Distances to Local Group Galaxies
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Distribution of Phantom Dark Matter in Dwarf Spheroidals Alistair O
A&A 640, A26 (2020) Astronomy https://doi.org/10.1051/0004-6361/202037634 & c ESO 2020 Astrophysics Distribution of phantom dark matter in dwarf spheroidals Alistair O. Hodson1,2, Antonaldo Diaferio1,2, and Luisa Ostorero1,2 1 Dipartimento di Fisica, Università di Torino, Via P. Giuria 1, 10125 Torino, Italy 2 Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino, Via P. Giuria 1, 10125 Torino, Italy e-mail: [email protected],[email protected] Received 31 January 2020 / Accepted 25 May 2020 ABSTRACT We derive the distribution of the phantom dark matter in the eight classical dwarf galaxies surrounding the Milky Way, under the assumption that modified Newtonian dynamics (MOND) is the correct theory of gravity. According to their observed shape, we model the dwarfs as axisymmetric systems, rather than spherical systems, as usually assumed. In addition, as required by the assumption of the MOND framework, we realistically include the external gravitational field of the Milky Way and of the large-scale structure beyond the Local Group. For the dwarfs where the external field dominates over the internal gravitational field, the phantom dark matter has, from the star distribution, an offset of ∼0:1−0:2 kpc, depending on the mass-to-light ratio adopted. This offset is a substantial fraction of the dwarf half-mass radius. For Sculptor and Fornax, where the internal and external gravitational fields are comparable, the phantom dark matter distribution appears disturbed with spikes at the locations where the two fields cancel each other; these features have little connection with the distribution of the stars within the dwarfs. -
Naming the Extrasolar Planets
Naming the extrasolar planets W. Lyra Max Planck Institute for Astronomy, K¨onigstuhl 17, 69177, Heidelberg, Germany [email protected] Abstract and OGLE-TR-182 b, which does not help educators convey the message that these planets are quite similar to Jupiter. Extrasolar planets are not named and are referred to only In stark contrast, the sentence“planet Apollo is a gas giant by their assigned scientific designation. The reason given like Jupiter” is heavily - yet invisibly - coated with Coper- by the IAU to not name the planets is that it is consid- nicanism. ered impractical as planets are expected to be common. I One reason given by the IAU for not considering naming advance some reasons as to why this logic is flawed, and sug- the extrasolar planets is that it is a task deemed impractical. gest names for the 403 extrasolar planet candidates known One source is quoted as having said “if planets are found to as of Oct 2009. The names follow a scheme of association occur very frequently in the Universe, a system of individual with the constellation that the host star pertains to, and names for planets might well rapidly be found equally im- therefore are mostly drawn from Roman-Greek mythology. practicable as it is for stars, as planet discoveries progress.” Other mythologies may also be used given that a suitable 1. This leads to a second argument. It is indeed impractical association is established. to name all stars. But some stars are named nonetheless. In fact, all other classes of astronomical bodies are named. -
Grant Proposals, 1991-1999
Grant Proposals, 1991-1999 Finding aid prepared by Smithsonian Institution Archives Smithsonian Institution Archives Washington, D.C. Contact us at [email protected] Table of Contents Collection Overview ........................................................................................................ 1 Administrative Information .............................................................................................. 1 Descriptive Entry.............................................................................................................. 1 Names and Subjects ...................................................................................................... 1 Container Listing ............................................................................................................. 2 Grant Proposals https://siarchives.si.edu/collections/siris_arc_251859 Collection Overview Repository: Smithsonian Institution Archives, Washington, D.C., [email protected] Title: Grant Proposals Identifier: Accession 99-171 Date: 1991-1999 Extent: 17 cu. ft. (17 record storage boxes) Creator:: Smithsonian Astrophysical Observatory. Contracts and Procurement Office Language: English Administrative Information Prefered Citation Smithsonian Institution Archives, Accession 99-171, Smithsonian Astrophysical Observatory, Contracts and Procurement Office, Grant Proposals Descriptive Entry This accession consists of records documenting Smithsonian Astrophysical Observatory projects and activities. Materials include proposals, correspondence, progress -
The Feeble Giant. Discovery of a Large and Diffuse Milky Way Dwarf Galaxy in the Constellation of Crater
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Apollo MNRAS 459, 2370–2378 (2016) doi:10.1093/mnras/stw733 Advance Access publication 2016 April 13 The feeble giant. Discovery of a large and diffuse Milky Way dwarf galaxy in the constellation of Crater G. Torrealba,‹ S. E. Koposov, V. Belokurov and M. Irwin Institute of Astronomy, Madingley Rd, Cambridge CB3 0HA, UK Downloaded from https://academic.oup.com/mnras/article-abstract/459/3/2370/2595158 by University of Cambridge user on 24 July 2019 Accepted 2016 March 24. Received 2016 March 24; in original form 2016 January 26 ABSTRACT We announce the discovery of the Crater 2 dwarf galaxy, identified in imaging data of the VLT Survey Telescope ATLAS survey. Given its half-light radius of ∼1100 pc, Crater 2 is the fourth largest satellite of the Milky Way, surpassed only by the Large Magellanic Cloud, Small Magellanic Cloud and the Sgr dwarf. With a total luminosity of MV ≈−8, this galaxy is also one of the lowest surface brightness dwarfs. Falling under the nominal detection boundary of 30 mag arcsec−2, it compares in nebulosity to the recently discovered Tuc 2 and Tuc IV and UMa II. Crater 2 is located ∼120 kpc from the Sun and appears to be aligned in 3D with the enigmatic globular cluster Crater, the pair of ultrafaint dwarfs Leo IV and Leo V and the classical dwarf Leo II. We argue that such arrangement is probably not accidental and, in fact, can be viewed as the evidence for the accretion of the Crater-Leo group. -
The Extragalactic Distance Scale
The Extragalactic Distance Scale Published in "Stellar astrophysics for the local group" : VIII Canary Islands Winter School of Astrophysics. Edited by A. Aparicio, A. Herrero, and F. Sanchez. Cambridge ; New York : Cambridge University Press, 1998 Calibration of the Extragalactic Distance Scale By BARRY F. MADORE1, WENDY L. FREEDMAN2 1NASA/IPAC Extragalactic Database, Infrared Processing & Analysis Center, California Institute of Technology, Jet Propulsion Laboratory, Pasadena, CA 91125, USA 2Observatories, Carnegie Institution of Washington, 813 Santa Barbara St., Pasadena CA 91101, USA The calibration and use of Cepheids as primary distance indicators is reviewed in the context of the extragalactic distance scale. Comparison is made with the independently calibrated Population II distance scale and found to be consistent at the 10% level. The combined use of ground-based facilities and the Hubble Space Telescope now allow for the application of the Cepheid Period-Luminosity relation out to distances in excess of 20 Mpc. Calibration of secondary distance indicators and the direct determination of distances to galaxies in the field as well as in the Virgo and Fornax clusters allows for multiple paths to the determination of the absolute rate of the expansion of the Universe parameterized by the Hubble constant. At this point in the reduction and analysis of Key Project galaxies H0 = 72km/ sec/Mpc ± 2 (random) ± 12 [systematic]. Table of Contents INTRODUCTION TO THE LECTURES CEPHEIDS BRIEF SUMMARY OF THE OBSERVED PROPERTIES OF CEPHEID -
What Is an Ultra-Faint Galaxy?
What is an ultra-faint Galaxy? UCSB KITP Feb 16 2012 Beth Willman (Haverford College) ~ 1/10 Milky Way luminosity Large Magellanic Cloud, MV = -18 image credit: Yuri Beletsky (ESO) and APOD NGC 205, MV = -16.4 ~ 1/40 Milky Way luminosity image credit: www.noao.edu Image credit: David W. Hogg, Michael R. Blanton, and the Sloan Digital Sky Survey Collaboration ~ 1/300 Milky Way luminosity MV = -14.2 Image credit: David W. Hogg, Michael R. Blanton, and the Sloan Digital Sky Survey Collaboration ~ 1/2700 Milky Way luminosity MV = -11.9 Image credit: David W. Hogg, Michael R. Blanton, and the Sloan Digital Sky Survey Collaboration ~ 1/14,000 Milky Way luminosity MV = -10.1 ~ 1/40,000 Milky Way luminosity ~ 1/1,000,000 Milky Way luminosity Ursa Major 1 Finding Invisible Galaxies bright faint blue red Willman et al 2002, Walsh, Willman & Jerjen 2009; see also e.g. Koposov et al 2008, Belokurov et al. Finding Invisible Galaxies Red, bright, cool bright Blue, hot, bright V-band apparent brightness V-band faint Red, faint, cool blue red From ARAA, V26, 1988 Willman et al 2002, Walsh, Willman & Jerjen 2009; see also e.g. Koposov et al 2008, Belokurov et al. Finding Invisible Galaxies Ursa Major I dwarf 1/1,000,000 MW luminosity Willman et al 2005 ~ 1/1,000,000 Milky Way luminosity Ursa Major 1 CMD of Ursa Major I Okamoto et al 2008 Distribution of the Milky Wayʼs dwarfs -14 Milky Way dwarfs 107 -12 -10 classical dwarfs V -8 5 10 Sun M L -6 ultra-faint dwarfs Canes Venatici II -4 Leo V Pisces II Willman I 1000 -2 Segue I 0 50 100 150 200 250 300 -
Is There Tension Between Observed Small Scale Structure and Cold Dark Matter?
Is there tension between observed small scale structure and cold dark matter? Louis Strigari Stanford University Cosmic Frontier 2013 March 8, 2013 Predictions of the standard Cold Dark Matter model 26 3 1 1. Density profiles rise towards the centersσannv 3of 10galaxies− cm s− (1) h i' ⇥ ⇢ Universal for all halo masses ⇢(r)= s (2) (r/r )(1 + r/r )2 Navarro-Frenk-White (NFW) model s s 2. Abundance of ‘sub-structure’ (sub-halos) in galaxies Sub-halos comprise few percent of total halo mass Most of mass contained in highest- mass sub-halos Subhalo Mass Function Mass[Solar mass] 1 Problems with the standard Cold Dark Matter model 1. Density of dark matter halos: Faint, dark matter-dominated galaxies appear less dense that predicted in simulations General arguments: Kleyna et al. MNRAS 2003, 2004;Goerdt et al. APJ2006; de Blok et al. AJ 2008 Dwarf spheroidals: Gilmore et al. APJ 2007; Walker & Penarrubia et al. APJ 2011; Angello & Evans APJ 2012 2. ‘Missing satellites problem’: Simulations have more dark matter subhalos than there are observed dwarf satellite galaxies Earilest papers: Kauffmann et al. 1993; Klypin et al. 1999; Moore et al. 1999 Solutions to the issues in Cold Dark Matter 1. The theory is wrong i) Not enough physics in theory/simulations (Talks yesterday by M. Boylan-Kolchin, M. Kuhlen) [Wadepuhl & Springel MNRAS 2011; Parry et al. MRNAS 2011; Pontzen & Governato MRNAS 2012; Brooks et al. ApJ 2012] ii) Cosmology/dark matter is wrong (Talk yesterday by A. Peter) 2. The data is wrong i) Kinematics of dwarf spheroidals (dSphs) are more difficult than assumed ii) Counting satellites a) Many more faint satellites around the Milky Way b) Milky Way is an oddball [Liu et al. -
And Ecclesiastical Cosmology
GSJ: VOLUME 6, ISSUE 3, MARCH 2018 101 GSJ: Volume 6, Issue 3, March 2018, Online: ISSN 2320-9186 www.globalscientificjournal.com DEMOLITION HUBBLE'S LAW, BIG BANG THE BASIS OF "MODERN" AND ECCLESIASTICAL COSMOLOGY Author: Weitter Duckss (Slavko Sedic) Zadar Croatia Pусскй Croatian „If two objects are represented by ball bearings and space-time by the stretching of a rubber sheet, the Doppler effect is caused by the rolling of ball bearings over the rubber sheet in order to achieve a particular motion. A cosmological red shift occurs when ball bearings get stuck on the sheet, which is stretched.“ Wikipedia OK, let's check that on our local group of galaxies (the table from my article „Where did the blue spectral shift inside the universe come from?“) galaxies, local groups Redshift km/s Blueshift km/s Sextans B (4.44 ± 0.23 Mly) 300 ± 0 Sextans A 324 ± 2 NGC 3109 403 ± 1 Tucana Dwarf 130 ± ? Leo I 285 ± 2 NGC 6822 -57 ± 2 Andromeda Galaxy -301 ± 1 Leo II (about 690,000 ly) 79 ± 1 Phoenix Dwarf 60 ± 30 SagDIG -79 ± 1 Aquarius Dwarf -141 ± 2 Wolf–Lundmark–Melotte -122 ± 2 Pisces Dwarf -287 ± 0 Antlia Dwarf 362 ± 0 Leo A 0.000067 (z) Pegasus Dwarf Spheroidal -354 ± 3 IC 10 -348 ± 1 NGC 185 -202 ± 3 Canes Venatici I ~ 31 GSJ© 2018 www.globalscientificjournal.com GSJ: VOLUME 6, ISSUE 3, MARCH 2018 102 Andromeda III -351 ± 9 Andromeda II -188 ± 3 Triangulum Galaxy -179 ± 3 Messier 110 -241 ± 3 NGC 147 (2.53 ± 0.11 Mly) -193 ± 3 Small Magellanic Cloud 0.000527 Large Magellanic Cloud - - M32 -200 ± 6 NGC 205 -241 ± 3 IC 1613 -234 ± 1 Carina Dwarf 230 ± 60 Sextans Dwarf 224 ± 2 Ursa Minor Dwarf (200 ± 30 kly) -247 ± 1 Draco Dwarf -292 ± 21 Cassiopeia Dwarf -307 ± 2 Ursa Major II Dwarf - 116 Leo IV 130 Leo V ( 585 kly) 173 Leo T -60 Bootes II -120 Pegasus Dwarf -183 ± 0 Sculptor Dwarf 110 ± 1 Etc. -
Variable Star Classification and Light Curves Manual
Variable Star Classification and Light Curves An AAVSO course for the Carolyn Hurless Online Institute for Continuing Education in Astronomy (CHOICE) This is copyrighted material meant only for official enrollees in this online course. Do not share this document with others. Please do not quote from it without prior permission from the AAVSO. Table of Contents Course Description and Requirements for Completion Chapter One- 1. Introduction . What are variable stars? . The first known variable stars 2. Variable Star Names . Constellation names . Greek letters (Bayer letters) . GCVS naming scheme . Other naming conventions . Naming variable star types 3. The Main Types of variability Extrinsic . Eclipsing . Rotating . Microlensing Intrinsic . Pulsating . Eruptive . Cataclysmic . X-Ray 4. The Variability Tree Chapter Two- 1. Rotating Variables . The Sun . BY Dra stars . RS CVn stars . Rotating ellipsoidal variables 2. Eclipsing Variables . EA . EB . EW . EP . Roche Lobes 1 Chapter Three- 1. Pulsating Variables . Classical Cepheids . Type II Cepheids . RV Tau stars . Delta Sct stars . RR Lyr stars . Miras . Semi-regular stars 2. Eruptive Variables . Young Stellar Objects . T Tau stars . FUOrs . EXOrs . UXOrs . UV Cet stars . Gamma Cas stars . S Dor stars . R CrB stars Chapter Four- 1. Cataclysmic Variables . Dwarf Novae . Novae . Recurrent Novae . Magnetic CVs . Symbiotic Variables . Supernovae 2. Other Variables . Gamma-Ray Bursters . Active Galactic Nuclei 2 Course Description and Requirements for Completion This course is an overview of the types of variable stars most commonly observed by AAVSO observers. We discuss the physical processes behind what makes each type variable and how this is demonstrated in their light curves. Variable star names and nomenclature are placed in a historical context to aid in understanding today’s classification scheme. -
Arxiv:1508.03622V2 [Astro-Ph.GA] 6 Nov 2015 – 2 –
Eight Ultra-faint Galaxy Candidates Discovered in Year Two of the Dark Energy Survey 1; 2;3; 4;5 6;7 6;7 8;4;5 A. Drlica-Wagner ∗, K. Bechtol y, E. S. Rykoff , E. Luque , A. Queiroz , Y.-Y. Mao , R. H. Wechsler8;4;5, J. D. Simon9, B. Santiago6;7, B. Yanny1, E. Balbinot10;7, S. Dodelson1;11, A. Fausti Neto7, D. J. James12, T. S. Li13, M. A. G. Maia7;14, J. L. Marshall13, A. Pieres6;7, K. Stringer13, A. R. Walker12, T. M. C. Abbott12, F. B. Abdalla15;16, S. Allam1, A. Benoit-L´evy15, G. M. Bernstein17, E. Bertin18;19, D. Brooks15, E. Buckley-Geer1, D. L. Burke4;5, A. Carnero Rosell7;14, M. Carrasco Kind20;21, J. Carretero22;23, M. Crocce22, L. N. da Costa7;14, S. Desai24;25, H. T. Diehl1, J. P. Dietrich24;25, P. Doel15, T. F. Eifler17;26, A. E. Evrard27;28, D. A. Finley1, B. Flaugher1, P. Fosalba22, J. Frieman1;11, E. Gaztanaga22, D. W. Gerdes28, D. Gruen29;30, R. A. Gruendl20;21, G. Gutierrez1, K. Honscheid31;32, K. Kuehn33, N. Kuropatkin1, O. Lahav15, P. Martini31;34, R. Miquel35;23, B. Nord1, R. Ogando7;14, A. A. Plazas26, K. Reil5, A. Roodman4;5, M. Sako17, E. Sanchez36, V. Scarpine1, M. Schubnell28, I. Sevilla-Noarbe36;20, R. C. Smith12, M. Soares-Santos1, F. Sobreira1;7, E. Suchyta31;32, M. E. C. Swanson21, G. Tarle28, D. Tucker1, V. Vikram37, W. Wester1, Y. Zhang28, J. Zuntz38 (The DES Collaboration) arXiv:1508.03622v2 [astro-ph.GA] 6 Nov 2015 { 2 { *[email protected] [email protected] 1Fermi National Accelerator Laboratory, P. -
Galactic Building Blocks: Searching for Dwarf Galaxies Near and Far Andrew Lipnicky [email protected]
Rochester Institute of Technology RIT Scholar Works Theses Thesis/Dissertation Collections 7-2017 Galactic Building Blocks: Searching for Dwarf Galaxies Near and Far Andrew Lipnicky [email protected] Follow this and additional works at: http://scholarworks.rit.edu/theses Recommended Citation Lipnicky, Andrew, "Galactic Building Blocks: Searching for Dwarf Galaxies Near and Far" (2017). Thesis. Rochester Institute of Technology. Accessed from This Dissertation is brought to you for free and open access by the Thesis/Dissertation Collections at RIT Scholar Works. It has been accepted for inclusion in Theses by an authorized administrator of RIT Scholar Works. For more information, please contact [email protected]. R I T · · Galactic Building Blocks: Searching for Dwarf Galaxies Near and Far Andrew Lipnicky A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Astrophysical Sciences and Technology in the College of Science, School of Physics and Astronomy Rochester Institute of Technology © A. Lipnicky July, 2017 Rochester Institute of Technology Ph.D. Dissertation Galactic Building Blocks: Searching for Dwarf Galaxies Near and Far Author: Advisor: Andrew Lipnicky Dr. Sukanya Chakrabarti A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Astrophysical Sciences and Technology in the College of Science, School of Physics and Astronomy Approved by Dr.AndrewRobinson Date Director, Astrophysical Sciences and Technology Certificate of Approval Astrophysical Sciences and Technology R I T College of Science · · Rochester, NY, USA The Ph.D. Dissertation of Andrew Lipnicky has been approved by the undersigned members of the dissertation committee as satisfactory for the degree of Doctor of Philosophy in Astrophysical Sciences and Technology. -
This Was the Year That Was HE PROGRESS of (Astrophysics in 1997) Science Is Not Generally Tmuch Like That of a Kangaroo
THE UNIVERSE AT LARGE by VIRGINIA TRIMBLE This Was the Year That Was HE PROGRESS of (Astrophysics in 1997) science is not generally Tmuch like that of a kangaroo. Rather, we tend to advance amoeba-like, cautiously extending pseudopods in some directions and retracting them in others. 1997 witnessed at least its share of advances and retreats, with perhaps a leap or two. The following sections are meant to be logically independent and readable (or at least no less readable) in any order. MICRO- AND MACRO-MARS: WATER, WATER, EVERYWHERE Readers my age may remember when “I don’t think so” was an expression of genuine doubt. Last year’s announcement of possible microfossils in a meteorite that had come to us (or anyhow to Antarctica) from Mars provided an opportunity to try out the X- generation meaning of the phrase. Our curmudgeonly pessimism has been justified. After several months of rat-like gnawings on the edges of the evidence by other experts, the original proponents have essentially with- drawn the suggestion. Tactfully, they switched from Science to Nature for the recantation. 22 SPRING 1998 Meanwhile, a number of Martians have acquired personal names. But it’s no use calling them, because, like cats and Victor Borge’s children, they don’t come anyhow. In fact, they all seem to be rocks. And while reports from the Sagan Memorial Station indicate that the said rocks have carefully washed their hands for dinner, there doesn’t seem to be anything to eat. Continued analysis of Pathfinder data will proba- bly yield additional information on Martian geology,* but more advanced probes will be needed to dig below the surface and look for possible relics of early pre-biological Mars Pathfinder.