DOCSLIB.ORG

Science with High Spatial Resolution Far-Infrared Data

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Science with High Spatial Resolution Far-Infrared Data JPL Publication 94-5 SCIENCE WITH HIGH SPATIAL RESOLUTION FAR-INFRARED DATA Edited by S. Terebey and J. Mazzarella 1994 (Pasadena: JPL) Proceedings of a Workshop held 14-16 June 1993 at the Infrared Processing and Analysis Center 770 S. Wilson, Caltech, Pasadena, California 91125 PREFACE Data at far-infrared wavelengths are difficult to obtain and usually have much lower spatial resolution than data which are routinely obtained at other wavelengths. However, the many astrophysical problems that can only be well addressed in the far-infrared have inspired efforts to extract high spatial resolution information from instruments including the Infrared Astronomical Satellite (IRAS) and the Kuiper Airborne Observatory (KAO). The IRAS data also provide a fundamental archive since IRAS produced a nearly complete survey of the infrared sky. Although the IRAS survey strategy was not designed with the specific purpose of constructing images of the sky, the ingenuity of software developers has recently resulted in innovative techniques which are allowing astronomers to push the limits of these and other far-infrared data. The goal of this workshop was to discuss new science and techniques relevant to high spatial resolution processing of far-infrared data, with particular focus on high resolution processing of IRAS data. Users of the maximum correlation method, maximum entropy, and other resolution enhancement algorithms applicable to far-infrared data gathered at the Infrared Processing and Analysis Center (IPAC) on the Caltech campus in Pasadena for two days in June 1993 to compare techniques and discuss new results. During a special session on the third day, interested astronomers were introduced to IRAS HIRES processing, which is IPAC's implementation of the maximum correlation method to the IRAS data. Individuals who desire further information about IRAS or HIRES processing are encouraged to contact IPAC. This workshop would not have been possible without the hard work of Donna Milton during all stages, from planning of the conference through formatting and editing of the proceedings. We also express our thanks to the Local Organizing Committee--- Chas Beichman (IPAC), Zhong Wang (IPAC), and Tom Soifer (Caltech), and the Scientific Advisory Committee--- Tj. Romke Bontekoe (ESA/ESTEC), John Hackwell (Aerospace Corp.), Dan Lester (U. Texas), and Erick Young (Steward Obs.). Thanks also go to Steve Lord, Pat McLane, Mary Ellen Barba, and David Stanley for help before and during the workshop. Some funding was provided by registration fees_ but this conference would not have been possible without substantial financial assistance from the Jet Propulsion Laboratory, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration. S. Terebey and J. Mazzarella, Editors May 1994, Pasadena, CA P_ PAGE BLgD_K NOT FtLb_._.,: .°. 111 L PAGE II INTENTION/kLLY5L..."._K Science with High Spatial Resolution Far-Infrared Data TABLE OF CONTENTS PART I: Introduction and Technical Overviews HiRes and Beyond .................................................................................... 1 J.W. Fowler and H.H. Aumann MEM Application to IRAS CPC Images .............................................................. 11 A.P. Marston An Assessment of Image Reconstruction from Balloon-borne and the IRAS Data ...................... 17 S.K. Ghosh, B. Das, T.N. Rengarajan and R.P. Verma In Search of Random Noise ........................................................................... 23 D. Kester and Tj.R. Bontekoe Pushing the Limits of Spatial Resolution with the Kuiper Airborne Observatory ...................... 33 D. Lester A High Resolution Atlas of the Galactic Plane at 12/am and 25/am ................................... 45 S.D. Price, R. Korte, R.S. Sample, J.P. Kennealy and R. Gonsalves Constraints as a Destriping Tool for HIRES Images ................................................... 55 Y. Cao and T.A. Prince Beyond Maximum Entropy: Fractal Pixon-Based Image Reconstruction ............................... 61 R. Puetter and R.K. Piiia HIRAS: High-Resolution IRAS Images ............................................................... 69 Tj.R. Bontekoe and D. Kester PART II: Extragalactic Astronomy Interacting Galaxies Resolved by IRAS ............................................................... 71 J.M. Mazzarella and J.A. Surace Azimuthally Averaged Radial Slooi,,n/S6o,m Dust Color Temperatures in Spiral Galaxies ............................................................................... 81 N.A. Devereux Far-Infrared Sources and Diffuse Emission in M31 .................................................... 87 C. Xu and G. ttelou Correlation of Far-Infrared Emission and Radio Continuum Emission Along the Major Axis of Edge-On Spiral Galaxies ...................................... 95 B. Heikkila and W.R. Webber Far-Infrared Mapping of Dusty Elliptical Galaxies ................................................... 101 J.F. Lees, D.A. Harper, M. P. Rupen, and G. R. Knapp Extended Far-Infrared Emission and Star Formation in Seyfert Galaxies ............................. 107 A.P. Marston Two-Dinmnsional Maps of the Infrared-to-Radio Ratio in Spiral Galaxies ............................ 115 K.A. Marsh and G. Helou The Variation of the Dust Tcmperature Within Late-Type Spiral Galaxies ........................... 121 Rh. Evans PART III: Galactic and Solar System Astronomy An IRAS HiRes Study of Low Mass Star Formation in the Taurus Molecular Ring ................................................................................. 127 S. Terebey and J. Surace HIRAS Images of Fossil Dust Shells Around AGB Stars ............................................. 137 L.B.F.M. Waters, D.J.M. Kester, J.R. Bontekoe, and C. Loup Wavelet Analysis Applied to the IRAS Cirrus ....................................................... 143 W. Langer, R. W. Wilson, and C. H. Anderson A HiRes Analysis of the F1R Emission of Supernova Remnants ...................................... 157 Z. Wang Arcminute Scale HI and IRAS Observations Toward High Latitude Cloud G86.5+59.6 .............................................................................. 165 P.G. Martin, C. Rogers, W.T. Reach, P.E. Dewdney and C.E. Heiles Application of MCM Image Construction to IRAS Comet Observations .............................. 173 M.F. Schlapfer and R.G. Walker Luminous Radio-Quiet Sources in the W3(Main) Cloud Core ........................................ 177 C.G. Wynn-Williams, E.F. Ladd, J.R. Deane, and D.B. Sanders hldex of Authors ................................................................................. 183 List of Attendees ................................................................................. 185 vi N95- 21750 HIRES AND BEYOND J. W. FOWLER AND H. H. AUMANN Infrared Processing and Analysis Center, MS 100-22 California Institute of Technology, Jet Propulsion Laboratory Pasadena, CA 91125 ABSTRACT The High-Resolution image construction program (Hi- Res) used at IPAC is based on the Maximum Correlation Method. After HiRes intensity images are constructed from IRAS data, additional im- ages are needed to aid in scientific interpretation. Some of the images that are available for this purpose show the fitting noise, estimates of the achieved resolution, and detector track maps. Two methods have been developed for creating color maps without discarding any more spa- tial information than absolutely necessary: the "cross-band simulation" and "prior-knowledge" methods. These maps are demonstrated using the survey observations of a 2 × 2 degree field centered on M31. Prior knowledge may also be used to achieve super-resolution and to suppress ringing around bright point sources observed against background emis- sion. Tools to suppress noise spikes and for accelerating convergence are also described. 1. INTRODUCTION The high-resolution image construction program used at IPAC is based on the Maximum Correlation Method (MCM; see Aumann, l,bwler, and Melnyk, 1990). This program uses IRAS survey and additional observation data to construct images in the four IRAS survey wavelength bands. These images are intensity maps covering typically one to four square degrees. The effective beam size varies significantly over these inlages because of the manner in which the IRAS tele- scope gathered infrared data. This makes interpreting the images and obtaining color ratios especially challenging. Complications are added by tile nature of tile celestial background (the varying zodiacal background) and the detectors. The more important effects caused by the detectors and the orbital environment are: hysteresis, residuals of radiation hits, saturation for bright sources, detectors of different noise amplitude, and baseline drift due to 1/f noise (1RAS Explanatory Supplement 1988). In this paper we discuss additionM tools and techniques that have been developed at IPAC over the last two years to address these difficulties. Some of these are byproducts of the intensity imaging (e.g., correction-factor variance and coverage maps), while others have I)een added recently to the default l)rod- ucts (e.g., beam-sample maps and detector track maps). Some techniques that have been developed are now employed by default (e.g., automatic llux-bias pro- S. Terebey as_d J. Mazzza'ella (eds.), Sciezlce with High-5)Jatial l'lesolutiou Far hJfi'ared Data, 1-10, 1994, Jet Propulsion Laboratory, Pasadena, CA. 2 FOWLER AND AUMANN q Fig. 1: Intensity
Load more

Recommended publications
  • Lateinischer Name: Deutscher Name: Hya Hydra Wasserschlange
    Lateinischer Name: Deutscher Name: Hya Hydra Wasserschlange Atlas Karte (2000.0) Kulmination um Cambridge 10, 16, Mitternacht: Star Atlas 17 12, 13, Sky Atlas Benachbarte Sternbilder: 20, 21 Ant Cnc Cen Crv Crt Leo Lib 9. Februar Lup Mon Pup Pyx Sex Vir Deklinationsbereic h: -35° ... 7° Fläche am Himmel: 1303° 2 Mythologie und Geschichte: Bei der nördlichen Wasserschlange überlagern sich zwei verschiedene Bilder aus der griechischen Mythologie. Das erste Bild zeugt von der eher harmlosen Wasserschlange aus der Geschichte des Raben : Der Rabe wurde von Apollon ausgesandt, um mit einem goldenen Becher frisches Quellwasser zu holen. Stattdessen tat sich dieser an Feigen gütlich und trug bei seiner Rückkehr die Wasserschlange in seinen Fängen, als angebliche Begründung für seine Verspätung. Um jedermann an diese Untat zu erinnern, wurden der Rabe samt Becher und Wasserschlange am Himmel zur Schau gestellt. Von einem ganz anderen Schlag war die Wasserschlange, mit der Herakles zu tun hatte: In einem Sumpf in der Nähe von Lerna, einem See und einer Stadt an der Küste von Argo, hauste ein unsagbar gefährliches und grässliches Untier. Diese Schlange soll mehrere Köpfe gehabt haben. Fünf sollen es gewesen sein, aber manche sprechen auch von sechs, neun, ja fünfzig oder hundert Köpfen, aber in jedem Falle war der Kopf in der Mitte unverwundbar. Fürchterlich war es, da diesen grässlichen Mäulern - ob die Schlange nun schlief oder wachte - ein fauliger Atem, ein Hauch entwich, dessen Gift tödlich war. Kaum schlug ein todesmutiger Mann dem Untier einen Kopf ab, wuchsen auf der Stelle zwei neue Häupter hervor, die noch furchterregender waren. Eurystheus, der König von Argos, beauftragte Herakles in seiner zweiten Aufgabe diese lernäische Wasserschlange zu töten.
    [Show full text]
  • The Skyscraper 2009 04.Indd
    A Better Galaxy Guide: Early Spring M67: One of the most ancient open clusters known and Craig Cortis is a great novelty in this regard. Located 1.7° due W of mag NGC 2419: 3.25° SE of mag 6.2 66 Aurigae. Hard to find 4.3 Alpha Cancri. and see; at E end of short row of two mag 7.5 stars. Highly NGC 2775: Located 3.7° ENE of mag 3.1 Zeta Hydrae. significant and worth the effort —may be approximately (Look for “Head of Hydra” first.) 300,000 light years distant and qualify as an extragalactic NGC 2903: Easily found at 1.5° due S of mag 4.3 Lambda cluster. Named the Intergalactic Wanderer. Leonis. NGC 2683: Marks NW “crook” of coathanger-type triangle M95: One of three bright galaxies forming a compact with easy double star mag 4.2 Iota Cancri (which is SSW by triangle, along with M96 and M105. All three can be seen 4.8°) and mag 3.1 Alpha Lyncis (at 6° to the ENE). together in a low power, wide field view. M105 is at the NE tip of triangle, midway between stars 52 and 53 Leonis, mag Object Type R.A. Dec. Mag. Size 5.5 and 5.3 respectively —M95 is at W tip. Lynx NGC 3521: Located 0.5° due E of mag 6.0 62 Leonis. M65: One of a pair of bright galaxies that can be seen in NGC 2419 GC 07h 38.1m +38° 53’ 10.3 4.2’ a wide field view along with M66, which lies just E.
    [Show full text]
  • October 2006
    OCTOBER 2 0 0 6 �������������� http://www.universetoday.com �������������� TAMMY PLOTNER WITH JEFF BARBOUR 283 SUNDAY, OCTOBER 1 In 1897, the world’s largest refractor (40”) debuted at the University of Chica- go’s Yerkes Observatory. Also today in 1958, NASA was established by an act of Congress. More? In 1962, the 300-foot radio telescope of the National Ra- dio Astronomy Observatory (NRAO) went live at Green Bank, West Virginia. It held place as the world’s second largest radio scope until it collapsed in 1988. Tonight let’s visit with an old lunar favorite. Easily seen in binoculars, the hexagonal walled plain of Albategnius ap- pears near the terminator about one-third the way north of the south limb. Look north of Albategnius for even larger and more ancient Hipparchus giving an almost “figure 8” view in binoculars. Between Hipparchus and Albategnius to the east are mid-sized craters Halley and Hind. Note the curious ALBATEGNIUS AND HIPPARCHUS ON THE relationship between impact crater Klein on Albategnius’ southwestern wall and TERMINATOR CREDIT: ROGER WARNER that of crater Horrocks on the northeastern wall of Hipparchus. Now let’s power up and “crater hop”... Just northwest of Hipparchus’ wall are the beginnings of the Sinus Medii area. Look for the deep imprint of Seeliger - named for a Dutch astronomer. Due north of Hipparchus is Rhaeticus, and here’s where things really get interesting. If the terminator has progressed far enough, you might spot tiny Blagg and Bruce to its west, the rough location of the Surveyor 4 and Surveyor 6 landing area.
    [Show full text]
  • Meeting Program
    A A S MEETING PROGRAM 211TH MEETING OF THE AMERICAN ASTRONOMICAL SOCIETY WITH THE HIGH ENERGY ASTROPHYSICS DIVISION (HEAD) AND THE HISTORICAL ASTRONOMY DIVISION (HAD) 7-11 JANUARY 2008 AUSTIN, TX All scientific session will be held at the: Austin Convention Center COUNCIL .......................... 2 500 East Cesar Chavez St. Austin, TX 78701 EXHIBITS ........................... 4 FURTHER IN GRATITUDE INFORMATION ............... 6 AAS Paper Sorters SCHEDULE ....................... 7 Rachel Akeson, David Bartlett, Elizabeth Barton, SUNDAY ........................17 Joan Centrella, Jun Cui, Susana Deustua, Tapasi Ghosh, Jennifer Grier, Joe Hahn, Hugh Harris, MONDAY .......................21 Chryssa Kouveliotou, John Martin, Kevin Marvel, Kristen Menou, Brian Patten, Robert Quimby, Chris Springob, Joe Tenn, Dirk Terrell, Dave TUESDAY .......................25 Thompson, Liese van Zee, and Amy Winebarger WEDNESDAY ................77 We would like to thank the THURSDAY ................. 143 following sponsors: FRIDAY ......................... 203 Elsevier Northrop Grumman SATURDAY .................. 241 Lockheed Martin The TABASGO Foundation AUTHOR INDEX ........ 242 AAS COUNCIL J. Craig Wheeler Univ. of Texas President (6/2006-6/2008) John P. Huchra Harvard-Smithsonian, President-Elect CfA (6/2007-6/2008) Paul Vanden Bout NRAO Vice-President (6/2005-6/2008) Robert W. O’Connell Univ. of Virginia Vice-President (6/2006-6/2009) Lee W. Hartman Univ. of Michigan Vice-President (6/2007-6/2010) John Graham CIW Secretary (6/2004-6/2010) OFFICERS Hervey (Peter) STScI Treasurer Stockman (6/2005-6/2008) Timothy F. Slater Univ. of Arizona Education Officer (6/2006-6/2009) Mike A’Hearn Univ. of Maryland Pub. Board Chair (6/2005-6/2008) Kevin Marvel AAS Executive Officer (6/2006-Present) Gary J. Ferland Univ. of Kentucky (6/2007-6/2008) Suzanne Hawley Univ.
    [Show full text]
  • Stars and Their Spectra: an Introduction to the Spectral Sequence Second Edition James B
    Cambridge University Press 978-0-521-89954-3 - Stars and Their Spectra: An Introduction to the Spectral Sequence Second Edition James B. Kaler Index More information Star index Stars are arranged by the Latin genitive of their constellation of residence, with other star names interspersed alphabetically. Within a constellation, Bayer Greek letters are given first, followed by Roman letters, Flamsteed numbers, variable stars arranged in traditional order (see Section 1.11), and then other names that take on genitive form. Stellar spectra are indicated by an asterisk. The best-known proper names have priority over their Greek-letter names. Spectra of the Sun and of nebulae are included as well. Abell 21 nucleus, see a Aurigae, see Capella Abell 78 nucleus, 327* ε Aurigae, 178, 186 Achernar, 9, 243, 264, 274 z Aurigae, 177, 186 Acrux, see Alpha Crucis Z Aurigae, 186, 269* Adhara, see Epsilon Canis Majoris AB Aurigae, 255 Albireo, 26 Alcor, 26, 177, 241, 243, 272* Barnard’s Star, 129–130, 131 Aldebaran, 9, 27, 80*, 163, 165 Betelgeuse, 2, 9, 16, 18, 20, 73, 74*, 79, Algol, 20, 26, 176–177, 271*, 333, 366 80*, 88, 104–105, 106*, 110*, 113, Altair, 9, 236, 241, 250 115, 118, 122, 187, 216, 264 a Andromedae, 273, 273* image of, 114 b Andromedae, 164 BDþ284211, 285* g Andromedae, 26 Bl 253* u Andromedae A, 218* a Boo¨tis, see Arcturus u Andromedae B, 109* g Boo¨tis, 243 Z Andromedae, 337 Z Boo¨tis, 185 Antares, 10, 73, 104–105, 113, 115, 118, l Boo¨tis, 254, 280, 314 122, 174* s Boo¨tis, 218* 53 Aquarii A, 195 53 Aquarii B, 195 T Camelopardalis,
    [Show full text]
  • 407 a Abell Galaxy Cluster S 373 (AGC S 373) , 351–353 Achromat
    Index A Barnard 72 , 210–211 Abell Galaxy Cluster S 373 (AGC S 373) , Barnard, E.E. , 5, 389 351–353 Barnard’s loop , 5–8 Achromat , 365 Barred-ring spiral galaxy , 235 Adaptive optics (AO) , 377, 378 Barred spiral galaxy , 146, 263, 295, 345, 354 AGC S 373. See Abell Galaxy Cluster Bean Nebulae , 303–305 S 373 (AGC S 373) Bernes 145 , 132, 138, 139 Alnitak , 11 Bernes 157 , 224–226 Alpha Centauri , 129, 151 Beta Centauri , 134, 156 Angular diameter , 364 Beta Chamaeleontis , 269, 275 Antares , 129, 169, 195, 230 Beta Crucis , 137 Anteater Nebula , 184, 222–226 Beta Orionis , 18 Antennae galaxies , 114–115 Bias frames , 393, 398 Antlia , 104, 108, 116 Binning , 391, 392, 398, 404 Apochromat , 365 Black Arrow Cluster , 73, 93, 94 Apus , 240, 248 Blue Straggler Cluster , 169, 170 Aquarius , 339, 342 Bok, B. , 151 Ara , 163, 169, 181, 230 Bok Globules , 98, 216, 269 Arcminutes (arcmins) , 288, 383, 384 Box Nebula , 132, 147, 149 Arcseconds (arcsecs) , 364, 370, 371, 397 Bug Nebula , 184, 190, 192 Arditti, D. , 382 Butterfl y Cluster , 184, 204–205 Arp 245 , 105–106 Bypass (VSNR) , 34, 38, 42–44 AstroArt , 396, 406 Autoguider , 370, 371, 376, 377, 388, 389, 396 Autoguiding , 370, 376–378, 380, 388, 389 C Caldwell Catalogue , 241 Calibration frames , 392–394, 396, B 398–399 B 257 , 198 Camera cool down , 386–387 Barnard 33 , 11–14 Campbell, C.T. , 151 Barnard 47 , 195–197 Canes Venatici , 357 Barnard 51 , 195–197 Canis Major , 4, 17, 21 S. Chadwick and I. Cooper, Imaging the Southern Sky: An Amateur Astronomer’s Guide, 407 Patrick Moore’s Practical
    [Show full text]
  • Observer's Handbook 1986
    OBSERVER’S HANDBOOK 1986 EDITOR: ROY L. BISHOP THE ROYAL ASTRONOMICAL SOCIETY OF CANADA CONTRIBUTORS AND ADVISORS A l a n H. B a t t e n , Dominion Astrophysical Observatory, 5071 W. Saanich Road, Victoria, BC, Canada V8X 4M6 (The Nearest Stars). L a r r y D. B o g a n , Department of Physics, Acadia University, Wolfville, NS, Canada B0P 1X0 (Configurations of Saturn’s Satellites). Terence Dickinson, R.R. 3, Odessa, ON, Canada K0H 2H0 (The Planets). David W. Dunham, International Occultation Timing Association, P.O. Box 7488, Silver Spring, MD 20907, U.S.A. (Lunar and Planetary Occultations). Alan Dyer, Queen Elizabeth Planetarium, 10004-104 Ave., Edmonton, AB, Canada T5J 0K1 (Messier Catalogue, Deep-Sky Objects). Fred Espenak, Planetary Systems Branch, NASA-Goddard Space Flight Centre, Greenbelt, MD, U.S.A. 20771 (Eclipses and Transits). M arie Fidler, The Royal Astronomical Society of Canada, 136 Dupont St., Toronto, ON, Canada M5R 1V2 (Observatories and Planetaria). Victor Gaizauskas, Herzberg Institute of Astrophysics, National Research Council, Ottawa, ON, Canada K1A 0R6 (Solar Activity). R o b e r t F. G a r r is o n , David Dunlap Observatory, University of Toronto, Box 360, Richmond Hill, ON, Canada L4C 4Y6 (The Brightest Stars). Ian H alliday, Herzberg Institute of Astrophysics, National Research Council, Ottawa, ON, Canada K1A 0R6 (Miscellaneous Astronomical Data). W illiam Herbst, Van Vleck Observatory, Wesleyan University, Middletown, CT, U.S.A. 06457 (Galactic Nebulae). H e l e n S. H o g g , David Dunlap Observatory, University of Toronto, Box 360, Richmond Hill, ON, Canada L4C 4Y6 (Foreword).
    [Show full text]
  • Soft X-Ray Properties of a Spectroscopically Selected Sample of Interacting and Isolated Seyfert Galaxies?
    A&A 368, 797–816 (2001) Astronomy DOI: 10.1051/0004-6361:20010055 & c ESO 2001 Astrophysics Soft X-ray properties of a spectroscopically selected sample of interacting and isolated Seyfert galaxies? F. Pfefferkorn1, Th. Boller1, and P. Rafanelli2 1 Max-Planck-Institut f¨ur extraterrestrische Physik, Postfach 1312, 85741 Garching, Germany 2 Department of Astronomy, University of Padova, Vicolo Osservatorio 5, 35122 Padova, Italy Received 12 October 2000 / Accepted 4 January 2001 Abstract. We present a catalogue of ROSAT detected sources in the sample of spectroscopically selected Seyfert 1 and Seyfert 2 galaxies of Rafanelli et al. (1995). The catalogue contains 102 Seyfert 1 and 36 Seyfert 2 galaxies. The identification is based on X-ray contour maps overlaid on optical images taken from the Digitized Sky Survey. We have derived the basic spectral and timing properties of the X-ray detected Seyfert galaxies. For Seyfert 1 galaxies a strong correlation between photon index and X-ray luminosity is detected. We confirm the presence of generally steeper X-ray continua in narrow-line Seyfert 1 galaxies (NLS1s) compared to broad-line Seyfert 1 galaxies. Seyfert 2 galaxies show photon indices similar to those of NLS1s. Whereas a tendency for an increasing X-ray luminosity with increasing interaction strength is found for Seyfert 1 galaxies, such a correlation is not found for Seyfert 2 galaxies. For Seyfert 1 galaxies we found also a strong correlation for increasing far-infrared luminosity with increasing interaction strength. Both NLS1s and Seyfert 2 galaxies show the highest values of far-infrared luminosity compared to Seyfert 1 galaxies, suggesting that NLS1s and Seyfert 2 galaxies host strong (circumnuclear) star formation.
    [Show full text]
  • Search for Associations Containing Young Stars (SACY). V. Is
    Astronomy & Astrophysics manuscript no. sacy˙1˙accepted˙arxiv˙2 c ESO 2018 October 2, 2018 Search for associations containing young stars (SACY) V. Is multiplicity universal? Tight multiple systems?;??;??? P. Elliott1;2, A. Bayo1;3;4, C. H. F. Melo1, C. A. O. Torres5, M. Sterzik1, and G. R. Quast5 1 European Southern Observatory, Alonso de Cordova 3107, Vitacura Casilla 19001, Santiago 19, Chile e-mail: [email protected] 2 School of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QL 3 Max Planck Institut fur¨ Astronomie, Konigstuhl¨ 17, 69117, Heidelberg, Germany 4 Departamento de F´ısica y Astronom´ıa, Facultad de Ciencias, Universidad de Valpara´ıso, Av. Gran Bretana˜ 1111, 5030 Casilla, Valpara´ıso, Chile 5 Laboratorio´ Nacional de Astrof´ısica/ MCT, Rua Estados Unidos 154, 37504-364 Itajuba´ (MG), Brazil Received 21 March 2014 / Accepted 5 June 2014 ABSTRACT Context. Dynamically undisrupted, young populations of stars are crucial in studying the role of multiplicity in relation to star formation. Loose nearby associations provide us with a great sample of close (<150 pc) pre-main sequence (PMS) stars across the very important age range (≈5-70 Myr) to conduct such research. Aims. We characterize the short period multiplicity fraction of the search for associations containing young stars (SACY) sample, accounting for any identifiable bias in our techniques and present the role of multiplicity fractions of the SACY sample in the context of star formation. Methods. Using the cross-correlation technique we identified double-lined and triple-lined spectroscopic systems (SB2/SB3s), in addition to this we computed radial velocity (RV) values for our subsample of SACY targets using several epochs of fiber-fed extended range optical spectrograph (FEROS) and ultraviolet and visual echelle spectrograph (UVES) data.
    [Show full text]
  • Kinematics of the Local Universe
    ASTRONOMY & ASTROPHYSICS JUNE I 1998, PAGE 333 SUPPLEMENT SERIES Astron. Astrophys. Suppl. Ser. 130, 333–339 (1998) Kinematics of the local universe VII. New 21-cm line measurements of 2112 galaxies?,?? G. Theureau1, L. Bottinelli1,3, N. Coudreau-Durand1, L. Gouguenheim1,3, N. Hallet1, M. Loulergue1, G. Paturel4, and P. Teerikorpi2 1 Observatoire de Paris/Meudon, ARPEGES/CNRS URA1757, F-92195 Meudon Principal Cedex, France 2 Tuorla Observatory, 21500 Piikki¨o, Finland 3 Universit´e Paris-Sud, F-91405 Orsay, France 4 Observatoire de Lyon, F-69561 Saint-Genis Laval Cedex, France Received November 28; accepted December 24, 1997 Abstract. This paper presents 2112 new 21-cm neutral hy- • the completeness of the sample (Paturel et al. 1994) drogen line measurements carried out with the meridian • the homogenization of optical and radio data in con- transit Nan¸cay radiotelescope. Among these data we give nexion with the Lyon-Meudon Extragalactic database also 213 new radial velocities which complement those LEDA (Bottinelli et al. 1990) listed in three previous papers of this series. These new • the effect of disc opaqueness on observed optical B- measurements, together with the HI data collected in band parameters (Bottinelli et al. 1995) LEDA, put to 6 700 the number of galaxies with 21-cm • the dependence of the TF relation on morphological line width, radial velocity, and apparent diameter in the type and mean surface brightness and the improve- so-called KLUN sample. ment of this distance indicator (Theureau et al. 1997a; Theureau 1998) Key words: catalogs — galaxies: distances and redshifts; • the determination of the Hubble constant H0 from TF ISM — radio lines: galaxies B-band and log D25 relations (Theureau et al.
    [Show full text]
  • Making a Sky Atlas
    Appendix A Making a Sky Atlas Although a number of very advanced sky atlases are now available in print, none is likely to be ideal for any given task. Published atlases will probably have too few or too many guide stars, too few or too many deep-sky objects plotted in them, wrong- size charts, etc. I found that with MegaStar I could design and make, specifically for my survey, a “just right” personalized atlas. My atlas consists of 108 charts, each about twenty square degrees in size, with guide stars down to magnitude 8.9. I used only the northernmost 78 charts, since I observed the sky only down to –35°. On the charts I plotted only the objects I wanted to observe. In addition I made enlargements of small, overcrowded areas (“quad charts”) as well as separate large-scale charts for the Virgo Galaxy Cluster, the latter with guide stars down to magnitude 11.4. I put the charts in plastic sheet protectors in a three-ring binder, taking them out and plac- ing them on my telescope mount’s clipboard as needed. To find an object I would use the 35 mm finder (except in the Virgo Cluster, where I used the 60 mm as the finder) to point the ensemble of telescopes at the indicated spot among the guide stars. If the object was not seen in the 35 mm, as it usually was not, I would then look in the larger telescopes. If the object was not immediately visible even in the primary telescope – a not uncommon occur- rence due to inexact initial pointing – I would then scan around for it.
    [Show full text]
  • THE CONSTELLATION HYDRA, WATER SNAKE Hydra Is the Largest of the 88 Modern Constellations, Measuring 1303 Square Degrees
    THE CONSTELLATION HYDRA, WATER SNAKE Hydra is the largest of the 88 modern constellations, measuring 1303 square degrees. Also one of the longest at over 100 degrees, its southern end abuts Libra and Centaurus and its northern end borders Cancer. It has a long history, having been included among the 48 constellations listed by the 2nd century astronomer Ptolemy. It is commonly represented as a water snake. It should not be confused with the similarly named constellation of Hydrus. The neighboring constellations are Antlia, Cancer, Canis Minor, Centaurus, Corvus, Crater, Leo, Libra, Lupus, Monoceros, Puppis, Pyxis, Sextans and Virgo. Despite its size, Hydra contains only one reasonably bright star, Alphard, designated Alpha Hydrae. It is an orange giant of magnitude 2.0, 177 light-years from Earth. Its traditional name means "the solitary one". Beta Hydrae is a blue-white star of magnitude 4.3, 365 light-years from Earth. Gamma Hydrae is a yellow giant of magnitude 3.0, 132 light-years from Earth. Hydra has one bright binary star, Epsilon Hydrae, which is difficult to split in amateur telescopes; it has a period of 1000 years and is 135 light-years from Earth. The other main named star in Hydra is Sigma Hydrae, which has the name of Minaruja, from the Arabic for snake's nose. At magnitude 4.54, it is rather dim. The head of the snake corresponds to the Ashlesha nakshatra, a lunar zodiacal constellation in Indian astronomy. Hydra is also home to several variable stars. R Hydrae is a Mira variable star 2000 light-years from Earth; it is one of the brightest Mira variables at its maximum of magnitude 3.5.
    [Show full text]