Stellar Disks of Collisional Ring Galaxies I. New Multiband Images, Radial Intensity and Color Profiles, and Confrontation with N-Body Simulations R

Total Page:16

File Type:pdf, Size:1020Kb

Stellar Disks of Collisional Ring Galaxies I. New Multiband Images, Radial Intensity and Color Profiles, and Confrontation with N-Body Simulations R Draft version July 9, 2008 Preprint typeset using LATEX style emulateapj v. 4/9/03 STELLAR DISKS OF COLLISIONAL RING GALAXIES I. NEW MULTIBAND IMAGES, RADIAL INTENSITY AND COLOR PROFILES, AND CONFRONTATION WITH N-BODY SIMULATIONS R. Romano1, Y.D. Mayya1 and E. I. Vorobyov2 (Accepted in Astronomical Journal; astroph/0807.1477) Draft version July 9, 2008 ABSTRACT We present new multi-band imaging data in the optical (BV RI and Hα) and near infrared bands (JHK) of 15 candidate ring galaxies from the sample of Appleton & Struck-Marcell (1987). We use these data to obtain color composite images, global magnitudes and colors of both the ring galaxy and its companion(s), and radial profiles of intensity and colors. We find that only nine of the observed galaxies have multi-band morphologies expected for the classical collisional scenario of ring formation, indicating the high degree of contamination of the ring galaxy sample by galaxies without a clear ring morphology. The radial intensity profiles, obtained by masking the off-centered nucleus, peak at the position of the ring, with the profiles in the continuum bands broader than that in the Hα line. The images as well as the radial intensity and color profiles clearly demonstrate the existence of the pre-collisional stellar disk outside the star-forming ring, which is in general bluer than the disk internal to the ring. The stellar disk seems to have retained its size, with the disk outside the ring having a shorter exponential scale length as compared to the values expected in normal spiral galaxies of comparable masses. The rings in our sample of galaxies are found to be located preferentially at around half-way through the stellar disk. The most likely reason for this preference is bias against detecting rings when they are close to the center (they would be confused with the resonant rings), and at the edge of the disk the gas surface density may be below the critical density required for star formation. Most of the observed characteristics point to relatively recent collisions (< 80 Myr ago) according to the N-body simulations of Gerber et al. (1996). Subject headings: galaxies: photometry — galaxies: interactions 1. introduction been tested observationally in the Cartwheel, the pro- Ring galaxies are a class of objects whose optical ap- totype ring galaxy. The ring in this galaxy is expand- pearance is dominated by a ring or a ring-like structure. ing (Fosbury & Hawarden 1977), and is forming massive In one of the earliest discussions of ring galaxies, Bur- stars (Higdon 1995). A radial color gradient was also bidge & Burbidge (1959) suggested that these objects noticed by Marcum et al. (1992), which was found to be may be the aftermath of a close collision between an el- in agreement with the sequential ordering of stellar ages liptical and spiral galaxy. On the other hand, Freeman & (Korchagin et al. 2001; Vorobyov & Bizyaev 2001). Ap- de Vaucouleurs (1974) suggested that the ring is proba- pleton & Marston (1997) established the color gradient bly the result of a collision between a spiral galaxy and an in some other ring galaxies. Marston & Appleton (1995) intergalactic cloud of Hi. Theys & Spiegel (1976, 1977) carried out Hα imaging observations of eight ring galax- systematically studied the basic observational properties ies and found that majority of the star-forming regions of a sample of ring galaxies and suggested that rings are are located exclusively in the ring. formed when an intruding galaxy passes nearly through In the collisional scenario proposed by Lynds & the center of a normal disk galaxy. Lynds & Toomre Toomre (1976), a stellar density wave is set off as the (1976) used numerical simulations and settled the is- collective response of the stars that were present in the sue regarding their origin. They demonstrated that ring pre-collisional disk of the target galaxy. However, we galaxies are formed as a result of an on-axis collision know very little about the underlying stellar disk of the between an intruder galaxy and a gas-rich disk-galaxy. target galaxy. It is generally believed that the observed In this scenario, the collision sets off an expanding ring rings, especially in the near infrared continuum bands, wave, which in turn triggers star formation in its wake. trace the location of the stellar density waves. The stel- Due to the expanding nature of the wave, the ring of star lar disk outside the ring should carry important informa- formation also advances successively to larger radii with tion on the nature of the pre-collisional disk. However, time. This scenario has stood the test of the multi-band such a disk has not been traced even in the Cartwheel. data those have become available since then (Appleton Appleton & Marston (1997) tried to infer an outer disk & Struck-Marcell 1996 and references therein). using radial profiles of surface brightness and color in Many of the predictions from theoretical models have four galaxies, and found such a disk in two cases (IIHz4 and VIIZw466). Their images were not deep enough to 1 Instituto Nacional de Astrof´ısica Optica y Electronica, Luis study the azimuthal structure of the outer disks. Enrique Erro No. 1, Tonantzintla, Apdo Postal 51 y 216, 72840, Korchagin et al. (2001) have developed a method to Puebla, Mexico: [email protected], [email protected] estimate the contribution of the newly formed stars in 2 The Institute for Computational Astrophysics, Saint Mary’s University, Halifax NS, B3H 3C3, Canada; and Institute of Physics, different wavelength bands as the density wave expands South Federal University, Stachki 194, Rostov-on-Don, Russia. in the target galaxy. The density wave in the underlying 2 Romano et al. stellar disk can be recovered by subtracting the contri- Table 2 contains a detailed log of the observations. bution of the newly formed stars. Availability of Hα and The observing runs for each galaxy are given in column continuum images are fundamental in achieving this ob- 2, followed by the exposure times in the broadband fil- jective. The continuum images should reach at least 2 ters. These broadband filters correspond to the standard magnitudes deeper than the brightness of the ring in or- Johnson-Cousins BV RI system. The central wavelength der to register the stellar disk on either side of the star- of the Hα filter for each galaxy is given in column 7, fol- forming ring. With this goal in mind, we carried out lowed by a column containing the exposure times in these new imaging observations of a sample of 15 candidate filters. The Hα filters were of square-shape with typically ring galaxies in the BV RIJHK broad bands and in the a width of 100A,˚ and include both the [Nii] lines flanking emission line of Hα. Some of the candidate galaxies may the Hα. For five galaxies, observations were carried out not have formed by the scenario proposed by Lynds & in emission-line free narrow bands to facilitate subtrac- Toomre (1976), and these galaxies were included in our tion of the in-band continuum from the Hα-filter images. observing list with the hope that the new observations The central wavelength of the off-band continuum filters would allow us to filter out contaminating galaxies. The used for these galaxies are given in column 9. For the data and detailed surface photometric analysis of all sam- rest of the galaxies, the R-band images were used for the ple galaxies are presented in this paper. In a forthcom- purpose of continuum subtraction. Twilight sky expo- ing paper (Paper II), we will discuss the results obtained sures were taken for flat-fielding purposes. Several bias from the extraction of the underlying stellar density wave frames were obtained at the start and end of each night. in galaxies that are most likely formed by the classical collisional scenario. 2.2. Near infrared imaging Sample and the details of our observations are dis- cussed in § 2. Morphological descriptions and one di- All near infrared observations were carried out in the mensional profiles of individual galaxies are presented in J, H and K bands with the Observatorio Astronomico § 3. In § 4, we compare the photometric properties of Nacional 2.1-m telescope at San Pedro Martir, Mexico. ring galaxies with that of normal galaxies. Results ob- The CAMILA instrument (Cruz-Gonzalez et al. 1994), tained from the new data are discussed in the context of that hosts a NICMOS 3 detector of 256×256 pixel for- N-body simulations in § 5. Conclusions from our study mat, was used in the imaging mode with the focal reducer configuration f/4.5. This results in a spatial sampling of are presented in § 6. Gray scale maps in the Hα and B- ′′ −1 ′ ′ bands and one dimensional surface brightness and color 0. 85 pixel and a total field of view of 3.6 × 3.6. Each profiles for each galaxy are presented in the Appendix. observation consisted of a sequence of object and sky ex- Throughout this paper, all distance scaling assumes a posures, with the integration time of an individual expo- value for the Hubble Constant of 75 km s−1 Mpc−1. sure limited by the sky counts, which was kept well below the non-linear regime of the detector. A typical image sequence consisted of 10 exposures, six on the object and 2. observations and reductions four on the sky. NIR observations could not be carried Ring galaxies from the sample of Appleton & Struck- out for three of the sample galaxies. Though of lesser sen- Marcell (1987) were selected for optical and NIR pho- sitivity, we used the 2MASS3 images of these three galax- tometric study.
Recommended publications
  • Star Formation in Ring Galaxies Susan C
    East Tennessee State University Digital Commons @ East Tennessee State University Undergraduate Honors Theses Student Works 5-2016 Star Formation in Ring Galaxies Susan C. Olmsted East Tennessee State Universtiy Follow this and additional works at: https://dc.etsu.edu/honors Part of the Astrophysics and Astronomy Commons, and the Physics Commons Recommended Citation Olmsted, Susan C., "Star Formation in Ring Galaxies" (2016). Undergraduate Honors Theses. Paper 322. https://dc.etsu.edu/honors/ 322 This Honors Thesis - Open Access is brought to you for free and open access by the Student Works at Digital Commons @ East Tennessee State University. It has been accepted for inclusion in Undergraduate Honors Theses by an authorized administrator of Digital Commons @ East Tennessee State University. For more information, please contact [email protected]. Star Formation in Ring Galaxies Susan Olmsted Honors Thesis May 5, 2016 Student: Susan Olmsted: ______________________________________ Mentor: Dr. Beverly Smith: ____________________________________ Reader 1: Dr. Mark Giroux: ____________________________________ Reader 2: Dr. Michele Joyner: __________________________________ 1 Abstract: Ring galaxies are specific types of interacting galaxies in which a smaller galaxy has passed through the center of the disk of another larger galaxy. The intrusion of the smaller galaxy causes the structure of the larger galaxy to compress as the smaller galaxy falls through, and to recoil back after the smaller galaxy passes through, hence the ring-like shape. In our research, we studied the star-forming regions of a sample of ring galaxies and compared to those of other interacting galaxies and normal galaxies. Using UV, optical, and IR archived images in twelve wavelengths from three telescopes, we analyzed samples of star-forming regions in ring and normal spiral galaxies using photometry.
    [Show full text]
  • The Denver Observer May 2016
    The Denver MAY 2016 OBSERVER A section of a recent Hubble image of the Antennae Galaxies, NGCs 4038 and 4039, reveals intense star formation resulting from the galaxies’ colliding gases. Pink star-forming nebulae and blue (hot), new stars are clearly visible. Image Credit: ESA/Hubble & NASA MAY SKIES by Zachary Singer The Solar System ing 18.6” across from a distance of 0.50 AU. Interestingly, at opposi- Quite frequently in these pages, you’ll see that such-and-so planet tion, Mars will be roughly the same distance from us as Mercury at the is “lost in the solar glare,” and this month, Mercury embraces the spirit transit—so their relative disk sizes, 12 arcseconds vs. 18, quickly give of that phrase with gusto: The planet transits the Sun on the morning you a feel for each planet’s physical size. of May 9th. Already crossing the Sun’s face as it rises just before 6 AM, As May gives way to June, Mars will shrink in the eyepiece, return- the planet will finish its transit around 12:40 PM, as seen from Denver. ing to a 16” disk by early July. Even at the smaller diameter, the planet The planet’s apparent diameter will be 12.1 seconds of arc, making it should present some quite obvious even at moderate power—even small telescopes (with so- of its larger features, Sky Calendar lar filters, naturally) should show it clearly. While the DAS won’t have like ice caps or large 6 New Moon an official presence there, DU will open the Chamberlin Observatory plains like Syrtis Ma- 9 Mercury Transit from 9 AM to 12 noon.
    [Show full text]
  • NGC 3628-UCD1: a Possible $\Omega $ Cen Analog Embedded
    DRAFT VERSION NOVEMBER 6, 2018 Preprint typeset using LATEX style emulateapj v. 5/2/11 NGC 3628-UCD1: A POSSIBLE ! CEN ANALOG EMBEDDED IN A STELLAR STREAM ZACHARY G. JENNINGS1 ,AARON J. ROMANOWSKY1,2 ,JEAN P. BRODIE1 ,JOACHIM JANZ3 ,MARK A. NORRIS4 ,DUNCAN A. FORBES3 , DAVID MARTINEZ-DELGADO5 ,MARTINA FAGIOLI3 ,SAMANTHA J. PENNY6 Draft version November 6, 2018 ABSTRACT Using Subaru/Suprime-Cam wide-field imaging and both Keck/ESI and LBT/MODS spectroscopy, we iden- tify and characterize a compact star cluster, which we term NGC 3628-UCD1, embedded in a stellar stream around the spiral galaxy NGC 3628. The size and luminosity of UCD1 are similar to ! Cen, the most luminous Milky Way globular cluster, which has long been suspected to be the stripped remnant of an accreted dwarf 6 galaxy. The object has a magnitude of i = 19:3 mag (Li = 1:4 × 10 L ). UCD1 is marginally resolved in our ground-based imaging, with a half-light radius of ∼ 10 pc. We measure an integrated brightness for the stellar stream of i = 13:1 mag, with (g - i) = 1:0. This would correspond to an accreted dwarf galaxy with an 8 approximate luminosity of Li ∼ 4:1 × 10 L . Spectral analysis reveals that UCD1 has an age of 6:6 Gyr , [Z=H] = -0:75, and [α=Fe] = -0:10. We propose that UCD1 is an example of an ! Cen-like star cluster possi- bly forming from the nucleus of an infalling dwarf galaxy, demonstrating that at least some of the massive star cluster population may be created through tidal stripping.
    [Show full text]
  • The Structure & Stellar Populations of Nuclear Star Clusters in Late-Type
    UC Irvine UC Irvine Electronic Theses and Dissertations Title The Structure and Stellar Populations of Nuclear Star Clusters in Late-Type Spiral Galaxies Permalink https://escholarship.org/uc/item/3634g66n Author Carson, Daniel James Publication Date 2016 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA, IRVINE The Structure & Stellar Populations of Nuclear Star Clusters in Late-Type Spiral Galaxies DISSERTATION submitted in partial satisfaction of the requirements for the degree of DOCTOR OF PHILOSOPHY in Physics by Daniel J. Carson Dissertation Committee: Professor Aaron Barth, Chair Associate Professor Michael Cooper Professor James Bullock 2016 Portion of Chapter 1 c 2015 The Astronomical Journal Chapter 2 c 2015 The Astronomical Journal Chapter 3 c 2015 The Astronomical Journal Portion of Chapter 5 c 2015 The Astronomical Journal All other materials c 2016 Daniel J. Carson TABLE OF CONTENTS Page LIST OF FIGURES iv LIST OF TABLES vi ACKNOWLEDGMENTS vii CURRICULUM VITAE viii ABSTRACT OF THE DISSERTATION x 1 Introduction 1 2 HST /WFC3 data 9 2.1 SampleSelection ................................. 9 2.2 DescriptionofObservations . 10 2.3 DataReduction.................................. 14 3 Analysis of Structural Properties 17 3.1 Surface Brightness Profile Fitting . 17 3.1.1 PSFModels................................ 18 3.1.2 FittingMethod .............................. 19 3.1.3 Comparison with ISHAPE ......................... 21 3.1.4 1DRadialProfiles ............................ 22 3.1.5 Uncertainties in Cluster Parameters . 25 3.2 Results....................................... 29 3.2.1 SingleBandResults ........................... 29 3.2.2 PanchromaticResults........................... 40 3.2.3 Stellar Populations . 46 3.3 CommentsonIndividualObjects . 51 3.3.1 IC342................................... 51 3.3.2 M33 ...................................
    [Show full text]
  • Popular Names of Deep Sky (Galaxies,Nebulae and Clusters) Viciana’S List
    POPULAR NAMES OF DEEP SKY (GALAXIES,NEBULAE AND CLUSTERS) VICIANA’S LIST 2ª version August 2014 There isn’t any astronomical guide or star chart without a list of popular names of deep sky objects. Given the huge amount of celestial bodies labeled only with a number, the popular names given to them serve as a friendly anchor in a broad and complicated science such as Astronomy The origin of these names is varied. Some of them come from mythology (Pleiades); others from their discoverer; some describe their shape or singularities; (for instance, a rotten egg, because of its odor); and others belong to a constellation (Great Orion Nebula); etc. The real popular names of celestial bodies are those that for some special characteristic, have been inspired by the imagination of astronomers and amateurs. The most complete list is proposed by SEDS (Students for the Exploration and Development of Space). Other sources that have been used to produce this illustrated dictionary are AstroSurf, Wikipedia, Astronomy Picture of the Day, Skymap computer program, Cartes du ciel and a large bibliography of THE NAMES OF THE UNIVERSE. If you know other name of popular deep sky objects and you think it is important to include them in the popular names’ list, please send it to [email protected] with at least three references from different websites. If you have a good photo of some of the deep sky objects, please send it with standard technical specifications and an optional comment. It will be published in the names of the Universe blog. It could also be included in the ILLUSTRATED DICTIONARY OF POPULAR NAMES OF DEEP SKY.
    [Show full text]
  • Effects of Rotation Arund the Axis on the Stars, Galaxy and Rotation of Universe* Weitter Duckss1
    Effects of Rotation Arund the Axis on the Stars, Galaxy and Rotation of Universe* Weitter Duckss1 1Independent Researcher, Zadar, Croatia *Project: https://www.svemir-ipaksevrti.com/Universe-and-rotation.html; (https://www.svemir-ipaksevrti.com/) Abstract: The article analyzes the blueshift of the objects, through realized measurements of galaxies, mergers and collisions of galaxies and clusters of galaxies and measurements of different galactic speeds, where the closer galaxies move faster than the significantly more distant ones. The clusters of galaxies are analyzed through their non-zero value rotations and gravitational connection of objects inside a cluster, supercluster or a group of galaxies. The constant growth of objects and systems is visible through the constant influx of space material to Earth and other objects inside our system, through percussive craters, scattered around the system, collisions and mergers of objects, galaxies and clusters of galaxies. Atom and its formation, joining into pairs, growth and disintegration are analyzed through atoms of the same values of structure, different aggregate states and contiguous atoms of different aggregate states. The disintegration of complex atoms is followed with the temperature increase above the boiling point of atoms and compounds. The effects of rotation around an axis are analyzed from the small objects through stars, galaxies, superclusters and to the rotation of Universe. The objects' speeds of rotation and their effects are analyzed through the formation and appearance of a system (the formation of orbits, the asteroid belt, gas disk, the appearance of galaxies), its influence on temperature, surface gravity, the force of a magnetic field, the size of a radius.
    [Show full text]
  • Outflow Or Galactic Wind: the Fate of Ionized Gas in the Halos of Dwarf
    Astronomy & Astrophysics manuscript no. 7335 c ESO 2018 October 30, 2018 Outflow or galactic wind: The fate of ionized gas in the halos of dwarf galaxies J. van Eymeren1, D. J. Bomans1, K. Weis1;2, and R.–J. Dettmar1 1 Astronomisches Institut der Ruhr-Universitat¨ Bochum, Universitatsstraße¨ 150, D-44780 Bochum e-mail: [email protected] 2 Lise Meitner Fellowship Received date; accepted date ABSTRACT Context. Hα images of star bursting irregular galaxies reveal a large amount of extended ionized gas structures, in some cases at kpc-distance away from any place of current star forming activity. A kinematic analysis of especially the faint structures in the halo of dwarf galaxies allows insights into the properties and the origin of this gas component. This is important for the chemical evolution of galaxies, the enrichment of the intergalactic medium, and for the understanding of the formation of galaxies in the early universe. Aims. We want to investigate whether the ionized gas detected in two irregular dwarf galaxies (NGC 2366 and NGC 4861) stays gravitationally bound to the host galaxy or can escape from it by becoming a freely flowing wind. Methods. Very deep Hα images of NGC 2366 and NGC 4861 were obtained to detect and catalog both small and large scale ionized gas structures down to very low surface brightnesses. Subsequently, high-resolution long-slit echelle spectroscopy of the Hα line was performed for a detailed kinematic analysis of the most prominent filaments and shells. To calculate the escape velocity of both galaxies and to compare it with the derived expansion velocities of the detected filaments and shells, we used dark matter halo models.
    [Show full text]
  • Dust Emission Profiles of Dustpedia Galaxies
    A&A 622, A132 (2019) https://doi.org/10.1051/0004-6361/201833932 Astronomy c ESO 2019 Astrophysics& Dust emission profiles of DustPedia galaxies?,?? A. V. Mosenkov1,2,3 , M. Baes1, S. Bianchi4, V. Casasola4,5, L. P. Cassarà6, C. J. R. Clark7, J. Davies7, I. De Looze1,8, P. De Vis9, J. Fritz10, M. Galametz11, F. Galliano11, A. P. Jones9, S. Lianou11, S. C. Madden11, A. Nersesian1,6,12 , M. W. L. Smith7, A. Trckaˇ 1, S. Verstocken1, S. Viaene1,13, M. Vika6, and E. Xilouris6 1 Sterrenkundig Observatorium, Department of Physics and Astronomy, Universiteit Ghent, Krijgslaan 281 S9, 9000 Ghent, Belgium e-mail: [email protected] 2 Central Astronomical Observatory of RAS, Pulkovskoye Chaussee 65/1, 196140 St. Petersburg, Russia 3 St. Petersburg State University, Universitetskij Pr. 28, 198504 St. Petersburg, Stary Peterhof, Russia 4 INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Florence, Italy 5 INAF-Istituto di Radioastronomia, Via Piero Gobetti 101, 40129 Bologna, Italy 6 National Observatory of Athens, Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, Ioannou Metaxa and Vasileos Pavlou, 15236 Athens, Greece 7 School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA, UK 8 Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK 9 Institut d’Astrophysique Spatiale, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Bât. 121, 91405 Orsay Cedex, France 10 Instituto de Radioastronomía y Astrofísica, UNAM, Campus Morelia, AP 3-72, CP 58089,
    [Show full text]
  • Gas Kinematics in the Haloes of Nearby Irregular Dwarf Galaxies
    Gas Kinematics in the Haloes of Nearby Irregular Dwarf Galaxies Dissertation zur Erlangung des Grades „Doktor der Naturwissenschaften” in der Fakultät für Physik und Astronomie der Ruhr–Universität Bochum von Janine van Eymeren aus Essen Bochum 2008 1. Gutachter: Prof. Dr. Ralf–Jürgen Dettmar (AIRUB) 2. Gutachter: Priv. Doz. Dr. Dominik J. Bomans (AIRUB) 3. Gutachter: Dr. Bärbel Koribalski (ATNF) Tag der Disputation: 30.06.2008 This document has been created with LATEX 2ε To my godfather ( 11.01.2008) † and my grandmother ( 21.01.2008) † Contents 1 Introduction 1 1.1 Motivation...................................... 1 1.2 Thesample ....................................... 4 1.3 Organisation of the thesis . ....... 5 2 Fabry-Perot Interferometry 7 2.1 Multiple-beam interference . ........ 7 2.1.1 Interference at plane-parallel plates . .......... 7 2.1.2 Finesse, peak transmission and the contrast factor . ............. 10 2.1.3 Resolution and the free spectral range . ........ 10 2.1.4 The FP etalon as a wavelength filter . ..... 11 2.2 A scanning Fabry-Perot interferometer . ........... 11 2.3 Thedetector..................................... 12 2.3.1 Photon-counting systems vs. CCDs ...................... 12 2.3.2 An overview over the Image Photon Counting System . ........ 12 2.4 Observations and data reduction . ........ 13 2.5 Technical issues of the observations and the data reduction .............. 16 3 Spiral structure in NGC 2366 19 3.1 Introduction.................................... 19 3.2 Observations and data reduction . ........ 20 3.2.1 Opticalimaging................................ 20 3.2.2 Fabry-Perot interferometry . ...... 20 3.3 Results......................................... 22 3.3.1 Generalmorphology ...... ..... ...... ...... ..... 22 3.3.2 Hα velocities .................................. 22 3.4 Discussion of the peculiarities in NGC 2366 .
    [Show full text]
  • June 2021 BRAS Newsletter
    A JPL Image of surface of Mars, and JPL Ingenuity Helicioptor illustration. Monthly Meeting June 14th at 7:00 PM, in person at last!!! (Monthly meetings are on 2nd Mondays at Highland Road Park Observatory) You can also join this meeting via meet.jit.si/BRASMeet PRESENTATION: a demonstration on how to clean the optics of an SCT or refracting telescope. What's In This Issue? President’s Message Member Meeting Minutes Business Meeting Minutes Outreach Report Asteroid and Comet News Light Pollution Committee Report Globe at Night SubReddit and Discord BRAS Member Astrophotos Messages from the HRPO REMOTE DISCUSSION American Radio Relay League Field Day Observing Notes: Coma Berenices – Berenices Hair Like this newsletter? See PAST ISSUES online back to 2009 Visit us on Facebook – Baton Rouge Astronomical Society BRAS YouTube Channel Baton Rouge Astronomical Society Newsletter, Night Visions Page 2 of 23 June 2021 President’s Message Spring is just flying by it seems. Already June, galaxy season is peeking and the nebulous treasures closer to the Milky Way are starting to creep into the late evening sky. And as a final signal of Spring, we have a variety of life creeping up at the observatory on Highland Road (and not just the ample wildlife that’s been pushed out of the bayou by the rising flood waters, either). Astronomy Day was pretty big success (a much larger crowd than showed up last spring, at any rate) and making good on the ancient prophecy, we began having meetings at HRPO once again. Thanks again to Melanie for helping us score such a fantastic speaker for our homecoming, too.
    [Show full text]
  • The Full Appendices with All References
    Breakthrough Listen Exotica Catalog References 1 APPENDIX A. THE PROTOTYPE SAMPLE A.1. Minor bodies We classify Solar System minor bodies according to both orbital family and composition, with a small number of additional subtypes. Minor bodies of specific compositions might be selected by ETIs for mining (c.f., Papagiannis 1978). From a SETI perspective, orbital families might be targeted by ETI probes to provide a unique vantage point over bodies like the Earth, or because they are dynamically stable for long periods of time and could accumulate a large number of artifacts (e.g., Benford 2019). There is a large overlap in some cases between spectral and orbital groups (as in DeMeo & Carry 2014), as with the E-belt and E-type asteroids, for which we use the same Prototype. For asteroids, our spectral-type system is largely taken from Tholen(1984) (see also Tedesco et al. 1989). We selected those types considered the most significant by Tholen(1984), adding those unique to one or a few members. Some intermediate classes that blend into larger \complexes" in the more recent Bus & Binzel(2002) taxonomy were omitted. In choosing the Prototypes, we were guided by the classifications of Tholen(1984), Tedesco et al.(1989), and Bus & Binzel(2002). The comet orbital classifications were informed by Levison(1996). \Distant minor bodies", adapting the \distant objects" term used by the Minor Planet Center,1 refer to outer Solar System bodies beyond the Jupiter Trojans that are not comets. The spectral type system is that of Barucci et al. (2005) and Fulchignoni et al.(2008), with the latter guiding our Prototype selection.
    [Show full text]
  • Herschel → SCIENCE and LEGACY ESA’S SPACE SCIENCE MISSIONS Solar System Astronomy
    herschel → SCIENCE AND LEGACY ESA’S SPACE SCIENCE MISSIONS solar system astronomy bepicolombo cheops Europe’s first mission to Mercury will study this mysterious Characterising exoplanets known to be orbiting around nearby planet’s interior, surface, atmosphere and magnetosphere to bright stars. understand its origins. euclid Studying the Saturn system from orbit, having sent ESA’s Exploring the nature of dark energy and dark matter, revealing Huygens probe to the planet’s giant moon, Titan. the history of the Universe’s accelerated expansion and the growth of cosmic structure. cluster gaia A four-satellite mission investigating in unparalleled detail the Cataloguing the night sky and finding clues to the origin, structure interaction between the Sun and Earth’s magnetosphere. and evolution of the Milky Way. juice herschel Jupiter icy moons explorer, performing detailed investigations of Searching in infrared to unlock the secrets of starbirth and the gas giant and assessing the habitability potential of its large galaxy formation and evolution. icy satellites. mars express hubble space telescope Europe’s first mission to Mars, providing a global picture of the Expanding the frontiers of the visible Universe, looking deep into Red Planet’s atmosphere, surface and subsurface. space with cameras that can see in infrared, optical and ultraviolet wavelengths. rosetta integral The first mission to fly alongside and land a probe on a comet, The first space observatory to observe celestial objects investigating the building blocks of the Solar System. simultaneously in gamma rays, X-rays and visible light. soho jwst Providing new views of the Sun’s atmosphere and interior, and A space observatory to observe the first galaxies, revealing the investigating the cause of the solar wind.
    [Show full text]