Wyn Evans Institute of Astronomy, Cambridge
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Spatial Distribution of Galactic Globular Clusters: Distance Uncertainties and Dynamical Effects
Juliana Crestani Ribeiro de Souza Spatial Distribution of Galactic Globular Clusters: Distance Uncertainties and Dynamical Effects Porto Alegre 2017 Juliana Crestani Ribeiro de Souza Spatial Distribution of Galactic Globular Clusters: Distance Uncertainties and Dynamical Effects Dissertação elaborada sob orientação do Prof. Dr. Eduardo Luis Damiani Bica, co- orientação do Prof. Dr. Charles José Bon- ato e apresentada ao Instituto de Física da Universidade Federal do Rio Grande do Sul em preenchimento do requisito par- cial para obtenção do título de Mestre em Física. Porto Alegre 2017 Acknowledgements To my parents, who supported me and made this possible, in a time and place where being in a university was just a distant dream. To my dearest friends Elisabeth, Robert, Augusto, and Natália - who so many times helped me go from "I give up" to "I’ll try once more". To my cats Kira, Fen, and Demi - who lazily join me in bed at the end of the day, and make everything worthwhile. "But, first of all, it will be necessary to explain what is our idea of a cluster of stars, and by what means we have obtained it. For an instance, I shall take the phenomenon which presents itself in many clusters: It is that of a number of lucid spots, of equal lustre, scattered over a circular space, in such a manner as to appear gradually more compressed towards the middle; and which compression, in the clusters to which I allude, is generally carried so far, as, by imperceptible degrees, to end in a luminous center, of a resolvable blaze of light." William Herschel, 1789 Abstract We provide a sample of 170 Galactic Globular Clusters (GCs) and analyse its spatial distribution properties. -
Galactic Archaeology. the Dwarfs That Survived and Perished
Galactic Archaeology. The dwarfs that survived and perished Vasily Belokurova,∗ aInstitute of Astronomy, Cambridge Abstract From the archaeological point of view, the local dwarf galaxies are unique objects in which the imprint of the conditions that shaped the early structure formation can be studied today at high resolution. Over the last decade, this new window into the high redshift Universe has started to be exploited using deep wide-field imaging, high resolution spectroscopy and cutting edge N- body and hydro-dynamical simulations. We review the recent advances in the observational studies of the Milky Way dwarf galaxies, with the aim to understand the properties of the population as a whole and to assist an objective comparison between the models and the data. Keywords: Galaxies: kinematics and dynamics, Galaxies: dwarf, dark matter, Local Group, Galaxies: stellar content. 1. Introduction The prehistoric stars whose formation epochs lie beyond the redshift ac- cessible by the Hubble Ultra Deep Field, have been found en masse in little satellites around the Milky Way. Other less fortunate dwarf galaxies have been pulled apart by gravity to furnish the diffuse Galactic halo. These re- cently uncovered relics of the ancient dwarf galaxy population may play a arXiv:1307.0041v2 [astro-ph.GA] 15 Jul 2013 vital role in the pursuit of reconstructing the formation of the Galaxy. Its path from the distant pre-reionisation era, through the most active growth ∗Corresponding author Email address: [email protected] (Vasily Belokurov) Preprint submitted to New Astronomy Reviews July 16, 2013 periods to the present day, can be gleaned by studying the chemical compo- sition and the phase-space density distribution of these halo denizens. -
What Is an Ultra-Faint Galaxy?
What is an ultra-faint Galaxy? UCSB KITP Feb 16 2012 Beth Willman (Haverford College) ~ 1/10 Milky Way luminosity Large Magellanic Cloud, MV = -18 image credit: Yuri Beletsky (ESO) and APOD NGC 205, MV = -16.4 ~ 1/40 Milky Way luminosity image credit: www.noao.edu Image credit: David W. Hogg, Michael R. Blanton, and the Sloan Digital Sky Survey Collaboration ~ 1/300 Milky Way luminosity MV = -14.2 Image credit: David W. Hogg, Michael R. Blanton, and the Sloan Digital Sky Survey Collaboration ~ 1/2700 Milky Way luminosity MV = -11.9 Image credit: David W. Hogg, Michael R. Blanton, and the Sloan Digital Sky Survey Collaboration ~ 1/14,000 Milky Way luminosity MV = -10.1 ~ 1/40,000 Milky Way luminosity ~ 1/1,000,000 Milky Way luminosity Ursa Major 1 Finding Invisible Galaxies bright faint blue red Willman et al 2002, Walsh, Willman & Jerjen 2009; see also e.g. Koposov et al 2008, Belokurov et al. Finding Invisible Galaxies Red, bright, cool bright Blue, hot, bright V-band apparent brightness V-band faint Red, faint, cool blue red From ARAA, V26, 1988 Willman et al 2002, Walsh, Willman & Jerjen 2009; see also e.g. Koposov et al 2008, Belokurov et al. Finding Invisible Galaxies Ursa Major I dwarf 1/1,000,000 MW luminosity Willman et al 2005 ~ 1/1,000,000 Milky Way luminosity Ursa Major 1 CMD of Ursa Major I Okamoto et al 2008 Distribution of the Milky Wayʼs dwarfs -14 Milky Way dwarfs 107 -12 -10 classical dwarfs V -8 5 10 Sun M L -6 ultra-faint dwarfs Canes Venatici II -4 Leo V Pisces II Willman I 1000 -2 Segue I 0 50 100 150 200 250 300 -
Searching for Dark Matter Annihilation in Recently Discovered Milky Way Satellites with Fermi-Lat A
The Astrophysical Journal, 834:110 (15pp), 2017 January 10 doi:10.3847/1538-4357/834/2/110 © 2017. The American Astronomical Society. All rights reserved. SEARCHING FOR DARK MATTER ANNIHILATION IN RECENTLY DISCOVERED MILKY WAY SATELLITES WITH FERMI-LAT A. Albert1, B. Anderson2,3, K. Bechtol4, A. Drlica-Wagner5, M. Meyer2,3, M. Sánchez-Conde2,3, L. Strigari6, M. Wood1, T. M. C. Abbott7, F. B. Abdalla8,9, A. Benoit-Lévy10,8,11, G. M. Bernstein12, R. A. Bernstein13, E. Bertin10,11, D. Brooks8, D. L. Burke14,15, A. Carnero Rosell16,17, M. Carrasco Kind18,19, J. Carretero20,21, M. Crocce20, C. E. Cunha14,C.B.D’Andrea22,23, L. N. da Costa16,17, S. Desai24,25, H. T. Diehl5, J. P. Dietrich24,25, P. Doel8, T. F. Eifler12,26, A. E. Evrard27,28, A. Fausti Neto16, D. A. Finley5, B. Flaugher5, P. Fosalba20, J. Frieman5,29, D. W. Gerdes28, D. A. Goldstein30,31, D. Gruen14,15, R. A. Gruendl18,19, K. Honscheid32,33, D. J. James7, S. Kent5, K. Kuehn34, N. Kuropatkin5, O. Lahav8,T.S.Li6, M. A. G. Maia16,17, M. March12, J. L. Marshall6, P. Martini32,35, C. J. Miller27,28, R. Miquel21,36, E. Neilsen5, B. Nord5, R. Ogando16,17, A. A. Plazas26, K. Reil15, A. K. Romer37, E. S. Rykoff14,15, E. Sanchez38, B. Santiago16,39, M. Schubnell28, I. Sevilla-Noarbe18,38, R. C. Smith7, M. Soares-Santos5, F. Sobreira16, E. Suchyta12, M. E. C. Swanson19, G. Tarle28, V. Vikram40, A. R. Walker7, and R. H. Wechsler14,15,41 (The Fermi-LAT and DES Collaborations) 1 Los Alamos National Laboratory, Los Alamos, NM 87545, USA; [email protected], [email protected] 2 Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden; [email protected] 3 The Oskar Klein Centre for Cosmoparticle Physics, AlbaNova, SE-106 91 Stockholm, Sweden 4 Dept. -
The Hubble Catalog of Variables (HCV)? A
Astronomy & Astrophysics manuscript no. hcv c ESO 2019 September 25, 2019 The Hubble Catalog of Variables (HCV)? A. Z. Bonanos1, M. Yang1, K. V. Sokolovsky1; 2; 3, P. Gavras4; 1, D. Hatzidimitriou1; 5, I. Bellas-Velidis1, G. Kakaletris6, D. J. Lennon7; 8, A. Nota9, R. L. White9, B. C. Whitmore9, K. A. Anastasiou5, M. Arévalo4, C. Arviset8, D. Baines10, T. Budavari11, V. Charmandaris12; 13; 1, C. Chatzichristodoulou5, E. Dimas5, J. Durán4, I. Georgantopoulos1, A. Karampelas14; 1, N. Laskaris15; 6, S. Lianou1, A. Livanis5, S. Lubow9, G. Manouras5, M. I. Moretti16; 1, E. Paraskeva1; 5, E. Pouliasis1; 5, A. Rest9; 11, J. Salgado10, P. Sonnentrucker9, Z. T. Spetsieri1; 5, P. Taylor9, and K. Tsinganos5; 1 1 IAASARS, National Observatory of Athens, Penteli 15236, Greece e-mail: [email protected] 2 Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA 3 Sternberg Astronomical Institute, Moscow State University, Universitetskii pr. 13, 119992 Moscow, Russia 4 RHEA Group for ESA-ESAC, Villanueva de la Cañada, 28692 Madrid, Spain 5 Department of Physics, National and Kapodistrian University of Athens, Panepistimiopolis, Zografos 15784, Greece 6 Athena Research and Innovation Center, Marousi 15125, Greece 7 Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife, Spain 8 ESA, European Space Astronomy Centre, Villanueva de la Canada, 28692 Madrid, Spain 9 Space Telescope Science Institute, Baltimore, MD 21218, USA 10 Quasar Science Resources for ESA-ESAC, Villanueva de la Cañada, 28692 Madrid, Spain 11 The Johns Hopkins University, Baltimore, MD 21218, USA 12 Institute of Astrophysics, FORTH, Heraklion 71110, Greece 13 Department of Physics, Univ. -
Draft181 182Chapter 10
Chapter 10 Formation and evolution of the Local Group 480 Myr <t< 13.7 Gyr; 10 >z> 0; 30 K > T > 2.725 K The fact that the [G]alactic system is a member of a group is a very fortunate accident. Edwin Hubble, The Realm of the Nebulae Summary: The Local Group (LG) is the group of galaxies gravitationally associ- ated with the Galaxy and M 31. Galaxies within the LG have overcome the general expansion of the universe. There are approximately 75 galaxies in the LG within a 12 diameter of ∼3 Mpc having a total mass of 2-5 × 10 M⊙. A strong morphology- density relation exists in which gas-poor dwarf spheroidals (dSphs) are preferentially found closer to the Galaxy/M 31 than gas-rich dwarf irregulars (dIrrs). This is often promoted as evidence of environmental processes due to the massive Galaxy and M 31 driving the evolutionary change between dwarf galaxy types. High Veloc- ity Clouds (HVCs) are likely to be either remnant gas left over from the formation of the Galaxy, or associated with other galaxies that have been tidally disturbed by the Galaxy. Our Galaxy halo is about 12 Gyr old. A thin disk with ongoing star formation and older thick disk built by z ≥ 2 minor mergers exist. The Galaxy and M 31 will merge in 5.9 Gyr and ultimately resemble an elliptical galaxy. The LG has −1 vLG = 627 ± 22 km s with respect to the CMB. About 44% of the LG motion is due to the infall into the region of the Great Attractor, and the remaining amount of motion is due to more distant overdensities between 130 and 180 h−1 Mpc, primarily the Shapley supercluster. -
N.W. Evans (Cambridge)
Satellites and Streams N.W. Evans (Cambridge) Friday, 23 July 2010 CDM models predict at least 1-2 orders of magnitude more low mass dark haloes at the present epoch compared to the observed abundance of of dwarf galaxies surrounding the Milky Way and M31 (Moore 1981, Klypin et al. 1999). In 1999, there were 9 established dwarf galaxies around the Milky Way (Leo I, Leo II, Sextans, Sculptor, Fornax, Carina, Draco, Sagittarius, Ursa Minor). The concensus was that the sample was complete Friday, 23 July 2010 This seemed to be confirmed by Willman et al. (2006) who made the first searches through Sloan Digital Sky Survey data and discovered only one new dwarf galaxy (Ursa Major) and one unusually large (probable) globular cluster (Willman 1). Most of the Sloan Data Release 5 was then made public. Friday, 23 July 2010 The breakthrough came when Belokurov and co- workers in Cambridge made the red-green-blue color image known as the Field of Streams This proved to be a treasure-trove for dwarf galaxy hunting and Canes Venatici I, Bootes I, Ursa Major II, Leo IV, Leo V, Canes Venatici II, Coma Berenices, Segue1 were discovered in quick succession. Friday, 23 July 2010 Friday, 23 July 2010 Friday, 23 July 2010 (i) The blue-colored, and hence nearby, overdensity in stars centered at (α≈185°, δ≈0°). This was found by Juric et al. (2005) and named the Virgo Overdensity. (ii) Multiple wraps of the Monoceros Ring (Newberg et al. 2002) are visible as the blue-colored structure at α≈ 120° (iii) Also showing clearly in this map is a new stream (the Orphan Stream) at latitudes of b≈50° and with longitudes satisfying 180°≤ l ≤ 230°. -
One Law to Rule Them All: the Radial Acceleration Relation of Galaxies
The Astrophysical Journal, 836:152 (23pp), 2017 February 20 https://doi.org/10.3847/1538-4357/836/2/152 © 2017. The American Astronomical Society. All rights reserved. One Law to Rule Them All: The Radial Acceleration Relation of Galaxies Federico Lelli1,2,5, Stacy S. McGaugh1, James M. Schombert3, and Marcel S. Pawlowski1,4,6 1 Department of Astronomy, Case Western Reserve University, Cleveland, OH 44106, USA; fl[email protected] 2 European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748, Garching, Germany 3 Department of Physics, University of Oregon, Eugene, OR 97403, USA 4 Department of Physics and Astronomy, University of California, Irvine, CA 92697, USA Received 2016 October 26; revised 2017 January 12; accepted 2017 January 12; published 2017 February 16 Abstract We study the link between baryons and dark matter (DM) in 240 galaxies with spatially resolved kinematic data. Our sample spans 9 dex in stellar mass and includes all morphological types. We consider (1) 153 late-type galaxies (LTGs; spirals and irregulars) with gas rotation curves from the SPARC database,(2) 25 early-type galaxies (ETGs; ellipticals and lenticulars) with stellar and H I data from ATLAS3D or X-ray data from Chandra,and (3) 62 dwarf spheroidals (dSphs) with individual-star spectroscopy. We find that LTGs, ETGs, and “ ” ( ) classical dSphs follow the same radial acceleration relation: the observed acceleration gobs correlates with that ( ) ( ) expected from the distribution of baryons gbar over 4 dex. The relation coincides with the 1:1 line no DM at high accelerations but systematically deviates from unity below a critical scale of ∼10−10 ms−2. -
000001 Proceedings New Directions in Modern Cosmology
000001 Proceedings New Directions in Modern Cosmology Proceedings New Directions in Modern Cosmology 000002 000003 Proceedings New Directions in Modern Cosmology 000004 Prediction for the neutrino mass in the KATRIN experiment from lensing by the galaxy cluster A1689 Theo M. Nieuwenhuizen Center for Cosmology and Particle Physics, New York University, New York, NY 10003 On leave of: Institute for Theoretical Physics, University of Amsterdam, Science Park 904, P.O. Box 94485, 1090 GL Amsterdam, The Netherlands Andrea Morandi Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel [email protected]; [email protected] Proceedings New Directions in Modern Cosmology ABSTRACT The KATRIN experiment in Karlsruhe Germany will monitor the decay of tritium, which produces an electron-antineutrino. While the present upper bound for its mass is 2 eV/c2, KATRIN will search down to 0.2 eV=c2. If the dark matter of the galaxy cluster Abell 1689 is modeled as degenerate isothermal fermions, the strong and weak lensing data may be explained by degenerate neutrinos with mass of 1.5 eV=c2. Strong lensing data beyond 275 kpc put tension on the standard cold dark matter interpretation. In the most natural scenario, the electron antineutrino will have a mass of 1.5 eV/c2, a value that will be tested in KATRIN. Subject headings: Introduction, NFW profile for cold dark matter, Isothermal neutrino mass models, Applications of the NFW and isothermal neutrino models, Fit to the most recent data sets, Conclusion 1. Introduction The neutrino sector of the Standard Model of elementary particles is one of today's most intense research fields (Kusenko, 2010; Altarelli and Feruglio 2010; Avignone et al. -
The Pristine Dwarf-Galaxy Survey – II
Mon. Not. R. Astron. Soc. 000, 000{000 (0000) Printed 8 October 2019 (MN LATEX style file v2.2) The Pristine Dwarf-Galaxy survey { II. In-depth observational study of the faint Milky Way satellite Sagittarius II Nicolas Longeard1, Nicolas Martin1;2, Else Starkenburg3, Rodrigo A. Ibata1, Michelle L. M. Collins4;6, Benjamin P. M. Laevens5, Dougal Mackey7, R. Michael Rich 8 , David S. Aguado9, Anke Arentsen3, Pascale Jablonka10;11, Jonay I. Gonz´alezHern´andez12;13, Julio F. Navarro14, Rub´enS´anchez-Janssen15;16 1 Universit´ede Strasbourg, CNRS, Observatoire astronomique de Strasbourg, UMR 7550, F-67000 Strasbourg, France 2 Max-Planck-Institut f¨urAstronomy, K¨onigstuhl17, D-69117, Heidelberg, Germany 3 Leibniz Institute for Astrophysics Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany 4 Department of Physics, University of Surrey, Guildford, GU2 7XH, Surrey, UK 5 Institute of Astrophysics, Pontificia Universidad Cat´olica de Chile, Av. Vicua Mackenna 4860, 7820436 Macul, Santiago, Chile 6 Department of Astronomy, Yale University, New Haven, CT 06520, USA 7 Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611, Australia 8 University of California Los Angeles, Department of Physics & Astronomy, Los Angeles, CA, USA 9 Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK 10 GEPI, Observatoire de Paris, PSL Research University, CNRS, Place Jules Janssen, 92190 Meudon, France 11 Laboratoire d'astrophysique, Ecole´ Polytechnique F´ed´erale de Lausanne (EPFL), Observatoire, 1290 Versoix, Switzerland 12 Instituto de Astrofisica de Canarias, Via Lactea, 38205 La Laguna, Tenerife, Spain 13 Universidad de La Laguna, Departamento de Astrofisica, 38206 La Laguna, Tenerife, Spain 14 Dept. -
Monitoring Survey of Pulsating Giant Stars in the M
Journal of Physics: Conference Series PAPER • OPEN ACCESS Related content - MASS LOSS AND R 136A-TYPE STARS. Monitoring survey of pulsating giant stars in the M. S. Vardya - M33 IR Variable Stars Local Group galaxies: survey description, science K. B. W. McQuinn, Charles E. Woodward, goals, target selection S. P. Willner et al. - MASS LOSS FROM EVOLVED STARS Robert J. Sopka To cite this article: E Saremi et al 2017 J. Phys.: Conf. Ser. 869 012068 View the article online for updates and enhancements. This content was downloaded from IP address 160.5.148.227 on 19/10/2017 at 09:54 Frontiers in Theoretical and Applied Physics/UAE 2017 (FTAPS 2017) IOP Publishing IOP Conf. Series: Journal of Physics: Conf. Series 1234567890869 (2017) 012068 doi :10.1088/1742-6596/869/1/012068 Monitoring survey of pulsating giant stars in the Local Group galaxies: survey description, science goals, target selection E Saremi1,2, A Javadi2, J Th van Loon3, H Khosroshahi2, A Abedi1, J Bamber3, S A Hashemi4, F Nikzat5 and A Molaei Nezhad2 1 Physics Department, University of Birjand, Birjand 97175-615, Iran 2 School of Astronomy, Institute for Research in Fundamental Sciences (IPM), Tehran, 19395-5531, Iran 3 Lennard-Jones Laboratories, Keele University, ST5 5BG, UK 4 Physics Department, Sharif University of Tecnology, Tehran 1458889694, Iran 5 Instituto de Astrofisica, Facultad de Fisica, Pontificia Universidad Catolica de Chile, Av. Vicuna Mackenna 4860, 782-0436 Macul, Santiago, Chile Email: [email protected] Abstract. The population of nearby dwarf galaxies in the Local Group constitutes a complete galactic environment, perfect suited for studying the connection between stellar populations and galaxy evolution. -
Galaxies on Sub-Galactic Scales
CSIRO PUBLISHING Publications of the Astronomical Society of Australia, 2012, 29, 383–394 http://dx.doi.org/10.1071/AS11023 Galaxies on Sub-Galactic Scales Helmut Jerjen Research School of Astronomy & Astrophysics, Australian National University, Mt. Stromlo Observatory, Weston, ACT 2611, Australia. Email: [email protected] Abstract: The Sloan Digital Sky Survey has been immensely successful in detecting new Milky Way satellite galaxies over the past seven years. It was instrumental in finding examples of the least luminous galaxies we know in the Universe, uncovering apparent inconsistencies between cold dark matter theory and dwarf galaxy properties, providing first evidence for a possible lower mass limit for dark matter halos in visible galaxies, and reopening the discussion about the building block scenario for the Milky Way halo. Nonetheless, these results are still drawn only from a relatively small number of galaxies distributed over an area covering about 29% of the sky, which leaves us currently with more questions than answers. The study of these extreme stellar systems is a multi-parameter problem: ages, metallicities, star formation histories, dark matter contents, population fractions and spatial distributions must be determined. Progress in the field is discussed and attention drawn to some of the limitations that currently hamper our ability to fully understand the phenomenon of the ‘ultra-faint dwarf galaxy’. In this context, the Stromlo Milky Way Satellite Survey represents a new initiative to systematically search and scrutinize optically elusive Milky Way satellite galaxies in the Southern hemisphere. In doing so, the program aims at investigating some of the challenging questions in stellar evolution, galaxy formation and near-field cosmology.