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Astronomie in Theorie Und Praxis 8. Auflage in Zwei Bänden Erik Wischnewski
Astronomie in Theorie und Praxis 8. Auflage in zwei Bänden Erik Wischnewski Inhaltsverzeichnis 1 Beobachtungen mit bloßem Auge 37 Motivation 37 Hilfsmittel 38 Drehbare Sternkarte Bücher und Atlanten Kataloge Planetariumssoftware Elektronischer Almanach Sternkarten 39 2 Atmosphäre der Erde 49 Aufbau 49 Atmosphärische Fenster 51 Warum der Himmel blau ist? 52 Extinktion 52 Extinktionsgleichung Photometrie Refraktion 55 Szintillationsrauschen 56 Angaben zur Beobachtung 57 Durchsicht Himmelshelligkeit Luftunruhe Beispiel einer Notiz Taupunkt 59 Solar-terrestrische Beziehungen 60 Klassifizierung der Flares Korrelation zur Fleckenrelativzahl Luftleuchten 62 Polarlichter 63 Nachtleuchtende Wolken 64 Haloerscheinungen 67 Formen Häufigkeit Beobachtung Photographie Grüner Strahl 69 Zodiakallicht 71 Dämmerung 72 Definition Purpurlicht Gegendämmerung Venusgürtel Erdschattenbogen 3 Optische Teleskope 75 Fernrohrtypen 76 Refraktoren Reflektoren Fokus Optische Fehler 82 Farbfehler Kugelgestaltsfehler Bildfeldwölbung Koma Astigmatismus Verzeichnung Bildverzerrungen Helligkeitsinhomogenität Objektive 86 Linsenobjektive Spiegelobjektive Vergütung Optische Qualitätsprüfung RC-Wert RGB-Chromasietest Okulare 97 Zusatzoptiken 100 Barlow-Linse Shapley-Linse Flattener Spezialokulare Spektroskopie Herschel-Prisma Fabry-Pérot-Interferometer Vergrößerung 103 Welche Vergrößerung ist die Beste? Blickfeld 105 Lichtstärke 106 Kontrast Dämmerungszahl Auflösungsvermögen 108 Strehl-Zahl Luftunruhe (Seeing) 112 Tubusseeing Kuppelseeing Gebäudeseeing Montierungen 113 Nachführfehler -
The Puzzle of the Strange Galaxy Made of 99.9% Dark Matter Is Solved 13 October 2020
The puzzle of the strange galaxy made of 99.9% dark matter is solved 13 October 2020 The galaxy Dragonfly 44 was discovered in a deep survey of the Coma cluster, a cluster with several thousand galaxies. From the start, the galaxy was considered remarkable by the researchers because the quantity of dark matter they inferred was almost as much as that in the Milky Way, the equivalent of a billion solar masses. However, instead of containing around a hundred thousand million stars, as has the Milky Way, DF44 has only a hundred million stars, a thousand times Image and amplification (in color) of the ultra-diffuse fewer. This means that the amount of dark matter galaxy Dragonfly 44 taken with the Hubble space was ten thousand times greater than that of its telescope. Credit: Teymoor Saifollahi and NASA/HST. stars. If this had been true, it would have been a unique object, with almost 100 times as much dark matter as that expected from the number of its stars. At present, the formation of galaxies is difficult to understand without the presence of a ubiquitous, Nevertheless, by an exhaustive analysis of the but mysterious component, termed dark matter. system of globular cluster around Dragonfly 44, the Astronomers have measure how much dark matter researchers have detected that the total number of there is around galaxies, and have found that it globular clusters is only 20, and that the total varies between 10 and 300 times the quantity of quantity of dark matter is around 300 times that of visible matter. -
A High Stellar Velocity Dispersion and ~100 Globular Clusters for the Ultra
San Jose State University From the SelectedWorks of Aaron J. Romanowsky 2016 A High Stellar Velocity Dispersion and ~100 Globular Clusters for the Ultra-Diffuse Galaxy Dragonfly 44 Pieter van Dokkum, Yale University Roberto Abraham, University of Toronto Jean P. Brodie, University of California Observatories Charlie Conroy, Harvard-Smithsonian Center for Astrophysics Shany Danieli, Yale University, et al. Available at: https://works.bepress.com/aaron_romanowsky/117/ The Astrophysical Journal Letters, 828:L6 (6pp), 2016 September 1 doi:10.3847/2041-8205/828/1/L6 © 2016. The American Astronomical Society. All rights reserved. A HIGH STELLAR VELOCITY DISPERSION AND ∼100 GLOBULAR CLUSTERS FOR THE ULTRA-DIFFUSE GALAXY DRAGONFLY 44 Pieter van Dokkum1, Roberto Abraham2, Jean Brodie3, Charlie Conroy4, Shany Danieli1, Allison Merritt1, Lamiya Mowla1, Aaron Romanowsky3,5, and Jielai Zhang2 1 Astronomy Department, Yale University, New Haven, CT 06511, USA 2 Department of Astronomy & Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4, Canada 3 University of California Observatories, 1156 High Street, Santa Cruz, CA 95064, USA 4 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA, USA 5 Department of Physics and Astronomy, San José State University, San Jose, CA 95192, USA Received 2016 June 20; revised 2016 July 14; accepted 2016 July 15; published 2016 August 25 ABSTRACT Recently a population of large, very low surface brightness, spheroidal galaxies was identified in the Coma cluster. The apparent survival of these ultra-diffuse galaxies (UDGs) in a rich cluster suggests that they have very high masses. Here, we present the stellar kinematics of Dragonfly44, one of the largest Coma UDGs, using a 33.5 hr fi +8 -1 integration with DEIMOS on the Keck II telescope. -
Messier Objects
Messier Objects From the Stocker Astroscience Center at Florida International University Miami Florida The Messier Project Main contributors: • Daniel Puentes • Steven Revesz • Bobby Martinez Charles Messier • Gabriel Salazar • Riya Gandhi • Dr. James Webb – Director, Stocker Astroscience center • All images reduced and combined using MIRA image processing software. (Mirametrics) What are Messier Objects? • Messier objects are a list of astronomical sources compiled by Charles Messier, an 18th and early 19th century astronomer. He created a list of distracting objects to avoid while comet hunting. This list now contains over 110 objects, many of which are the most famous astronomical bodies known. The list contains planetary nebula, star clusters, and other galaxies. - Bobby Martinez The Telescope The telescope used to take these images is an Astronomical Consultants and Equipment (ACE) 24- inch (0.61-meter) Ritchey-Chretien reflecting telescope. It has a focal ratio of F6.2 and is supported on a structure independent of the building that houses it. It is equipped with a Finger Lakes 1kx1k CCD camera cooled to -30o C at the Cassegrain focus. It is equipped with dual filter wheels, the first containing UBVRI scientific filters and the second RGBL color filters. Messier 1 Found 6,500 light years away in the constellation of Taurus, the Crab Nebula (known as M1) is a supernova remnant. The original supernova that formed the crab nebula was observed by Chinese, Japanese and Arab astronomers in 1054 AD as an incredibly bright “Guest star” which was visible for over twenty-two months. The supernova that produced the Crab Nebula is thought to have been an evolved star roughly ten times more massive than the Sun. -
Spatially Resolved Stellar Kinematics of the Ultra-Diffuse Galaxy Dragonfly 44
The Astrophysical Journal, 880:91 (26pp), 2019 August 1 https://doi.org/10.3847/1538-4357/ab2914 © 2019. The American Astronomical Society. All rights reserved. Spatially Resolved Stellar Kinematics of the Ultra-diffuse Galaxy Dragonfly 44. I. Observations, Kinematics, and Cold Dark Matter Halo Fits Pieter van Dokkum1 , Asher Wasserman2 , Shany Danieli1 , Roberto Abraham3 , Jean Brodie2 , Charlie Conroy4 , Duncan A. Forbes5, Christopher Martin6, Matt Matuszewski6, Aaron J. Romanowsky2,7 , and Alexa Villaume2 1 Astronomy Department, Yale University, 52 Hillhouse Avenue, New Haven, CT 06511, USA 2 University of California Observatories, 1156 High Street, Santa Cruz, CA 95064, USA 3 Department of Astronomy & Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4, Canada 4 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA, USA 5 Centre for Astrophysics and Supercomputing, Swinburne University, Hawthorn, VIC 3122, Australia 6 Cahill Center for Astrophysics, California Institute of Technology, 1216 East California Boulevard, Mail Code 278-17, Pasadena, CA 91125, USA 7 Department of Physics and Astronomy, San José State University, San Jose, CA 95192, USA Received 2019 March 31; revised 2019 May 25; accepted 2019 June 5; published 2019 July 30 Abstract We present spatially resolved stellar kinematics of the well-studied ultra-diffuse galaxy (UDG) Dragonfly44, as determined from 25.3 hr of observations with the Keck Cosmic Web Imager. The luminosity-weighted dispersion +3 −1 within the half-light radius is s12= 33-3 km s , lower than what we had inferred before from a DEIMOS spectrum in the Hα region. There is no evidence for rotation, with Vmax áñ<s 0.12 (90% confidence) along the major axis, in possible conflict with models where UDGs are the high-spin tail of the normal dwarf galaxy distribution. -
The Origin of Ultra Diffuse Galaxies: Stellar Feedback and Quenching
MNRAS 478, 906–925 (2018) doi:10.1093/mnras/sty1153 Advance Access publication 2018 May 4 The origin of ultra diffuse galaxies: stellar feedback and quenching T. K. Chan,1‹ D. Keres,ˇ 1 A. Wetzel,2,3,4† P. F. Hopkins,2 C.-A. Faucher-Giguere,` 5 K. El-Badry,6 S. Garrison-Kimmel2 and M. Boylan-Kolchin7 1Department of Physics, Center for Astrophysics and Space Sciences, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA 2TAPIR, Mailcode 350-17, California Institute of Technology, Pasadena, CA 91125, USA 3The Observatories of the Carnegie Institution for Science, Pasadena, CA 91101, USA 4Department of Physics, University of California, Davis, CA 95616, USA 5Department of Physics and Astronomy and CIERA, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA 6Department of Astronomy and Theoretical Astrophysics Center, University of California Berkeley, Berkeley, CA 94720, USA 7Department of Astronomy, The University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205, USA Accepted 2018 May 1. Received 2018 March 21; in original form 2017 November 12 ABSTRACT We test if the cosmological zoom-in simulations of isolated galaxies from the FIRE project reproduce the properties of ultra diffuse galaxies (UDGs). We show that outflows that dy- namically heat galactic stars, together with a passively aging stellar population after imposed quenching, naturally reproduce the observed population of red UDGs, without the need for high spin haloes, or dynamical influence from their host cluster. We reproduce the range of surface brightness, radius, and absolute magnitude of the observed red UDGs by quenching simulated galaxies at a range of different times. -
Highlighting Ultra Diffuse Galaxies: VCC 1287 and Dragonfly 44 AS DISCUSSED in VAN DOKKUM ET AL
Highlighting Ultra Diffuse Galaxies: VCC 1287 and Dragonfly 44 AS DISCUSSED IN VAN DOKKUM ET AL. 2016, BEASLEY ET AL. 2016 PRESENTED BY MICHAEL SANDOVAL Overview §Brief Overview of Galactic Structure and Globular Clusters (GCs) §Background of Ultra Diffuse Galaxies (UDGs) §The Search Process: Challenges and Importance §Dragonfly 44 §VCC 1287 §Big Picture: what do the results mean? Crash Course: Galactic Structure and GCs §Focusing on two features: § Globular Clusters (GCs) § Dark Matter Halo (DMH) §GCs extend to the outer halo and are used for dynamics measurements §DMH extends passed the visible structure What is a UDG? •Galaxies the size of the Milky Way, but significantly less bright •Problem: Act like they have very high mass, but have very little mass….? •Large dark matter fractions •Relatively featureless, but round and red •Not sure how they are formed • Perhaps they are “failed” galaxies? • Maybe from tidal forces? Reference: van Dokkum et al. 2016 Reference: Sandoval et al. 2015 Search Process – The Dragonfly •The Dragonfly Telephoto Array • Collaboration between Yale and University of Toronto in 2013 • Designed by Pieter van Dokkum & Roberto Abraham • Multi-lens array designed for ultra-low brightness visible astro • 400mm Canon lenses – as of 2016 Dragonfly has 48 lenses • Cold Dark Matter (CDM) cosmology Reference: Abraham & van Dokkum 2014 Search Process – Computational Method •Utilize images from Canada France Hawaii Telescope (CFHT) •MegaPrime/MegaCam is the wide-field optical imaging facility at CFHT. •Comparable to the Sloan Digital Sky Survey’s (SDSS) navigation tool. •Search through optical images looking for diffuse galaxies. •Analyze photometry The Early Discoveries •47 UDGs found with the Dragonfly in 2014 in the Coma cluster • Combined data with SDSS, CFHT • Radial velocity measurements (Coma: cz ∼ 7090 km/s) •Stony Brook, National Astronomical Observatory of Japan (NAOJ) follow up • Discovery of 854 UDGs in the Coma cluster • Analyzed data from the Subaru Reference: van Dokkum et al. -
Error in Modern Astronomy
Error in Modern Astronomy Eric Su [email protected] https://sites.google.com/view/physics-news/home (Dated: August 1, 2019) The conservation of the interference pattern from double slit interference proves that the wave- length is conserved in all inertial reference frames. However, there is a popular belief in modern astronomy that the wavelength can be changed by the choice of reference frame. This erroneous belief results in the problematic prediction of the radial speed of galaxy. The reflection symmetry shows that the elapsed time is conserved in all inertial reference frames. From both conservation properties, the velocity of the light is proved to be different in a different reference frame. This different velocity was confirmed by lunar laser ranging test at NASA in 2009. The relative motion between the light source and the light detector bears great similarity to the magnetic force on a moving charge. The motion changes the interference pattern but not the wavelength in the rest frame of the star. This is known as the blueshift or the redshift in astronomy. The speed of light in the rest frame of the grism determines how the spectrum is shifted. Wide Field Camera 3 in Hubble Space Telescope provides an excellent example on how the speed of light can change the spectrum. I. INTRODUCTION location of the light band is y1. The separation between the parallel slits is d1. The double slit interference can be formulated with the If d1 << y1 and d1 << D1, the constructive interfer- principle of superposition[1]. The interference pattern is ence can be described by the equation of phase shift[1] a function of the incident wavelength. -
New Type of Black Hole Detected in Massive Collision That Sent Gravitational Waves with a 'Bang'
New type of black hole detected in massive collision that sent gravitational waves with a 'bang' By Ashley Strickland, CNN Updated 1200 GMT (2000 HKT) September 2, 2020 <img alt="Galaxy NGC 4485 collided with its larger galactic neighbor NGC 4490 millions of years ago, leading to the creation of new stars seen in the right side of the image." class="media__image" src="//cdn.cnn.com/cnnnext/dam/assets/190516104725-ngc-4485-nasa-super-169.jpg"> Photos: Wonders of the universe Galaxy NGC 4485 collided with its larger galactic neighbor NGC 4490 millions of years ago, leading to the creation of new stars seen in the right side of the image. Hide Caption 98 of 195 <img alt="Astronomers developed a mosaic of the distant universe, called the Hubble Legacy Field, that documents 16 years of observations from the Hubble Space Telescope. The image contains 200,000 galaxies that stretch back through 13.3 billion years of time to just 500 million years after the Big Bang. " class="media__image" src="//cdn.cnn.com/cnnnext/dam/assets/190502151952-0502-wonders-of-the-universe-super-169.jpg"> Photos: Wonders of the universe Astronomers developed a mosaic of the distant universe, called the Hubble Legacy Field, that documents 16 years of observations from the Hubble Space Telescope. The image contains 200,000 galaxies that stretch back through 13.3 billion years of time to just 500 million years after the Big Bang. Hide Caption 99 of 195 <img alt="A ground-based telescope&amp;#39;s view of the Large Magellanic Cloud, a neighboring galaxy of our Milky Way. -
Proton! Physics Under the Direction of Guido Energy Physics Under the Direction of We’Ll Even Print Your Abstract! Mueller
P R O T O N Physics Report on Things of Note January 2006 -- Vol. 5 No. 1 Physics Department Year-End Awards Announced Featured Publication(s) Each December, the Department holds an Awards Ceremony during the Annual Holiday Party, to recognize staff and faculty who have achieved superior perfor- T. S. Nunner, B. M. Ander- mance, and to announce the Graduate Student Awards which recognize outstand- sen, A. Melikyan, and P. J. ing graduate students from the past year. Hirschfeld. “Dopant-Modulated Pair Physics Teacher of the Year (2005) Interaction in Cuprate Super- Stephen Hill conductors.” Phys. Rev. Lett. 95, 177003 (2005). Physics Employee Excellence Awards (2005) Yvonne Dixon and Greg Labbe B. Abbott et al. (LIGO Scien- tific Collaboration). Graduate Student Awards (2005) “Upper Limits on a Stochastic Background of Gravitational Tom Scott Memorial Award : TA of the Year for the Introductory Waves.” James Ira Thorpe Labs : Sung-Soo Kim Phys. Rev. Lett. 95, 221101 (2005) This award is made annually to a se- This award recognizes Sung-Soo’s nior graduate student, in experimental commitment to his students and to the Submit your article to be featured physics, who has shown distinction in educational atmosphere in the labora- in this section. Whether it’s just research. Ira is a 2nd year graduate tory setting. Sung-Soo is a 4th year been submitted or accepted, we’d student working in experimental astro- student working in theoretical high like to feature it in the proton! physics under the direction of Guido energy physics under the direction of We’ll even print your abstract! Mueller. -
Some Astrophysical and Cosmological Findings from TGD Point of View
Some astrophysical and cosmological findings from TGD point of view M. Pitk¨anen Email: [email protected]. http://tgdtheory.com/. June 20, 2019 Abstract There are five rather recent findings not easy to understand in the framework of standard astrophysics and cosmology. The first finding is that the model for the absorption of dark matter by blackholes predicts must faster rate than would be consistent with observations. Second finding is that Milky Way has large void extending from 150 ly up to 8,000 light years. Third finding is the existence of galaxy estimated to have mass of order Milky Way mass but for which 98 per cent of mass within half-light radius is estimated to be dark in halo model. The fourth finding confirms the old finding that the value of Hubble constant is 9 per cent larger in short scales (of order of the size large voids) than in cosmological scales. The fifth finding is that astrophysical object do not co-expand but only co-move in cosmic expansion. TGD suggests an explanation for the two first observation in terms of dark matter with gravitational Planck constant hgr, which is very large so that dark matter is at some level quantum coherent even in galactic scales. Second and third findings can be explained using TGD based model of dark matter and energy assigning them to long cosmic strings having galaxies along them like pearls in necklace. Fourth finding can be understood in terms of many-sheeted space-time. The space-time sheets assignable to large void and entire cosmology have different Hubble constants and expansion rate. -
High Resolution Search for Dark Matter Axions in Milky Way Halo Substructure
HIGH RESOLUTION SEARCH FOR DARK MATTER AXIONS IN MILKY WAY HALO SUBSTRUCTURE By LEANNE DELMA DUFFY A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2006 ACKNOWLEDGMENTS This work is based on research performed by the Axion Dark Matter eX- periment (ADMX). I am grateful to my ADMX collaborators for their efforts, particularly in running the experiment and providing the high resolution data. Without these efforts, this work would not have been possible. I thank my advisor, Pierre Sikivie, for his support and guidance thoughout graduate school. It has been a priviege to collaborate with him on this and other projects. I also thank Dave Tanner for his assistance and advice on this work. I would like to thank the other members of my advisory committee, Jim Fry, Guenakh Mitselmakher, Pierre Ramond, Richard Woodard and Fred Hamann, for their roles in my progress. I am also grateful to the other members of the University of Florida Physics Department who have contributed to my graduate school experience. I am especially grateful to my family and friends, both near and far, who have supported me through this long endeavor. Special thanks go to Lisa Everett and Ethan Siegel. ii TABLE OF CONTENTS page ACKNOWLEDGMENTS ............................. ii LIST OF TABLES ................................. v LIST OF FIGURES ................................ vi ABSTRACT .................................... viii CHAPTER 1 INTRODUCTION .............................. 1 2 AXIONS .................................... 7 2.1 Introduction ............................... 7 2.2 The Strong CP Problem ........................ 7 2.3 The Axion ................................ 11 2.3.1 Introduction ........................... 11 2.3.2 The Peccei-Quinn Solution to the Strong CP Problem ...