annual report 2013 Report 2013 was a year in which earlier efforts began to bear fruit. In particular, the various hardware and firmware changes made to the LOFAR telescope system in 2012, resulted in science quality data being delivered to the various Key Science Projects, and in particular the EoR (Epoch of Reionisation) Team. -
Coma Cluster of Galaxies
Coma Cluster of Galaxies In 2006, Hubble Space Telescope aimed at a nearby collection of NAT I O N A L SC I E N C E ED U C AT I O N STA N D A R D S galaxies called the Coma Cluster. Using the HST images, astronomers • Content Standard in 9-12 Science as gained fascinating insights into the evolution of galaxies in dense Inquiry (Abilities necessary to do sci- galactic neighborhoods. In this activity, students will first learn the entific inquiry, Understanding about basics of galaxy classification and grouping, then use HST images to scientific inquiry) discover the “morphology-density effect” and make hypotheses about • Content Standard in 9-12 Earth and its causes. Space Science (Origin and evolution of the universe) MAT E R I A L S & PR E PA R AT I O N • Each student needs a copy of the next 7 pages (not this page). You may InvIsIble Clu s t e r copy the pages out of this guide, but it is recommended that you go to If you aim a big telescope at the Coma mcdonaldobservatory.org/teachers/classroom and download the student Cluster, you’ll see galaxies galore worksheets. The galaxy images in the online worksheets are “negatives” — thousands of galaxies of all sizes of the real images, which provides better detail when printing. Supple and shapes, from little puffballs to mental materials for this activity are also available on the website. big, fuzzy footballs. Even so, you won’t • Each student or student team will need a calculator and a magnifying see most of the cluster because it’s invis glass (a linen tester works well). -
Astronomy Magazine 2012 Index Subject Index
Astronomy Magazine 2012 Index Subject Index A AAR (Adirondack Astronomy Retreat), 2:60 AAS (American Astronomical Society), 5:17 Abell 21 (Medusa Nebula; Sharpless 2-274; PK 205+14), 10:62 Abell 33 (planetary nebula), 10:23 Abell 61 (planetary nebula), 8:72 Abell 81 (IC 1454) (planetary nebula), 12:54 Abell 222 (galaxy cluster), 11:18 Abell 223 (galaxy cluster), 11:18 Abell 520 (galaxy cluster), 10:52 ACT-CL J0102-4915 (El Gordo) (galaxy cluster), 10:33 Adirondack Astronomy Retreat (AAR), 2:60 AF (Astronomy Foundation), 1:14 AKARI infrared observatory, 3:17 The Albuquerque Astronomical Society (TAAS), 6:21 Algol (Beta Persei) (variable star), 11:14 ALMA (Atacama Large Millimeter/submillimeter Array), 2:13, 5:22 Alpha Aquilae (Altair) (star), 8:58–59 Alpha Centauri (star system), possibility of manned travel to, 7:22–27 Alpha Cygni (Deneb) (star), 8:58–59 Alpha Lyrae (Vega) (star), 8:58–59 Alpha Virginis (Spica) (star), 12:71 Altair (Alpha Aquilae) (star), 8:58–59 amateur astronomy clubs, 1:14 websites to create observing charts, 3:61–63 American Astronomical Society (AAS), 5:17 Andromeda Galaxy (M31) aging Sun-like stars in, 5:22 black hole in, 6:17 close pass by Triangulum Galaxy, 10:15 collision with Milky Way, 5:47 dwarf galaxies orbiting, 3:20 Antennae (NGC 4038 and NGC 4039) (colliding galaxies), 10:46 antihydrogen, 7:18 antimatter, energy produced when matter collides with, 3:51 Apollo missions, images taken of landing sites, 1:19 Aristarchus Crater (feature on Moon), 10:60–61 Armstrong, Neil, 12:18 arsenic, found in old star, 9:15 -
Evolution of Proto-Galaxy-Clusters to Their Present Form: Theory and Observations
Journal of Cosmology, 2010, 6, 1365-1384 Evolution of proto-galaxy-clusters … Gibson & Schild 1365 Evolution of proto-galaxy-clusters to their present form: theory and observations Carl H. Gibson 1,2 1 University of California San Diego, La Jolla, CA 92093-0411, USA [email protected], http://sdcc3.ucsd.edu/~ir118 and Rudolph E. Schild3,4 3 Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 4 [email protected] ABSTRACT From hydro-gravitational-dynamics theory HGD, gravitational structure formation begins 30,000 years (1012 s) after the turbulent big bang by viscous-gravitational fragmentation into super-cluster-voids and 1046 kg proto-galaxy-super-clusters. Linear and spiral gas- proto-galaxies GPGs are the smallest fragments to emerge from the plasma epoch at de- 13 1/2 coupling at 10 s with Nomura turbulence morphology and length scale LN ~ (/G) ~1020 m, determined by rate-of-strain , photon viscosity , and density of the plasma fossilized at 1012 s. GPGs fragment into 1036 kg proto-globular-star-cluster PGC clumps of 1024 kg primordial-fog-particle PFP dark matter planets. All stars form from planet mergers, with ~97% unmerged as galaxy baryonic-dark-matter BDM. The non-baryonic- dark-matter NBDM is so weakly collisional it diffuses to form galaxy cluster halos. It does not guide galaxy formation, contrary to conventional cold-dark-matter hierarchical clustering CDMHC theory (=0). NBDM has ~97% of the mass of the universe. It binds rotating clusters of galaxies by gravitational forces. The galaxy rotational spin axis matches that for low wavenumber spherical harmonic components of CMB temperature anomalies and extends to 4.5x1025 m (1.5 Gpc) in quasar polarization vectors, requiring a big bang turbulence origin.