Cycle 11 Approved Programs
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The Scale-Invariant Vacuum (SIV) Theory: a Possible Origin of Dark Matter and Dark Energy
universe Article The Scale-Invariant Vacuum (SIV) Theory: A Possible Origin of Dark Matter and Dark Energy Andre Maeder 1,* and Vesselin G. Gueorguiev 2,3 1 Geneva Observatory, University of Geneva, chemin des Maillettes 51, CH-1290 Sauverny, Switzerland 2 Institute for Advanced Physical Studies, Montevideo Street, Sofia 1618, Bulgaria; [email protected] 3 Ronin Institute for Independent Scholarship, 127 Haddon Pl., Montclair, NJ 07043, USA * Correspondence: [email protected] Received: 7 February 2020; Accepted: 9 March 2020; Published: 18 March 2020 Abstract: The Scale Invariant Vacuum (SIV) theory rests on the basic hypothesis that the macroscopic empty space is scale invariant. This hypothesis is applied in the context of the Integrable Weyl Geometry, where it leads to considerable simplifications in the scale covariant cosmological equations. After an initial explosion and a phase of braking, the cosmological models show a continuous acceleration of the expansion. Several observational tests of the SIV cosmology are performed: on the relation between H0 and the age of the Universe, on the m − z diagram for SNIa data and its extension to z = 7 with quasars and GRBs, and on the H(z) vs. z relation. All comparisons show a very good agreement between SIV predictions and observations. Predictions for the future observations of the redshift drifts are also given. In the weak field approximation, the equation of motion contains, in addition to the classical Newtonian term, an acceleration term (usually very small) depending on the velocity. The two-body problem is studied, showing a slow expansion of the classical conics. The new equation has been applied to clusters of galaxies, to rotating galaxies (some proximities with Modifies Newtonian Dynamics, MOND, are noticed), to the velocity dispersion vs. -
Where Are the Distant Worlds? Star Maps
W here Are the Distant Worlds? Star Maps Abo ut the Activity Whe re are the distant worlds in the night sky? Use a star map to find constellations and to identify stars with extrasolar planets. (Northern Hemisphere only, naked eye) Topics Covered • How to find Constellations • Where we have found planets around other stars Participants Adults, teens, families with children 8 years and up If a school/youth group, 10 years and older 1 to 4 participants per map Materials Needed Location and Timing • Current month's Star Map for the Use this activity at a star party on a public (included) dark, clear night. Timing depends only • At least one set Planetary on how long you want to observe. Postcards with Key (included) • A small (red) flashlight • (Optional) Print list of Visible Stars with Planets (included) Included in This Packet Page Detailed Activity Description 2 Helpful Hints 4 Background Information 5 Planetary Postcards 7 Key Planetary Postcards 9 Star Maps 20 Visible Stars With Planets 33 © 2008 Astronomical Society of the Pacific www.astrosociety.org Copies for educational purposes are permitted. Additional astronomy activities can be found here: http://nightsky.jpl.nasa.gov Detailed Activity Description Leader’s Role Participants’ Roles (Anticipated) Introduction: To Ask: Who has heard that scientists have found planets around stars other than our own Sun? How many of these stars might you think have been found? Anyone ever see a star that has planets around it? (our own Sun, some may know of other stars) We can’t see the planets around other stars, but we can see the star. -
XIII Publications, Presentations
XIII Publications, Presentations 1. Refereed Publications E., Kawamura, A., Nguyen Luong, Q., Sanhueza, P., Kurono, Y.: 2015, The 2014 ALMA Long Baseline Campaign: First Results from Aasi, J., et al. including Fujimoto, M.-K., Hayama, K., Kawamura, High Angular Resolution Observations toward the HL Tau Region, S., Mori, T., Nishida, E., Nishizawa, A.: 2015, Characterization of ApJ, 808, L3. the LIGO detectors during their sixth science run, Classical Quantum ALMA Partnership, et al. including Asaki, Y., Hirota, A., Nakanishi, Gravity, 32, 115012. K., Espada, D., Kameno, S., Sawada, T., Takahashi, S., Ao, Y., Abbott, B. P., et al. including Flaminio, R., LIGO Scientific Hatsukade, B., Matsuda, Y., Iono, D., Kurono, Y.: 2015, The 2014 Collaboration, Virgo Collaboration: 2016, Astrophysical Implications ALMA Long Baseline Campaign: Observations of the Strongly of the Binary Black Hole Merger GW150914, ApJ, 818, L22. Lensed Submillimeter Galaxy HATLAS J090311.6+003906 at z = Abbott, B. P., et al. including Flaminio, R., LIGO Scientific 3.042, ApJ, 808, L4. Collaboration, Virgo Collaboration: 2016, Observation of ALMA Partnership, et al. including Asaki, Y., Hirota, A., Nakanishi, Gravitational Waves from a Binary Black Hole Merger, Phys. Rev. K., Espada, D., Kameno, S., Sawada, T., Takahashi, S., Kurono, Lett., 116, 061102. Y., Tatematsu, K.: 2015, The 2014 ALMA Long Baseline Campaign: Abbott, B. P., et al. including Flaminio, R., LIGO Scientific Observations of Asteroid 3 Juno at 60 Kilometer Resolution, ApJ, Collaboration, Virgo Collaboration: 2016, GW150914: Implications 808, L2. for the Stochastic Gravitational-Wave Background from Binary Black Alonso-Herrero, A., et al. including Imanishi, M.: 2016, A mid-infrared Holes, Phys. -
1. Introduction
THE ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 122:109È150, 1999 May ( 1999. The American Astronomical Society. All rights reserved. Printed in U.S.A. GALAXY STRUCTURAL PARAMETERS: STAR FORMATION RATE AND EVOLUTION WITH REDSHIFT M. TAKAMIYA1,2 Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637; and Gemini 8 m Telescopes Project, 670 North Aohoku Place, Hilo, HI 96720 Received 1998 August 4; accepted 1998 December 21 ABSTRACT The evolution of the structure of galaxies as a function of redshift is investigated using two param- eters: the metric radius of the galaxy(Rg) and the power at high spatial frequencies in the disk of the galaxy (s). A direct comparison is made between nearby (z D 0) and distant(0.2 [ z [ 1) galaxies by following a Ðxed range in rest frame wavelengths. The data of the nearby galaxies comprise 136 broad- band images at D4500A observed with the 0.9 m telescope at Kitt Peak National Observatory (23 galaxies) and selected from the catalog of digital images of Frei et al. (113 galaxies). The high-redshift sample comprises 94 galaxies selected from the Hubble Deep Field (HDF) observations with the Hubble Space Telescope using the Wide Field Planetary Camera 2 in four broad bands that range between D3000 and D9000A (Williams et al.). The radius is measured from the intensity proÐle of the galaxy using the formulation of Petrosian, and it is argued to be a metric radius that should not depend very strongly on the angular resolution and limiting surface brightness level of the imaging data. It is found that the metric radii of nearby and distant galaxies are comparable to each other. -
Hubble Finds Birth Certificate of Oldest Known Star 7 March 2013
Hubble finds birth certificate of oldest known star 7 March 2013 But earlier estimates from observations dating back to 2000 placed the star as old as 16 billion years. And this age range presented a potential dilemma for cosmologists. "Maybe the cosmology is wrong, stellar physics is wrong, or the star's distance is wrong," Bond said. "So we set out to refine the distance." The new Hubble age estimates reduce the range of measurement uncertainty, so that the star's age overlaps with the universe's age—as independently determined by the rate of expansion of space, an analysis of the microwave background from the big bang, and measurements of radioactive decay. This "Methuselah star," cataloged as HD 140283, has been known about for more than a century because of its fast motion across the sky. The high This is a Digitized Sky Survey image of the oldest star rate of motion is evidence that the star is simply a with a well-determined age in our galaxy. The aging star, cataloged as HD 140283, lies 190.1 light-years away. visitor to our stellar neighborhood. Its orbit carries it The Anglo-Australian Observatory UK Schmidt telescope down through the plane of our galaxy from the photographed the star in blue light. Credit: Digitized Sky ancient halo of stars that encircle the Milky Way, Survey (DSS), STScI/AURA, Palomar/Caltech, and and will eventually slingshot back to the galactic UKSTU/AAO halo. (Phys.org) —A team of astronomers using NASA's Hubble Space Telescope has taken an important step closer to finding the birth certificate of a star that's been around for a very long time. -
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. -
HIPPARCOS Age-Metallicity Relation of the Solar Neighbourhood Disc Stars
HIPPARCOS age-metallicity relation of the solar neighbourhood disc stars A. Ibukiyama1 and N. Arimoto1;2 1 Institute of Astronomy (IoA), School of Science, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015, Japan 2 National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan Received /Accepted 1 July 2002 Abstract. We derive age-metallicity relations (AMRs) and orbital parameters for the 1658 solar neighbourhood stars to which accurate distances are measured by the HIPPARCOS satellite. The sample stars comprise 1382 thin disc stars, 229 thick disc stars, and 47 halo stars according to their orbital parameters. We find a considerable scatter for thin disc AMR along the one-zone Galactic chemical evolution (GCE) model. Orbits and metallicities of thin disc stars show now clear relation each other. The scatter along the AMR exists even if the stars with the same orbits are selected. We examine simple extension of one-zone GCE models which account for inhomogeneity in the effective yield and inhomogeneous star formation rate in the Galaxy. Both extensions of one-zone GCE model cannot account for the scatter in age - [Fe/H] - [Ca/Fe] relation simultaneously. We conclude, therefore, that the scatter along the thin disc AMR is an essential feature in the formation and evolution of the Galaxy. The AMR for thick disc stars shows that the star formation terminated 8 Gyr ago in thick disc. As already reported by ?)and?), thick disc stars are more Ca-rich than thin disc stars with the same [Fe/H]. We find that thick disc stars show a vertical abundance gradient. -
Study of the Element Abundances in Hd 140283
The Astrophysical Journal, 813:56 (9pp), 2015 November 1 doi:10.1088/0004-637X/813/1/56 © 2015. The American Astronomical Society. All rights reserved. STUDY OF THE ELEMENT ABUNDANCES IN HD 140283: THE ABUNDANCE ROBUSTNESS OF THE WEAK r- AND MAIN r-PROCESS STARS Ping Niu1,2, Wenyuan Cui1, and Bo Zhang1 1 Department of Physics, Hebei Normal University, 20 Nanerhuan Dong Road, Shijiazhuang 050024, China; [email protected] 2 Department of Physics, Shijiazhuang University, Shijiazhuang 050035, China Received 2014 November 25; accepted 2015 September 18; published 2015 October 28 ABSTRACT Many works have attempted to investigate the astrophysical origin of the neutron-capture elements in the metal- poor star HD 140283. However, no definite conclusions have been drawn. In this work, using the abundance- decomposed approach, we find that the metal-poor star HD 140283 is a weak r-process star. Although this star is a weak r-process star, its Ba abundance mainly originates from the main r-process. This is the reason that the ratio [Ba/Eu]=-0.58 0.15 for HD 140283 is close to the ratio of the main r-process. Based on the comparison of the abundances in the six-weak r-process stars, we find that their element abundances possess a robust nature. On the other hand, we find that the robust nature of the abundance of the extreme main r-process stars ([r/Fe] 1.5) can be extended to the lighter neutron-capture elements. Furthermore, the abundance characteristics of the weak r-process and main r-process are investigated. -
Thesis, Anton Pannekoek Institute, Universiteit Van Amsterdam
UvA-DARE (Digital Academic Repository) The peculiar climates of ultra-hot Jupiters Arcangeli, J. Publication date 2020 Document Version Final published version License Other Link to publication Citation for published version (APA): Arcangeli, J. (2020). The peculiar climates of ultra-hot Jupiters. General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. UvA-DARE is a service provided by the library of the University of Amsterdam (https://dare.uva.nl) Download date:09 Oct 2021 Jacob Arcangeli of Ultra-hot Jupiters The peculiar climates The peculiar climates of Ultra-hot Jupiters Jacob Arcangeli The peculiar climates of Ultra-hot Jupiters Jacob Arcangeli © 2020, Jacob Arcangeli Contact: [email protected] The peculiar climates of Ultra-hot Jupiters Thesis, Anton Pannekoek Institute, Universiteit van Amsterdam Cover by Imogen Arcangeli ([email protected]) Printed by Amsterdam University Press ANTON PANNEKOEK INSTITUTE The research included in this thesis was carried out at the Anton Pannekoek Institute for Astronomy (API) of the University of Amsterdam. -
Synapses of Active Galactic Nuclei: Comparing X-Ray and Optical Classifications Using Artificial Neural Networks?
A&A 567, A92 (2014) Astronomy DOI: 10.1051/0004-6361/201322592 & c ESO 2014 Astrophysics Synapses of active galactic nuclei: Comparing X-ray and optical classifications using artificial neural networks? O. González-Martín1;2;??, D. Díaz-González3, J. A. Acosta-Pulido1;2, J. Masegosa4, I. E. Papadakis5;6, J. M. Rodríguez-Espinosa1;2, I. Márquez4, and L. Hernández-García4 1 Instituto de Astrofísica de Canarias (IAC), C/Vía Láctea s/n, 38205 La Laguna, Spain e-mail: [email protected] 2 Departamento de Astrofísica, Universidad de La Laguna (ULL), 38205 La Laguna, Spain 3 Shidix Technologies, 38320, La Laguna, Spain 4 Instituto de Astrofísica de Andalucía, CSIC, C/ Glorieta de la Astronomía s/n, 18005 Granada, Spain 5 Physics Department, University of Crete, PO Box 2208, 710 03 Heraklion, Crete, Greece 6 IESL, Foundation for Research and Technology, 711 10 Heraklion, Crete, Greece Received 2 September 2013 / Accepted 3 April 2014 ABSTRACT Context. Many classes of active galactic nuclei (AGN) have been defined entirely through optical wavelengths, while the X-ray spectra have been very useful to investigate their inner regions. However, optical and X-ray results show many discrepancies that have not been fully understood yet. Aims. The main purpose of the present paper is to study the synapses (i.e., connections) between X-ray and optical AGN classifications. Methods. For the first time, the newly implemented efluxer task allowed us to analyse broad band X-ray spectra of a sample of emission-line nuclei without any prior spectral fitting. Our sample comprises 162 spectra observed with XMM-Newton/pn of 90 lo- cal emission line nuclei in the Palomar sample. -
High-Resolution Abundance Analysis of HD 140283⋆⋆⋆⋆⋆⋆
A&A 584, A86 (2015) Astronomy DOI: 10.1051/0004-6361/201526695 & c ESO 2015 Astrophysics High-resolution abundance analysis of HD 140283,, C. Siqueira-Mello1,S.M.Andrievsky2,3,B.Barbuy1, M. Spite3, F. Spite3, and S. A. Korotin2 1 Universidade de São Paulo, IAG, Departamento de Astronomia, Rua do Matão 1226, 05508-900 São Paulo, Brazil e-mail: [email protected] 2 Department of Astronomy and Astronomical Observatory, Odessa National University, and Isaac Newton Institute of Chile Odessa branch, Shevchenko Park, 65014 Odessa, Ukraine 3 GEPI, Observatoire de Paris, PSL Research University, CNRS, Université Paris Diderot, Sorbonne Paris Cité, Place Jules Janssen, 92195 Meudon, France Received 8 June 2015 / Accepted 10 August 2015 ABSTRACT Context. HD 140283 is a reference subgiant that is metal poor and confirmed to be a very old star. The element abundances of this type of old star can constrain the nature and nucleosynthesis processes that occurred in its (even older) progenitors. The present study may shed light on nucleosynthesis processes yielding heavy elements early in the Galaxy. Aims. A detailed analysis of a high-quality spectrum is carried out, with the intent of providing a reference on stellar lines and abun- dances of a very old, metal-poor subgiant. We aim to derive abundances from most available and measurable spectral lines. Methods. The analysis is carried out using high-resolution (R = 81 000) and high signal-to-noise ratio (800 < S/N/pixel < 3400) spec- trum, in the wavelength range 3700 <λ(Å) < 10475, obtained with a seven-hour exposure time, using the Echelle SpectroPolarimetric Device for the Observation of Stars (ESPaDOnS) at the Canada-France-Hawaii Telescope (CFHT). -
Superflares and Giant Planets
Superflares and Giant Planets From time to time, a few sunlike stars produce gargantuan outbursts. Large planets in tight orbits might account for these eruptions Eric P. Rubenstein nvision a pale blue planet, not un- bushes to burst into flames. Nor will the lar flares, which typically last a fraction Elike the Earth, orbiting a yellow star surface of the planet feel the blast of ul- of an hour and release their energy in a in some distant corner of the Galaxy. traviolet light and x rays, which will be combination of charged particles, ul- This exercise need not challenge the absorbed high in the atmosphere. But traviolet light and x rays. Thankfully, imagination. After all, astronomers the more energetic component of these this radiation does not reach danger- have now uncovered some 50 “extra- x rays and the charged particles that fol- ous levels at the surface of the Earth: solar” planets (albeit giant ones). Now low them are going to create havoc The terrestrial magnetic field easily de- suppose for a moment something less when they strike air molecules and trig- flects the charged particles, the upper likely: that this planet teems with life ger the production of nitrogen oxides, atmosphere screens out the x rays, and and is, perhaps, populated by intelli- which rapidly destroy ozone. the stratospheric ozone layer absorbs gent beings, ones who enjoy looking So in the space of a few days the pro- most of the ultraviolet light. So solar up at the sky from time to time. tective blanket of ozone around this flares, even the largest ones, normally During the day, these creatures planet will largely disintegrate, allow- pass uneventfully.