Oca Club Meeting Star Parties Coming Up
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Searching for Diffuse Light in the M96 Group
Draft version June 30, 2016 Preprint typeset using LATEX style emulateapj v. 5/2/11 SEARCHING FOR DIFFUSE LIGHT IN THE M96 GALAXY GROUP Aaron E. Watkins1, J. Christopher Mihos1,Paul Harding1,John J. Feldmeier2 Draft version June 30, 2016 ABSTRACT We present deep, wide-field imaging of the M96 galaxy group (also known as the Leo I Group). Down to surface brightness limits of µB = 30:1 and µV = 29:5, we find no diffuse, large-scale optical counterpart to the “Leo Ring”, an extended HI ring surrounding the central elliptical M105 (NGC 3379). However, we do find a number of extremely low surface-brightness (µB & 29) small-scale streamlike features, possibly tidal in origin, two of which may be associated with the Ring. In addition we present detailed surface photometry of each of the group’s most massive members – M105, NGC 3384, M96 (NGC 3368), and M95 (NGC 3351) – out to large radius and low surface brightness, where we search for signatures of interaction and accretion events. We find that the outer isophotes of both M105 and M95 appear almost completely undisturbed, in contrast to NGC 3384 which shows a system of diffuse shells indicative of a recent minor merger. We also find photometric evidence that M96 is accreting gas from the HI ring, in agreement with HI data. In general, however, interaction signatures in the M96 Group are extremely subtle for a group environment, and provide some tension with interaction scenarios for the formation of the Leo HI Ring. The lack of a significant component of diffuse intragroup starlight in the M96 Group is consistent with its status as a loose galaxy group in which encounters are relatively mild and infrequent. -
ALFALFA Survey of the Leo Region S
ALFALFA Survey of the Leo Region S. Stierwalt, M.P. Haynes, R. Giovanelli, B. Kent, A. Saintonge (Cornell University), I.D. Karachentsev (Russian Academy of Sciences), V.E. Karachentseva (Astronomical Observatory of Kiev), N. Brosch (Wise Observatory), L. Hoffman (Lafayette College), B.Catinella, E. Momjian (Arecibo Observatory) ABSTRACT: The Leo region offers a detailed view of several nearby groups Points of Interest in the Leo Region of galaxies including Leo I at 10.4 Mpc and another slightly more distant (10h30m<RA<11h30m, 8º<dec<16º) structure within the Local Supercluster (Leo II). Leo I is of particular interest because it contains both a large ring of intergalactic gas of unknown origin (the Leo Ring) as well as a long tidal stream of stars and gas in the Leo Triplet. Because of its proximity, Leo can also offer insight M66 into the nature of low-mass, low-surface brightness galaxies believed to be the building blocks of galaxy formation. A direct comparison of optically and HI selected samples of dwarf galaxy candidates in the region has been made. This work has been supported by NSF grants AST-0307661 and AST--0435697 & by the Brinson Foundation. NNGGCC 3 6326828 OPTICALLY-SELECTED SAMPLE: Dwarf galaxy candidates in the Leo region were optically selected via a visual inspection of POSS-II/ESO/Serc plates by Karachentsev and Karachentseva. Sensitive, targeted single-pixel Arecibo Leo Ring of M65 gas in M96 group observations were taken of those candidates. Twenty-one of a possible thirty- Leo Triplet (Image from five dwarf galaxies were detected in HI including five background sources. -
Astronomers Discover a Distant Galaxy with a Pulse 16 November 2015
We've got the beat: Astronomers discover a distant galaxy with a pulse 16 November 2015 phase. Until now, no one had considered the effects of these stars on the light coming from more distant galaxies. In distant galaxies the light of each pulsating star is mixed with the light of many more stars that do not vary in brightness. "We realized that these stars are so bright and their pulsations so strong that they are difficult to hide," said Charlie Conroy, an assistant professor at Harvard, who led the research. "We decided to see if the pulsations of these stars could be detected even if we could not separate their light from the Hubble Space Telescope photograph of the galaxy M87, sea of unchanging stars that are their neighbors." which is 50 million light years from Earth. Credit: NASA/ESA Astronomers at Yale and Harvard have found a galaxy with a heartbeat—and they've taken its pulse. It is the first time scientists have measured the effect that pulsating, older red stars have on the light of their surrounding galaxy. The findings are published in the Nov. 16 online edition of the journal Nature. "We tend to think of galaxies as steady beacons in the sky, but they are actually 'shimmering' due to all the giant, pulsating stars in them," said Pieter van Dokkum, the Sol Goldman Professor and chair of astronomy at Yale, and co-author of the study. Later in life, stars like our Sun undergo significant changes. They become very bright and swell up to an enormous size, swallowing any planets within a An image of the pulsating star T Leporis, compared to the radius roughly equivalent to Earth's distance from size of the orbit of the Earth around the Sun. -
Mètodes De Detecció I Anàlisi D'exoplanetes
MÈTODES DE DETECCIÓ I ANÀLISI D’EXOPLANETES Rubén Soussé Villa 2n de Batxillerat Tutora: Dolors Romero IES XXV Olimpíada 13/1/2011 Mètodes de detecció i anàlisi d’exoplanetes . Índex - Introducció ............................................................................................. 5 [ Marc Teòric ] 1. L’Univers ............................................................................................... 6 1.1 Les estrelles .................................................................................. 6 1.1.1 Vida de les estrelles .............................................................. 7 1.1.2 Classes espectrals .................................................................9 1.1.3 Magnitud ........................................................................... 9 1.2 Sistemes planetaris: El Sistema Solar .............................................. 10 1.2.1 Formació ......................................................................... 11 1.2.2 Planetes .......................................................................... 13 2. Planetes extrasolars ............................................................................ 19 2.1 Denominació .............................................................................. 19 2.2 Història dels exoplanetes .............................................................. 20 2.3 Mètodes per detectar-los i saber-ne les característiques ..................... 26 2.3.1 Oscil·lació Doppler ........................................................... 27 2.3.2 Trànsits -
A STUDY of DWARF GALAXIES EMBEDDED in a LARGE-SCALE H I RING in the LEO I GROUP a Large-Scale Neutral Hydrogen (H I) Ring Serend
Publications of the Korean Astronomical Society pISSN: 1225-1534 30: 517 ∼ 519, 2015 September eISSN: 2287-6936 c 2015. The Korean Astronomical Society. All rights reserved. http://dx.doi.org/10.5303/PKAS.2015.30.2.517 A STUDY OF DWARF GALAXIES EMBEDDED IN A LARGE-SCALE H i RING IN THE LEO I GROUP Myo Jin Kim1, Aeree Chung y1, Jong Chul Lee2, Sungsoon Lim3, Minjin Kim2,5, Jongwan Ko2, Joon Hyeop Lee2,5, Soung-Chul Yang2,4, and Hye-Ran Lee2,5 1Department of Astronomy, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Korea 2Korea Astronomy and Space Science Institute, 776 Daedeok-daero, Yuseong-gu, Daejeon 305-348, Korea 3Peking University, No.5 Yiheyuan Road, Haidian District, Beijing, China 4The Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, California, USA 5Korea University of Science and Technology, 217 Gajeong-ro, Yuseong-gu, Daejeon 305-350, Korea E-mail: [email protected], [email protected] (Received November 30, 2014; Reviced May 31, 2015; Aaccepted June 30, 2015) ABSTRACT A large-scale neutral hydrogen (H i) ring serendipitously found in the Leo I galaxy group is 200 kpc 9 in diameter with MH i ∼ 1:67 × 10 M , unique in size in the Local Universe. It is still under debate where this H i ring originated - whether it has formed out of the gas remaining after the formation of a galaxy group (primordial origin) or been stripped during galaxy-galaxy interactions (tidal origin). We are investigating the optical and H i gas properties of the dwarf galaxies located within the gas ring in order to probe its formation mechanism. -
April 2016 BRAS Newsletter
April 2016 Issue th Next Meeting: Monday, April 11 at 7PM at HRPO (2nd Mondays, Highland Road Park Observatory) April 6th through April 10th is our annual Hodges Gardens Star Party. You can pre-register using the form on the BRAS website. If you have never attended this star party, make plans to attend this one. What's In This Issue? President’s Message Photos: BRAS Telescope donated to EBRP Library Secretary's Summary of March Meeting Recent BRAS Forum Entries 20/20 Vision Campaign Message from the HRPO Astro Short: Stellar Dinosaurs? International Astronomy Day Observing Notes: Leo The Lion, by John Nagle Newsletter of the Baton Rouge Astronomical Society April 2016 Page 2 President’s Message There were 478 people who stopped by the BRAS display at the March 19th ―Rockin at the Swamp‖ event at the Bluebonnet Swamp and Nature Center. I give thanks to all our volunteers for our success in this outreach event. April 6th through April 10th is our annual Hodges Gardens Star Party. You can pre-register on the BRAS website, or register when you arrive (directions are on the BRAS website). If you have never attended a star party, of if you are an old veteran star partier; make plans to attend this one. Our Guest Speaker for the BRAS meeting on April 11th will be Dr. Joseph Giaime, Observatory Head, LIGO Livingston (Caltech), Professor of Physics and Astronomy (LSU). Yes, he will be talking about gravity waves and the extraordinary discovery LIGO has made. We need volunteers to help at our display on Earth Day on Sunday, April 17th. -
Arxiv:1204.4363V1 [Astro-Ph.IM] 19 Apr 2012
Noname manuscript No. (will be inserted by the editor) Imaging the heart of astrophysical objects with optical long-baseline interferometry J.-P. Berger1;2 · F. Malbet1 · F. Baron3;4 · A. Chiavassa5;19 · G. Duvert1;6 · M. Elitzur7 · B. Freytag8 · F. Gueth9 · S. Honig¨ 10;11 · J. Hron12 · H. Jang-Condell13 · J.-B. Le Bouquin2;1 · J.-L. Monin1 · J.D. Monnier3 · G. Perrin14 · B. Plez15 · T. Ratzka16 · S. Renard1 · S. Stefl2 · E. Thiebaut´ 8 · K. Tristram10 · T. Verhoelst17 · S. Wolf18 · J. Young4 Received: date / Accepted: date Abstract The number of publications of aperture-synthesis images based on optical long- baseline interferometry measurements has recently increased due to easier access to visi- ble and infrared interferometers. The interferometry technique has now reached a technical maturity level that opens new avenues for numerous astrophysical topics requiring milli- arcsecond model-independent imaging. In writing this paper our motivation was twofold: 1) review and publicize emblematic excerpts of the impressive corpus accumulated in the field of optical interferometry image reconstruction; 2) discuss future prospects for this technique by selecting four representative astrophysical science cases in order to review the potential benefits of using optical long baseline interferometers. For this second goal we have simulated interferometric data from those selected astro- physical environments and used state-of-the-art codes to provide the reconstructed images that are reachable with current or soon-to-be facilities. The image reconstruction process was “blind” in the sense that reconstructors had no knowledge of the input brightness distri- butions. We discuss the impact of optical interferometry in those four astrophysical fields. -
Astronomy 2009 Index
Astronomy Magazine 2009 Index Subject Index 1RXS J160929.1-210524 (star), 1:24 4C 60.07 (galaxy pair), 2:24 6dFGS (Six Degree Field Galaxy Survey), 8:18 21-centimeter (neutral hydrogen) tomography, 12:10 93 Minerva (asteroid), 12:18 2008 TC3 (asteroid), 1:24 2009 FH (asteroid), 7:19 A Abell 21 (Medusa Nebula), 3:70 Abell 1656 (Coma galaxy cluster), 3:8–9, 6:16 Allen Telescope Array (ATA) radio telescope, 12:10 ALMA (Atacama Large Millimeter/sub-millimeter Array), 4:21, 9:19 Alpha (α) Canis Majoris (Sirius) (star), 2:68, 10:77 Alpha (α) Orionis (star). See Betelgeuse (Alpha [α] Orionis) (star) Alpha Centauri (star), 2:78 amateur astronomy, 10:18, 11:48–53, 12:19, 56 Andromeda Galaxy (M31) merging with Milky Way, 3:51 midpoint between Milky Way Galaxy and, 1:62–63 ultraviolet images of, 12:22 Antarctic Neumayer Station III, 6:19 Anthe (moon of Saturn), 1:21 Aperture Spherical Telescope (FAST), 4:24 APEX (Atacama Pathfinder Experiment) radio telescope, 3:19 Apollo missions, 8:19 AR11005 (sunspot group), 11:79 Arches Cluster, 10:22 Ares launch system, 1:37, 3:19, 9:19 Ariane 5 rocket, 4:21 Arianespace SA, 4:21 Armstrong, Neil A., 2:20 Arp 147 (galaxy pair), 2:20 Arp 194 (galaxy group), 8:21 art, cosmology-inspired, 5:10 ASPERA (Astroparticle European Research Area), 1:26 asteroids. See also names of specific asteroids binary, 1:32–33 close approach to Earth, 6:22, 7:19 collision with Jupiter, 11:20 collisions with Earth, 1:24 composition of, 10:55 discovery of, 5:21 effect of environment on surface of, 8:22 measuring distant, 6:23 moons orbiting, -
In This Issue: Rod’S Previous Book, the Urban Astronomer’S Guide Has Also Been Very Popular
The Rosette Gazette Volume 25,, IssueIssue 01 Newsletter of the Rose CityCity AstronomersAstronomers January, 2012 The Past, Present, and Future of the Schmidt Cassegrain Telescope by Rod Mollise “Uncle” Rod Mollise is familiar to amateur astronomers as the author of numerous books and magazine articles on every aspect of astronomy, amateur and professional. He is most well‐known, however, for his books on Schmidt Cassegrain Telescopes, SCTs, especially his latest one, Choosing and Using a New CAT (Springer), which has become the standard reference for these popular instruments. In This Issue: Rod’s previous book, The Urban Astronomer’s Guide has also been very popular. That’s no 1….General Meeting surprise, since it is designed to help the majority of amateurs who must observe from light polluted urban and suburban sites see deep sky wonders. 2….Special Interest Groups In addition to his books, Rod’s writing can be found in magazines including Sky and Telescope, Sky and Telescope’s SKYWATCH, Astronomy Technology Today, Amateur ……Observing Reports Astronomy Magazine, and others. Look for Unk Rod on numerous online forums, too, 3….Club Officers especially his popular blog, Uncle Rod’s Astro Blog. He is also one of the editors of the acclaimed online double star magazine, The University of South Alabama’s The Journal of …...Magazines Double Star Observations. …...RCA Library Rod Mollise is an engineer by profession, working on the U.S. Navy’s LPD Landing Ship 4….The Observers Corner program in Pascagoula, Mississippi, where he serves as the Combined Test Team’s Navigation Systems Engineer. Despite long 8.....Dawn Takes A Closer hours devoted to the new ships, he also finds time to teach Look astronomy to undergraduates at the University of South Alabama in 10...RCA Board Minutes Mobile. -
Gaseous Nebulae and Massive Stars in the Giant HI Ring In
Astronomy & Astrophysics manuscript no. astroph_leoring ©ESO 2021 April 16, 2021 Gaseous nebulae and massive stars in the giant H i ring in Leo Edvige Corbelli1, Filippo Mannucci1, David Thilker2, Giovanni Cresci1, and Giacomo Venturi3; 1 1 INAF-Osservatorio di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy e-mail: [email protected] 2 Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD, USA 3 Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22, Chile Received ....; accepted ...... ABSTRACT Context. Chemical abundances in the Leo ring, the largest H i cloud in the local Universe, have recently been determined to be close or above solar (Corbelli et al. 2021), incompatible with a previously claimed primordial origin of the ring. The gas, pre-enriched in a galactic disk and tidally stripped, did not manage to form stars very efficiently in intergalactic space. Aims. Using Hα emission and a multi wavelengths analysis of its extremely faint optical counterpart we investigate the process of star formation and the slow building up of a stellar population. Methods. We map nebular lines in 3 dense H i clumps of the Leo ring and complement these data with archival stellar continuum observations and population synthesis models. Results. A sparse population of stars is detected in the main body of the ring, with individual young stars as massive as O7-types −5 −1 −2 powering some H ii region. The average star formation rate density in the ring is of order of 10 M yr kpc and proceeds with local bursts a few hundred parsecs in size, where loose stellar associations of 500 – 1000 M occasionally host massive outliers. -
Substructures, Accretion Events, and Surrounding Diffuse Intra-Group Light
Substructures, accretion events, and surrounding diffuse intra-group light in bright early-type galaxies Johanna Hartke M¨unchen2018 Substructures, accretion events, and surrounding diffuse intra-group light in bright early-type galaxies Johanna Hartke Dissertation an der Fakult¨atf¨urPhysik der Ludwig{Maximilians{Universit¨at M¨unchen vorgelegt von Johanna Hartke aus Lohne (Oldenburg) M¨unchen, den 14. August 2018 Erstgutachter: Prof. Dr. Ortwin Gerhard Zweitgutachter: Dr. Klaus Dolag Tag der m¨undlichen Pr¨ufung:26. September 2018 v \Hope" is the thing with feathers That perches in the soul, And sings the tune without the words, And never stops at all, And sweetest in the gale is heard; And sore must be the storm That could abash the little bird That kept so many warm. I've heard it in the chillest land, And on the strangest sea; Yet, never, in extremity, It asked a crumb of me. Emily Dickinson vi Contents Zusammenfassung xxi Abstract xxiii 1 Introduction 1 1.1 Galaxy formation and evolution in the ΛCDM paradigm . .1 1.2 Galaxies: an overview . .3 1.2.1 A census of morphological types . .3 1.2.2 Tidal interactions and the effect of environment . .6 1.2.3 The extended halos of early-type galaxies . .8 1.3 Galaxy clusters and their galaxy population . 10 1.3.1 Galaxies in clusters . 11 1.3.2 The brightest cluster and group galaxies . 11 1.3.3 The intra-cluster and intra-group light . 12 1.4 Planetary nebulae as tracers of galaxy evolution . 15 1.4.1 What are planetary nebulae? . -
Environmental Influences on Dwarf Galaxy Evolution: the Group Environment
ENVIRONMENTAL INFLUENCES ON DWARF GALAXY EVOLUTION: THE GROUP ENVIRONMENT A Dissertation Presented to the Faculty of the Graduate School of Cornell University in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy by Sabrina Renee Stierwalt February 2010 c 2010 Sabrina Renee Stierwalt ALL RIGHTS RESERVED ENVIRONMENTAL INFLUENCES ON DWARF GALAXY EVOLUTION: THE GROUP ENVIRONMENT Sabrina Renee Stierwalt, Ph.D. Cornell University 2010 Galaxy groups are a rich source of information concerning galaxy evolution as they represent a fundamental link between individual galaxies and large scale structures. Nearby groups probe the low end of the galaxy mass function for the dwarf systems that constitute the most numerous extragalactic population in the local universe [Karachentsev et al., 2004]. Inspired by recent progress in our understanding of the Local Group, this dissertation addresses how much of this knowledge can be applied to other nearby groups by focusing on the Leo I Group at 11 Mpc. Gas-deficient, early-type dwarfs dominate the Local Group (Mateo [1998]; Belokurov et al. [2007]), but a few faint, HI-bearing dwarfs have been discovered in the outskirts of the Milky Way’s influence (e.g. Leo T; Irwin et al. [2007]). We use the wide areal coverage of the Arecibo Legacy Fast ALFA (ALFALFA) HI survey to search the full extent of Leo I and exploit the survey’s superior sensitivity, spatial and spectral resolution to probe lower HI masses than previous HI surveys. ALFALFA finds in Leo I a significant population of low surface brightness dwarfs missed by optical surveys which suggests similar systems in the Local Group may represent a so far poorly studied population of widely distributed, optically faint yet gas-bearing dwarfs.