Jessica Ryan Lu
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POSTERS SESSION I: Atmospheres of Massive Stars
Abstracts of Posters 25 POSTERS (Grouped by sessions in alphabetical order by first author) SESSION I: Atmospheres of Massive Stars I-1. Pulsational Seeding of Structure in a Line-Driven Stellar Wind Nurdan Anilmis & Stan Owocki, University of Delaware Massive stars often exhibit signatures of radial or non-radial pulsation, and in principal these can play a key role in seeding structure in their radiatively driven stellar wind. We have been carrying out time-dependent hydrodynamical simulations of such winds with time-variable surface brightness and lower boundary condi- tions that are intended to mimic the forms expected from stellar pulsation. We present sample results for a strong radial pulsation, using also an SEI (Sobolev with Exact Integration) line-transfer code to derive characteristic line-profile signatures of the resulting wind structure. Future work will compare these with observed signatures in a variety of specific stars known to be radial and non-radial pulsators. I-2. Wind and Photospheric Variability in Late-B Supergiants Matt Austin, University College London (UCL); Nevyana Markova, National Astronomical Observatory, Bulgaria; Raman Prinja, UCL There is currently a growing realisation that the time-variable properties of massive stars can have a funda- mental influence in the determination of key parameters. Specifically, the fact that the winds may be highly clumped and structured can lead to significant downward revision in the mass-loss rates of OB stars. While wind clumping is generally well studied in O-type stars, it is by contrast poorly understood in B stars. In this study we present the analysis of optical data of the B8 Iae star HD 199478. -
A Gas Cloud on Its Way Towards the Super-Massive Black Hole in the Galactic Centre
1 A gas cloud on its way towards the super-massive black hole in the Galactic Centre 1 1,2 1 3 4 4,1 5 S.Gillessen , R.Genzel , T.K.Fritz , E.Quataert , C.Alig , A.Burkert , J.Cuadra , F.Eisenhauer1, O.Pfuhl1, K.Dodds-Eden1, C.F.Gammie6 & T.Ott1 1Max-Planck-Institut für extraterrestrische Physik (MPE), Giessenbachstr.1, D-85748 Garching, Germany ( [email protected], [email protected] ) 2Department of Physics, Le Conte Hall, University of California, 94720 Berkeley, USA 3Department of Astronomy, University of California, 94720 Berkeley, USA 4Universitätssternwarte der Ludwig-Maximilians-Universität, Scheinerstr. 1, D-81679 München, Germany 5Departamento de Astronomía y Astrofísica, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, 7820436 Macul, Santiago, Chile 6Center for Theoretical Astrophysics, Astronomy and Physics Departments, University of Illinois at Urbana-Champaign, 1002 West Green St., Urbana, IL 61801, USA Measurements of stellar orbits1-3 provide compelling evidence4,5 that the compact radio source Sagittarius A* at the Galactic Centre is a black hole four million times the mass of the Sun. With the exception of modest X-ray and infrared flares6,7, Sgr A* is surprisingly faint, suggesting that the accretion rate and radiation efficiency near the event horizon are currently very low3,8. Here we report the presence of a dense gas cloud approximately three times the mass of Earth that is falling into the accretion zone of Sgr A*. Our observations tightly constrain the cloud’s orbit to be highly eccentric, with an innermost radius of approach of only ~3,100 times the event horizon that will be reached in 2013. -
The Orbital Motion of the Quintuplet Cluster—A Common Origin for the Arches and Quintuplet Clusters?∗
The Astrophysical Journal, 789:115 (20pp), 2014 July 10 doi:10.1088/0004-637X/789/2/115 C 2014. The American Astronomical Society. All rights reserved. Printed in the U.S.A. THE ORBITAL MOTION OF THE QUINTUPLET CLUSTER—A COMMON ORIGIN FOR THE ARCHES AND QUINTUPLET CLUSTERS?∗ A. Stolte1,B.Hußmann1, M. R. Morris2,A.M.Ghez2, W. Brandner3,J.R.Lu4, W. I. Clarkson5, M. Habibi1, and K. Matthews6 1 Argelander Institut fur¨ Astronomie, Auf dem Hugel¨ 71, D-53121 Bonn, Germany; [email protected] 2 Division of Astronomy and Astrophysics, UCLA, Los Angeles, CA 90095-1547, USA; [email protected], [email protected] 3 Max-Planck-Institut fur¨ Astronomie, Konigstuhl¨ 17, D-69117 Heidelberg, Germany; [email protected] 4 Institute for Astronomy, University of Hawai’i, 2680 Woodlawn Drive, Honolulu, HI 96822, USA; [email protected] 5 Department of Natural Sciences, University of Michigan-Dearborn, 125 Science Building, 4901 Evergreen Road, Dearborn, MI 48128, USA; [email protected] 6 Caltech Optical Observatories, California Institute of Technology, MS 320-47, Pasadena, CA 91225, USA; [email protected] Received 2014 January 16; accepted 2014 May 14; published 2014 June 20 ABSTRACT We investigate the orbital motion of the Quintuplet cluster near the Galactic center with the aim of constraining formation scenarios of young, massive star clusters in nuclear environments. Three epochs of adaptive optics high-angular resolution imaging with the Keck/NIRC2 and Very Large Telescope/NAOS-CONICA systems were obtained over a time baseline of 5.8 yr, delivering an astrometric accuracy of 0.5–1 mas yr−1. -
121012-AAS-221 Program-14-ALL, Page 253 @ Preflight
221ST MEETING OF THE AMERICAN ASTRONOMICAL SOCIETY 6-10 January 2013 LONG BEACH, CALIFORNIA Scientific sessions will be held at the: Long Beach Convention Center 300 E. Ocean Blvd. COUNCIL.......................... 2 Long Beach, CA 90802 AAS Paper Sorters EXHIBITORS..................... 4 Aubra Anthony ATTENDEE Alan Boss SERVICES.......................... 9 Blaise Canzian Joanna Corby SCHEDULE.....................12 Rupert Croft Shantanu Desai SATURDAY.....................28 Rick Fienberg Bernhard Fleck SUNDAY..........................30 Erika Grundstrom Nimish P. Hathi MONDAY........................37 Ann Hornschemeier Suzanne H. Jacoby TUESDAY........................98 Bethany Johns Sebastien Lepine WEDNESDAY.............. 158 Katharina Lodders Kevin Marvel THURSDAY.................. 213 Karen Masters Bryan Miller AUTHOR INDEX ........ 245 Nancy Morrison Judit Ries Michael Rutkowski Allyn Smith Joe Tenn Session Numbering Key 100’s Monday 200’s Tuesday 300’s Wednesday 400’s Thursday Sessions are numbered in the Program Book by day and time. Changes after 27 November 2012 are included only in the online program materials. 1 AAS Officers & Councilors Officers Councilors President (2012-2014) (2009-2012) David J. Helfand Quest Univ. Canada Edward F. Guinan Villanova Univ. [email protected] [email protected] PAST President (2012-2013) Patricia Knezek NOAO/WIYN Observatory Debra Elmegreen Vassar College [email protected] [email protected] Robert Mathieu Univ. of Wisconsin Vice President (2009-2015) [email protected] Paula Szkody University of Washington [email protected] (2011-2014) Bruce Balick Univ. of Washington Vice-President (2010-2013) [email protected] Nicholas B. Suntzeff Texas A&M Univ. suntzeff@aas.org Eileen D. Friel Boston Univ. [email protected] Vice President (2011-2014) Edward B. Churchwell Univ. of Wisconsin Angela Speck Univ. of Missouri [email protected] [email protected] Treasurer (2011-2014) (2012-2015) Hervey (Peter) Stockman STScI Nancy S. -
2012 Annual Progress Report and 2013 Program Plan of the Gemini Observatory
2012 Annual Progress Report and 2013 Program Plan of the Gemini Observatory Association of Universities for Research in Astronomy, Inc. Table of Contents 0 Executive Summary ....................................................................................... 1 1 Introduction and Overview .............................................................................. 5 2 Science Highlights ........................................................................................... 6 2.1 Highest Resolution Optical Images of Pluto from the Ground ...................... 6 2.2 Dynamical Measurements of Extremely Massive Black Holes ...................... 6 2.3 The Best Standard Candle for Cosmology ...................................................... 7 2.4 Beginning to Solve the Cooling Flow Problem ............................................... 8 2.5 A Disappearing Dusty Disk .............................................................................. 9 2.6 Gas Morphology and Kinematics of Sub-Millimeter Galaxies........................ 9 2.7 No Intermediate-Mass Black Hole at the Center of M71 ............................... 10 3 Operations ...................................................................................................... 11 3.1 Gemini Publications and User Relationships ............................................... 11 3.2 Science Operations ........................................................................................ 12 3.2.1 ITAC Software and Queue Filling Results .................................................. -
The Circumnuclear Ring (CNR) (11 Slides) – Quintuplet Proper Members (Qpms) (6 Slides) – Pistol Nebula (10 Slides)
SOFIA/FORCAST Observations of the Galactic Center Ryan M. Lau SOFIA Community Collaborators: T. L. Herter, M. R. Morris, E. E. Becklin, M. J. Hankins, Task Force Teletalks, J. D. Adams, G. E. Gull, C. P. Henderson, J. Schoenwald February 6, 2013 SOFIA/FORCAST Observations of the Galactic Center R. M. Lau Talk Outline • Background – The Galactic Center – Observations • Results and Science – The Circumnuclear Ring (CNR) (11 slides) – Quintuplet Proper Members (QPMs) (6 slides) – Pistol Nebula (10 slides) • Further Work 2 SOFIA/FORCAST Observations of the Galactic Center R. M. Lau The Galactic Center • ~500 pc unique region containing a 4,000,000 solar mass black hole, massive stars, supernovae, and star formation regions QC & Pistol • 10% of present SF activity in Galaxy occurs in GC yet only tiny fraction of a percent of volume in Galactic disk CNR 10 pc • Contains ~4/12 of the LBVs and ~90/240 of Wolf-Rayet stars in galaxy 3 SOFIA/FORCAST Observations of the Galactic Center R. M. Lau The Galactic Center: Inner 50 Pc • Circumnuclear Ring (CNR) – Dense ring of gas and dust surrounding Sgr A* by 1.4 pc • Quintuplet Cluster (QC) QC & Pistol – ~4 Myr cluster of hot, massive stars – Named after 5 bright IR sources within cluster (we observe 4 of them) • Pistol Nebula CNR – Asymmetric shell of dust and 10 pc gas surrounding the Pistol star – Appears to be shaped by 8 μm Spitzer/IRAC image of the inner interaction with QC winds 50 pc of the Galactic Center 4 SOFIA/FORCAST Observations of the Galactic Center R. -
The Stellar Content of the Quintuplet Cluster Donald
THE STELLAR CONTENT OF THE QUINTUPLET CLUSTER DONALD F. FIGER, IAN S. MCLEAN AND MARK MORRIS University of California, Los Angeles Division of Astronomy, Department of Physics and Astronomy, Los Angeles, CA 90095-1562 AND FRANCISCO NAJARRO Institut für Astronomie und Astrophysik der Universität München Scheinerstr. 1, D-81679 München, Germany Abstract. The Quintuplet cluster contains over two dozen post main sequence descendants of massive O-stars, including Wolf-Rayet and OBI stars. The five Quintuplet-proper members (QPMs) may be dusty late-type Wolf-Rayet carbon stars (DWCLs), and the Pistol star may have a very high luminosity, « io6,7±0*5 L®. Coupled with its rather cool temperature, 12—23 kK, the Pistol Star is well in violation of the Humphreys—Davidson limit. We argue that the surrounding "Pistol" nebula was ejected from the star a few thousand years ago. The cluster stars imply the following approximate cluster properties: 4 7 3±α2 49 9 1 tage - 2 to 7 Myrs, M ~ 10 M®, L ~ 10 · L®, and NL2/,C > 10 · s" . The "Sickle" (GO.18-0.04) radio feature and the mid-IR ring (seen in MSX images) may naturally be explained by the presence of a young cluster and a nearby molecular cloud. 1. The Quintuplet Cluster We have used K-band spectra to identify the following cluster stars: 14 OBI, 2 Ofpe/WN9, 4 WN, 4 WC, 1 LBV candidate, 1 red supergiant (RSG), and 5 possible DWCLs (Figer, Morris, & McLean 1996). The ages are between 2 to 7 Myrs according to recent stellar evolution models (Meynet 1995); the low (high) end of the range applies to the OBI stars (RSG). -
Massive Stars in the Galactic Center Quintuplet Cluster
Institut für Physik und Astronomie Astrophysik Massive stars in the Galactic Center Quintuplet cluster Dissertation zur Erlangung des akademischen Grades Doktor der Naturwissenschaften (Dr. rer. nat.) eingereicht an der Mathematisch-Naturwissenschaftlichen Fakultät der Universität Potsdam von Adriane Liermann Potsdam, Juni 2009 This work is licensed under a Creative Commons License: Attribution - Noncommercial - No Derivative Works 3.0 Germany To view a copy of this license visit http://creativecommons.org/licenses/by-nc-nd/3.0/de/deed.en Published online at the Institutional Repository of the University of Potsdam: URL http://opus.kobv.de/ubp/volltexte/2009/3722/ URN urn:nbn:de:kobv:517-opus-37223 [http://nbn-resolving.org/urn:nbn:de:kobv:517-opus-37223] Summary The presented thesis describes the observations of the Galactic center Quintuplet cluster, the spectral analysis of the cluster Wolf-Rayet stars of the nitrogen sequence to determine their fundamental stellar parameters, and discusses the obtained results in a general context. The Quintuplet cluster was discovered in one of the first infrared surveys of the Galactic center region (Okuda et al. 1987, 1989) and was observed for this project with the ESO-VLT near-infrared integral field instrument SINFONI-SPIFFI. The subsequent data reduction was performed in parts with a self-written pipeline to obtain flux-calibrated spectra of all objects detected in the imaged field of view. First results of the observation were compiled and published in a spectral catalog of 160 flux-calibrated K-band spectra in the range of 1.95 to 2.45 µm, containing 85 early-type (OB) stars, 62 late-type (KM) stars, and 13 Wolf-Rayet stars. -
The 13Th HEAD Program Book
13th Meeting of the High Energy Astrophysics Division Program Book Monterey CA 7-11 April 2013 13th Meeting of the American Astronomical Society’s High Energy Astrophysics Division (HEAD) 7-11 April 2013 Monterey, California Scientific sessions will be held at the: Portola Hotel and Spa 2 Portola Plaza ATTENDEE Monterey, CA 93940 SERVICES.......... 4 HEAD Paper Sorters SCHEDULE......... 6 Keith Arnaud Joshua Bloom MONDAY............ 12 Joel Bregman Paolo Coppi Rosanne Di Stefano POSTERS........... 17 Daryl Haggard Chryssa Kouveliotou TUESDAY........... 43 Henric Krawczynski Stephen Reynolds WEDNESDAY...... 48 Randall Smith Jan Vrtilek THURSDAY......... 52 Nicholas White AUTHOR INDEX.. 56 Session Numbering Key 100’s Monday and posters NASA PCOS X-RAY SAG 200’s Tuesday 300’s Wednesday HEAD DISSERTATIONS 400’s Thursday Please Note: All posters are displayed Monday-Thursday. Current HEAD Officers Current HEAD Committee Joel Bregman Chair Daryl Haggard 2013-2016 Nicholas White Vice-Chair Henric Krawczynski 2013-2016 Randall Smith Secretary Rosanne DiStefano 2011-2014 Keith Arnaud Treasurer Stephen Reynolds 2011-2014 Megan Watzke Press Officer Jan Vrtilek 2011-2014 Chryssa Kouveliotou Past Chair Joshua Bloom 2012-2015 Paolo Coppi 2012-2015 1 2 Peter B’s Entrance Cottonwood Plaza Jacks Restaurant Brew Pub s p o h S Cottonwood Bonsai III e Lower Atrium Bonsai II ung Restrooms o e nc cks L Ironwood Redwood Bonsai I a a J Entr Elevators Elevators a l o rt o P Restrooms s De Anza De Anza p Ballroom II-III Ballroom I o De Anza Sh Foyer Upper Atrium Entrance OOMS R Entrance BONZAI Entrance De ANZA BALLROOM FA ELEVATORS TO BONZAI ROOMS Y B OB L TEL O General eANZA D A H O Z T Session ANCE R OLA PLA T ENT R PO FA FA STORAGE A UP F ENTRANCE TO 3 De ANZA FOYER ATTENDEE SERVICES Registration De Anza Foyer Sunday: 1:00pm-7:00pm Monday-Wednesday: 7:30am-6:00pm Thursday: 8:00am-5:00pm Poster Viewing Monday-Wednesday: 7:30am-6:45pm Thursday: 7:30am-5:00pm Please do not leave personal items unattended. -
Orders of Magnitude (Length) - Wikipedia
03/08/2018 Orders of magnitude (length) - Wikipedia Orders of magnitude (length) The following are examples of orders of magnitude for different lengths. Contents Overview Detailed list Subatomic Atomic to cellular Cellular to human scale Human to astronomical scale Astronomical less than 10 yoctometres 10 yoctometres 100 yoctometres 1 zeptometre 10 zeptometres 100 zeptometres 1 attometre 10 attometres 100 attometres 1 femtometre 10 femtometres 100 femtometres 1 picometre 10 picometres 100 picometres 1 nanometre 10 nanometres 100 nanometres 1 micrometre 10 micrometres 100 micrometres 1 millimetre 1 centimetre 1 decimetre Conversions Wavelengths Human-defined scales and structures Nature Astronomical 1 metre Conversions https://en.wikipedia.org/wiki/Orders_of_magnitude_(length) 1/44 03/08/2018 Orders of magnitude (length) - Wikipedia Human-defined scales and structures Sports Nature Astronomical 1 decametre Conversions Human-defined scales and structures Sports Nature Astronomical 1 hectometre Conversions Human-defined scales and structures Sports Nature Astronomical 1 kilometre Conversions Human-defined scales and structures Geographical Astronomical 10 kilometres Conversions Sports Human-defined scales and structures Geographical Astronomical 100 kilometres Conversions Human-defined scales and structures Geographical Astronomical 1 megametre Conversions Human-defined scales and structures Sports Geographical Astronomical 10 megametres Conversions Human-defined scales and structures Geographical Astronomical 100 megametres 1 gigametre -
Astrophysical Applications of Gravitational Microlensing in the Milky
ASTROPHYSICAL APPLICATIONS OF GRAVITATIONAL MICROLENSING IN THE MILKY WAY Przemysław Mróz Ph.D. thesis written under the supervision of prof. dr hab. Andrzej Udalski Warsaw University Observatory Warsaw, April 2019 Acknowledgements First and foremost, I would like to thank my supervisor, Prof. Andrzej Udalski, for the encouragement and advice he has provided throughout my time as his student. I have been extraordinarily lucky to have the supervisor who gave me immeasurable amount of his time, as a researcher and a mentor. This dissertation would not be possible without the sheer amount of work from all members of the OGLE team and their time spent at Cerro Las Campanas. In particular, I would like to thank Prof. Michał Szymanski,´ Prof. Igor Soszynski,´ Łukasz Wyrzykowski, Paweł Pietrukowicz, Szymon Kozłowski, Radek Poleski, and Jan Skowron, who have helped me since my very first steps at the Warsaw University Observatory. I thank all my collegues from the Warsaw Observatory for many helpful discussions and support. I am also grateful to Andrew Gould, Takahiro Sumi, and Yossi Shvartzvald, who shared the photometric data that are a part of this thesis. I thank Calen Henderson and all Pasadena-based microlensers for their hospitality during my stay at Caltech. I also thank my family for their support in my effort to pursue my chosen field of astronomy. I acknowledge financial support from the Polish Ministry of Science and Higher Education (“Diamond Grant” number DI2013/014743), the Foundation for Polish Science (Program START), and the National Science Center, Poland (grant ETIUDA 2018/28/T/ST9/00096). I also received support from the European Research Council grant No. -
Black Hole Math Is Designed to Be Used As a Supplement for Teaching Mathematical Topics
National Aeronautics and Space Administration andSpace Aeronautics National ole M a th B lack H i This collection of activities, updated in February, 2019, is based on a weekly series of space science problems distributed to thousands of teachers during the 2004-2013 school years. They were intended as supplementary problems for students looking for additional challenges in the math and physical science curriculum in grades 10 through 12. The problems are designed to be ‘one-pagers’ consisting of a Student Page, and Teacher’s Answer Key. This compact form was deemed very popular by participating teachers. The topic for this collection is Black Holes, which is a very popular, and mysterious subject among students hearing about astronomy. Students have endless questions about these exciting and exotic objects as many of you may realize! Amazingly enough, many aspects of black holes can be understood by using simple algebra and pre-algebra mathematical skills. This booklet fills the gap by presenting black hole concepts in their simplest mathematical form. General Approach: The activities are organized according to progressive difficulty in mathematics. Students need to be familiar with scientific notation, and it is assumed that they can perform simple algebraic computations involving exponentiation, square-roots, and have some facility with calculators. The assumed level is that of Grade 10-12 Algebra II, although some problems can be worked by Algebra I students. Some of the issues of energy, force, space and time may be appropriate for students taking high school Physics. For more weekly classroom activities about astronomy and space visit the NASA website, http://spacemath.gsfc.nasa.gov Add your email address to our mailing list by contacting Dr.