INFORMATION CIRCULAR No. 176 (FEBRUARY 2012)
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Hubbl E Space T El Escope Wfpc2 Imaging of Fs Tauri and Haro 6-5B1 John E.Krist,2 Karl R.Stapelfeldt,3 Christopher J.Burrows,2,4 Gilda E.Ballester,5 John T
THE ASTROPHYSICAL JOURNAL, 501:841È852, 1998 July 10 ( 1998. The American Astronomical Society. All rights reserved. Printed in U.S.A. HUBBL E SPACE T EL ESCOPE WFPC2 IMAGING OF FS TAURI AND HARO 6-5B1 JOHN E.KRIST,2 KARL R.STAPELFELDT,3 CHRISTOPHER J.BURROWS,2,4 GILDA E.BALLESTER,5 JOHN T. CLARKE,5 DAVID CRISP,3 ROBIN W.EVANS,3 JOHN S.GALLAGHER III,6 RICHARD E.GRIFFITHS,7 J. JEFF HESTER,8 JOHN G.HOESSEL,6 JON A.HOLTZMAN,9 JEREMY R.MOULD,10 PAUL A. SCOWEN,8 JOHN T.TRAUGER,3 ALAN M. WATSON,11 AND JAMES A. WESTPHAL12 Received 1997 December 18; accepted 1998 February 16 ABSTRACT We have observed the Ðeld of FS Tauri (Haro 6-5) with the Wide Field Planetary Camera 2 on the Hubble Space Telescope. Centered on Haro 6-5B and adjacent to the nebulous binary system of FS Tauri A there is an extended complex of reÑection nebulosity that includes a di†use, hourglass-shaped structure. H6-5B, the source of a bipolar jet, is not directly visible but appears to illuminate a compact, bipolar nebula which we assume to be a protostellar disk similar to HH 30. The bipolar jet appears twisted, which explains the unusually broad width measured in ground-based images. We present the Ðrst resolved photometry of the FS Tau A components at visual wavelengths. The Ñuxes of the fainter, eastern component are well matched by a 3360 K blackbody with an extinction ofAV \ 8. For the western star, however, any reasonable, reddened blackbody energy distribution underestimates the K-band photometry by over 2 mag. -
Hard X-Ray Emission Clumps in the Γ-Cygni Supernova Remnant: the an INTEGRAL-ISGRI View To
A&A 427, L21–L24 (2004) Astronomy DOI: 10.1051/0004-6361:200400089 & c ESO 2004 Astrophysics Editor Hard X-ray emission clumps in the γ-Cygni supernova remnant: the An INTEGRAL-ISGRI view to A. M. Bykov1, A. M. Krassilchtchikov1 , Yu. A. Uvarov1,H.Bloemen2,R.A.Chevalier3, M. Yu. Gustov1, W. Hermsen2,F.Lebrun4,T.A.Lozinskaya5,G.Rauw6,T.V.Smirnova7, S. J. Sturner8, J.-P. Swings6, R. Terrier4, and I. N. Toptygin1 Letter 1 A. F. Ioffe Institute for Physics and Technology, 26 Polytechnicheskaia, 194021 St. Petersburg, Russia e-mail: [email protected] 2 SRON National Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands 3 Department of Astronomy, University of Virginia, PO Box 3818, Charlottesville, VA 22903, USA 4 CEA – Saclay, DSM/DAPNIA/Service d’Astrophysique, 91191 Gif-sur-Yvette Cedex, France 5 Sternberg Astronomical Institute, Moscow State University, 13 Universitetskij, 119899 Moscow, Russia 6 Institut d’Astrophysique et de Géophysique, Université de Liège, Allée du 6 Août 17, Bât. B5c, 4000 Liège, Belgium 7 Astro Space Center of the Lebedev Physics Institute, 84/32 Profsoyuznaia, 117810 Moscow, Russia 8 NASA Goddard Space Flight Center, Code 661, Greenbelt, MD 20771, USA Received 22 September 2004 / Accepted 9 October 2004 Abstract. Spatially resolved images of the galactic supernova remnant G78.2+2.1 (γ-Cygni) in hard X-ray energy bands from 25 keV to 120 keV are obtained with the IBIS-ISGRI imager aboard the International Gamma-Ray Astrophysics Laboratory INTEGRAL. The images are dominated by localized clumps of about ten arcmin in size. -
Dynamical Dust Traps in Misaligned Circumbinary Discs: Analytical Theory and Numerical Simulations
MNRAS 000,1–10 (2021) Preprint 24 March 2021 Compiled using MNRAS LATEX style file v3.0 Dynamical dust traps in misaligned circumbinary discs: analytical theory and numerical simulations Cristiano Longarini,1¢ Giuseppe Lodato,1 Claudia Toci1 and Hossam Aly2 1Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano, Italy 2Univ Lyon, Univ Claude Bernard Lyon 1, Ens de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, F-69230, Saint-Genis-Laval, France Accepted XXX. Received YYY; in original form ZZZ ABSTRACT Recent observations have shown that circumbinary discs can be misaligned with respect to the binary orbital plane.The lack of spherical symmetry, together with the non-planar geometry of these systems, causes differential precession which might induce the propagation of warps. While gas dynamics in such environments is well understood, little is known about dusty discs. In this work, we analytically study the problem of dust traps formation in misaligned circumbinary discs. We find that pile-ups may be induced not by pressure maxima, as the usual dust traps, but by a difference in precession rates between the gas and dust. Indeed, this difference makes the radial drift inefficient in two locations, leading to the formation of two dust rings whose position depends on the system parameters. This phenomenon is likely to occur to marginally coupled dust particles ¹St & 1º as both the effect of gravitational and drag force are considerable. We then perform a suite of three-dimensional SPH numerical simulations to compare the results with our theoretical predictions. We explore the parameter space, varying stellar mass ratio, disc thickness, radial extension, and we find a general agreement with the analytical expectations. -
The Study of Astronomical Transients in the Infrared
The Study of Astronomical Transients in the Infrared by Robert Strausbaugh A Dissertation Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy Approved May 2019 by the Graduate Supervisory Committee: Nathaniel Butler, Chair Rolf Jansen Phillip Mauskopf Rogier Windhorst ARIZONA STATE UNIVERSITY August 2019 ©2019 Robert Strausbaugh All Rights Reserved ABSTRACT Several key, open questions in astrophysics can be tackled by searching for and mining large datasets for transient phenomena. The evolution of massive stars and compact objects can be studied over cosmic time by identifying supernovae (SNe) and gamma-ray bursts (GRBs) in other galaxies and determining their redshifts. Modeling GRBs and their afterglows to probe the jets of GRBs can shed light on the emission mechanism, rate, and energetics of these events. In Chapter 1, I discuss the current state of astronomical transient study, including sources of interest, instrumentation, and data reduction techniques, with a focus on work in the infrared. In Chapter 2, I present original work published in the Proceedings of the Astronomical Society of the Pacific, testing InGaAs infrared detectors for astronomical use (Strausbaugh, Jackson, and Butler 2018); highlights of this work include observing the exoplanet transit of HD189773B, and detecting the nearby supernova SN2016adj with an InGaAs detector mounted on a small telescope at ASU. In Chapter 3, I discuss my work on GRB jets published in the Astrophysical Journal Letters, highlighting the interesting case of GRB 160625B (Strausbaugh et al. 2019), where I interpret a late-time bump in the GRB afterglow lightcurve as evidence for a bright-edged jet. -
International Astronomical Union Commission 42 BIBLIOGRAPHY of CLOSE BINARIES No. 93
International Astronomical Union Commission 42 BIBLIOGRAPHY OF CLOSE BINARIES No. 93 Editor-in-Chief: C.D. Scarfe Editors: H. Drechsel D.R. Faulkner E. Kilpio E. Lapasset Y. Nakamura P.G. Niarchos R.G. Samec E. Tamajo W. Van Hamme M. Wolf Material published by September 15, 2011 BCB issues are available via URL: http://www.konkoly.hu/IAUC42/bcb.html, http://www.sternwarte.uni-erlangen.de/pub/bcb or http://www.astro.uvic.ca/∼robb/bcb/comm42bcb.html The bibliographical entries for Individual Stars and Collections of Data, as well as a few General entries, are categorized according to the following coding scheme. Data from archives or databases, or previously published, are identified with an asterisk. The observation codes in the first four groups may be followed by one of the following wavelength codes. g. γ-ray. i. infrared. m. microwave. o. optical r. radio u. ultraviolet x. x-ray 1. Photometric data a. CCD b. Photoelectric c. Photographic d. Visual 2. Spectroscopic data a. Radial velocities b. Spectral classification c. Line identification d. Spectrophotometry 3. Polarimetry a. Broad-band b. Spectropolarimetry 4. Astrometry a. Positions and proper motions b. Relative positions only c. Interferometry 5. Derived results a. Times of minima b. New or improved ephemeris, period variations c. Parameters derivable from light curves d. Elements derivable from velocity curves e. Absolute dimensions, masses f. Apsidal motion and structure constants g. Physical properties of stellar atmospheres h. Chemical abundances i. Accretion disks and accretion phenomena j. Mass loss and mass exchange k. Rotational velocities 6. Catalogues, discoveries, charts a. -
GW ORIONIS: a T-TAURI MULTIPLE SYSTEM OBSERVED with AU-SCALE RESOLUTION. J. P. Berger, Laboratoire D'astrophysique De Grenoble
Protostars and Planets V 2005 8398.pdf GW ORIONIS: A T-TAURI MULTIPLE SYSTEM OBSERVED WITH AU-SCALE RESOLUTION. J. P.Berger, Laboratoire d’Astrophysique de Grenoble,, BP-53, F-38041 Grenoble Cedex, France,[email protected], J. Monnier, E. Pedretti, University of Michigan, , Ann Arbor, MI 48109-1090. USA , R. Millan-Gabet, California Institute of Technology, Pasadena, CA 91125, USA, F. Malbet, K. Perraut, P. Kern, M. Benisty, P. Haguenauer, Laboratoire d’Astrophysique de Grenoble, F-38041 Grenoble Cedex, France, P. Labeye, CEA-LETI 38054 Grenoble, Cedex, France, W. Traub, N. Carleton, M. Lacasse, Harvard Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA, S. Meimon, ONERA, Chatillon, France, C. Brechet, E. Thiebaut, CRAL, Lyon, France, P.Schloerb, University of Massachusetts at Amherst, Astronomy Department, Amherst, MA 01003, USA. GW Orionis is a well known single-line spectroscopic bi- 3 instrument which allows to measure simultaneously 3 vis- nary classified as a T Tauri star. The measured period is ≈ 242 ibilities and one closure phase (Monnier et al. 2004). The days. The stars are separated by ≈ 1.1AU and have a nearly addition of several measurements at different hour angle and circular orbit. The analysis of the residuals have revealed the two IOTA configuration allowed a map of the (u,v) plane suf- signature of a putative third companion with orbital period ficient to carry out the first reconstruction of an image of a T ≈ 1000 days. Tauri star with Astronomical Unit resolution (see Figure 1). The combination of spectroscopic measurements and spec- A detailed analysis of visibilities and closure phases is tral energy distribution modelization has lead Mathieu et al.(1991) however preferable if one is to quantify the system parameters to describe GW Orionis as a primary star surrounded with a cir- with a certain accuracy (see Figure 2). -
Astronomy Astrophysics
A&A 453, 101–119 (2006) Astronomy DOI: 10.1051/0004-6361:20053894 & c ESO 2006 Astrophysics On the difference between nuclear and contraction ages, W. Lyra1,2,3,A.Moitinho4,N.S.vanderBliek1,andJ.Alves5 1 Cerro Tololo Interamerican Observatory, Casilla 603 La Serena, Chile 2 Observatório do Valongo/UFRJ, Ladeira do Pedro Antônio 43, 20080-090 Rio de Janeiro, Brazil 3 Department of Astronomy and Space Physics, Uppsala Astronomical Observatory, Box 515, 751 20 Uppsala, Sweden e-mail: [email protected] 4 Observatório Astronómico de Lisboa, Tapada da Ajuda, 1349-018 Lisbon, Portugal 5 European Southern Observatory, Karl-Schwarzschild 2, 85748 Garching, Germany Received 23 July 2005 / Accepted 20 February 2006 ABSTRACT Context. Ages derived from low mass stars still contracting onto the main sequence often differ from ages derived from the high mass ones that have already evolved away from it. Aims. We investigate the general claim of disagreement between these two independent age determinations by presenting UBVRI pho- tometry for the young galactic open clusters NGC 2232, NGC 2516, NGC 2547 and NGC 4755, spanning the age range ∼10–150 Myr Methods. We derived reddenings, distances, and nuclear ages by fitting ZAMS and isochrones to color–magnitudes and color–color di- agrams. To derive contraction ages, we used four different pre-main sequence models, with an empirically calibrated color-temperature relation to match the Pleiades cluster sequence. Results. When exclusively using the V vs. V − I color–magnitude diagram and empirically calibrated isochrones, there is consistency between nuclear and contraction ages for the studied clusters. -
The Star Newsletter
THE HOT STAR NEWSLETTER ? An electronic publication dedicated to A, B, O, Of, LBV and Wolf-Rayet stars and related phenomena in galaxies No. 37 February 1998 editor: Philippe Eenens http://www.astro.ugto.mx/∼eenens/hot/ [email protected] http://www.star.ucl.ac.uk/∼hsn/index.html Contents of this newsletter Abstracts of 6 accepted papers . 1 Abstracts of 2 submitted papers . .4 Abstract of 2 dissertation theses . 6 Accepted Papers The WC10 Central Stars CPD–56o8032 and He 2–113: III. Wind Electron Temperature and Abundances O. De Marco, P. J. Storey and M. J.Barlow Dept. of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK We present a direct spectroscopic measurement of the wind electron temperatures and a determination of the stellar wind abundances of the WC10 central stars of planetary nebulae CPD–56o8032 and He 2– 113, for which high resolution (0.15 A)˚ UCLES echelle spectra have been obtained using the 3.9 m AAT. The intensities of dielectronic recombination lines, originating from auto–ionising resonance states situated in the C2+ + e− continuum, are sensitive to the electron temperature through the populations of these states which are close to their LTE values. The high resolution spectra allow the intensities of fine–structure components of the dielectronic multiplets to be measured. New atomic data for the autoionization and radiative transition probabilities of the resonance states are presented and used to derive wind electron temperatures in the two stars of 21 300 K for CPD–56o8023 and 16 400 K for He 2–113. -
High-Resolution Optical and Near-Infrared Imaging of Young Circumstellar Disks
HIGH-RESOLUTION OPTICAL AND NEAR-INFRARED IMAGING OF YOUNG CIRCUMSTELLAR DISKS MARK McCAUGHREAN Astrophysikalisches Institut Potsdam KARL STAPELFELDT Jet Propulsion Laboratory, California Institute of Technology and LAIRD CLOSE Institute for Astronomy, University of Hawaii In the past five years, observations at optical and near-infrared wavelengths obtained with the Hubble Space Telescope and ground-based adaptive op- tics have provided the first well-resolved images of young circumstellar disks which may form planetary systems. We review these two observational tech- niques and highlight their results by presenting prototype examples of disks imaged in the Taurns-Auriga and Orion star-forming regions. As appropri- ate, we discuss the disk parameters that may be typically derived from the observations, as well as the implications that the observations may have on our understanding of, for example, the role of the ambient environment in shaping the disk evolution. We end with a brief summary of the prospects for future improvements in space- and ground-based optical/IR imaging tech- niques, and how they may impact disk studies. I. DIRECT IMAGING OF CIRCUMSTELLAR DISKS The Copernican demotion of humankind away from the center of our local planetary system also provided the shift in perspective re- quired to understand its cosmogony. Once it was apparent that the solar system comprised a number of planets in essentially circular and coplanar orbits around the Sun, theories for its formation were devel- oped involving condensation from a rotating disk-shaped primordial nebula, or Urnebel. The so-called "Kant-Laplace nebular hypothesis" eventually held sway in the latter half of the twentieth century af- ter lengthy competition with rival "catastrophic" theories (see Koerner 1997 for a review), and was subsequently vindicated by the discovery of analogues to the Urnebel around young stars elsewhere in the galaxy. -
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. -
WIS-2015-07-Radioastronomie ALMA Teil4.Pdf (Application/Pdf 4.0
Das Projekt ALMA Mater* Teil 4: Eine Beobachtung, die es in sich hat: eine „Kinderstube“ für Planeten *Wir verwenden die Bezeichnung Alma Mater als Synonym für eine Universität. Seinen Ursprung hat das Doppelwort im Lateinischen (alma: nähren, mater: Mutter). Im übertragenen Sinne ernährt die (mütterliche) Universität ihre Studenten mit Wissen. Und weiter gesponnen ernährt das Projekt ALMA auch die Schüler und Studenten mit Anreizen für das Lernen. (Zudem bedeutet das spanische Wort ‚Alma‘: Seele.) In Bezug (Materie bei T-Tauri-Sternen) zum Beitrag „Der Staubring von GG Tauri“ von Wolfgang Brandner in der Zeitschrift „Sterne und Weltraum“ (SuW) 7/2015, S.30/31, WIS-ID: 1285836 Olaf Fischer Im folgenden WIS-Beitrag steht ein atemberaubendes Beobachtungsergebnis von ALMA im Brennpunkt – die detaillierte Abbildung einer protoplanetaren Scheibe um einen entstehenden Stern – die potentielle Geburtsstätte für Planeten. Neben Beschreibungen und Erklärungen werden vor allem verschiedenartige Aktivitäten (Rechnungen zur Ma und Ph, Arbeit mit Karten, Bildauswertung, Diagramminterpretation, Papiermodell, Quartett) für Schüler angeboten, um diese Beobachtung und damit im Zusammenhang stehende Inhalte (insbesondere die Sternentstehung) besser zu verstehen, auch indem diese den Nutzen des Schulwissen entdecken. Der Wert von Kenntnissen auf verschiedenen Gebieten (Sprache, Mathematik, Naturwis- senschaft, Technik) wird spürbar. Der Beitrag eignet sich als Grundlage für Schülervorträge, die Arbeit in einer AG, wie auch für den Fachunterricht in der Oberstufe. -
Basic Notations
Appendix A Basic Notations In this Appendix, the basic notations for the mathematical operators and astronom- ical and physical quantities used throughout the book are given. Note that only the most frequently used quantities are mentioned; besides, overlapping symbol definitions and deviations from the basically adopted notations are possible, when appropriate. Mathematical Quantities and Operators kxk is the length (norm) of vector x x y is the scalar product of vectors x and y rr is the gradient operator in the direction of vector r f f ; gg is the Poisson bracket of functions f and g K.m/ or K.k/ (where m D k2) is the complete elliptic integral of the first kind with modulus k E.m/ or E.k/ is the complete elliptic integral of the second kind F.˛; m/ is the incomplete elliptic integral of the first kind E.˛; m/ is the incomplete elliptic integral of the second kind ƒ0 is Heuman’s Lambda function Pi is the Legendre polynomial of degree i x0 is the initial value of a variable x Coordinates and Frames x, y, z are the Cartesian (orthogonal) coordinates r, , ˛ are the spherical coordinates (radial distance, longitude, and latitude) © Springer International Publishing Switzerland 2017 171 I. I. Shevchenko, The Lidov-Kozai Effect – Applications in Exoplanet Research and Dynamical Astronomy, Astrophysics and Space Science Library 441, DOI 10.1007/978-3-319-43522-0 172 A Basic Notations In the three-body problem: r1 is the position vector of body 1 relative to body 0 r2 is the position vector of body 2 relative to the center of mass of the inner