A Consistent Spectral Model of WR 136 and Its Associated Bubble NGC 6888 J
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A 2.4-12 Microns Spectrophotometric Study with ISO of Cygnus X-3 in Quiescence
1 Abstract. We present mid-infrared spectrophotometric results obtained with the ISO on the peculiar X-ray bi- nary Cygnus X-3 in quiescence, at orbital phases 0.83 to 1.04. The 2.4 - 12 µm continuum radiation observed with ISOPHOT-S can be explained by thermal free-free emis- sion in an expanding wind with, above 6.5 µm, a possi- ble additional black-body component with temperature T ∼ 250K and radius R ∼ 5000R⊙ at 10 kpc, likely due to thermal emission by circumstellar dust. The observed brightness and continuum spectrum closely match that of the Wolf-Rayet star WR 147, a WN8+B0.5 binary system, when rescaled at the same 10 kpc distance as Cygnus X- 3. A rough mass loss estimate assuming a WN wind gives −4 −1 ∼ 1.2 × 10 M⊙.yr . A line at ∼ 4.3 µm with a more than 4.3 σ detection level, and with a dereddened flux of 126 mJy, is interpreted as the expected He I 3p-3s line at 4.295 µm, a prominent line in the WR 147 spectrum. These results are consistent with a Wolf-Rayet-like com- panion to the compact object in Cyg X-3 of WN8 type, a later type than suggested by earlier works. Key words: binaries: close - stars: individual: Cyg X-3 - stars: Wolf-Rayet - stars: mass loss - infrared: stars arXiv:astro-ph/0207466v1 22 Jul 2002 A&A manuscript no. ASTRONOMY (will be inserted by hand later) AND Your thesaurus codes are: missing; you have not inserted them ASTROPHYSICS A 2.4 - 12 µm spectrophotometric study with ISO of CygnusX-3 in quiescence ⋆ Lydie Koch-Miramond1, P´eter Abrah´am´ 2,3, Ya¨el Fuchs1,4, Jean-Marc Bonnet-Bidaud1, and Arnaud Claret1 1 DAPNIA/Service d’Astrophysique, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France 2 Konkoly Observatory, P.O. -
ŞAR Shao SPECIAL ISSUE 2013 CİLD 8 № 2 AZERBAIJANI ASTRONOMICAL JOURNAL
ISSN: 2078-4163 XÜSUSİ BURAXILIŞ ŞAR ShAO SPECIAL ISSUE 2013 CİLD 8 № 2 AZERBAIJANI ASTRONOMICAL JOURNAL ISSN: 2078-4163 Azәrbaycan Milli Elmlәr Akademiyası AZӘRBAYCAN ASTRONOMİYA JURNALI Cild 8 – № 2 – 2013 | XÜSUSİ BURAXILIŞ ŞAR - ShAO - ШАО - 60 Azerbaijan National Academy of Sciences Национальная Академия Наук Азербайджана AZERBAIJANI АСТРОНОМИЧЕСКИЙ ASTRONOMICAL ЖУРНАЛ JOURNAL АЗЕРБАЙДЖАНА Volume 8 – No 2 – 2013 Том 8 – № 2 – 2013 SPECIAL ISSUE СПЕЦИАЛЬНЫЙ ВЫПУСК Azәrbaycan Milli Elmlәr Akademiyasının “AZӘRBAYCAN ASTRONOMIYA JURNALI” Azәrbaycan Milli Elmlәr Akademiyası (AMEA) Rәyasәt Heyәtinin 28 aprel 2006-cı il tarixli 50-saylı Sәrәncamı ilә tәsis edilmişdir. Baş Redaktor: Ә.S. Quliyev Baş Redaktorun Müavini: E.S. Babayev Mәsul Katib: P.N. Şustarev REDAKSIYA HEYӘTİ: Cәlilov N.S. AMEA N.Tusi adına Şamaxı Astrofizika Rәsәdxanası Hüseynov R.Ә. Baki Dövlәt Universiteti İsmayılov N.Z. AMEA N.Tusi adına Şamaxı Astrofizika Rәsәdxanası Qasımov F. Q. AMEA Fizika İnsitutu Quluzadә C.M. Baki Dövlәt Universiteti Texniki redaktor: A.B. Әsgәrov İnternet sәhifәsi: http://www.shao.az/AAJ Ünvan: Azәrbaycan, Bakı, AZ-1001, İstiqlaliyyәt küç. 10, AMEA Rәyasәt Heyәti Jurnal AMEA N.Tusi adına Şamaxı Astrofizika Rәsәdxanasında (www.shao.az) nәşr olunur. Мәktublar üçün: ŞAR, Azәrbaycan, Bakı, AZ-1000, Mәrkәzi Poçtamt, a/q №153 e-mail: [email protected] tel.: (+99412) 439 82 48 faкs: (+99412) 497 52 68 2013 Azәrbaycan Milli Elmlәr Akademiyası. 2013 AMEA N.Tusi adına Şamaxı Astrofizika Rәsәdxanası. Bütün hüquqlar qorunmuşdur. Bakı – 2013 ____________________________________________________________________________________________________________ “Астрономический Журнал Азербайджана” Национальной Azerbaijani Astronomical Journal of the Azerbaijan National Академии Наук Азербайджана (НАНА). Academy of Sciences (ANAS) is founded in 28 Aprel 2006. Основан 28 апреля 2006 г. Web- адрес: http://www.shao.az/AAJ Online version: http://www.shao.az/AAJ Главный редактор: А.С.Гулиев Editor-in-Chief: A.S. -
CURRICULUM VITAE: Dr Richard Ignace
CURRICULUM VITAE: Dr Richard Ignace Address: Department of Physics & Astronomy Office of Undergraduate Research College of Arts & Sciences Honors College EAST TENNESSEE STATE UNIVERSITY EAST TENNESSEE STATE UNIVERSITY Johnson City, TN 37614 Johnson City, TN 37614 Email: [email protected] [email protected] Web: faculty.etsu.edu/ignace www.etsu.edu/honors/ug research Phone/Fax: (423) 439-6904 / (423) 439-6905 (423) 439-6073 / (423) 439-6080 EDUCATION Ph.D. in Astronomy, University of Wisconsin 1996 M.S. in Physics, University of Wisconsin 1994 M.S. in Astronomy, University of Wisconsin 1993 B.S. in Astronomy, Indiana University 1991 POSITIONS HELD Aug 2016–present, Consultant, Tri-Alpha Energy Jan 2015–present, Director of Undergraduate Research Activities, East Tennessee State University Aug 2013–present, Full Professor: East Tennessee State University Aug 2007–Jul 2013, Associate Professor: East Tennessee State University Aug 2003–Jul 2007, Assistant Professor: East Tennessee State University Sep 2002–Jul 2003, Assistant Scientist: University of Wisconsin Aug 1999–Aug 2002, Visiting Assistant Professor: University of Iowa Nov 1996–Aug 1999, Postdoctoral Research Assistant: University of Glasgow SELECTED PROFESSIONAL ACTIVITIES Involved with service to discipline, institution, and community As Director of Undergraduate Research & Creative Activities, I administrate grant programs and activ- ities that support undergraduate scholarship, plus advocate for undergraduate research. Successful with publishing scholarly articles and competing for grant funding; author of the astron- omy textbook “Astro4U: An Introduction to the Science of the Cosmos,” of the popular astronomy book “Understanding the Universe,” and co-editor of the conference proceedings “The Nature and Evolution of Disks around Hot Stars” Principal organizer for STELLAR POLARIMETRY: FROM BIRTH TO DEATH, Jun 2011; and THE NATURE AND EVOLUTION OF DISKS AROUND HOT STARS, Jul 2004. -
Absence of Hot Gas Within the Wolft-Rayet Bubble Around WR16
Astronomy & Astrophysics manuscript no. ms c ESO 2018 April 30, 2018 Absence of hot gas within the Wolf-Rayet bubble around WR 16 J.A. Toal´aand M.A. Guerrero Instituto de Astrof´ısica de Andaluc´ıa, IAA-CSIC, Glorieta de la Astronom´ıa s/n, 18008 Granada, Spain; [email protected] Preprint online version: April 30, 2018 ABSTRACT We present the analysis of XMM-Newton archival observations towards the Wolf-Rayet (WR) bubble around WR 16. Despite the closed bubble morphology of this WR nebula, the XMM-Newton observations show no evidence of diffuse emission in its interior as in the similar WR bubbles NGC 6888 and S 308. We use the present observations to estimate a 3-σ upper limit to the X-ray luminosity in the 0.3–1.5 keV energy band equal to 7.4×1032 erg s−1 for the diffuse emission from the WR nebula, assuming a distance of 2.37 kpc. The WR nebula around WR 16 is the fourth observed by the current generation of X-ray satellites and the second not detected. We also examine FUSE spectra to search for nebular O vi absorption lines in the stellar continuum of WR 16. The present far-UV data and the lack of measurements of the dynamics of the optical WR bubble do not allow us to confirm the existence of a conductive layer of gas at T∼3×105 K between the cold nebular gas and the hot gas in its interior. The present observations result in an upper limit of −3 ne <0.6 cm on the electron density of the X-ray emitting material within the nebula. -
Pennsylvania Science Olympiad Southeast Regional Tournament 2013 Astronomy C Division Exam March 4, 2013
PENNSYLVANIA SCIENCE OLYMPIAD SOUTHEAST REGIONAL TOURNAMENT 2013 ASTRONOMY C DIVISION EXAM MARCH 4, 2013 SCHOOL:________________________________________ TEAM NUMBER:_________________ INSTRUCTIONS: 1. Turn in all exam materials at the end of this event. Missing exam materials will result in immediate disqualification of the team in question. There is an exam packet as well as a blank answer sheet. 2. You may separate the exam pages. You may write in the exam. 3. Only the answers provided on the answer page will be considered. Do not write outside the designated spaces for each answer. 4. Include school name and school code number at the bottom of the answer sheet. Indicate the names of the participants legibly at the bottom of the answer sheet. Be prepared to display your wristband to the supervisor when asked. 5. Each question is worth one point. Tiebreaker questions are indicated with a (T#) in which the number indicates the order of consultation in the event of a tie. Tiebreaker questions count toward the overall raw score, and are only used as tiebreakers when there is a tie. In such cases, (T1) will be examined first, then (T2), and so on until the tie is broken. There are 12 tiebreakers. 6. When the time is up, the time is up. Continuing to write after the time is up risks immediate disqualification. 7. In the BONUS box on the answer sheet, name the gentleman depicted on the cover for a bonus point. 8. As per the 2013 Division C Rules Manual, each team is permitted to bring “either two laptop computers OR two 3-ring binders of any size, or one binder and one laptop” and programmable calculators. -
Introduction to Astronomical Spectroscopy Trough the Eyes of an Alpy 600 Spectrograph in Cygnus Constellation
Introduction to astronomical spectroscopy trough the eyes of an Alpy 600 spectrograph in Cygnus constellation Olivier THIZY Webb Society annual meeting Cambridge, 20 june 2015 Photo: Jim Edlin, OHP AgendaAgenda ● How does a slit spectroscope works? ● Kirchhoff's law through Albireo exemple ● P Cygni: Doppler Fizeau effect ● Nova Del 2013: Spectro-photometry, pro/am ● Pulsating stars: quest for higher resolution ● Some other variable stars ● Conclusions InsideInside thethe AlpyAlpy 600600 spectroscopespectroscope objective collimator lens lens disperser (prism or grating) sensor source slit ImportanceImportance ofof thethe slitslit 3mm slit (hole) 300µm slit 25µm slit Cat'sCat's eyeeye nebulanebula // nono slitslit VsVs slitslit R=100, without slit R=17000, slit R=1000, 23µm slit © Torsten Hansen, Robin Leadbeater, O. Thizy MirrorMirror slitslit ● Centering ● (auto)Guiding © C. Buil, O. Thizy TheThe AlpyAlpy 600600 systemsystem onon aa scopescope a spectrum is an image that can be also displayed as a spectral profile Kirchhoff's law's through Albireo beta Cygni (Albireo) Photos: Jim Edlin (Cygne), Eric Coustal (Albireo) Albireo (1) (1) Overshape profile (2) Absorption lines (3) Emission line (3) (1) (2) Perfect exemple of Kirchhoff's laws... Photos: Eric Coustal (Albireo) & Wikipedia 1: overall profile --> Temp. 4000K Wikipedia: 4080K 13000K Wikipedia: 13200K Analyse: VisualSpec; photo Aliréo: Eric Coustal 2: stellar atmosphere Hydrogen lines Spectral classification hydrogène 68 Cyg O5V lam Cyg B5V 40 Cyg A3V the Cyg F4V zet Cyg G8II 61 Cyg K5V 19 Cyg M2IIIa H/K Na (D) atmosphère Oh, Be A Fine Girl/Guy... Kiss Me ! Absorption lines physics Exemple for the hydrogen atom Sources: http://culturesciencesphysique.ens-lyon.fr/ressource/Quantique.xml &: http://e.m.c.2.free.fr/niveaux-energie-hydrogene-emission-absorption.htm Temperature Vs line strength 40 Cyg A3V the Cyg F4V 19 Cyg M2IIIa ex: calcium 'Ca II' hydrogène toward cooler effective temperature Luminosity class Alp Cyg (A2I) 40 Cyg (A3V) Hertzspring-Russell diagram © J. -
UV Spectroscopy of Massive Stars
galaxies Review UV Spectroscopy of Massive Stars D. John Hillier Department of Physics and Astronomy & Pittsburgh Particle Physics, Astrophysics and Cosmology Center (PITT PACC), University of Pittsburgh, 3941 O’Hara Street, Pittsburgh, PA 15260, USA; [email protected] Received: 11 July 2020; Accepted: 6 August 2020; Published: 12 August 2020 Abstract: We present a review of UV observations of massive stars and their analysis. We discuss O stars, luminous blue variables, and Wolf–Rayet stars. Because of their effective temperature, the UV (912 − 3200 Å) provides invaluable diagnostics not available at other wavebands. Enormous progress has been made in interpreting and analysing UV data, but much work remains. To facilitate the review, we provide a brief discussion on the structure of stellar winds, and on the different techniques used to model and interpret UV spectra. We discuss several important results that have arisen from UV studies including weak-wind stars and the importance of clumping and porosity. We also discuss errors in determining wind terminal velocities and mass-loss rates. Keywords: massive stars; O stars; Wolf–Rayet stars; UV; mass loss; stellar winds 1. Introduction According to Wien’s Law, the peak of a star’s energy distribution occurs in the UV for a star whose temperature exceeds 10,000 K. In practice, the temperature needs to exceed 10,000 K because of the presence of the Balmer jump. Temperatures greater than 10,000 K correspond to main-sequence stars of mass greater than ∼ 2 M and spectral types B9 and earlier. Early UV observations were made by rocket-flown instruments (e.g., [1,2]). -
Wolf-Rayet Spin at Low Metallicity and Its Implication for Black Hole Formation Channels Jorick S
A&A 603, A120 (2017) Astronomy DOI: 10.1051/0004-6361/201730503 & c ESO 2017 Astrophysics Wolf-Rayet spin at low metallicity and its implication for black hole formation channels Jorick S. Vink1 and Tim J. Harries2 1 Armagh Observatory and Planetarium, College Hill, Armagh BT61 9DG, Northern Ireland, UK e-mail: [email protected] 2 Department of Physics and Astronomy, University of Exeter, Exeter EX4 4QL, UK Received 26 January 2017 / Accepted 28 March 2017 ABSTRACT Context. The spin of Wolf-Rayet (WR) stars at low metallicity (Z) is most relevant for our understanding of gravitational wave sources, such as GW 150914, and of the incidence of long-duration gamma-ray bursts (GRBs). Two scenarios have been suggested for both phenomena: one of them involves rapid rotation and quasi-chemical homogeneous evolution (CHE) and the other invokes classical evolution through mass loss in single and binary systems. Aims. The stellar spin of WR stars might enable us to test these two scenarios. In order to obtain empirical constraints on black hole progenitor spin we infer wind asymmetries in all 12 known WR stars in the Small Magellanic Cloud (SMC) at Z = 1=5 Z and within a significantly enlarged sample of single and binary WR stars in the Large Magellanic Cloud (LMC at Z = 1=2 Z ), thereby tripling the sample of Vink from 2007. This brings the total LMC sample to 39, making it appropriate for comparison to the Galactic sample. Methods. We measured WR wind asymmetries with VLT-FORS linear spectropolarimetry, a tool that is uniquely poised to perform such tasks in extragalactic environments. -
Arxiv:0912.1326V3 [Astro-Ph.SR] 24 Dec 2009 Etrfratohsc N Pc Srnm CS) Nv O Univ
To appear in the Astronomical Journal X-ray Emission from Nitrogen-Type Wolf-Rayet Stars Stephen L. Skinner Center for Astrophysics and Space Astronomy (CASA), Univ. of Colorado, Boulder, CO 80309-0389; email: [email protected] Svetozar A. Zhekov1 JILA, Univ. of Colorado, Boulder, CO 80309-0440 Manuel G¨udel Institute of Astronomy, ETH Z¨urich, Wolfgang-Pauli-Str. 27, 8093 Z¨urich, Switzerland Werner Schmutz Physikalisch-Meteorologisches Observatorium Davos and World Radiation Center (PMOD/WRC), Dorfstrasse 33, CH-7260 Davos Dorf, Switzerland and Kimberly R. Sokal Center for Astrophysics and Space Astronomy (CASA), Univ. of Colorado, Boulder, CO 80309-0389 ABSTRACT arXiv:0912.1326v3 [astro-ph.SR] 24 Dec 2009 We summarize new X-ray detections of four nitrogen-type Wolf-Rayet (WR) stars obtained in a limited survey aimed at establishing the X-ray properties of WN stars across their full range of spectral subtypes. None of the detected stars is so far known to be a close binary. We report Chandra detections of WR 2 (WN2), WR 18 (WN4), and WR 134 (WN6), and an XMM-Newton detection of WR79a (WN9ha). These observations clearly demonstrate that both WNE and WNL stars are X-ray sources. We also discuss Chandra archive detections 1On leave from Space Research Institute, Sofia, Bulgaria –2– of the WN6h stars WR 20b, WR 24, and WR 136 and ROSAT non-detections of WR 16 (WN8h) and WR 78 (WN7h). The X-ray spectra of all WN detections show prominent emission lines and an admixture of cool (kT < 1 keV) and hot (kT > 2 keV) plasma. -
Theory of Stellar Atmospheres
© Copyright, Princeton University Press. No part of this book may be distributed, posted, or reproduced in any form by digital or mechanical means without prior written permission of the publisher. EXTENDED BIBLIOGRAPHY References [1] D. Abbott. The terminal velocities of stellar winds from early{type stars. Astrophys. J., 225, 893, 1978. [2] D. Abbott. The theory of radiatively driven stellar winds. I. A physical interpretation. Astrophys. J., 242, 1183, 1980. [3] D. Abbott. The theory of radiatively driven stellar winds. II. The line acceleration. Astrophys. J., 259, 282, 1982. [4] D. Abbott. The theory of radiation driven stellar winds and the Wolf{ Rayet phenomenon. In de Loore and Willis [938], page 185. Astrophys. J., 259, 282, 1982. [5] D. Abbott. Current problems of line formation in early{type stars. In Beckman and Crivellari [358], page 279. [6] D. Abbott and P. Conti. Wolf{Rayet stars. Ann. Rev. Astr. Astrophys., 25, 113, 1987. [7] D. Abbott and D. Hummer. Photospheres of hot stars. I. Wind blan- keted model atmospheres. Astrophys. J., 294, 286, 1985. [8] D. Abbott and L. Lucy. Multiline transfer and the dynamics of stellar winds. Astrophys. J., 288, 679, 1985. [9] D. Abbott, C. Telesco, and S. Wolff. 2 to 20 micron observations of mass loss from early{type stars. Astrophys. J., 279, 225, 1984. [10] C. Abia, B. Rebolo, J. Beckman, and L. Crivellari. Abundances of light metals and N I in a sample of disc stars. Astr. Astrophys., 206, 100, 1988. [11] M. Abramowitz and I. Stegun. Handbook of Mathematical Functions. (Washington, DC: U.S. Government Printing Office), 1972. -
Quarterly 2–Fall 2012 Calendar Con’T from Page 1 Doomsayers
Fall 2012 EVENTS CALENDAR Issue 99 (unless otherwise noted, all events are at the Edwin Ritchie Observatory, Battle Point Park) SEPTEMBER uarterlywww.bpastro.org Bainbridge Island, WA September 22 Autumnal Equinox Q (7:49 a.m. PDT) September 27 7:00 p.m. Introduction to Mermaid Amateur Astronomy class begins September 29 (8:19 p.m. PDT) Politics CALENDAR NOTES: It’s fall, time OCTOBER for school, and we have once again October 1 8:00 p.m. The City Dark teamed up PhD Astronomer David at Open Mic Science, Fong, BPAA Education Director, and Treehouse Café Steve Ruhl, BPAA president, to teach our popular Introduction to Amateur October 4 7:00 p.m. Intro to Astronomy course. Having taken this Amateur Astronomy course myself, I can assure you that week #2 regardless how much or how little October 5 Robert Goddard’s 130th you think you know, you’ll find it birthday worthwhile and enjoyable. Cassiopeia from Firmamentum Sobiescianum Talk of education reminds me that October 11 7:00 p.m. Intro to sive Uranographia star atlas by Johannes Hevelius, Amateur Astronomy courtesy U.S. Naval Observatory and the Space when my eyes turn northward this Telescope Science Institute. autumn, they will frequently greet the week #3 familiar “W” of Cassiopeia. Although October 13 7:00 p.m. Planetarium the “W” doesn’t really stand for Washington, this asterism is particularly prominent Show “Dancing with the in our state’s skies, and, from Bainbridge Island, could even be said to point slightly Stars” and Stargazing east towards the UW campus, perhaps serving as a subconscious stimulus towards October 15 higher education. -
Reflector December 2019 Pages.Pdf
Published by the Astronomical League Vol. 72, No. 1 December 2019 EXOPLANET NEWS AN ASTRONOMICAL VOYAGE TO CHILE GRAVITATIONAL LENSES Contents Get Off the Beaten Path Join a Astronomy Tour African Stargazing Safari Join astronomer Stephen James July 17–23, 2020 O’Meara in wildlife-rich Botswana for evening stargazing and daytime safari drives at three luxury field camps. Only 16 spaces available! Optional extension to Victoria Falls. skyandtelescope.com/botswana2020 S&T’s 2020 solar eclipse cruise offers 2 2020 Eclipse Cruise: Chile, Argentina, minutes, 7 seconds of totality off the and Antarctica coast of Argentina and much more: Nov. 27–Dec. 19, 2020 Chilean fjords and glaciers, the legendary Drake Passage, and four days amid Antarctica’s waters and icebergs. skyandtelescope.com/chile2020 Total Solar Eclipse in Patagonia December 9–18, 2020 Come along with Sky & Telescope to view this celestial spectacle in the lakes region of southern Argentina. Experience breathtaking vistas of the lush landscape by day — and the southern sky’s incomparable stars by night. Optional visit to the world-famous Iguazú Falls. skyandtelescope.com/argentina2020 Astronomy Across Italy May, 2021 As you travel in comfort from Rome to Florence, Pisa, and Pad- ua, visit some of the country’s great astronomical sites: the Vat- ican Observatory, the Galileo Museum, Arcetri Observatory, and lots more. Enjoy fine food, hotels, and other classic Italian treats. Extensions in Rome and Venice available.Moved to May 2021 — skyandtelescope.com/italy2020 new dates coming soon! See all S&T tours at skyandtelescope.com/astronomy-travel Contents 2020Amateur Shrine to the Stars Fast Facts CalendarStellafane t, a quiet revolution A century ago in Springfield, Vermon in astronomy took place.