DOCSLIB.ORG

Multi-Color Photometry of Supergiants and Cepheids

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Multi-Color Photometry of Supergiants and Cepheids https://ntrs.nasa.gov/search.jsp?R=19710016472 2020-03-23T15:41:27+00:00Z X-641-71-184 $" 'PREPRINT MULTI-COLOR PHOTOMETRY OF SUPERGIANTS AND CEPHEIDS THOMAS KELSALL MAY 1971 S~z5-p ----- GODARDd SPACE-48,wFLIGHT -CENTER GREENBELT, MARYLAND -30- (NASA CKUKOTMX OR AD NUMBER) (CATEGORY) LLTGOY MULTI-COLOR PHOTOMETRY OF SUPERGIATS AND CEPHEIDS by Thomas Kelsall Dissertation submitted to the Faculty of the Graduate School of the University of Maryland in partial fulfillment of the requirements for the degree of Doctor of Philosophy 1971 ABSTRACT Title of Thesis: Multi-color Photometry of Supergiants and Cepheids Thomas Kelsall, Doctor of Philosophy, 1971 Thesis directed by: Roger A. Bell, Associate Professor of Astronomy The results of photometry of supergiants and cepheids in a seven filter system are presented. A color index is used in combination with other colors to produce four indices freed from the effects of inter­ stellar reddening. These four indices give measures of the Balmer discontinuity, effects of the metallic line absorption in the violet region of the spectra, break in the spectrum across the G-band, and the strength of the cyanogen band head at 4216. The separation of supergiants from stars of other luminosity classes is possible. This is performed by a non-linear mapping of the colors onto an M ,logT H-R diagram. Population discrimination for cepheids appears impossible from a study of the colors. However, it is shown that the values of various color-color loop areas can be used to distinguish cepheids of Pop. I and Pop. II. This procedure is superior as it is independent of interstellar reddening. The Balmer discontinuity index for supergiants and cepheids is insensitive to the effects of line blanketing. We speculate that this will allow for a precise calibration in terms of gravity. The strengths of the metallic line absorption and CN absorption are strongly corre­ lated. No obvious correlation is found between galactic position and and chemical composition, as indicated from the strength of the metallic line index. DEDICATION I dedicate this thesis to two gentlemen who gave me much for which I am thankfnl -­ my father Mr. Bernard Kelsall my teacher and friend Dr. Uco Van Wijk ii ACkNOWLEDGEMENTS I offer sincere thanks to Dr. Roger A. Bell, my advisor, for the giving of his critical insights, time, and patience. I am grateful to Dr. Nicholas U. Mayall, Director of Kitt Peak National Observatory, for the opportunity to use the facilitids of his observatory. I also thank the observatory staff for their assistance and friendliness, and in particular, Dr. David L. Crawford, Mrs' Jeannette Barnes, and Mr. J. C. Golson. For the reading of the manuscript and helpful advice I thank the Drs. Donat Wentzel and Michael A'Hearn. Acknowledgement is made to Dr. Richard J. Drachman and Dr. Bengt Strimgren for their many useful discussions. Mr. Andrew Butz and Mr. Charles Mahaffey gave aid in the reading of the charts, proof reading of the punched data, and numerous othe assistances for which I am thankful. To my wife Ann I offer appreciation for the aid given, both direct and indirect. "Opereted by the Association of Universities for Research in Astronomy, Inc., under contract with the National Science Foundation. iii TABLE OF CONTENTS Chapter Page DEDICATION . ii ACKNOWLEDGEMENTS ................................................ iii I INTRODUCTION .1 1-1. Preamble .......................................... 1 1-2. Theoretical Work and Its Motivational Basis ....... 1 1-3. Basic Cepheid Parameters from Observations ....... 16 1-4. Intrinsic Colors .................................. 35 1-5. Aims of the Investigation ......................... 37 II. THE OBSERVATIONS.......................................... 49 2-1. The Filters....................................... 49 2-2. Equipment and Data Gathering...................... 50 III. TIE STANDARD SYSTEM....................................... 58 3-1. Photometric Quantities............................ 58 3-2. Basic Processing Procedure ...................... 59 3-3. Construction of the Observational System's Standards......................................... 61 5-4. Final Comments................................... 65 IV. ORDINARY,STAR RESULTS..................................... 76 4-1. Reduction and Results............................. 76 4-2. Mode of Analysis.................................. 76 4-3. Color Excess Ratios............................... 79 4-4. Bracketed Colors Versus Spectral Type............. 82 4-5. Intrinsic Values for (b-y) and G .................. 83 4-6. Physical Meaning of [G] and [N] ................... 84 iv Chapter Page V. LUMINOSITY CLASSIFICATION.................................. 107 5-1. Objective and Procedure ............................ 107 5-2. Source of the Data .................................. 107 5-5. Color-Spectral Type Relationships .................. 109 5-4- Supergiant Discriminants ........................... 111 VI. BASIC CEPHEID RESULTS....................................... 129 6-1. Photometry and Data ................................ 129 6-2. The Periods .............................. .... .... 129 6-3. Color-Phase Results ................................ 132 6-4. Comparison with the Supergiants.................... 132 6-5. A Population II Discriminant....................... 133 6-6. (b-y) Color Excesses ............................... 134 6-7. (b-y)0 and the Effective Temperature............... 136 VII. COMBINED CEPEEID-SUPERGIANT RESULTS........................ 169 7-1. The 'Supercolor' Method ............................ 169 7-2. Comparison of the Cepheid and Supergiant Mean Colors ......................................... 172 7-3. Metal Content and Galactic Structure ............... 175 7-. Comments on Williams' Work ......................... 173 7-5. Conclusions ........................................ 175 APPENDIX A. STAR IDENTIFICATIONS ................................. 195 APPENDIX B. DATA FROM WILLIAMS AND STROMOREN ..................... 205 APPENDIX C. COEFFICIENTS OF THE SUPEECOLORS ...................... 216 LITERATURE CITED .................................................. 218 LIST OF TABLES Table Page 1.1. Slope of the P-L relation for SMC cepheids ................ 42 1.2. Physical properties of classical cepheids ................. 43 2.1. Transmission characteristics of the filters used in this investigation ........................................ 53 2.2. Comparison of the transmission characteristics of uvby filter sets No. 1 and.No. 2 ............................... 54 2.3. Summary of the observational runs at Kitt Peak National Observatory ............................................... 55 3.1. The color-extinction coefficients ........................ 65 3.2. Observations of the standard stars........................ 66 3.3. Standard star probable errors ........................... 70 4.1. Observations of the ordinary stars....................... 86 4.2. Effective wavelengths .................................... 98 4.3. Color excess ratios from external sources................ 98 4.4. Color excess ratios determined from cepheids at maximum light..................................................... 99 4.5. Color excess ratios determined from free parameter fitting ................................................... 99 4.6. Final adopted color excess ratios ......................... 99 5.1. The mean reddening-free colors for all luminosity classes ................................................... 114 5.2. RDMS dispersions in the mean colors at any spectral type ... 18 6.1. Observations of the cepheids .............................. 138 6.2. Cepheid periods ........................................... 149 6.3. Cepheid color excesses determined from using the relation - G0 = 0.543*(b-y)0 -,0.1l0 ...................... 151 7-1. Deviations of the FO to KO supergiants about the mean color lines defined with [G] as independent coordinate.... 178 vi vii Table Page 7.2. Average deviations of the Pop. I cepheids about the mean color lines defined with [G] as independent coordinate ................................................ 182 7.3. Reanalysis of Williams' long period cepheid data ......-.... 184 A.1. Catalog of identificatioa data for the program stars ...... 196 BA1. Comparison of Williams' original and transformed reddening-free colors to those of Kelsall's ................ 206 B.2. Comparison of Stromgren's original and transformed reddening-free colors to those of Kelsall's ................ 210 0.1. The Mv.upercolor coefficients for the various [G] regions .................................................... 217 LIST OF FIGURES Figure Page 1.1. Magnitude differences versus relative surface displacements at points of equal color for 6 Cep ......... 44 1.2. Comparison of the observed and computed light curves for 8 Cep .............. .......................... 44 1.3. Observed and computed line profiles for weak Fe I lines in p Aql .......................................... 45 1.4. Contribution of various regions in a star to the maintenance of pulsation ................................. 45 1.5. Variation with temperature of the V and B magnitudes for black-bodies. The observed dependence of the mean V and B magnitudes with period ................................. 46 1.6. Location of the F, G and K supergiants and the cepheid S Sge in a six-color (V-B),(R-I) diagram ................. 47 1.7. Determination of the (B-V) color excess through the use of r photometry ...................................... 48 2.1.
Load more

Recommended publications
  • September 2020 BRAS Newsletter
    A Neowise Comet 2020, photo by Ralf Rohner of Skypointer Photography Monthly Meeting September 14th at 7:00 PM, via Jitsi (Monthly meetings are on 2nd Mondays at Highland Road Park Observatory, temporarily during quarantine at meet.jit.si/BRASMeets). GUEST SPEAKER: NASA Michoud Assembly Facility Director, Robert Champion What's In This Issue? President’s Message Secretary's Summary Business Meeting Minutes Outreach Report Asteroid and Comet News Light Pollution Committee Report Globe at Night Member’s Corner –My Quest For A Dark Place, by Chris Carlton Astro-Photos by BRAS Members Messages from the HRPO REMOTE DISCUSSION Solar Viewing Plus Night Mercurian Elongation Spooky Sensation Great Martian Opposition Observing Notes: Aquila – The Eagle Like this newsletter? See PAST ISSUES online back to 2009 Visit us on Facebook – Baton Rouge Astronomical Society Baton Rouge Astronomical Society Newsletter, Night Visions Page 2 of 27 September 2020 President’s Message Welcome to September. You may have noticed that this newsletter is showing up a little bit later than usual, and it’s for good reason: release of the newsletter will now happen after the monthly business meeting so that we can have a chance to keep everybody up to date on the latest information. Sometimes, this will mean the newsletter shows up a couple of days late. But, the upshot is that you’ll now be able to see what we discussed at the recent business meeting and have time to digest it before our general meeting in case you want to give some feedback. Now that we’re on the new format, business meetings (and the oft neglected Light Pollution Committee Meeting), are going to start being open to all members of the club again by simply joining up in the respective chat rooms the Wednesday before the first Monday of the month—which I encourage people to do, especially if you have some ideas you want to see the club put into action.
    [Show full text]
  • Referierte Publikationen
    14 Publikationslisten Referierte Publikationen Abbott, T.M.C., M. Aguena, A. Alarcon, S. Allam, S. Allen, J. Granot, D. Green, I.A. Grenier, M.-H. Grondin, S. Guiriec, J. Annis, S. Avila, D. Bacon, K. Bechtol, A. Bermeo, G.M. E. Hays, D. Horan, G. Jóhannesson, D. Kocevski, M. Kova- Bernstein, E. Bertin, S. Bhargava, S. Bocquet, D. Brooks, D. cevic, M. Kuss, S. Larsson, L. Latronico, M. Lemoine-Gou- Brout, E. Buckley-Geer, D.L. Burke, A. Carnero Rosell, M. mard, J. Li, I. Liodakis, F. Longo, F. Loparco, M.N. Lovel- Carrasco Kind, J. Carretero, F.J. Castander, R. Cawthon, C. lette, P. Lubrano, S. Maldera, D. Malyshev, A. Manfreda, Chang, X. Chen, A. Choi, M. Costanzi, M. Crocce, L.N. da G. Martí-Devesa, M.N. Mazziotta, J.E. McEnery, I. Mereu, Costa, T.M. Davis, J. de Vicente, J. de Rose, S. Desai, H.T. M. Meyer, P.F. Michelson, W. Mitthumsiri, T. Mizuno, Diehl, J.P. Dietrich, S. Dodelson, P. Doel, A. Drlica-Wagner, M.E. Monzani, E. Moretti, A. Morselli, I.V. Moskalenko, K. Eckert, T.F. Eifl er, J. Elvin-Poole, J. Estrada, S. Everett, M. Negro, E. Nuss, N. Omodei, M. Orienti, E. Orlando, M. A.E. Evrard, A. Farahi, I. Ferrero, B. Flaugher, P. Fosalba, Palatiello, V.S. Paliya, D. Paneque, Z. Pei, M. Persic, M. J. Frieman, J. García-Bellido, M. Gatti, E. Gaztanaga, D.W. Pesce-Rollins, V. Petrosian, F. Piron, H. Poon, T.A. Porter, Gerdes, T. Giannantonio, P. Giles, S. Grandis, D. Gruen, G. Principe, J.L.
    [Show full text]
  • 283 — 12 July 2016 Editor: Bo Reipurth ([email protected]) List of Contents
    THE STAR FORMATION NEWSLETTER An electronic publication dedicated to early stellar/planetary evolution and molecular clouds No. 283 — 12 July 2016 Editor: Bo Reipurth ([email protected]) List of Contents The Star Formation Newsletter Interview ...................................... 3 Perspective .................................... 5 Editor: Bo Reipurth [email protected] Abstracts of Newly Accepted Papers ........... 9 Technical Editor: Eli Bressert Abstracts of Newly Accepted Major Reviews . 33 [email protected] Dissertation Abstracts ........................ 34 Technical Assistant: Hsi-Wei Yen New Jobs ..................................... 35 [email protected] Meetings ..................................... 37 Editorial Board Summary of Upcoming Meetings ............. 37 Joao Alves Alan Boss Jerome Bouvier Lee Hartmann Thomas Henning Cover Picture Paul Ho Jes Jorgensen The image, obtained with the Hubble Space Tele- Charles J. Lada scope, shows photoevaporating globules embedded Thijs Kouwenhoven in the Carina Nebula. Michael R. Meyer Image courtesy NASA, ESA, N. Smith (University Ralph Pudritz of California, Berkeley), and The Hubble Heritage Luis Felipe Rodr´ıguez Team (STScI/AURA) Ewine van Dishoeck Hans Zinnecker The Star Formation Newsletter is a vehicle for fast distribution of information of interest for as- tronomers working on star and planet formation Submitting your abstracts and molecular clouds. You can submit material for the following sections: Abstracts of recently Latex macros for submitting abstracts
    [Show full text]
  • On the Binary Orbit of Henry Draper One (HD 1)
    Received <day> <Month>, <year>; Revised <day> <Month>, <year>; Accepted <day> <Month>, <year> DOI: xxx/xxxx ORIGINAL PAPER On the binary orbit of Henry Draper one (HD 1) Klaus G. Strassmeier* | Michael Weber* 1Leibniz-Institute for Astrophysics Potsdam (AIP), An der Sternwarte 16, D-14482 Abstract Potsdam, Germany We present our final orbit for the late-type spectroscopic binary HD 1. Employed Correspondence are 553 spectra from 13 years of observations with our robotic STELLA facility *Email: [email protected], Email: and its high-resolution echelle spectrograph SES. Its long-term radial-velocity sta- [email protected] bility is ù50 m s*1. A single radial velocity of HD 1 reached a rms residual of 63 m s*1, close to the expected precision. Spectral lines of HD 1 are rotationally broadened with v sin i of 9.1,0.1 km s*1. The overall spectrum appears single-lined and yielded an orbit with an eccentricity of 0.5056,0.0005 and a semi-amplitude of 4.44 km s*1. We constrain and refine the orbital period based on the SES data alone to 2318.70,0.32 d, compared to 2317.8,1.1 d when including the older data set published by DAO and Cambridge/Coravel. Owing to the higher precision of the SES data, we base the orbit calculation only on the STELLA/SES velocities in order not to degrade its solution. We redetermine astrophysical parameters for HD 1 from spectrum synthesis and, together with the new Gaia DR-2 parallax, suggest a higher luminosity than published previously.
    [Show full text]
  • Astrophysics
    Publications of the Astronomical Institute rais-mf—ii«o of the Czechoslovak Academy of Sciences Publication No. 70 EUROPEAN REGIONAL ASTRONOMY MEETING OF THE IA U Praha, Czechoslovakia August 24-29, 1987 ASTROPHYSICS Edited by PETR HARMANEC Proceedings, Vol. 1987 Publications of the Astronomical Institute of the Czechoslovak Academy of Sciences Publication No. 70 EUROPEAN REGIONAL ASTRONOMY MEETING OF THE I A U 10 Praha, Czechoslovakia August 24-29, 1987 ASTROPHYSICS Edited by PETR HARMANEC Proceedings, Vol. 5 1 987 CHIEF EDITOR OF THE PROCEEDINGS: LUBOS PEREK Astronomical Institute of the Czechoslovak Academy of Sciences 251 65 Ondrejov, Czechoslovakia TABLE OF CONTENTS Preface HI Invited discourse 3.-C. Pecker: Fran Tycho Brahe to Prague 1987: The Ever Changing Universe 3 lorlishdp on rapid variability of single, binary and Multiple stars A. Baglln: Time Scales and Physical Processes Involved (Review Paper) 13 Part 1 : Early-type stars P. Koubsfty: Evidence of Rapid Variability in Early-Type Stars (Review Paper) 25 NSV. Filtertdn, D.B. Gies, C.T. Bolton: The Incidence cf Absorption Line Profile Variability Among 33 the 0 Stars (Contributed Paper) R.K. Prinja, I.D. Howarth: Variability In the Stellar Wind of 68 Cygni - Not "Shells" or "Puffs", 39 but Streams (Contributed Paper) H. Hubert, B. Dagostlnoz, A.M. Hubert, M. Floquet: Short-Time Scale Variability In Some Be Stars 45 (Contributed Paper) G. talker, S. Yang, C. McDowall, G. Fahlman: Analysis of Nonradial Oscillations of Rapidly Rotating 49 Delta Scuti Stars (Contributed Paper) C. Sterken: The Variability of the Runaway Star S3 Arietis (Contributed Paper) S3 C. Blanco, A.
    [Show full text]
  • February 2008 Volume 33 Number 1
    login_february08_covers.qxp:login covers 1/22/08 1:38 PM Page 1 FEBRUARY 2008 VOLUME 33 NUMBER 1 OPINION Musings 2 RIK FARROW SYSADMIN Fear and Loathing in the Routing System 5 JOE ABLEY THE USENIX MAGAZINE From x=1 to (setf x 1): What Does Configuration Management Mean? 12 ALVA COUCH http:BL: Taking DNSBL Beyond SMTP 19 ERIC LANGHEINRICH Centralized Package Management Using Stork 25 JUSTIN SAMUEL, JEREMY PLICHTA, AND JUSTIN CAPPOS Managing Distributed Applications with Plush 32 JEANNIE ALBRECHT, RYAN BRAUD, DARREN DAO, NIKOLAY TOPILSKI, CHRISTOPHER TUTTLE, ALEX C. SNOEREN, AND AMIN VAHDAT An Introduction to Logical Domains 39 OCTAVE ORGERON PROGRAMMING Insecurities in Designing XML Signatures 48 ADITYA K SOOD COLUMNS Practical Perl Tools: Why I Live at the P.O. 54 DAVID N. BLANK-EDELMAN Pete’s All Things Sun (PATS): The Future of Sun 61 PETER BAER GALVIN iVoyeur: Permission to Parse 65 DAVID JOSEPHSEN /dev/random 72 ROBERT G. FERRELL Toward Attributes 74 NICK STOUGHTON BOOK REVIEWS Book Reviews 78 ÆLEEN FRISCH, BRAD KNOWLES, AND SAM STOVER USENIX NOTES 2008 USENIX Nominating Committee Report 82 MICHAEL B. JONES AND DAN GEER Summary of USENIX Board of Directors Meetings and Actions 83 ELLIE YOUNG New on the USENIX Web Site: The Multimedia Page 83 ANNE DICKISON CONFERENCE LISA ’07: 21st Large Installation SUMMARIES System Administration Conference 84 The Advanced Computing Sytems Association login_february08_covers.qxp:login covers 1/17/08 12:11 PM Page 2 Upcoming Events 2008 ACM INTERNATIONAL CONFERENCE ON 2ND INTERNATIONAL CONFERENCE ON
    [Show full text]
  • Thesis Is Closely Related to This Question
    UvA-DARE (Digital Academic Repository) The processing and evolution of dust in Herbig Ae/Be systems. Bouwman, J. Publication date 2001 Document Version Final published version Link to publication Citation for published version (APA): Bouwman, J. (2001). The processing and evolution of dust in Herbig Ae/Be systems. General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. UvA-DARE is a service provided by the library of the University of Amsterdam (https://dare.uva.nl) Download date:10 Oct 2021 Thee processing and evolution of dustt in Herbig Ae/Be systems Jeroenn Bouwman Thee processing and evolution of dust in Herbig Ae/Be systems s Thee processing and evolution of dust in Herbig Ae/Be systems s Dee evolutie van stof in Herbig Ae/Be systemen. Academischh Proefschrift terr verkrijging van de graad van doctor aann de Universiteit van Amsterdam, opp gezag van de Rector Magnificus prof.
    [Show full text]
  • Spitzer Approved Galactic Spitzer Approved Galactic
    Printed_by_SSC Mar 25, 10 16:33Spitzer_Approved_Galactic Page 1/847 Mar 25, 10 16:33Spitzer_Approved_Galactic Page 2/847 Spitzer Space Telescope − Archive Research Proposal #20309 Spitzer Space Telescope − Archive Research Proposal #30144 PAH Emission Features in the 15 to 20 Micron Region: Emitting to the Beat of a Diamonds are a PAHs Best Friend Different Drummer Principal Investigator: Louis Allamandola Principal Investigator: Louis Allamandola Institution: NASA Ames Research Center Institution: NASA Ames Research Center Technical Contact: Louis Allamandola, NASA Ames Research Center Technical Contact: Louis Allamandola, NASA Ames Research Center Co−Investigators: Co−Investigators: Andrew Mattioda, SETI Andrew Mattioda, SETI Institute and NASA Ames Els Peeters, SETI Els Peeters, NASA Ames Research Center Douglas Hudgins, NASA Ames Research Center Douglas Hudgins, NASA Ames Research Center Alexander Tielens, NASA Ames Research Center Xander Tielens, Kapteyn Institute, The Netherlands Charles Bauschlicher, Jr., NASA Ames Research Center Charlie Bauschlicher, Jr., NASA Ames Research Center Science Category: ISM Science Category: ISM Dollars Approved: 56727.0 Dollars Approved: 72000.0 Abstract: Abstract: The mid−IR spectroscopic capabilities and unprecedented sensitivity of the Spitzer has added a new complex of bands near 17 um to the PAH emission band Spitzer Space Telescope has shown that the ubiquitious infrared (IR) emission family. This 17 um band complex, the second most intense of the PAH features, features can be used as probes of many galactic and extragalactic objects. carries unique information about the emitting species. Because these bands arise These features, formerly called the Unidentified Infrared (UIR) Bands, are now from drumhead vibrations of the hexagonal carbon skeleton, they carry generally attributed to the vibrational emission from polycyclic aromatic information directly related to PAH shape, size, and charge.
    [Show full text]
  • Consistent Scenarios for Cosmic-Ray Excesses from Sommerfeld-Enhanced Dark Matter Annihilation
    Prepared for submission to JCAP Consistent Scenarios for Cosmic-Ray Excesses from Sommerfeld-Enhanced Dark Matter Annihilation Douglas P. Finkbeinera,b Lisa Goodenoughc Tracy R. Slatyera,b,d Mark Vogelsbergera Neal Weinerc,d aHarvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USA bPhysics Department, Harvard University, Cambridge, MA 02138, USA cCenter for Cosmology and Particle Physics, Department of Physics, New York University, New York, NY 10003, USA dSchool of Natural Sciences, Institute for Advanced Study, Princeton, NJ 08540, USA E-mail: [email protected] Abstract. Anomalies in direct and indirect detection have motivated models of dark matter consisting of a multiplet of nearly-degenerate states, coupled by a new GeV-scale interaction. We perform a careful analysis of the thermal freezeout of dark matter annihilation in such a scenario. We compute the range of “boost factors” arising from Sommerfeld enhancement in the local halo for models which produce the correct relic density, and show the effect of including constraints on the saturated enhancement from the cosmic microwave background (CMB). We find that boost factors from Sommerfeld enhancement of up to 800 are possible ∼ in the local halo. When the CMB bounds on the saturated enhancement are applied, the maximal boost factor is reduced to 400 for 1-2 TeV dark matter and sub-GeV force ∼ carriers, but remains large enough to explain the observed Fermi and PAMELA electronic signals. We describe regions in the DM mass-boost factor plane where the cosmic ray data is well fit for a range of final states, and show that Sommerfeld enhancement alone is enough to provide the large annihilation cross sections required to fit the data, although for light arXiv:1011.3082v2 [hep-ph] 12 Apr 2011 mediator masses (mφ .
    [Show full text]
  • V. Oxygen Abundance in the Metal-Poor Giant HD 122563 from OH UV Lines
    A&A 599, A128 (2017) Astronomy DOI: 10.1051/0004-6361/201629306 & c ESO 2017 Astrophysics Three-dimensional hydrodynamical CO5BOLD model atmospheres of red giant stars V. Oxygen abundance in the metal-poor giant HD 122563 from OH UV lines D. Prakapaviciusˇ 1, A. Kucinskasˇ 1; 2, V.Dobrovolskas1, J. Klevas1, M. Steffen3; 4, P.Bonifacio4, H.-G. Ludwig4; 5, and M. Spite4 1 Institute of Theoretical Physics and Astronomy, Vilnius University, Sauletekio˙ al. 5, 10221 Vilnius, Lithuania e-mail: [email protected] 2 Astronomical Observatory, Vilnius University, M. K. Ciurlionioˇ 29, 03100 Vilnius, Lithuania 3 Leibniz-Institut für Astrophysik Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany 4 GEPI, Observatoire de Paris, CNRS, Université Paris Diderot, Place Jules Janssen, 92190 Meudon, France 5 Landessternwarte – Zentrum für Astronomie der Universität Heidelberg, Königstuhl 12, 69117 Heidelberg, Germany Received 13 July 2016 / Accepted 9 November 2016 ABSTRACT Context. Although oxygen is an important tracer of the early Galactic evolution, its abundance trends with metallicity are still rela- tively poorly known at [Fe=H] . −2:5. This is in part due to a lack of reliable oxygen abundance indicators in the metal-poor stars, and in part due to shortcomings in 1D LTE abundance analyses where different abundance indicators, such as OH lines located in the UV and IR or the forbidden [O I] line at 630 nm, frequently provide inconsistent results. Aims. In this study, we determined the oxygen abundance in the metal-poor halo giant HD 122563 using a 3D hydrodynamical CO5BOLD model atmosphere. Our main goal was to understand whether a 3D LTE analysis can help to improve the reliability of oxygen abundances that are determined from OH UV lines in comparison to those obtained using standard 1D LTE methodology.
    [Show full text]
  • Xerox University Microfilms 300 North Zeeb Road Ann Arbor, Michigan 48106 76-21,100
    THE MAGNETIC FIELD STRUCTURE AND EMBEDDED STELLAR POPULATION OF DARK CLOUD COMPLEXES Item Type text; Dissertation-Reproduction (electronic) Authors Vrba, Frederick John, 1949- Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 06/10/2021 05:15:52 Link to Item http://hdl.handle.net/10150/289404 INFORMATION TO USERS This material was produced from a microfilm copy of the original document. While the most advanced technological means to photograph and reproduce this document have been used, the quality is heavily dependent upon the quality of the original submitted. The following explanation of techniques is provided to help you understand markings or patterns which may appear on this reproduction. 1.The sign or "target" for pages apparently lacking from the document photographed is "Missing Page(s)". If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting thru an image and duplicating adjacent pages to insure you complete continuity. 2. When an image on the film is obliterated with a large round black mark, it is an indication that the photographer suspected that the copy may have moved during exposure and thus cause a blurred image. You will find a good image of the page in the adjacent frame. 3. When a map, drawing or chart, etc., was part of the material being photographed the photographer followed a definite method in "sectioning" the material.
    [Show full text]
  • Spectroscopic Ananlyses of the Planetary System Candidates: 55 Cnc, 51 Peg, 47 Uma, 70 Vir, and HD 114762
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by CERN Document Server Spectroscopic Ananlyses of the Planetary System Candidates: 55 Cnc, 51 Peg, 47 UMa, 70 Vir, and HD 114762 Guillermo Gonzalez Department of Astronomy, University of Texas, Austin, TX 78712 Received ; accepted –2– ABSTRACT The stars 55 Cnc, 51 Peg, 47 UMa, 70 Vir, and HD 114762 have recently been proposed to harbor planetary mass companions. Using spectroscopic methods we find that 55 Cnc and 51 Peg are super metal-rich, 47 UMa and 70 Vir have roughly solar metallicities, and HD 114762 is metal-poor. Otherwise, the abundance patterns, expressed as [X/Fe], are approximately solar. The ages of 47 UMa and 51 Peg are similar to that of the Sun; 70 Vir is slightly older, and 55 Cnc and HD 114762 are at least 10 Gyrs old. Our estimates of v sin i for the parent stars are 1.4 ± 0.5, 1.8 ± 0.4, 2.0 ± 0.3, < 1, and < 1.5 km s−1 for 55 Cnc, 51 Peg, 47 UMa, 70 Vir, and HD 114762, respectively. Using these data and estimates for the rotation periods and radii, the corresponding masses +0.22 of the companions are: > 0.6, 0.51−0.03,4.6±1.0, > 20, and > 8.5 MJ.The systems appear to fall into three groups: roughly Jupiter mass companions with small circular orbits with metal-rich parent stars (55 Cnc and 51 Peg), larger companions with larger circular orbits (47 UMa), and much more massive companions with large eccentric orbits orbiting moderately metal-poor parent stars (70 Vir and HD 114762).
    [Show full text]