Extremely Extended Dust Shells Around Evolved Intermediate Mass Stars: Probing Mass Loss Histories,Thermal Pulses and Stellar Evolution
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Hunting Down Stars with Unusual Infrared Properties Using Supervised Machine Learning
. Magnificent beasts of the Milky Way: Hunting down stars with unusual infrared properties using supervised machine learning Julia Ahlvind1 Supervisor: Erik Zackrisson1 Subject reader: Eric Stempels1 Examiner: Andreas Korn1 Degree project E in Physics { Astronomy, 30 ECTS 1Department of Physics and Astronomy { Uppsala University June 22, 2021 Contents 1 Background 2 1.1 Introduction................................................2 2 Theory: Machine Learning 2 2.1 Supervised machine learning.......................................3 2.2 Classification...............................................3 2.3 Various models..............................................3 2.3.1 k-nearest neighbour (kNN)...................................3 2.3.2 Decision tree...........................................4 2.3.3 Support Vector Machine (SVM)................................4 2.3.4 Discriminant analysis......................................5 2.3.5 Ensemble.............................................6 2.4 Hyperparameter tuning.........................................6 2.5 Evaluation.................................................6 2.5.1 Confusion matrix.........................................6 2.5.2 Precision and classification accuracy..............................7 3 Theory: Astronomy 7 3.1 Dyson spheres...............................................8 3.2 Dust-enshrouded stars..........................................8 3.3 Gray Dust.................................................9 3.4 M-dwarf.................................................. 10 3.5 post-AGB -
Musical Composition Graduate Portfolio
University of Northern Iowa UNI ScholarWorks Dissertations and Theses @ UNI Student Work 2021 Musical composition graduate portfolio Juan Marulanda University of Northern Iowa Let us know how access to this document benefits ouy Copyright ©2021 Juan Marulanda Follow this and additional works at: https://scholarworks.uni.edu/etd Recommended Citation Marulanda, Juan, "Musical composition graduate portfolio" (2021). Dissertations and Theses @ UNI. 1102. https://scholarworks.uni.edu/etd/1102 This Open Access Thesis is brought to you for free and open access by the Student Work at UNI ScholarWorks. It has been accepted for inclusion in Dissertations and Theses @ UNI by an authorized administrator of UNI ScholarWorks. For more information, please contact [email protected]. Copyright by JUAN MARULANDA 2021 All Rights Reserved MUSICAL COMPOSITION GRADUATE PORTFOLIO An Abstract Submitted in Partial Fulfillment of the Requirements for the Degree Master of Music Juan Marulanda University of Northern Iowa May 2021 This Study By: Juan Carlos Marulanda Entitled: Musical Composition Graduate Portfolio has been approved as meeting the thesis requirement for the Degree of Master of Music: Composition Date Dr. Daniel Swilley, Chair, Recital Committee Date Dr. Michael Conrad, Recital Committee Member Date Dr. Jonathan Schwabe, Recital Committee Member Date Dr. Jennifer Waldron, Dean, Graduate College This Recital Performance By: Juan Marulanda Entitled: Musical Composition Graduate Portfolio has been approved as meeting the thesis requirement for the Degree of Master of Music: Composition Date Dr. Daniel Swilley, Chair, Recital Committee Date Dr. Michael Conrad, Recital Committee Member Date Dr. Jonathan Schwabe, Recital Committee Member Date Dr. Jennifer Waldron, Dean, Graduate College ABSTRACT The musical works included in this portfolio were composed between Fall 2019 and Spring 2021. -
Astro2020 Science White Paper Unlocking the Secrets of Late-Stage Stellar Evolution and Mass Loss Through Radio Wavelength Imaging
Astro2020 Science White Paper Unlocking the Secrets of Late-Stage Stellar Evolution and Mass Loss through Radio Wavelength Imaging Thematic Areas: Planetary Systems Star and Planet Formation Formation and Evolution of Compact Objects Cosmology and Fundamental Physics 7 Stars and Stellar Evolution Resolved Stellar Populations and their Environments Galaxy Evolution Multi-Messenger Astronomy and Astrophysics Principal Author: Name: Lynn D. Matthews Institution: Massachusetts Institute of Technology Haystack Observatory Email: [email protected] Co-authors: Mark J Claussen (National Radio Astronomy Observatory) Graham M. Harper (University of Colorado - Boulder) Karl M. Menten (Max Planck Institut fur¨ Radioastronomie) Stephen Ridgway (National Optical Astronomy Observatory) Executive Summary: During the late phases of evolution, low-to-intermediate mass stars like our Sun undergo periods of extensive mass loss, returning up to 80% of their initial mass to the interstellar medium. This mass loss profoundly affects the stellar evolutionary history, and the resulting circumstellar ejecta are a primary source of dust and heavy element enrichment in the Galaxy. However, many details concerning the physics of late-stage stellar mass loss remain poorly understood, including the wind launching mechanism(s), the mass loss geometry and timescales, and the mass loss histories of stars of various initial masses. These uncertainties have implications not only for stellar astrophysics, but for fields ranging from star formation to extragalactic astronomy and cosmology. Observations at centimeter, millimeter, and submillimeter wavelengths that resolve the radio surfaces and extended atmospheres of evolved arXiv:1903.05592v1 [astro-ph.SR] 13 Mar 2019 stars in space, time, and frequency are poised to provide groundbreaking new insights into these questions in the coming decade. -
August 13 2016 7:00Pm at the Herrett Center for Arts & Science College of Southern Idaho
Snake River Skies The Newsletter of the Magic Valley Astronomical Society www.mvastro.org Membership Meeting President’s Message Saturday, August 13th 2016 7:00pm at the Herrett Center for Arts & Science College of Southern Idaho. Public Star Party Follows at the Colleagues, Centennial Observatory Club Officers It's that time of year: The City of Rocks Star Party. Set for Friday, Aug. 5th, and Saturday, Aug. 6th, the event is the gem of the MVAS year. As we've done every Robert Mayer, President year, we will hold solar viewing at the Smoky Mountain Campground, followed by a [email protected] potluck there at the campground. Again, MVAS will provide the main course and 208-312-1203 beverages. Paul McClain, Vice President After the potluck, the party moves over to the corral by the bunkhouse over at [email protected] Castle Rocks, with deep sky viewing beginning sometime after 9 p.m. This is a chance to dig into some of the darkest skies in the west. Gary Leavitt, Secretary [email protected] Some members have already reserved campsites, but for those who are thinking of 208-731-7476 dropping by at the last minute, we have room for you at the bunkhouse, and would love to have to come by. Jim Tubbs, Treasurer / ALCOR [email protected] The following Saturday will be the regular MVAS meeting. Please check E-mail or 208-404-2999 Facebook for updates on our guest speaker that day. David Olsen, Newsletter Editor Until then, clear views, [email protected] Robert Mayer Rick Widmer, Webmaster [email protected] Magic Valley Astronomical Society is a member of the Astronomical League M-51 imaged by Rick Widmer & Ken Thomason Herrett Telescope Shotwell Camera https://herrett.csi.edu/astronomy/observatory/City_of_Rocks_Star_Party_2016.asp Calendars for August Sun Mon Tue Wed Thu Fri Sat 1 2 3 4 5 6 New Moon City Rocks City Rocks Lunation 1158 Castle Rocks Castle Rocks Star Party Star Party Almo, ID Almo, ID 7 8 9 10 11 12 13 MVAS General Mtg. -
Red Giant Mass-Loss: Studying Evolved Stellar Winds with FUSE and HST/STIS
Red Giant Mass-Loss: Studying Evolved Stellar Winds with FUSE and HST/STIS A dissertation submitted to the University of Dublin for the degree of Doctor of Philosophy Cian Crowley Supervisor: Dr. Brian R. Espey Trinity College Dublin, July 2006 School of Physics University of Dublin Trinity College Dublin ii For Mam and Dad Declaration I hereby declare that this thesis has not been submitted as an exercise for a degree at this or any other University and that it is entirely my own work. I agree that the Library may lend or copy this thesis upon request. Signed, Cian Crowley July 25, 2006. Publications Crowley, C., Espey, B. R.,. & McCandliss, S. R., 2006, In prep., ‘FUSE and HST/STIS Observations of the Eclipsing Symbiotic Binary EG Andromedae’ Acknowledgments I wish to acknowledge and thank Brian Espey, Stephan McCandliss and Peter Hauschildt for their contributions to this work. Most especially I would like to express my gratitude to my supervisor Brian Espey for his enthusiastic supervision, patience and encourage- ment. His help, support and advice is very much appreciated. In addition, the helpful and insightful comments and advice from numerous people, inlcuding, Graham Harper, Philip Bennett, Alex Brown, Gary Ferland, Tom Ake, B-G Anderson and Dugan With- erick, were invaluable and again, very much appreciated. Also, a special word of thanks for their viva comments and feedback for Alex Brown and Peter Gallagher. This work was supported by Enterprise Ireland Basic Research grant SC/2002/370 from EU funded NDP. The FUSE data were obtained under the Guest Investigator Pro- gram and supported by NASA grants NAG5-8994 and NAG5-10403 to the Johns Hopkins University (JHU). -
Jpc-Final-Program.Pdf
49th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit (JPC) Advancing Propulsion Capabilities in a New Fiscal Reality 14–17 July 2013 San Jose Convention Center 11th International Energy Conversion San Jose, California Engineering Conference (IECEC) FINAL PROGRAM www.aiaa.org/jpc2013 www.iecec.org #aiaaPropEnergy www.aiaa.org/jpc2013 • www.iecec.org 1 #aiaaPropEnergy GET YOUR CONFERENCE INFO ON THE GO! Download the FREE Conference Mobile App FEATURES • Browse Program – View the program at your fingertips • My Itinerary – Create your own conference schedule • Conference Info – Including special events • Take Notes – Take notes during sessions • Venue Map – San Jose Convention Center • City Map – See the surrounding area • Connect to Twitter – Tweet about what you’re doing and who you’re meeting with #aiaaPropEnergy HOW TO DOWNLOAD Any version can be run without an active Internet connection! You can also sync an Compatible with itinerary you created online with the app by entering your unique itinerary name. iPhone/iPad, MyItinerary Mobile App MyItinerary Web App Android, and • For optimal use, we recommend • For optimal use, we recommend: rd BlackBerry! iPhone 3GS, iPod Touch (3 s iPhone 3GS, iPod Touch (3rd generation), iPad iOS 4.0, or later generation), iPad iOS 4.0, • Download the MyItinerary app by or later searching for “ScholarOne” in the s Most mobile devices using Android App Store directly from your mobile 2.2 or later with the default browser device. Or, access the link below or scan the QR code to access the iTunes s BlackBerry Torch or later device Sponsored by: page for the app. -
The Maunder Minimum and the Variable Sun-Earth Connection
The Maunder Minimum and the Variable Sun-Earth Connection (Front illustration: the Sun without spots, July 27, 1954) By Willie Wei-Hock Soon and Steven H. Yaskell To Soon Gim-Chuan, Chua Chiew-See, Pham Than (Lien+Van’s mother) and Ulla and Anna In Memory of Miriam Fuchs (baba Gil’s mother)---W.H.S. In Memory of Andrew Hoff---S.H.Y. To interrupt His Yellow Plan The Sun does not allow Caprices of the Atmosphere – And even when the Snow Heaves Balls of Specks, like Vicious Boy Directly in His Eye – Does not so much as turn His Head Busy with Majesty – ‘Tis His to stimulate the Earth And magnetize the Sea - And bind Astronomy, in place, Yet Any passing by Would deem Ourselves – the busier As the Minutest Bee That rides – emits a Thunder – A Bomb – to justify Emily Dickinson (poem 224. c. 1862) Since people are by nature poorly equipped to register any but short-term changes, it is not surprising that we fail to notice slower changes in either climate or the sun. John A. Eddy, The New Solar Physics (1977-78) Foreword By E. N. Parker In this time of global warming we are impelled by both the anticipated dire consequences and by scientific curiosity to investigate the factors that drive the climate. Climate has fluctuated strongly and abruptly in the past, with ice ages and interglacial warming as the long term extremes. Historical research in the last decades has shown short term climatic transients to be a frequent occurrence, often imposing disastrous hardship on the afflicted human populations. -
Astrometrically Registered Maps of H2O and Sio Masers Toward VX Sagittarii
ARTICLE DOI: 10.1038/s41467-018-04767-8 OPEN Astrometrically registered maps of H2O and SiO masers toward VX Sagittarii Dong-Hwan Yoon1,2, Se-Hyung Cho2,3, Youngjoo Yun2, Yoon Kyung Choi2, Richard Dodson4, María Rioja4,5, Jaeheon Kim6, Hiroshi Imai7, Dongjin Kim3, Haneul Yang1,2 & Do-Young Byun2 The supergiant VX Sagittarii is a strong emitter of both H2O and SiO masers. However, previous VLBI observations have been performed separately, which makes it difficult to 1234567890():,; spatially trace the outward transfer of the material consecutively. Here we present the astrometrically registered, simultaneous maps of 22.2 GHz H2O and 43.1/42.8/86.2/129.3 GHz SiO masers toward VX Sagittarii. The H2O masers detected above the dust-forming layers have an asymmetric distribution. The multi-transition SiO masers are nearly circular ring, suggesting spherically symmetric wind within a few stellar radii. These results provide the clear evidence that the asymmetry in the outflow is enhanced after the smaller molecular gas clump transform into the inhomogeneous dust layers. The 129.3 GHz maser arises from the outermost region compared to that of 43.1/42.8/86.2 GHz SiO masers. The ring size of the 129.3 GHz maser is maximized around the optical maximum, suggesting that radiative pumping is dominant. 1 Astronomy Program, Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea. 2 Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Korea. 3 Department of Astronomy, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea. -
Sodium and Potassium Signatures Of
Sodium and Potassium Signatures of Volcanic Satellites Orbiting Close-in Gas Giant Exoplanets Apurva Oza, Robert Johnson, Emmanuel Lellouch, Carl Schmidt, Nick Schneider, Chenliang Huang, Diana Gamborino, Andrea Gebek, Aurelien Wyttenbach, Brice-Olivier Demory, et al. To cite this version: Apurva Oza, Robert Johnson, Emmanuel Lellouch, Carl Schmidt, Nick Schneider, et al.. Sodium and Potassium Signatures of Volcanic Satellites Orbiting Close-in Gas Giant Exoplanets. The Astro- physical Journal, American Astronomical Society, 2019, 885 (2), pp.168. 10.3847/1538-4357/ab40cc. hal-02417964 HAL Id: hal-02417964 https://hal.sorbonne-universite.fr/hal-02417964 Submitted on 18 Dec 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. The Astrophysical Journal, 885:168 (19pp), 2019 November 10 https://doi.org/10.3847/1538-4357/ab40cc © 2019. The American Astronomical Society. Sodium and Potassium Signatures of Volcanic Satellites Orbiting Close-in Gas Giant Exoplanets Apurva V. Oza1 , Robert E. Johnson2,3 , Emmanuel Lellouch4 , Carl Schmidt5 , Nick Schneider6 , Chenliang Huang7 , Diana Gamborino1 , Andrea Gebek1,8 , Aurelien Wyttenbach9 , Brice-Olivier Demory10 , Christoph Mordasini1 , Prabal Saxena11, David Dubois12 , Arielle Moullet12, and Nicolas Thomas1 1 Physikalisches Institut, Universität Bern, Bern, Switzerland; [email protected] 2 Engineering Physics, University of Virginia, Charlottesville, VA 22903, USA 3 Physics, New York University, 4 Washington Place, New York, NY 10003, USA 4 LESIA–Observatoire de Paris, CNRS, UPMC Univ. -
Astronomy & Astrophysics on the Properties of Massive Population III
A&A 382, 28–42 (2002) Astronomy DOI: 10.1051/0004-6361:20011619 & c ESO 2002 Astrophysics On the properties of massive Population III stars and metal-free stellar populations D. Schaerer Observatoire Midi-Pyr´en´ees, Laboratoire d’Astrophysique, UMR 5572, 14 Av. E. Belin, 31400 Toulouse, France Received 2 July 2001 / Accepted 13 November 2001 Abstract. We present realistic models for massive Population III stars and stellar populations based on non-LTE model atmospheres, recent stellar evolution tracks and up-to-date evolutionary synthesis models, with the aim to study their spectral properties, including their dependence on age, star formation history, and IMF. A comparison of plane parallel non-LTE model atmospheres and comoving frame calculations shows that even in the presence of some putative weak mass loss, the ionising spectra of metal-free populations differ little or negligibly from those obtained using plane parallel non-LTE models. As already discussed by Tumlinson & Shull (2000), the main salient property of Pop III stars is their increased ionising flux, especially in the He+ continuum (>54 eV). The main result obtained for individual Pop III stars is the following: due to their redward evolution off the zero age main sequence (ZAMS) the spectral hardness measured by the He+/H ionising flux is decreased by a factor ∼2 when averaged over their lifetime. If such stars would suffer strong mass loss, their spectral appearance could, however, remain similar to that of their ZAMS position. The main results regarding integrated stellar populations are: – for young bursts and the case of a constant SFR, nebular continuous emission – neglected in previous studies – dominates the spectrum redward of Lyman-α if the escape fraction of ionising photons out of the considered region is small or negligible. -
Aerosols in Astrophysics Stars Complete Their Cycle of Existence, There R.E.Stencel, C.A
Aerosols in Astrophysics stars complete their cycle of existence, there R.E.Stencel, C.A. Jurgenson & is a wholesale return of modified material T.A. Ostrowski-Fukuda back to the interstellar medium, affecting the The Observatories, University of Denver, next generation of star and planet formation. Department of Physics & Astronomy, Denver, Colorado 80208, USA Submitted: Evolved stars are characterized by surface 2002December30, Email: [email protected] temperatures low enough to allow molecules and solid-phase particles to exist in their ABSTRACT: atmospheres. In contrast to the nearly 6000K surface temperature of the Sun, the Solid phase material exists in low density kinetic temperatures of evolved stars may astrophysical environments, from stellar range between 2000K near their “surfaces” atmospheres to interstellar clouds, from to a few hundred K in their circumstellar current times to early phases of the universe. envelopes [CSE] at a few stellar radii We consider the origin, composition and distance. Time-dependent phase transitions evolution of solid phase materials in the from ionized plasma to cold, solid state are particular case of stellar outer atmospheres, observed, spectroscopically, to exist. as representative of many conditions. Also considered are the dynamics and interactions Some terminology may be helpful for the in circumstellar and galactic environments. reader not already acquainted with stellar Finally, new observational prospects for evolution. Solar mass stars are predicted to spectroscopy, polarimetry and leave the hydrogen-fusing “main sequence” interferometry are discussed. after approximately ten billion years, and progress through a rapid series of internal changes during what is known as the red 1.0 INTRODUCTION giant and asymptotic giant branch [RGB, AGB] phases, lasting one percent of the Solid phase material can be found nearly main sequence lifetime. -
CSIRO Australia Telescope National Facility
ASTRONOMY AND SPACE SCIENCE www.csiro.au CSIRO Australia Telescope National Facility Annual Report 2014 CSIRO Australia Telescope National Facility Annual Report 2014 ISSN 1038-9554 This is the report of the CSIRO Australia Telescope National Facility for the calendar year 2014, approved by the Australia Telescope Steering Committee. Editor: Helen Sim Designer: Angela Finney, Art when you need it Cover image: An antenna of the Australia Telescope Compact Array. Credit: Michael Gal Inner cover image: Children and a teacher from the Pia Wadjarri Remote Community School, visiting CSIRO's Murchison Radio-astronomy Observatory in 2014. Credit: CSIRO ii CSIRO Australia Telescope National Facility – Annual Report 2014 Contents Director’s Report 2 Chair’s Report 4 The ATNF in Brief 5 Performance Indicators 17 Science Highlights 23 Operations 35 Observatory and Project Reports 43 Management Team 53 Appendices 55 A: Committee membership 56 B: Financial summary 59 C: Staff list 60 D: Observing programs 65 E: PhD students 73 F: PhD theses 74 G: Publications 75 H: Abbreviations 84 1 Director’s Report Credit: Wheeler Studios Wheeler Credit: This year has seen some very positive an excellent scorecard from the Australia Dr Lewis Ball, Director, Australia results achieved by the ATNF staff, as well Telescope Users Committee. Telescope National Facility as some significant challenges. We opened We began reducing CSIRO expenditure a new office in the Australian Resources on the Mopra telescope some five years Research Centre building in Perth, installed ago. This year’s funding cut pushed us to phased-array feeds (PAFs) on antennas of take the final step along this path, and we our Australian SKA Pathfinder (ASKAP), and will no longer support Mopra operations collected data with a PAF-equipped array for using CSIRO funds after the end of the 2015 the first time ever in the world.