Isolated Elliptical Galaxies
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A Multivariate Statistical Analysis of Spiral Galaxy Luminosities. I. Data and Results
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by CERN Document Server A Multivariate Statistical Analysis of Spiral Galaxy Luminosities. I. Data and Results Alice Shapley California Institute of Technology, Pasadena CA, 91125, USA G. Fabbiano Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 P. B. Eskridge Ohio State University, Dept. of Astronomy, 140 W 18th Ave, Columbus, OH 43210 ABSTRACT We have performed a multiparametric analysis of luminosity data for a sample of 234 normal spiral and irregular galaxies observed in X-rays with the Einstein Observatory. This sample is representative of S and Irr galaxies, with a good coverage of morphological types and absolute magnitudes. In addition to X-ray and optical data, we have compiled H-band magnitudes, IRAS near- and far-infrared, and 6cm radio continuum observations for the sample from the literature. We have also performed a careful compilation of distance estimates. We have explored the effect of morphology by dividing the sample into early (S0/a-Sab), intermediate (Sb-Sbc), and late-type (Sc-Irr) subsamples. The data were analysed with bivariate and multivariate survival analysis techniques that make full use of all the information available in both detections and limits. We find that most pairs of luminosities are correlated when considered individually, and this is not due to a distance bias. Different luminosity-luminosity correlations follow different power-law relations. Contrary to previous reports, the LX LB correlation follows a power-law with exponent − larger than 1. Both the significances of some correlations and their power-law relations are morphology dependent. -
Dynamos on Galactic Scales, Or Dynamos Around Us
Dynamos on galactic scales, or Dynamos around us. Part I. Galaxies and galaxy clusters Anvar Shukurov School of Mathematics and Statistics, Newcastle University, U.K. 1. Introduction: basic facts and parameters 2. Spiral galaxies 2.1. Rotation 2.2. Hydrostatic equilibrium of the gas layer 2.3. Interstellar gas and its multi-phase structure 2.4. Interstellar turbulence 3. Elliptical galaxies 4. Galaxy clusters Warning cgs units will be used, 1 G = 10 -4 T, 1 µG = 10 -6 G = 0.1 nT. G ≈ 6.67 ×10 −8 cm 3 g−1 s−2; k ≈ 1.38 ×10 −16 erg K −1; ≈ × −24 ≈ × 7 ≈ × −12 mp 1.7 10 g, 1 year 3 10 s; 1 eV 1.6 10 erg. 1 parsec ≈ 3 × 10 18 cm ≈ 3.26 light years, 1 kpc = 10 3 pc; c ≈ 3×10 10 cm 3 cm s −1 (1 parsec distance: Earth orbit’s par allax = 1 sec ond of arc). Solar mass, radius and luminosity: ≈ × 33 ≈ × 10 ≈ × 33 −1 M 2 10 g; R 7 10 cm; L 4 10 erg s . Notation: HI = neutral hydrogen, HII = p+ = ionized hydrogen, CIV = triply ionized carbon, etc. Further reading R. G. Tayler, Galaxies: Structures and Evolution , Cambridge Univ. Press, 1993 (a high-level scientific popular book on galactic astrophysics, entertaining and informative, very well written). J.E Dyson and D.A Williams, The Physics of the Interstellar Medium , Second Edition (The Graduate Series in Astronomy), IOP, 1997 (a good textbook on interstellar medium, presents appropriate equations and their solutions together with clear qualitative arguments and explanations and order of magnitude estimates). -
Lateinischer Name: Deutscher Name: Hya Hydra Wasserschlange
Lateinischer Name: Deutscher Name: Hya Hydra Wasserschlange Atlas Karte (2000.0) Kulmination um Cambridge 10, 16, Mitternacht: Star Atlas 17 12, 13, Sky Atlas Benachbarte Sternbilder: 20, 21 Ant Cnc Cen Crv Crt Leo Lib 9. Februar Lup Mon Pup Pyx Sex Vir Deklinationsbereic h: -35° ... 7° Fläche am Himmel: 1303° 2 Mythologie und Geschichte: Bei der nördlichen Wasserschlange überlagern sich zwei verschiedene Bilder aus der griechischen Mythologie. Das erste Bild zeugt von der eher harmlosen Wasserschlange aus der Geschichte des Raben : Der Rabe wurde von Apollon ausgesandt, um mit einem goldenen Becher frisches Quellwasser zu holen. Stattdessen tat sich dieser an Feigen gütlich und trug bei seiner Rückkehr die Wasserschlange in seinen Fängen, als angebliche Begründung für seine Verspätung. Um jedermann an diese Untat zu erinnern, wurden der Rabe samt Becher und Wasserschlange am Himmel zur Schau gestellt. Von einem ganz anderen Schlag war die Wasserschlange, mit der Herakles zu tun hatte: In einem Sumpf in der Nähe von Lerna, einem See und einer Stadt an der Küste von Argo, hauste ein unsagbar gefährliches und grässliches Untier. Diese Schlange soll mehrere Köpfe gehabt haben. Fünf sollen es gewesen sein, aber manche sprechen auch von sechs, neun, ja fünfzig oder hundert Köpfen, aber in jedem Falle war der Kopf in der Mitte unverwundbar. Fürchterlich war es, da diesen grässlichen Mäulern - ob die Schlange nun schlief oder wachte - ein fauliger Atem, ein Hauch entwich, dessen Gift tödlich war. Kaum schlug ein todesmutiger Mann dem Untier einen Kopf ab, wuchsen auf der Stelle zwei neue Häupter hervor, die noch furchterregender waren. Eurystheus, der König von Argos, beauftragte Herakles in seiner zweiten Aufgabe diese lernäische Wasserschlange zu töten. -
Teacher's Guide
Teacher’s guide CESAR Science Case – The secrets of galaxies Material that is necessary during the laboratory o CESAR Booklet o Computer with an Internet browser o CESAR List of Galaxies (.txt file) o Paper, pencil or pen o CESAR Student’s guide o o Introduction o o This Science Case provides an introduction to galaxies based on real multi-wavelength observations with space missions. It discusses concepts such as the Hubble Tuning Fork and the morphological classification of galaxies, stellar and ISM content of the different types of galaxies, and galaxy interaction and evolution. The activity is designed to encourage students to discover the properties of galaxies on their own. o During the laboratory, students make use of ESASky1, a portal for exploration and retrieval of space astronomical data, to visualise different galaxies and classify them according to their shapes and optical colours. Students can load different sky maps to see how the galaxies look like when they are observed at different wavelength ranges, and discuss how the presence of the ISM is affecting these observations. o Before starting this activity, students must be familiar with the properties of stars and of the interstellar medium, as well as have some basic concepts of stellar evolution. In particular, they must understand that young, massive stars display blue colors, while evolved stars look yellowish or reddish. They must also understand the relation between the ISM and young stars. o o Learning Outcomes o o By the end of this laboratory, students will be able to: 1. Explain how astronomers classify galaxies according to their shapes and contents. -
Hubble Space Telescope Images of Stephan's Quintet
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by CERN Document Server Hubble Space Telescope Images of Stephan's Quintet: Star Cluster Formation in a Compact Group Environment1;2 Sarah C. Gallagher, Jane C. Charlton3, Sally D. Hunsberger Department of Astronomy and Astrophysics The Pennsylvania State University University Park PA 16802 gallsc, charlton, [email protected] Dennis Zaritsky Steward Observatory University of Arizona Tucson, AZ 85721 [email protected] and Bradley C. Whitmore Space Telescope Science Institute 3700 San Martin Drive Baltimore, MD 21218 [email protected] ABSTRACT Analysis of Hubble Space Telescope/Wide Field Planetary Camera 2 images of Stephan’s Quintet, Hickson Compact Group 92, yielded 115 candidate star clusters (with V I<1:5). Unlike in merger remants, the cluster candidates in Stephan’s Quintet are not clustered in the inner− regions of the galaxies; they are spread over the debris and surrounding area. Specifically, these sources are located in the long sweeping tail and spiral arms of NGC 7319, in the tidal debris of NGC 7318B/A, and in the intragroup starburst region north of these galaxies. Analysis of the colors of the clusters indicate several distinct epochs of star formation that appear to trace the complex history of dynamical interactions in this compact group. Subject headings: galaxies: interactions | galaxies: individual (NGC 7318A, NGC 7318B, NGC 7319) | galaxies: star clusters | intergalactic medium 1. Introduction the central regions of mergers (Holtzman et al. 1992; Whitmore et al. 1993; Schweizer et al. 1996; Miller et al. The interactions of galaxies trigger bursts of star for- 1997; Whitmore et al. -
Scaling Mass Profiles Around Elliptical Galaxies Observed with Chandra
Scaling Mass Profiles around Elliptical Galaxies Observed with Chandra and XMM-Newton Y. Fukazawa1, J. G. Betoya-Nonesa1, J. Pu1, A. Ohto1, and N. Kawano1 Department of Physical Science, School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 [email protected] ABSTRACT We investigated the dynamical structure of 53 elliptical galaxies, based on the Chandra archival X-ray data. In X-ray luminous galaxies, a temperature increases with radius and a gas density is systematically higher at the optical outskirts, indicating a presence of a significant amount of the group-scale hot gas. In contrast, X-ray dim galaxies show a flat or declining temperature profile against radius and the gas density is relatively lower at the optical outskirts. Thus it is found that X-ray bright and faint elliptical galaxies are clearly distinguished by the temperature and gas density profile. The mass profile is well scaled by a virial radius r200 rather than an optical-half radius re, and is quite similar at (0.001 − 0.03)r200 between X-ray luminous and dim galaxies, and smoothly connects to those of clusters of galaxies. At the inner region of (0.001 − 0.01)r200 or (0.1 − 1)re, the mass profile well traces a stellar mass with a constant mass-to- light ratio of M/LB =3 − 10(M⊙/L⊙). M/LB ratio of X-ray bright galaxies rises up steeply beyond 0.01r200, and thus requires a presence of massive dark matter halo. From the deprojection analysis combined with the XMM-Newton data, we arXiv:astro-ph/0509521v1 18 Sep 2005 found that X-ray dim galaxies, NGC 3923, NGC 720, and IC 1459, also have a high M/LB ratio of 20–30 at 20 kpc, comparable to that of X-ray luminous galaxies. -
Dwarf Galaxies
Europeon South.rn Ob.ervotory• ESO ML.2B~/~1 ~~t.· MAIN LIBRAKY ESO Libraries ,::;,q'-:;' ..-",("• .:: 114 ML l •I ~ -." "." I_I The First ESO/ESA Workshop on the Need for Coordinated Space and Ground-based Observations - DWARF GALAXIES Geneva, 12-13 May 1980 Report Edited by M. Tarenghi and K. Kjar - iii - INTRODUCTION The Space Telescope as a joint undertaking between NASA and ESA will provide the European community of astronomers with the opportunity to be active partners in a venture that, properly planned and performed, will mean a great leap forward in the science of astronomy and cosmology in our understanding of the universe. The European share, however,.of at least 15% of the observing time with this instrumentation, if spread over all the European astrono mers, does not give a large amount of observing time to each individual scientist. Also, only well-planned co ordinated ground-based observations can guarantee success in interpreting the data and, indeed, in obtaining observ ing time on the Space Telescope. For these reasons, care ful planning and cooperation between different European groups in preparing Space Telescope observing proposals would be very essential. For these reasons, ESO and ESA have initiated a series of workshops on "The Need for Coordinated Space and Ground based Observations", each of which will be centred on a specific subject. The present workshop is the first in this series and the subject we have chosen is "Dwarf Galaxies". It was our belief that the dwarf galaxies would be objects eminently suited for exploration with the Space Telescope, and I think this is amply confirmed in these proceedings of the workshop. -
Arxiv:1704.06661V1 [Astro-Ph.CO]
Mon. Not. R. Astron. Soc. 000, 000{000 (0000) Printed 26 April 2017 (MN LATEX style file v2.2) Can cluster merger shocks reproduce the luminosity and shape distribution of radio relics? Sebasti´anE. Nuza1;2;3?, Jakob Gelszinnis4, Matthias Hoeft4, and Gustavo Yepes5 1Leibniz-Institut f¨urAstrophysik Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany 2Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Buenos Aires, Argentina 3CONICET-Universidad de Buenos Aires, Instituto de Astronom´ıay F´ısica del Espacio (IAFE), Buenos Aires, Argentina 4Th¨uringerLandessternwarte, Sternwarte 5, 07778 Tautenburg, Germany 5Grupo de Astrof´ısica, Universidad Aut´onomade Madrid, Cantoblanco, 28039 Madrid, Spain ABSTRACT Radio relics in galaxy clusters are believed to trace merger shock fronts. If cosmological structure formation determines the luminosity, size and shape distributions of radio relics then merger shocks need to be lighted up in a homogeneous way. We investigate if a mock relic sample, obtained from zoomed galaxy cluster simulations, is able to match the properties of relics measured in the NRAO VLA Sky Survey (NVSS). We compile a list of all radio relics known to date and homogeneously measure their parameters in all NVSS images and apply the same procedure to relics in our simulations. Number counts in the mock relic sample increase more steeply towards lower relic flux densities, suggesting an incompleteness of NVSS in this regime. Overall, we find that NVSS and mock samples show similar properties. However, large simulated relics tend to be somewhat smaller and closer to the cluster centre than observed ones. Besides this, the mock sample reproduces very well-known correlations for radio relics, in particular those relating the radio luminosity with the largest linear size and the X- ray luminosity. -
Structural Parameters of Compact Stellar Systems
Structural Parameters of Compact Stellar Systems Juan Pablo Madrid Presented in fulfillment of the requirements of the degree of Doctor of Philosophy May 2013 Faculty of Information and Communication Technology Swinburne University Abstract The objective of this thesis is to establish the observational properties and structural parameters of compact stellar systems that are brighter or larger than the “standard” globular cluster. We consider a standard globular cluster to be fainter than M 11 V ∼ − mag and to have an effective radius of 3 pc. We perform simulations to further un- ∼ derstand observations and the relations between fundamental parameters of dense stellar systems. With the aim of establishing the photometric and structural properties of Ultra- Compact Dwarfs (UCDs) and extended star clusters we first analyzed deep F475W (Sloan g) and F814W (I) Hubble Space Telescope images obtained with the Advanced Camera for Surveys. We fitted the light profiles of 5000 point-like sources in the vicinity of NGC ∼ 4874 — one of the two central dominant galaxies of the Coma cluster. Also, NGC 4874 has one of the largest globular cluster systems in the nearby universe. We found that 52 objects have effective radii between 10 and 66 pc, in the range spanned by extended star ∼ clusters and UCDs. Of these 52 compact objects, 25 are brighter than M 11 mag, V ∼ − a magnitude conventionally thought to separate UCDs and globular clusters. We have discovered both a red and a blue subpopulation of Ultra-Compact Dwarf (UCD) galaxy candidates in the Coma galaxy cluster. Searching for UCDs in an environment different to galaxy clusters we found eleven Ultra-Compact Dwarf and 39 extended star cluster candidates associated with the fossil group NGC 1132. -
Discovery of Extended Radio Emission in the Merging Galaxy Cluster Abell 2146.', Monthly Notices of the Royal Astronomical Society., 475 (2)
Durham Research Online Deposited in DRO: 29 March 2018 Version of attached le: Published Version Peer-review status of attached le: Peer-reviewed Citation for published item: Hlavacek-Larrondo, J. and Gendron-Marsolais, M.-L. and Fecteau-Beaucage, D. and van Weeren, R. J. and Russell, H. R. and Edge, A. and Olamaie, M. and Rumsey, C. and King, L. and Fabian, A. C. and McNamara, B. and Hogan, M. and Mezcua, M. and Taylor, G. (2018) 'Mystery solved : discovery of extended radio emission in the merging galaxy cluster Abell 2146.', Monthly notices of the Royal Astronomical Society., 475 (2). pp. 2743-2753. Further information on publisher's website: https://doi.org/10.1093/mnras/stx3160 Publisher's copyright statement: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society c : 2017 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. Additional information: Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full DRO policy for further details. Durham University Library, Stockton Road, Durham DH1 3LY, United Kingdom Tel : +44 (0)191 334 3042 | Fax : +44 (0)191 334 2971 https://dro.dur.ac.uk MNRAS 475, 2743–2753 (2018) doi:10.1093/mnras/stx3160 Advance Access publication 2017 December 8 Mystery solved: discovery of extended radio emission in the merging galaxy cluster Abell 2146 J. -
Key Information • This Exam Contains 6 Parts, 79 Questions, and 180 Points Total
Reach for the Stars *** Practice Test 2020-2021 Season Answer Key Information • This exam contains 6 parts, 79 questions, and 180 points total. • You may take this test apart. Put your team number on each page. There is not a separate answer page, so write all answers on this exam. • You are permitted the resources specified on the 2021 rules. • Don't worry about significant figures, use 3 or more in your answers. However, be sure your answer is in the correct units. • For calculation questions, any answers within 10% (inclusive) of the answer on the key will be accepted. • Ties will be broken by section score in reverse order (i.e. Section F score is the first tiebreaker, Section A the last). • Written by RiverWalker88. Feel free to PM me if you have any questions, feedback, etc. • Good Luck! Reach for the stars! Reach for the Stars B Team #: Constants and Conversions CONSTANTS Stefan-Boltzmann Constant = σ = 5:67 × 10−8 W=m2K4 Speed of light = c = 3 × 108m/s 30 Mass of the sun = M = 1:99 × 10 kg 5 Radius of the sun = R = 6:96 × 10 km Temperature of the sun = T = 5778K 26 Luminosity of the sun = L = 3:9 × 10 W Absolute Magnitude of the sun = MV = 4.83 UNIT CONVERSIONS 1 AU = 1:5 × 106km 1 ly = 9:46 × 1012km 1 pc = 3:09 × 1013km = 3.26 ly 1 year = 31557600 seconds USEFUL EQUATIONS 2900000 Wien's Law: λ = peak T • T = Temperature (K) • λpeak = Peak Wavelength in Blackbody Spectrum (nanometers) 1 Parallax: d = p • d = Distance (pc) • p = Parallax Angle (arcseconds) Page 2 of 13Page 13 Reach for the Stars B Team #: Part A: Astrophotographical References 9 questions, 18 points total For each of the following, identify the star or deep space object pictured in the image. -
Existence and Importance of Magnetic Fields in Tight Pairs and Groups of Galaxies 15 3 Summary of the Published Articles 17 3.1
EXISTENCEANDIMPORTANCEOFMAGNETICFIELDSIN TIGHTPAIRSANDGROUPSOFGALAXIES błazej˙ nikiel-wroczynski´ A PhD thesis written under the supervision of Professor Marek Urbanik and co-supervision of Doctor Marek Jamrozy Astronomical Observatory Faculty of Physics, Astronomy and Applied Computer Science Jagiellonian University June 2015 Błazej˙ Nikiel-Wroczy´nski: Existence and importance of magnetic fields in tight pairs and groups of galaxies, © June 2015 supervisors: Prof. dr hab. Marek Urbanik Dr Marek Jamrozy alma mater: Jagiellonian University, Faculty of Physics, Astronomy and Applied Computer Science Dedication This work is dedicated to Rugia for being (probably unknowingly) an Earth-based analogue of the MHD dynamo, that amplified my determination to collect all the presented articles into one thesis, transferring the kinetic energy of my turbulent movements into a genuinely regular (not just anisotropic), scientific dissertation. ABSTRACT This dissertation is an attempt to investigate the existence and role of the intergalactic magnetic fields in compact groups and tight pairs of galaxies. Radio emission from several, well known objects of these types is analysed and properties of the discovered intergalactic mag- netised structures are discussed. Together, these results are used to show that wherever found, intergalactic magnetic fields play impor- tant role in the galactic dynamics and evolution. Non-thermal, in- tergalactic radio emission, which signifies existence of the magnetic fields, can be used as a very sensitive tracer of interactions and gas flows. Unusual magnetised objects and structures can be found in the intergalactic space, and their studies open a possibility to discover more about the cosmic magnetism itself. v PUBLICATIONS This dissertation has been written as a summary of the scientific ac- tivities previously reported in these articles: • Nikiel-Wroczy ´nski,B., Jamrozy, M., Soida, M., Urbanik, M., Multiwavelength study of the radio emission from a tight galaxy pair Arp 143, 2014, MNRAS, 444, 1729 • Nikiel-Wroczy ´nski,B., Soida, M., Bomans, D.