DOCSLIB.ORG

Structure of the Obscured Galactic Disk with Pulsating Variables

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

STRUCTURE OF THE OBSCURED GALACTIC DISK WITH PULSATING VARIABLES Gergely Hajdu FACULTAD DE FÍSICA INSTITUTO DE ASTROFÍSICA STRUCTURE OF THE OBSCURED GALACTIC DISK WITH PULSATING VARIABLES BY GERGELY HAJDU Thesis submitted to the Faculty of Physics at Pontificia Universidad Católica de Chile in partial fulfillment of the requirements for the degree of Doctor in Astrophysics Thesis submitted to the Combined Faculties for the Natural and for Mathematics of the Ruperto-Carola University of Heidelberg for the degree of Doctor of Natural Sciences Thesis Advisor MÁRCIO CATELAN Santiago de Chile, September 2019 c MMXIX, GERGELY HAJDU Se autoriza la reproducción total o parcial, con fines académicos, por cualquier medio o procedimiento, incluyendo la cita bibliográfica del documento. FACULTAD DE FÍSICA INSTITUTO DE ASTROFÍSICA STRUCTURE OF THE OBSCURED GALACTIC DISK WITH PULSATING VARIABLES BY GERGELY HAJDU Members of the Committee Márcio Catelan (IA – PUC) Eva K. Grebel (ARI – UH) Mario Trieloff (GEOW – UH) Thomas H. Puzia (IA – PUC) Manuela Zoccali (IA – PUC) Santiago de Chile, September 2019 c MMXIX, GERGELY HAJDU ACKNOWLEDGEMENTS I would like to thank all the support I have received during the wonderful years I have spent at the Pontificia Universidad Católica de Chile, Santiago, as well as during my one year exchange at the Astronomisches Rechen-Institut der Universität Heidelberg. First and foremost, I would like to thank my supervisor, Prof. Márcio Catelan, for all the support, encouragement, and motivation I have received from him. Secondly, I am also deeply thankful for my co-advisor and exchange host, Prof. Eva Grebel, for allowing me to spend a very productive, wonderful year in Heidelberg. The work presented in this thesis would not have been possible without that of Dr. István Dékány. We started working together on VVV data at Católica, and continued to do so after he moved to Heidelberg, which has resulted in all the results presented here. I cannot overstate his inspirational effect on my work, as well on my development as an astronomer. I would like to thank my mother for all the patience she has displayed while I was con- ducting my studies in Chile and Germany. I cannot end the acknowledgements without mentioning my comrades among the stu- dents, both at the IA, as well as at the ARI. At the former, I could always count upon Diego Calderón, Rodrigo Carvajal, Camila Navarrete, Katerine Joachimi, and many others, to have stimulating conversations about our research, as well as just to remind ourselves to relax, and spend time together, in order to ease our minds of the everyday stress experienced by the majority of students, in this otherwise unforgiving academic environment. During my time at ARI, I have received much support from Michael Hanke, Zdenek Prudil and Josefina Michea in the daily goings of both the university, as well as Heidelberg. I would like to thank my officemates at ARI, Bekdaulet Shukirgaliyev and Clio Bertelli Motta for a wonderful time. Finally, I would like to acknowledge the “First La Serena School for Data Science"", where I have been introduced for the first time to many of the statistical and data science methods iv ACKNOWLEDGEMENTS v utilized throughout this thesis. In this endevour, the book “Statistics, Data Mining, and Ma- chine Learning in Astronomy” (Ivezić et al. 2014) has also been indispensable. During my studies, I have been financially supported by CONICYT-PCHA (Doctorado Nacional 2014-63140099), by the Graduate Student Exchange Fellowship Program between the Institute of Astrophysics of the Pontificia Universidad Católica de Chile and the Zentrum für Astronomie der Universität Heidelberg, funded by the Heidelberg Center in Santiago de Chile and the Deutscher Akademischer Austauschdienst, as well as by the Ministry for Econ- omy, Development, and Tourism’s Programa Iniciativa Milenio through grant IC1200009. Additional support is acknowledged by Proyecto Basal PFB-06/2007 and AFB-170002, by FONDECYT grants #1141141 and #1171273, by CONICYT Anillo grant ACT 1101, by CON- ICYT’s PCI program through grant DPI20140066, and the CONICYT’s “Beca Asistencia a eventos y cursos cortos para estudiantes de doctorado - convocatoria 2015”. Processing and analysis of data were partly performed on the Milky Way supercomputer, which is partly funded by the Sonderforschungsbereich SFB 881 “The Milky Way System” (subproject Z2) of the Deutsche Forschungsgemeinschaft. CONTENTS ACKNOWLEDGEMENTS iv LIST OF TABLES ix LIST OF FIGURES x 1 INTRODUCTION 1 1.1 The Milky Way disk . .1 1.2 RR Lyrae variables . .5 1.3 Cepheid variables . .9 1.4 The VISTA Variables in the Vía Láctea survey . 13 1.5 The layout of the thesis . 14 2 RR LYRAE LIGHT CURVES IN THE NEAR-INFRARED 17 2.1 Light-curve properties of RR Lyrae variables . 17 2.2 Model representation of near-IR RRab light-curves . 21 2.2.1 The light-curve training set . 22 2.2.2 Data preparation . 23 2.2.3 Application of PCA to the KS-band light curves . 27 2.2.4 Approximation of the J-band light curve shape . 32 2.3 Robust fitting of RRL KS-band light curves . 35 2.4 Metallicity estimation from KS-band photometry . 39 2.4.1 VVV photometry of bulge RR Lyrae variables . 40 2.4.2 Revision of I-band RR Lyrae photometric metallicity estimates . 41 2.4.3 Iron abundance estimation from the KS-band light-curve shapes . 48 vi 2.4.4 Validation of the metallicity estimates . 52 3 RR LYRAE VARIABLES IN THE VVV DISK FIELDS 57 3.1 Searching for RR Lyrae stars in the VVV disk fields . 57 3.1.1 The VVV disk data set . 57 3.1.2 Variability and period search . 58 3.1.3 Classification of RRL candidates . 59 3.1.4 Calculation of individual RRL properties . 61 3.2 Properties of the RRL sample . 63 3.2.1 Spatial distribution . 63 3.2.2 Metallicity distribution . 69 3.2.3 Spatial variations in metallicity . 72 3.2.4 Comparison of the MDF to independent results . 75 3.3 Discussion and future directions . 78 4 RECALIBRATION OF VISTA PHOTOMETRY 81 4.1 VVV photometric inconsistencies . 81 4.2 VISTA calibration procedures . 82 4.2.1 The 2MASS Point Source catalog in the VISTA system . 83 4.3 Revision of H-band VISTA observations . 84 4.4 VISTA zero point bias in dense stellar fields . 86 4.5 Recalibration of VVV JHKS observations . 91 4.5.1 Effects of the photometric corrections . 93 4.5.2 Recommendations for future usage of VISTA observations . 96 5 CEPHEIDS IN THE VVV SURVEY 100 5.1 Cepheid search in the corrected VVV photometry . 100 5.1.1 Classification of Cepheid candidates . 101 5.1.2 Cepheid period-luminosity relationships . 105 vii 5.1.3 The near-infrared extinction law . 107 5.2 Distribution of the VVV classical Cepheid sample . 112 5.2.1 Apparent Cepheid pairs . 118 5.3 The radial age trend of VVV Classical Cepheids . 120 5.4 The VVV Classical Cepheids and the spiral arms . 124 5.5 Summary and future outlook . 128 6 CONCLUSIONS 130 6.1 Outlook . 132 AUTHOR’S PUBLICATIONS 134 REFERENCES 138 viii LIST OF TABLES 2.1 Collection of RR Lyrae near-IR photometric observations . 18 2.2 Parameters of the hyperparameter grid search . 50 2.3 Number of RR Lyrae variables in different metallicity bins . 51 3.1 Parameters of the GMM components towards the bulge and the disk . 71 5.1 Candidate Classical Cepheid pairs in the VVV Cepheid sample . 119 ix LIST OF FIGURES 1.1 Face-on map of the atomic hydrogen distribution in the Milky Way disk . .2 1.2 Galactic map of high mass star forming regions with measured parallaxes . .3 1.3 SDSS images of galaxies with warping disks . .4 1.4 Schematic Hertzsprung-Russel diagram of the positions of pulsating variable classes . .6 1.5 UBVIKS light curves of a typical RR Lyrae . .8 1.6 UBVRIJK light curves of a typical Classical Cepheid variable . 10 1.7 Galactic distribution of Classical Cepheids in the local neighborhood . 12 2.1 Example of local LASSO fits of RR Lyrae J and KS light curves . 24 2.2 Comparison of light-curve fits with circular normal and Fourier bases. 26 2.3 KS -band normalized, and J-band zero-point aligned RR Lyrae light curves . 27 2.4 RR Lyrae KS band principal components . 29 2.5 Principal component amplitude distribution . 31 2.6 Residuals of the J-band light-curve approximations . 34 2.7 Continuous Fourier representation of the principal components and the J-band regression coefficients . 35 2.8 Example light-curve fits of RR Lyrae stars . 38 2.9 I-band photometric metallicity distribution of bulge RR Lyrae 1 . 43 2.10 Separation of Oosterhoff classes . 44 2.11 I-band photometric metallicity distribution of bulge RR Lyrae 2 . 45 2.12 Photometric metallicities of bulge RR Lyrae with the Kepler calibration . 47 2.13 The KS-band light-curve parameter – metallicity training sample . 49 2.14 Revision of the KS-band metallicity estimates . 53 x 2.15 RR Lyrae KS band principal components . 55 3.1 Examples of VVV disk RR Lyrae light curves . 60 3.2 Principal component amplitude – period distribution of disk RR Lyrae . 62 3.3 Distribution of VVV disk RR Lyrae on the Galactic plane . 64 3.4 Distribution of VVV disk RR Lyrae in Galactic coordinates . 66 3.5 Color excess and magnitude distribution of disk RR Lyrae . 67 3.6 Galactic height and distance distribution of VVV disk RR Lyrae . 68 3.7 Kernel density estimates of the MDF of the bulge and disk RR Lyrae samples .
Recommended publications
  • Annual Report 2017

    Annual Report 2017

    Koninklijke Sterrenwacht van België Observatoire royal de Belgique Royal Observatory of Belgium Jaarverslag 2017 Rapport Annuel 2017 Annual Report 2017 Cover illustration: Above: One billion star map of our galaxy created with the optical telescope of the satellite Gaia (Credit: ESA/Gaia/DPAC). Below: Three armillary spheres designed by Jérôme de Lalande in 1775. Left: the spherical sphere; in the centre: the geocentric model of our solar system (with the Earth in the centre); right: the heliocentric model of our solar system (with the Sun in the centre). Royal Observatory of Belgium - Annual Report 2017 2 De activiteiten beschreven in dit verslag werden ondersteund door Les activités décrites dans ce rapport ont été soutenues par The activities described in this report were supported by De POD Wetenschapsbeleid De Nationale Loterij Le SPP Politique Scientifique La Loterie Nationale The Belgian Science Policy The National Lottery Het Europees Ruimtevaartagentschap De Europese Gemeenschap L’Agence Spatiale Européenne La Communauté Européenne The European Space Agency The European Community Het Fonds voor Wetenschappelijk Onderzoek – Le Fonds de la Recherche Scientifique Vlaanderen Royal Observatory of Belgium - Annual Report 2017 3 Table of contents Preface .................................................................................................................................................... 6 Reference Systems and Planetology ......................................................................................................
  • Effemeridi Astronomiche Di Milano Per L'anno

    Effemeridi Astronomiche Di Milano Per L'anno

    Informazioni su questo libro Si tratta della copia digitale di un libro che per generazioni è stato conservata negli scaffali di una biblioteca prima di essere digitalizzato da Google nell’ambito del progetto volto a rendere disponibili online i libri di tutto il mondo. Ha sopravvissuto abbastanza per non essere più protetto dai diritti di copyright e diventare di pubblico dominio. Un libro di pubblico dominio è un libro che non è mai stato protetto dal copyright o i cui termini legali di copyright sono scaduti. La classificazione di un libro come di pubblico dominio può variare da paese a paese. I libri di pubblico dominio sono l’anello di congiunzione con il passato, rappresentano un patrimonio storico, culturale e di conoscenza spesso difficile da scoprire. Commenti, note e altre annotazioni a margine presenti nel volume originale compariranno in questo file, come testimonianza del lungo viaggio percorso dal libro, dall’editore originale alla biblioteca, per giungere fino a te. Linee guide per l’utilizzo Google è orgoglioso di essere il partner delle biblioteche per digitalizzare i materiali di pubblico dominio e renderli universalmente disponibili. I libri di pubblico dominio appartengono al pubblico e noi ne siamo solamente i custodi. Tuttavia questo lavoro è oneroso, pertanto, per poter continuare ad offrire questo servizio abbiamo preso alcune iniziative per impedire l’utilizzo illecito da parte di soggetti commerciali, compresa l’imposizione di restrizioni sull’invio di query automatizzate. Inoltre ti chiediamo di: + Non fare un uso commerciale di questi file Abbiamo concepito Google Ricerca Libri per l’uso da parte dei singoli utenti privati e ti chiediamo di utilizzare questi file per uso personale e non a fini commerciali.
  • 197 6Apjs. . .30. .451H the Astrophysical Journal Supplement Series, 30:451-490, 1976 April © 1976. the American Astronomical S

    197 6Apjs. . .30. .451H the Astrophysical Journal Supplement Series, 30:451-490, 1976 April © 1976. the American Astronomical S

    .451H The Astrophysical Journal Supplement Series, 30:451-490, 1976 April .30. © 1976. The American Astronomical Society. All rights reserved. Printed in U.S.A. 6ApJS. 197 EVOLVED STARS IN OPEN CLUSTERS Gretchen L. H. Harris* David Dunlap Observatory, Richmond Hill, Ontario Received 1974 September 16; revised 1975 June 18 ABSTRACT Radial-velocity observations and MK classifications have been used to study evolved stars in 25 open clusters. Published data on stars in 72 additional clusters are rediscussed and com- bined with the observations friade in this investigation to yield positions in the Hertzsprung- Russell diagram for 559 evolved stars in 97 clusters. Ages for the parent clusters were estimated from the main-sequence turnoff points, earliest spectral types, and bluest stars in the clusters themselves. The evolved stars were sorted into six age groups ranging from 4 x 106 yr to 4 x 108 yr, and the composite H-R diagram for each age group was then used to study the evolutionary tracks for stars of various masses. The observational results were found to be in reasonably good agreement with recent theoretical computations. The composite color-magnitude diagrams were found to be strikingly different from those of the rich open clusters in the Magellanic Clouds. At a given age the red giants in the Small Magellanic Cloud and the Large Magellanic Cloud clusters are brighter and bluer than their galactic counterparts. It is suggested that these effects may be accounted for by differences in metal abundance. Subject headings: clusters: open — galaxies: Magellanic Clouds — radial velocities — stars : evolution — stars : late-type — stars : spectral classification 1.
  • Variable Star Classification and Light Curves Manual

    Variable Star Classification and Light Curves Manual

    Variable Star Classification and Light Curves An AAVSO course for the Carolyn Hurless Online Institute for Continuing Education in Astronomy (CHOICE) This is copyrighted material meant only for official enrollees in this online course. Do not share this document with others. Please do not quote from it without prior permission from the AAVSO. Table of Contents Course Description and Requirements for Completion Chapter One- 1. Introduction . What are variable stars? . The first known variable stars 2. Variable Star Names . Constellation names . Greek letters (Bayer letters) . GCVS naming scheme . Other naming conventions . Naming variable star types 3. The Main Types of variability Extrinsic . Eclipsing . Rotating . Microlensing Intrinsic . Pulsating . Eruptive . Cataclysmic . X-Ray 4. The Variability Tree Chapter Two- 1. Rotating Variables . The Sun . BY Dra stars . RS CVn stars . Rotating ellipsoidal variables 2. Eclipsing Variables . EA . EB . EW . EP . Roche Lobes 1 Chapter Three- 1. Pulsating Variables . Classical Cepheids . Type II Cepheids . RV Tau stars . Delta Sct stars . RR Lyr stars . Miras . Semi-regular stars 2. Eruptive Variables . Young Stellar Objects . T Tau stars . FUOrs . EXOrs . UXOrs . UV Cet stars . Gamma Cas stars . S Dor stars . R CrB stars Chapter Four- 1. Cataclysmic Variables . Dwarf Novae . Novae . Recurrent Novae . Magnetic CVs . Symbiotic Variables . Supernovae 2. Other Variables . Gamma-Ray Bursters . Active Galactic Nuclei 2 Course Description and Requirements for Completion This course is an overview of the types of variable stars most commonly observed by AAVSO observers. We discuss the physical processes behind what makes each type variable and how this is demonstrated in their light curves. Variable star names and nomenclature are placed in a historical context to aid in understanding today’s classification scheme.
  • Gaia Data Release 2 Special Issue

    Gaia Data Release 2 Special Issue

    A&A 623, A110 (2019) Astronomy https://doi.org/10.1051/0004-6361/201833304 & © ESO 2019 Astrophysics Gaia Data Release 2 Special issue Gaia Data Release 2 Variable stars in the colour-absolute magnitude diagram?,?? Gaia Collaboration, L. Eyer1, L. Rimoldini2, M. Audard1, R. I. Anderson3,1, K. Nienartowicz2, F. Glass1, O. Marchal4, M. Grenon1, N. Mowlavi1, B. Holl1, G. Clementini5, C. Aerts6,7, T. Mazeh8, D. W. Evans9, L. Szabados10, A. G. A. Brown11, A. Vallenari12, T. Prusti13, J. H. J. de Bruijne13, C. Babusiaux4,14, C. A. L. Bailer-Jones15, M. Biermann16, F. Jansen17, C. Jordi18, S. A. Klioner19, U. Lammers20, L. Lindegren21, X. Luri18, F. Mignard22, C. Panem23, D. Pourbaix24,25, S. Randich26, P. Sartoretti4, H. I. Siddiqui27, C. Soubiran28, F. van Leeuwen9, N. A. Walton9, F. Arenou4, U. Bastian16, M. Cropper29, R. Drimmel30, D. Katz4, M. G. Lattanzi30, J. Bakker20, C. Cacciari5, J. Castañeda18, L. Chaoul23, N. Cheek31, F. De Angeli9, C. Fabricius18, R. Guerra20, E. Masana18, R. Messineo32, P. Panuzzo4, J. Portell18, M. Riello9, G. M. Seabroke29, P. Tanga22, F. Thévenin22, G. Gracia-Abril33,16, G. Comoretto27, M. Garcia-Reinaldos20, D. Teyssier27, M. Altmann16,34, R. Andrae15, I. Bellas-Velidis35, K. Benson29, J. Berthier36, R. Blomme37, P. Burgess9, G. Busso9, B. Carry22,36, A. Cellino30, M. Clotet18, O. Creevey22, M. Davidson38, J. De Ridder6, L. Delchambre39, A. Dell’Oro26, C. Ducourant28, J. Fernández-Hernández40, M. Fouesneau15, Y. Frémat37, L. Galluccio22, M. García-Torres41, J. González-Núñez31,42, J. J. González-Vidal18, E. Gosset39,25, L. P. Guy2,43, J.-L. Halbwachs44, N. C. Hambly38, D.
  • Many New Variable Stars Discovered in the Core of the Globular Cluster NGC 6715 (M 54) with EMCCD Observations DOI: 10.1051/0004-6361/201628864

    Many New Variable Stars Discovered in the Core of the Globular Cluster NGC 6715 (M 54) with EMCCD Observations DOI: 10.1051/0004-6361/201628864

    The University of Manchester Research Many new variable stars discovered in the core of the globular cluster NGC 6715 (M 54) with EMCCD observations DOI: 10.1051/0004-6361/201628864 Document Version Accepted author manuscript Link to publication record in Manchester Research Explorer Citation for published version (APA): Figuera Jaimes, R., Bramich, D. M., Kains, N., Skottfelt, J., Jørgensen, U. G., Horne, K., Dominik, M., Alsubai, K. A., Bozza, V., Burgdorf, M. J., Calchi Novati, S., Ciceri, S., D'Ago, G., Evans, D. F., Galianni, P., Gu, S. H., W Harpsøe, K. B., Haugbølle, T., Hinse, T. C., ... Wertz, O. (2016). Many new variable stars discovered in the core of the globular cluster NGC 6715 (M 54) with EMCCD observations. Astronomy and Astrophysics, 592, [A120]. https://doi.org/10.1051/0004-6361/201628864 Published in: Astronomy and Astrophysics Citing this paper Please note that where the full-text provided on Manchester Research Explorer is the Author Accepted Manuscript or Proof version this may differ from the final Published version. If citing, it is advised that you check and use the publisher's definitive version. General rights Copyright and moral rights for the publications made accessible in the Research Explorer are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Takedown policy If you believe that this document breaches copyright please refer to the University of Manchester’s Takedown Procedures [http://man.ac.uk/04Y6Bo] or contact [email protected] providing relevant details, so we can investigate your claim.
  • Stars and Their Spectra: an Introduction to the Spectral Sequence Second Edition James B

    Stars and Their Spectra: an Introduction to the Spectral Sequence Second Edition James B

    Cambridge University Press 978-0-521-89954-3 - Stars and Their Spectra: An Introduction to the Spectral Sequence Second Edition James B. Kaler Index More information Star index Stars are arranged by the Latin genitive of their constellation of residence, with other star names interspersed alphabetically. Within a constellation, Bayer Greek letters are given first, followed by Roman letters, Flamsteed numbers, variable stars arranged in traditional order (see Section 1.11), and then other names that take on genitive form. Stellar spectra are indicated by an asterisk. The best-known proper names have priority over their Greek-letter names. Spectra of the Sun and of nebulae are included as well. Abell 21 nucleus, see a Aurigae, see Capella Abell 78 nucleus, 327* ε Aurigae, 178, 186 Achernar, 9, 243, 264, 274 z Aurigae, 177, 186 Acrux, see Alpha Crucis Z Aurigae, 186, 269* Adhara, see Epsilon Canis Majoris AB Aurigae, 255 Albireo, 26 Alcor, 26, 177, 241, 243, 272* Barnard’s Star, 129–130, 131 Aldebaran, 9, 27, 80*, 163, 165 Betelgeuse, 2, 9, 16, 18, 20, 73, 74*, 79, Algol, 20, 26, 176–177, 271*, 333, 366 80*, 88, 104–105, 106*, 110*, 113, Altair, 9, 236, 241, 250 115, 118, 122, 187, 216, 264 a Andromedae, 273, 273* image of, 114 b Andromedae, 164 BDþ284211, 285* g Andromedae, 26 Bl 253* u Andromedae A, 218* a Boo¨tis, see Arcturus u Andromedae B, 109* g Boo¨tis, 243 Z Andromedae, 337 Z Boo¨tis, 185 Antares, 10, 73, 104–105, 113, 115, 118, l Boo¨tis, 254, 280, 314 122, 174* s Boo¨tis, 218* 53 Aquarii A, 195 53 Aquarii B, 195 T Camelopardalis,
  • ESO Annual Report 2004 ESO Annual Report 2004 Presented to the Council by the Director General Dr

    ESO Annual Report 2004 ESO Annual Report 2004 Presented to the Council by the Director General Dr

    ESO Annual Report 2004 ESO Annual Report 2004 presented to the Council by the Director General Dr. Catherine Cesarsky View of La Silla from the 3.6-m telescope. ESO is the foremost intergovernmental European Science and Technology organi- sation in the field of ground-based as- trophysics. It is supported by eleven coun- tries: Belgium, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Sweden, Switzerland and the United Kingdom. Created in 1962, ESO provides state-of- the-art research facilities to European astronomers and astrophysicists. In pur- suit of this task, ESO’s activities cover a wide spectrum including the design and construction of world-class ground-based observational facilities for the member- state scientists, large telescope projects, design of innovative scientific instruments, developing new and advanced techno- logies, furthering European co-operation and carrying out European educational programmes. ESO operates at three sites in the Ataca- ma desert region of Chile. The first site The VLT is a most unusual telescope, is at La Silla, a mountain 600 km north of based on the latest technology. It is not Santiago de Chile, at 2 400 m altitude. just one, but an array of 4 telescopes, It is equipped with several optical tele- each with a main mirror of 8.2-m diame- scopes with mirror diameters of up to ter. With one such telescope, images 3.6-metres. The 3.5-m New Technology of celestial objects as faint as magnitude Telescope (NTT) was the first in the 30 have been obtained in a one-hour ex- world to have a computer-controlled main posure.
  • Arxiv:2006.10868V2 [Astro-Ph.SR] 9 Apr 2021 Spain and Institut D’Estudis Espacials De Catalunya (IEEC), C/Gran Capit`A2-4, E-08034 2 Serenelli, Weiss, Aerts Et Al

    Arxiv:2006.10868V2 [Astro-Ph.SR] 9 Apr 2021 Spain and Institut D’Estudis Espacials De Catalunya (IEEC), C/Gran Capit`A2-4, E-08034 2 Serenelli, Weiss, Aerts Et Al

    Noname manuscript No. (will be inserted by the editor) Weighing stars from birth to death: mass determination methods across the HRD Aldo Serenelli · Achim Weiss · Conny Aerts · George C. Angelou · David Baroch · Nate Bastian · Paul G. Beck · Maria Bergemann · Joachim M. Bestenlehner · Ian Czekala · Nancy Elias-Rosa · Ana Escorza · Vincent Van Eylen · Diane K. Feuillet · Davide Gandolfi · Mark Gieles · L´eoGirardi · Yveline Lebreton · Nicolas Lodieu · Marie Martig · Marcelo M. Miller Bertolami · Joey S.G. Mombarg · Juan Carlos Morales · Andr´esMoya · Benard Nsamba · KreˇsimirPavlovski · May G. Pedersen · Ignasi Ribas · Fabian R.N. Schneider · Victor Silva Aguirre · Keivan G. Stassun · Eline Tolstoy · Pier-Emmanuel Tremblay · Konstanze Zwintz Received: date / Accepted: date A. Serenelli Institute of Space Sciences (ICE, CSIC), Carrer de Can Magrans S/N, Bellaterra, E- 08193, Spain and Institut d'Estudis Espacials de Catalunya (IEEC), Carrer Gran Capita 2, Barcelona, E-08034, Spain E-mail: [email protected] A. Weiss Max Planck Institute for Astrophysics, Karl Schwarzschild Str. 1, Garching bei M¨unchen, D-85741, Germany C. Aerts Institute of Astronomy, Department of Physics & Astronomy, KU Leuven, Celestijnenlaan 200 D, 3001 Leuven, Belgium and Department of Astrophysics, IMAPP, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands G.C. Angelou Max Planck Institute for Astrophysics, Karl Schwarzschild Str. 1, Garching bei M¨unchen, D-85741, Germany D. Baroch J. C. Morales I. Ribas Institute of· Space Sciences· (ICE, CSIC), Carrer de Can Magrans S/N, Bellaterra, E-08193, arXiv:2006.10868v2 [astro-ph.SR] 9 Apr 2021 Spain and Institut d'Estudis Espacials de Catalunya (IEEC), C/Gran Capit`a2-4, E-08034 2 Serenelli, Weiss, Aerts et al.
  • Astro-Ph/0605646

    Astro-Ph/0605646

    On the Iron content of NGC 1978 in the LMC: a metal rich, chemically homogeneous cluster1 Francesco R. Ferraro2, Alessio Mucciarelli2, Eugenio Carretta 3, Livia Origlia3 ABSTRACT We present a detailed abundance analysis of giant stars in NGC 1978, a mas- sive, intermediate-age stellar cluster in the Large Magellanic Cloud, characterized by a high ellipticity and suspected to have a metallicity spread. We analyzed 11 giants, all cluster members, by using high resolution spectra acquired with the UVES/FLAMES spectrograph at the ESO-Very Large Telescope. We find an iron content of [Fe/H]=-0.38 dex with very low σ[Fe/H] = 0.07 dex dispersion, and a mean heliocentric radial velocity vr = 293.1 ± 0.9 km/s and a velocity dispersion σvr = 3.1 km/s, thus excluding the presence of a significant metallicity, as well as velocity, spread within the cluster. Subject headings: Magellanic Clouds — globular clusters: individual (NGC 1978) — techniques: spectroscopic — stars:abundances 1. Introduction The Large Magellanic Cloud (LMC) is the nearest galaxy of the Local Group with a very populous system of Globular Clusters (GCs) that cover a wide range of metallicity and age. arXiv:astro-ph/0605646v1 25 May 2006 At least three main populations can be distinguished, namely an old population, coeval with the Galactic GC system, an intermediate population (1-3 Gyr) and a young one (< 1Gyr). Despite its importance, there is still a lack of systematic and homogeneous works aimed at determining the accurate chemical abundances and abundance patterns of the LMC GC system. Starting from the first compilation of metallicity by Sagar & Pandey (1989), the 1Based on observations collected at the Very Large Telescope of the European Southern Observatory (ESO), Cerro Paranal, Chile, under programme 072.D-0342 and 074.D-0369.
  • GEORGE HERBIG and Early Stellar Evolution

    GEORGE HERBIG and Early Stellar Evolution

    GEORGE HERBIG and Early Stellar Evolution Bo Reipurth Institute for Astronomy Special Publications No. 1 George Herbig in 1960 —————————————————————– GEORGE HERBIG and Early Stellar Evolution —————————————————————– Bo Reipurth Institute for Astronomy University of Hawaii at Manoa 640 North Aohoku Place Hilo, HI 96720 USA . Dedicated to Hannelore Herbig c 2016 by Bo Reipurth Version 1.0 – April 19, 2016 Cover Image: The HH 24 complex in the Lynds 1630 cloud in Orion was discov- ered by Herbig and Kuhi in 1963. This near-infrared HST image shows several collimated Herbig-Haro jets emanating from an embedded multiple system of T Tauri stars. Courtesy Space Telescope Science Institute. This book can be referenced as follows: Reipurth, B. 2016, http://ifa.hawaii.edu/SP1 i FOREWORD I first learned about George Herbig’s work when I was a teenager. I grew up in Denmark in the 1950s, a time when Europe was healing the wounds after the ravages of the Second World War. Already at the age of 7 I had fallen in love with astronomy, but information was very hard to come by in those days, so I scraped together what I could, mainly relying on the local library. At some point I was introduced to the magazine Sky and Telescope, and soon invested my pocket money in a subscription. Every month I would sit at our dining room table with a dictionary and work my way through the latest issue. In one issue I read about Herbig-Haro objects, and I was completely mesmerized that these objects could be signposts of the formation of stars, and I dreamt about some day being able to contribute to this field of study.
  • Lowmetallicity Pulsating Stars in the Lamost

    Lowmetallicity Pulsating Stars in the Lamost

    LOW-METALLICITY PULSATING STARS IN THE LAMOST DR1 F. Kahraman Aliçavuş Çanakkale Onsekiz Mart University [email protected] Aim Finding new low-metallicity pulsating stars in the LAMOST DR1 and uncovering their pulsation and atmospheric parameters. WHY ? They protect detailed information about the place where they were born. Alow us to understand evolution of the Galaxy, formation of stars Low-metallicity pulsating stars (taken from Jeffery (2008)) Low-metallicity pulsating stars RR Lyare stars: ● Classical radial pulsator, Pulsation period = ~0.5 days ● Exication mechanism, HeII, HeIII ionization zone ● Mass => ~0.6 ± 0.8 Msun ● Horizontal bracnh stars ● Teff => 6100 ± 7400 K (Taken from http://www.physics.usyd.edu.au/~bedding/animations/visual.html) RRab RRd RRc (Smolec et al., 2017, MNRAS, 467, 2349) Low-metallicity pulsating stars Type II Cepheids ● partial ionization zone of He ii ± Heiii and of Hi ± Hii ● Period 1 ± 5 d ==> BL Herculis ● Period 10 ± 20 d ==> W Virginis ● Period > 20 d ==> RV Tauri Taken from Aerts C., Christensen-Dalsgaard J., Kurtz D. W., 2010, Astroseismology, Springer, Berlin Low-metallicity pulsating stars Anomalous Cepheids: ● 1 ± 2 Msun ● spread between classical and type II Cepheids in the period-luminosity diagram (http://ogle.astrouw.edu.pl/atlas/anomalous_Cepheids.html) Low-metallicity pulsating stars SX Phoenix stars: ● Similar to high amplitude d Scuti star, Low- metallicity ● Mass => 0.9 ± 1.5 Msun ● Sx Phe stars are believed to be blue stragglers. ● Amplitude > 0.1 mag, Amplitude >~0.02 ± 0.03 mag Taken from Aerts C., Christensen- Dalsgaard J., Kurtz D. W., 2010, Astroseismology, Springer, Berlin Target Selection ● DR1 AFGK Stars Catalog, R=1800, SNg > 6, l = 370 ± 900 nm ● Teff ==> 6500 ± 8600 K ● log g ==> 3.8 ± 4.5 ● Fe/H ==> -2.4 ± -0.5 dex (http://dr1.lamost.org/) Target Selection ● SuperWASP Data, extra-solar planet detection programme ● Two robotic observatories, eight wide-angle cameras ● 10 objects showing light variation were found.