National Science Olympiad Astronomy 2020 (Division C) Star and Galaxy Formation and Evolution
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Masamune Oguri
New directions in strong lensing Masamune Oguri RESCEU/Physics/Kavli IPMU University of Tokyo 2019/8/23 CosmoCruise@Sea Reference − arXiv:1907.06830 Strong gravitational lensing of explosive transients Masamune Oguri1,2,3 1Research Center for the Early Universe, University of Tokyo, Tokyo 113-0033, Japan 2Department of Physics, University of Tokyo, Tokyo 113-0033, Japan 3Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, WPI), University of Tokyo, Chiba 277-8582, Japan E-mail: [email protected] Abstract. Recent rapid progress in time domain surveys makes it possible to detect various types of explosive transients in the Universe in large numbers, some of which will be gravitationally lensed into multiple images. Although alargenumberofstronglylenseddistantgalaxiesandquasarshavealready been discovered, strong lensing of explosive transients opens up new applications, including improved measurements of cosmological parameters, powerful probes of small scale structure of the Universe, and new observational tests of dark matter scenarios, thanks to their rapidly evolving light curves as well as their compact sizes. In particular, the compactness of these transient events indicates that the wave optics e↵ect plays an important role in some cases, which can lead to totally new applications of these lensing events. Recently we have witnessed first discoveries of strongly lensed supernovae, and strong lensing events of other types of explosive transients such as gamma-ray bursts, fast radio bursts, and gravitational waves from compact binary mergers are expected to be observed soon. In this review article, we summarize the current state of research on strong gravitational lensing of explosive transients and discuss future prospects. -
Set 4: Active Galaxies
Set 4: Active Galaxies Phenomenology • History: Seyfert in the 1920’s reported that a small fraction (few tenths of a percent) of galaxies have bright nuclei with broad emission lines. 90% are in spiral galaxies • Seyfert galaxies categorized as 1 if emission lines of HI, HeI and HeII are very broad - Doppler broadening of 1000-5000 km/s and narrower forbidden lines of ∼ 500km/s. Variable. Seyfert 2 if all lines are ∼ 500km/s. Not variable. • Both show a featureless continuum, for Seyfert 1 often more luminous than the whole galaxy • Seyferts are part of a class of galaxies with active galactic nuclei (AGN) • Radio galaxies mainly found in ellipticals - also broad and narrow line - extremely bright in the radio - often with extended lobes connected to center by jets of ∼ 50kpc in extent Radio Galaxy 3C31, NGC 383 Phenomenology • Quasars discovered in 1960 by Matthews and Sandage are extremely distant, quasi-starlike, with broad emission lines. Faint fuzzy halo reveals the parent galaxy of extremely luminous object 38−41 11−14 - visible luminosity L ∼ 10 W or ∼ 10 L • Quasars can be both radio loud (QSR) and quiet (QSO) • Blazars (BL Lac) highly variable AGN with high degree of polarization, mostly in ellipticals • ULIRGs - ultra luminous infrared galaxies - possibly dust enshrouded AGN (alternately may be starburst) • LINERS - similar to Seyfert 2 but low ionization nuclear emission line region - low luminosity AGN with strong emission lines of low ionization species Spectrum . • AGN share a basic general form for their continuum emission • Flat broken power law continuum - specific flux −α Fν / ν . -
Source-Plane Reconstruction of the Giant Gravitational Arc in A2667: a Candidate Wolf–Rayet Galaxy At
SOURCE-PLANE RECONSTRUCTION OF THE GIANT GRAVITATIONAL ARC IN A2667: A CANDIDATE WOLF–RAYET GALAXY AT z ∼ 1 Shuo Cao, Giovanni Covone, Eric Jullo, Johan Richard, Luca Izzo, Zong-Hong Zhu To cite this version: Shuo Cao, Giovanni Covone, Eric Jullo, Johan Richard, Luca Izzo, et al.. SOURCE-PLANE RE- CONSTRUCTION OF THE GIANT GRAVITATIONAL ARC IN A2667: A CANDIDATE WOLF– RAYET GALAXY AT z ∼ 1. Astronomical Journal, American Astronomical Society, 2015, 149, pp.8. 10.1088/0004-6256/149/1/3. hal-01109685 HAL Id: hal-01109685 https://hal.archives-ouvertes.fr/hal-01109685 Submitted on 26 Jan 2015 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 Astronomical Journal, 149:3 (8pp), 2015 January doi:10.1088/0004-6256/149/1/3 C 2015. The American Astronomical Society. All rights reserved. SOURCE-PLANE RECONSTRUCTION OF THE GIANT GRAVITATIONAL ARC IN A2667: A CANDIDATE WOLF–RAYET GALAXY AT z ∼ 1 Shuo Cao1,2, Giovanni Covone2,3, Eric Jullo4, Johan Richard5, Luca Izzo6,7, and Zong-Hong Zhu1 1 Department of Astronomy, Beijing Normal University, 100875 Beijing, China; [email protected] 2 Dipartimento di Scienze Fisiche, Universita` di Napoli “Federico II,” Via Cinthia, I-80126 Napoli, Italy 3 INFN Sez. -
Resolving the Radio Loud/Radio Quiet Dichotomy Without Thick Disks David
Resolving the radio loud/radio quiet dichotomy without thick disks David Garofalo Department of Physics, Kennesaw State University, Marietta GA 30060, USA Abstract Observations of radio loud active galaxies in the XMM-Newton archive by Mehdipour & Costantini show a strong anti-correlation between the column density of the ionized wind and the radio loudness parameter, providing evidence that jets may thrive in thin disks. This is in contrast with decades of analytic and numerical work suggesting jet formation is contingent on the presence of an inner, geometrically thick disk structure, which serves to both collimate and accelerate the jet. Thick disks emerge in radiatively inefficient disks which are associated with sub-Eddington as well as super-Eddington accretion regimes yet we show that the inverse correlation between winds and jets survives where it should not, namely in a luminosity regime normally attributed to radio quiet active galaxies which are modeled with thin disks. This along with other lines of evidence argues against thick disks as the foundation behind the radio loud/radio quiet dichotomy, opening up the possibility that jetted versus non jetted black holes may be understood within the context of radiatively efficient thin disk accretion. 1. Introduction Sikora et al (2007) explored the inverse correlation between radio loudness and Eddington accretion rate for a large sample of active galaxies (AGN) including Seyfert galaxies and LINERs, optically selected quasars, FRI radio galaxies, FRII quasars, and broad line radio galaxies. Despite a clear dichotomy in radio loudness between objects referred to as radio loud and those as radio quiet, the data was insufficiently detailed to shed light on the jet-disk connection near the Eddington limit where we traditionally model the radio quiet subset of the AGN family. -
Lessons from the First Multiply Imaged Supernova: a Revised Light-Traces
Draft version August 26, 2020 Typeset using LATEX twocolumn style in AASTeX63 Lessons from the first multiply imaged supernova: A revised Light-Traces-Mass strong lensing model for the galaxy cluster MACS J1149.5+2223 Adi Zitrin1 1Physics Department, Ben-Gurion University of the Negev, P.O. Box 653, Be'er-Sheva 84105, Israel (Received; Revised; Accepted) Submitted to ApJ ABSTRACT Our light-traces-mass (LTM) strong-lensing model for MACS J1149.5+2223 has played several key roles over the last decade: it aided the identification of multiple images in this cluster and the study of MACS1149-JD1 at redshift z ' 9, it was used to estimate the properties of the first multiply imaged supernova, Refsdal, in its discovery paper, and of the first caustic crossing event by a cluster, Lensed Star 1. Supernova Refsdal supplied an invaluable opportunity to conduct a blind test of the ability of common lens-modeling techniques to accurately describe the properties of SN Refsdal's images and predict the reappearance of one of its counter images that was due about a year post-discovery of the original Einstein cross. Thanks to this practice, in which our submitted model yielded some outlying results, we located a numerical artifact in the time delay (TD) calculation part of the code, which was now fixed. This artifact did not influence the reproduction of multiple images (i.e., the deflection fields { which are those constrained directly from the observations) or the derived mass model, and so it remained unnoticed prior to supernova Refsdal, emphasizing the importance of blind tests in astronomy. -
Powerful Jets from Radiatively Efficient Disks, a Decades-Old Unresolved Problem in High Energy Astrophysics
galaxies Article Powerful Jets from Radiatively Efficient Disks, a Decades-Old Unresolved Problem in High Energy Astrophysics Chandra B. Singh 1,*,†, David Garofalo 2,† and Benjamin Lang 3 1 South-Western Institute for Astronomy Research, Yunnan University, University Town, Chenggong, Kunming 650500, China 2 Department of Physics, Kennesaw State University, Marietta, GA 30060, USA; [email protected] 3 Department of Physics & Astronomy, California State University, Northridge, CA 91330, USA; [email protected] * Correspondence: [email protected] † These authors contributed equally to this work. Abstract: The discovery of 3C 273 in 1963, and the emergence of the Kerr solution shortly thereafter, precipitated the current era in astrophysics focused on using black holes to explain active galactic nuclei (AGN). But while partial success was achieved in separately explaining the bright nuclei of some AGN via thin disks, as well as powerful jets with thick disks, the combination of both powerful jets in an AGN with a bright nucleus, such as in 3C 273, remained elusive. Although numerical simulations have taken center stage in the last 25 years, they have struggled to produce the conditions that explain them. This is because radiatively efficient disks have proved a challenge to simulate. Radio quasars have thus been the least understood objects in high energy astrophysics. But recent simulations have begun to change this. We explore this milestone in light of scale-invariance and show that transitory jets, possibly related to the jets seen in these recent simulations, as some have proposed, cannot explain radio quasars. We then provide a road map for a resolution. -
The Milky Way Tomography with SDSS I. Stellar Number Density
The Astrophysical Journal, 673:864Y914, 2008 February 1 A # 2008. The American Astronomical Society. All rights reserved. Printed in U.S.A. THE MILKY WAY TOMOGRAPHY WITH SDSS. I. STELLAR NUMBER DENSITY DISTRIBUTION Mario Juric´,1,2 Zˇ eljko Ivezic´,3 Alyson Brooks,3 Robert H. Lupton,1 David Schlegel,1,4 Douglas Finkbeiner,1,5 Nikhil Padmanabhan,4,6 Nicholas Bond,1 Branimir Sesar,3 Constance M. Rockosi,3,7 Gillian R. Knapp,1 James E. Gunn,1 Takahiro Sumi,1,8 Donald P. Schneider,9 J. C. Barentine,10 Howard J. Brewington,10 J. Brinkmann,10 Masataka Fukugita,11 Michael Harvanek,10 S. J. Kleinman,10 Jurek Krzesinski,10,12 Dan Long,10 Eric H. Neilsen, Jr.,13 Atsuko Nitta,10 Stephanie A. Snedden,10 and Donald G. York14 Received 2005 October 21; accepted 2007 September 6 ABSTRACT Using the photometric parallax method we estimate the distances to 48 million stars detected by the Sloan Digital Sky Survey (SDSS) and map their three-dimensional number density distribution in the Galaxy. The currently avail- able data sample the distance range from 100 pc to 20 kpc and cover 6500 deg2 of sky, mostly at high Galactic lati- tudes (jbj > 25). These stellar number density maps allow an investigation of the Galactic structure with no a priori assumptions about the functional form of its components. The data show strong evidence for a Galaxy consisting of an oblate halo, a disk component, and a number of localized overdensities. The number density distribution of stars as traced by M dwarfs in the solar neighborhood (D < 2 kpc) is well fit by two exponential disks (the thin and thick disk) with scale heights and lengths, bias corrected for an assumed 35% binary fraction, of H1 ¼ 300 pc and L1 ¼ 2600 pc, and H2 ¼ 900 pc and L2 ¼ 3600 pc, and local thick-to-thin disk density normalization thick(R )/thin(R ) ¼ 12%. -
The Age of the Galaxy's Thick Disk
The Ages of Stars Proceedings IAU Symposium No. 258, 2008 c 2009 International Astronomical Union E.E. Mamajek, D.R. Soderblom & R.F.G. Wyse, eds. doi:10.1017/S1743921309031676 The age of the Galaxy’s thick disk Sofia Feltzing1† and Thomas Bensby2 1 Lund Observatory, Box 43, SE-22100, Lund, Sweden email: [email protected] 2 European Southern Observatory, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago, Chile email: [email protected] Abstract. We discuss the age of the stellar disks in the solar neighborhood. After reviewing the various methods for age dating, we discuss current estimates of the ages of both the thin- and the thick disks. We present preliminary results for kinematically-selected stars that belong to the thin- as well as the thick disk. All of these dwarf and sub-giant stars have been studied spectroscopically and we have derived both elemental abundances as well as ages for them. A general conclusion is that in the solar neighborhood, on average, the thick disk is older than the thin disk. However, we caution that the exclusion of stars with effective temperatures around 6500 K might result in a biased view of the full age distribution for the stars in the thick disk. Keywords. Galaxy: structure, Galaxy: disk, kinematics and dynamics, solar neighborhood, Hertzsprung-Russell diagram, stars: late-type 1. Introduction The age of a stellar population can be determined in several ways. For groups of stars, isochrones may be fitted to the stellar sequence in the Hertzsprung-Russell diagram (HRD; see, e.g., Schuster et al. -
Bibliography of Refereed Papers: Roger L
Bibliography of refereed papers: Roger L. Davies 203 refereed papers, >24,000 citations, h=75 62 papers >100 citations; 13 papers >500 citations and one has more than 1000 citations. [203] Francesco D'Eugenio, Matthew Colless, Nicholas Scott, Arjen van der Wel, Roger L. Davies, Jesse van de Sande, Sarah M. Sweet, Sree Oh, Brent Groves, Rob Sharp, Matt S. Owers, Joss Bland-Hawthorn, Scott M. Croom, Sarah Brough, Julia J. Bryant, Michael Goodwin, Jon S. Lawrence, Nuria P. F. Lorente, and Samuel N. Richards. The SAMI Galaxy Survey: stellar population and structural trends across the Fundamental Plane. MNRAS, April 2021. [202] Scott M. Croom, Matt S. Owers, Nicholas Scott, Henry Poetrodjojo, Brent Groves, Jesse van de Sande, Tania M. Barone, Luca Cortese, Francesco D'Eugenio, Joss Bland-Hawthorn, Julia Bryant, Sree Oh, Sarah Brough, James Agostino, Sarah Casura, Barbara Catinella, Matthew Colless, Gerald Cecil, Roger L. Davies, Michael J. Drinkwater, Simon P. Driver, Ignacio Ferreras, Caroline Foster, Amelia Fraser-McKelvie, Jon Lawrence, Sarah K. Leslie, Jochen Liske, Angel´ R. L´opez-S´anchez, Nuria P. F. Lorente, Rebecca McElroy, Anne M. Medling, Danail Obreschkow, Samuel N. Richards, Rob Sharp, Sarah M. Sweet, Dan S. Taranu, Edward N. Taylor, Edoardo Tescari, Adam D. Thomas, James Tocknell, and Sam P. Vaughan. The SAMI Galaxy Survey: the third and final data release. MNRAS, February 2021. [201] Romina Ahumada and others. The 16th Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra. ApJS, 249(1):3, July 2020. [200] S. -
Arxiv:1801.05235V1 [Astro-Ph.CO] 16 Jan 2018
YITP-18-04 KUNS-2714 RUP-18-2 Primordial Black Holes - Perspectives in Gravitational Wave Astronomy - Misao Sasakia, Teruaki Suyamab, Takahiro Tanakac;a, and Shuichiro Yokoyamad;e a Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan b Research Center for the Early Universe (RESCEU), Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan c Department of Physics, Kyoto University, Kyoto 606-8502, Japan d Department of Physics, Rikkyo University, Tokyo 171-8501, Japan e Kavli IPMU (WPI), UTIAS, The University of Tokyo, Kashiwa, Chiba 277-8583, Japan Abstract This is a review article on the primordial black holes (PBHs), with particular focus on 15 the massive ones (& 10 g) which have not evaporated by the present epoch by the Hawking radiation. By the detections of gravitational waves by LIGO, we have gained a completely novel tool to observationally search for PBHs complementary to the electromagnetic waves. Based on the perspective that gravitational-wave astronomy will make a significant progress in the next decades, a purpose of this article is to give a comprehensive review covering a wide range of topics on PBHs. After discussing PBH formation as well as several inflation models leading to PBH production, we summarize various existing and future observational constraints. We then present topics on formation of PBH binaries, gravitational waves from PBH binaries, various observational tests of PBHs by using gravitational waves. arXiv:1801.05235v1 [astro-ph.CO] 16 Jan 2018 1 Contents 1 Introduction 4 2 Formation of PBHs 6 2.1 Basis of primordial black holes formation in the early Universe . -
HOLISMOKES--I. Highly Optimised Lensing Investigations of Supernovae, Microlensing Objects, and Kinematics of Ellipticals and Spirals
Astronomy & Astrophysics manuscript no. holismokesI ©ESO 2020 November 13, 2020 HOLISMOKES - I. Highly Optimised Lensing Investigations of Supernovae, Microlensing Objects, and Kinematics of Ellipticals and Spirals S. H. Suyu1; 2; 3, S. Huber1; 2, R. Cañameras1, M. Kromer4, S. Schuldt1; 2, S. Taubenberger1, A. Yıldırım1, V. Bonvin5, J. H. H. Chan5, F. Courbin5, U. Nöbauer1; 6, S. A. Sim7, and D. Sluse8 1 Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching, Germany e-mail: [email protected] 2 Physik-Department, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany 3 Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), 11F of ASMAB, No.1, Section 4, Roosevelt Road, Taipei 10617, Taiwan 4 Heidelberger Institut für Theoretische Studien, Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany 5 Institute of Physics, Laboratory of Astrophysics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Observatoire de Sauverny, 1290 Versoix, Switzerland 6 MunichRe IT 1.6.4.1, Königinstraße 107, 80802, Munich, Germany 7 Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast BT7 1NN, UK 8 STAR Institute, Quartier Agora - Allée du six Août, 19c B-4000 Liège, Belgium Received February –, 2020; accepted – ABSTRACT We present the HOLISMOKES programme on strong gravitational lensing of supernovae as a probe of supernova (SN) physics and cosmology. We investigate the effects of microlensing on early-phase SN Ia spectra using four different SN explosion models, and find that within 10 rest-frame days after SN explosion, distortions of SN Ia spectra due to microlensing are typically negligible (<1% distortion within the 1σ spread, and .10% distortion within the 2σ spread). -
Download a PDF of the Abstracts Booklet
TALKS SN2016 ABSTRACTS BOOKLET 2 1.- SESSION: Cultural NAME: Cristian Moreno Pakarati AFFILIATION: Ahirenga Research TITTLE: A new proposal for a division of Easter Island's history ABSTRACT: This paper presents an original interpretation of the long-term history of the island, dividing it in three main periods. By this, it pretends to contribute a new vision on a topic long abandoned by the growingly specialized archaeology that focuses more and more on the smallest of details. The scheme is as follows: a first period, as an era of open ocean navigation and relatively frequent contact with other Polynesian people; a second period, as an era of extreme isolation where the Rapanui culture developed many of its unique traits within the Polynesian and World context; and a third period, of contacts with "the West", starting in 1722 with the Dutch expedition of Roggeveen. By this, it pretends to simplify the timeline of events on the island and contextualize better the statue-carving era and the Bird-cult of Easter Island. 2.- SESSION: 01 NAME: Edmundo Edwards AFFILIATION: Pacific Islands Research Institute TITTLE: Archeoastronomy of Eastern Polynesia and Easter Island ABSTRACT: Some 3,500 years ago in a span of about 500 years, the Lapita, the ancestors of the Polynesians, used their knowledge of the stars to settle an area 4,300 km wide in what is considered one of the speediest human expansions of the pre-historic world. Their descendants, the Polynesians, eventually settled hundreds of islands crossing millions of square kilometres of water without navigational instruments, guided by nothing more than complex astronomical observations and an understanding of natural signs.