Analysis of the Spiral Structure in Disk Galaxies Using the Fft Transform
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John J. Cowan Date of Birth: April 3, 1948 Place of Birth: Washington, D.C
VITA NAME: John J. Cowan Date of Birth: April 3, 1948 Place of Birth: Washington, D.C. EDUCATION: 1970 B.A. George Washington University, Washington, D.C. 1972 M.S. Case Institute of Technology, Cleveland, OH 1976 Ph.D. University of Maryland, College Park, MD PROFESSIONAL EXPERIENCE: 2002–present David Ross Boyd Professor, University of Oklahoma, 2002–2002 Research Fellow, University of Texas, Austin, TX 1998–2002 Samuel Roberts Noble Foundation Presidential Professor, University of Oklahoma, Norman, OK 1997–1998 Big XIIFaculty Fellow,University ofOklahoma 1991–1992 Visiting Professor, Department of Astronomy, Columbia University, New York, NY 1989–present Professor, Department of Physics and Astronomy, University of Oklahoma, Norman, OK 1988–1994 Consultant and Participating Guest, Lawrence Livermore National Laboratory, Livermore, CA 1987–1988 Visiting Research Associate, Harvard-Smithsonian Center for Astrophysics, Harvard University, Cambridge, MA 1984–1989 Associate Professor, University of Oklahoma 1979–1984 Assistant Professor, University of Oklahoma 1976–1979 Postdoctoral Research Fellow, Harvard-Smithsonian Center for Astrophysics, Harvard University PROFESSIONAL AND HONORARY SOCIETIES: American Astronomical Society International Astronomical Union Phi Beta Kappa RESEARCH INTERESTS: Stellar evolution, supernovae, nucleosynthesis and abundances Radio observations of supernovae and galaxies JOHN J. COWAN Page 2 PUBLICATIONS J. J. Cowan and W. K. Rose, “Production of 17O and 18O by Means of the Hot CNO Tri-Cycle,” Astrophys. J. (Letters) 201, L45 (1975) J. J. Cowan, M. Kafatos, and W. K. Rose, “Sources of Excitation of the Interstellar Gas and Galactic Structure,” Astrophys. J. 195, 47 (1975) M. F. A’Hearn and J. J. Cowan, “Molecular Production Rates in Comet Kohoutek,” As- tron. -
Near-Infrared Luminosity Relations and Dust Colors L
A&A 578, A47 (2015) Astronomy DOI: 10.1051/0004-6361/201525817 & c ESO 2015 Astrophysics Obscuration in active galactic nuclei: near-infrared luminosity relations and dust colors L. Burtscher1, G. Orban de Xivry1, R. I. Davies1, A. Janssen1, D. Lutz1, D. Rosario1, A. Contursi1, R. Genzel1, J. Graciá-Carpio1, M.-Y. Lin1, A. Schnorr-Müller1, A. Sternberg2, E. Sturm1, and L. Tacconi1 1 Max-Planck-Institut für extraterrestrische Physik, Postfach 1312, Gießenbachstr., 85741 Garching, Germany e-mail: [email protected] 2 Raymond and Beverly Sackler School of Physics & Astronomy, Tel Aviv University, 69978 Ramat Aviv, Israel Received 5 February 2015 / Accepted 5 April 2015 ABSTRACT We combine two approaches to isolate the AGN luminosity at near-IR wavelengths and relate the near-IR pure AGN luminosity to other tracers of the AGN. Using integral-field spectroscopic data of an archival sample of 51 local AGNs, we estimate the fraction of non-stellar light by comparing the nuclear equivalent width of the stellar 2.3 µm CO absorption feature with the intrinsic value for each galaxy. We compare this fraction to that derived from a spectral decomposition of the integrated light in the central arcsecond and find them to be consistent with each other. Using our estimates of the near-IR AGN light, we find a strong correlation with presumably isotropic AGN tracers. We show that a significant offset exists between type 1 and type 2 sources in the sense that type 1 MIR X sources are 7 (10) times brighter in the near-IR at log LAGN = 42.5 (log LAGN = 42.5). -
On the Origin and Propagation of Ultra-High Energy Cosmic Rays (Measurements & Prediction Techniques)
Dissertation On the Origin and Propagation of Ultra-High Energy Cosmic Rays (Measurements & Prediction Techniques) Nils Nierstenhoefer Wuppertal, 2011 University of Wuppertal Supervisor/First reviewer: Prof. Dr. K.-H. Kampert Second reviewer: Prof. Dr. M. Risse Motivation & Preface It is a long known fact that cosmic rays reach Earth with tremendous energies of even above 1020 eV. Despite of decades of intensive research, it was not possible to finally reveal the origin of these par- ticles. The main obstacle in this field is their rare occurrence. This is due to a very steep energy spectrum. To make this point more clear, one roughly expects to observe less than one particle per km2 in one century exceeding energies larger than 1020 eV. To overcome the limitation of low statis- tics, larger and larger cosmic ray detectors have been deployed. Today’s largest cosmic ray detector is the Pierre Auger observatory (PAO) which was constructed in the Pampa Amarilla in Argentina. It covers an area of 3000 km2 and provides the largest set of observations of ultra-high energy cosmic rays (UHECR) in history. A second difficulty in understanding the origin of UHECR should be pointed out: Galactic and extra- galactic magnetic fields might alter the direction of even the highest energy events in a way that they do not point back to their source. In 2007 and 2008, already before the completion of the full detector, the Auger collaboration pub- lished a set of three important papers [1, 2, 3]. The first paper dealt with the correlation of the arrival directions of the highest energetic events with the distribution of active galactic nuclei (AGN) closer than 75Mpc from a catalog compiled by Veron-Cetty and Veron (VC-V) [4]. -
CO Multi-Line Imaging of Nearby Galaxies (COMING) IV. Overview Of
Publ. Astron. Soc. Japan (2018) 00(0), 1–33 1 doi: 10.1093/pasj/xxx000 CO Multi-line Imaging of Nearby Galaxies (COMING) IV. Overview of the Project Kazuo SORAI1, 2, 3, 4, 5, Nario KUNO4, 5, Kazuyuki MURAOKA6, Yusuke MIYAMOTO7, 8, Hiroyuki KANEKO7, Hiroyuki NAKANISHI9 , Naomasa NAKAI4, 5, 10, Kazuki YANAGITANI6 , Takahiro TANAKA4, Yuya SATO4, Dragan SALAK10, Michiko UMEI2 , Kana MOROKUMA-MATSUI7, 8, 11, 12, Naoko MATSUMOTO13, 14, Saeko UENO9, Hsi-An PAN15, Yuto NOMA10, Tsutomu, T. TAKEUCHI16 , Moe YODA16, Mayu KURODA6, Atsushi YASUDA4 , Yoshiyuki YAJIMA2 , Nagisa OI17, Shugo SHIBATA2, Masumichi SETA10, Yoshimasa WATANABE4, 5, 18, Shoichiro KITA4, Ryusei KOMATSUZAKI4 , Ayumi KAJIKAWA2, 3, Yu YASHIMA2, 3, Suchetha COORAY16 , Hiroyuki BAJI6 , Yoko SEGAWA2 , Takami TASHIRO2 , Miho TAKEDA6, Nozomi KISHIDA2 , Takuya HATAKEYAMA4 , Yuto TOMIYASU4 and Chey SAITA9 1Department of Physics, Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810, Japan 2Department of Cosmosciences, Graduate School of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810, Japan 3Department of Physics, School of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo 060-0810, Japan 4Division of Physics, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan 5Tomonaga Center for the History of the Universe (TCHoU), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan 6Department of Physical Science, Osaka Prefecture University, Gakuen 1-1, -
Distances to PHANGS Galaxies: New Tip of the Red Giant Branch Measurements and Adopted Distances
MNRAS 501, 3621–3639 (2021) doi:10.1093/mnras/staa3668 Advance Access publication 2020 November 25 Distances to PHANGS galaxies: New tip of the red giant branch measurements and adopted distances Gagandeep S. Anand ,1,2‹† Janice C. Lee,1 Schuyler D. Van Dyk ,1 Adam K. Leroy,3 Erik Rosolowsky ,4 Eva Schinnerer,5 Kirsten Larson,1 Ehsan Kourkchi,2 Kathryn Kreckel ,6 Downloaded from https://academic.oup.com/mnras/article/501/3/3621/6006291 by California Institute of Technology user on 25 January 2021 Fabian Scheuermann,6 Luca Rizzi,7 David Thilker ,8 R. Brent Tully,2 Frank Bigiel,9 Guillermo A. Blanc,10,11 Med´ eric´ Boquien,12 Rupali Chandar,13 Daniel Dale,14 Eric Emsellem,15,16 Sinan Deger,1 Simon C. O. Glover ,17 Kathryn Grasha ,18 Brent Groves,18,19 Ralf S. Klessen ,17,20 J. M. Diederik Kruijssen ,21 Miguel Querejeta,22 Patricia Sanchez-Bl´ azquez,´ 23 Andreas Schruba,24 Jordan Turner ,14 Leonardo Ubeda,25 Thomas G. Williams 5 and Brad Whitmore25 Affiliations are listed at the end of the paper Accepted 2020 November 20. Received 2020 November 13; in original form 2020 August 24 ABSTRACT PHANGS-HST is an ultraviolet-optical imaging survey of 38 spiral galaxies within ∼20 Mpc. Combined with the PHANGS- ALMA, PHANGS-MUSE surveys and other multiwavelength data, the data set will provide an unprecedented look into the connections between young stars, H II regions, and cold molecular gas in these nearby star-forming galaxies. Accurate distances are needed to transform measured observables into physical parameters (e.g. -
Structure and Star Formation in Disk Galaxies I. Sample Selection And
Mon. Not. R. Astron. Soc. 000, 1–9 (2003) Printed 31 October 2018 (MN LATEX style file v1.4) Structure and star formation in disk galaxies I. Sample selection and near infrared imaging J. H. Knapen1,2, R. S. de Jong3, S. Stedman1 and D. M. Bramich4 1University of Hertfordshire, Department of Physical Sciences, Hatfield, Herts AL10 9AB 2Isaac Newton Group of Telescopes, Apartado 321, E-38700 Santa Cruz de La Palma, Spain 3Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA 4School of Physics and Astronomy, University of St. Andrews, Scotland KY16 9SS Accepted March 2003. Received ; in original form ABSTRACT We present near-infrared imaging of a sample of 57 relatively large, Northern spiral galaxies with low inclination. After describing the selection criteria and some of the basic properties of the sample, we give a detailed description of the data collection and reduction procedures. The Ks λ =2.2µm images cover most of the disk for all galaxies, with a field of view of at least 4.2 arcmin. The spatial resolution is better than an arcsec for most images. We fit bulge and exponential disk components to radial profiles of the light distribution. We then derive the basic parameters of these components, as well as the bulge/disk ratio, and explore correlations of these parameters with several galaxy parameters. Key words: galaxies: spiral – galaxies: structure – infrared: galaxies 1 INTRODUCTION only now starting to be published (e.g., 2MASS: Skrutskie et al. 1997, Jarrett et al. 2003; Seigar & James 1998a, 1998b; Near-infrared (NIR) imaging of galaxies is a better tracer Moriondo 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. -
Cold Gas Accretion in Galaxies
Astron Astrophys Rev (2008) 15:189–223 DOI 10.1007/s00159-008-0010-0 REVIEW ARTICLE Cold gas accretion in galaxies Renzo Sancisi · Filippo Fraternali · Tom Oosterloo · Thijs van der Hulst Received: 28 January 2008 / Published online: 17 April 2008 © The Author(s) 2008 Abstract Evidence for the accretion of cold gas in galaxies has been rapidly accumulating in the past years. H I observations of galaxies and their environment have brought to light new facts and phenomena which are evidence of ongoing or recent accretion: (1) A large number of galaxies are accompanied by gas-rich dwarfs or are surrounded by H I cloud complexes, tails and filaments. This suggests ongoing minor mergers and recent arrival of external gas. It may be regarded, therefore, as direct evidence of cold gas accretion in the local universe. It is probably the same kind of phenomenon of material infall as the stellar streams observed in the halos of our galaxy and M 31. (2) Considerable amounts of extra-planar H I have been found in nearby spiral galaxies. While a large fraction of this gas is undoubtedly produced by galactic fountains, it is likely that a part of it is of extragalactic origin. Also the Milky Way has extra-planar gas complexes: the Intermediate- and High-Velocity Clouds (IVCs and HVCs). (3) Spirals are known to have extended and warped outer layers of H I. It is not clear how these have formed, and how and for how long the warps can R. Sancisi (B) Osservatorio Astronomico di Bologna, Via Ranzani 1, 40127 Bologna, Italy e-mail: [email protected] R. -
194 9 Ce Le B Rating 65 Ye Ars O F Br Inging As Tr on Omy T O No Rth Te X As 2
1949 Celebrating 65 Years of Bringing Astronomy to North Texas 2014 Contact information: Inside this issue: Info Officer (General Info) – [email protected] Website Administrator – [email protected] Page Postal Address: November Club Calendar 3 Fort Worth Astronomical Society Celestial Events 4 c/o Matt McCullar 5801 Trail Lake Drive Sky Chart 5 Fort Worth, TX 76133 Moon Phase Calendar 6 Web Site: http://www.fortworthastro.org Facebook: http://tinyurl.com/3eutb22 Lunar Occultations/Conjs 7 Twitter: http://twitter.com/ftwastro Yahoo! eGroup (members only): http://tinyurl.com/7qu5vkn Mercury/Venus Chart 8 Officers (2014-2015): Mars/Minor Planets Charts 9 President – Bruce Cowles, [email protected] Jupiter Charts 10 Vice President – Russ Boatwright, [email protected] Sec/Tres – Michelle Theisen, [email protected] Planet Vis & ISS Passes 11 Board Members: CSAC Event Update 12 2014-2016 Mike Langohr Young Astronomer News 12 Tree Oppermann ‘66 Leonids Remembered 13 2013-2015 Bill Nichols Cloudy Night Library 15 Jim Craft Cover Photo: Monthly AL Observing Club 17 Composite image taken by FWAS mem- bers: Left to right, from top to bottom— Constellation of the Month 18 Laura Cowles, Mike Ahner, Brian Wortham, Constellation Mythology 19 Shawn Kirchdorfer, Mark Wainright, Phil Stage, Patrick McMahon, Dennis Webb, Ben Prior Club Meeting Minutes 20 Hudgens, Shawn Kirchdorfer, John McCrea, and Chris Mlodnicki General Club Information 21 That’s A Fact 21 Observing Site Reminders: Be careful with fire, mind all local burn bans! Full Moon Name 21 Dark Site Usage Requirements (ALL MEMBERS): FWAS Foto Files 22 Maintain Dark-Sky Etiquette (http://tinyurl.com/75hjajy) Turn out your headlights at the gate! Sign the logbook (in camo-painted storage shed. -
Lopsided Spiral Galaxies: Evidence for Gas Accretion
A&A 438, 507–520 (2005) Astronomy DOI: 10.1051/0004-6361:20052631 & c ESO 2005 Astrophysics Lopsided spiral galaxies: evidence for gas accretion F. Bournaud1, F. Combes1,C.J.Jog2, and I. Puerari3 1 Observatoire de Paris, LERMA, 61 Av. de l’Observatoire, 75014 Paris, France e-mail: [email protected] 2 Department of Physics, Indian Institute of Science, Bangalore 560012, India 3 Instituto Nacional de Astrofísica, Optica y Electrónica, Calle Luis Enrique Erro 1, 72840 Tonantzintla, Puebla, Mexico Received 3 January 2005 / Accepted 15 March 2005 Abstract. We quantify the degree of lopsidedness for a sample of 149 galaxies observed in the near-infrared from the OSUBGS sample, and try to explain the physical origin of the observed disk lopsidedness. We confirm previous studies, but for a larger sample, that a large fraction of galaxies have significant lopsidedness in their stellar disks, measured as the Fourier amplitude of the m = 1 component normalised to the average or m = 0 component in the surface density. Late-type galaxies are found to be more lopsided, while the presence of m = 2 spiral arms and bars is correlated with disk lopsidedness. We also show that the m = 1 amplitude is uncorrelated with the presence of companions. Numerical simulations were carried out to study the generation of m = 1viadifferent processes: galaxy tidal encounters, galaxy mergers, and external gas accretion with subsequent star formation. These simulations show that galaxy interactions and mergers can trigger strong lopsidedness, but do not explain several independent statistical properties of observed galaxies. To explain all the observational results, it is required that a large fraction of lopsidedness results from cosmological accretion of gas on galactic disks, which can create strongly lopsided disks when this accretion is asymmetrical enough. -
An Atlas of Calcium Triplet Spectra of Active Galaxies 3
Mon. Not. R. Astron. Soc. 000, 000–000 (0000) Printed 1 December 2018 (MN LATEX style file v2.2) An atlas of Calcium triplet spectra of active galaxies A. Garcia-Rissmann1⋆, L. R. Vega1,2†, N. V. Asari1‡, R. Cid Fernandes1§, H. Schmitt3,4¶, R. M. Gonz´alez Delgado5k, T. Storchi-Bergmann6⋆⋆ 1 Depto. de F´ısica - CFM - Universidade Federal de Santa Catarina, C.P. 476, 88040-900, Florian´opolis, SC, Brazil 2 Observatorio Astron´omico de C´ordoba, Laprida 854, 5000, C´ordoba, Argentina 3 Remote Sensing Division, Code 7210, Naval Research Laboratory, 4555 Overlook Avenue, SW, Washington, DC 20375 4 Interferometric Inc., 14120 Parke Long Court, 103, Chantilly, VA20151 5 Instituto de Astrof´ısica de Andaluc´ıa (CSIC), P.O. Box 3004, 18080 Granada, Spain 6 Instituto de F´ısica, Universidade Federal do Rio Grande do Sul, C.P. 15001, 91501-970, Porto Alegre, RS, Brazil 1 December 2018 ABSTRACT We present a spectroscopic atlas of active galactic nuclei covering the region around the λλ8498, 8542, 8662 Calcium triplet (CaT). The sample comprises 78 ob- jects, divided into 43 Seyfert 2s, 26 Seyfert 1s, 3 Starburst and 6 normal galaxies. The spectra pertain to the inner ∼ 300 pc in radius, and thus sample the central kine- matics and stellar populations of active galaxies. The data are used to measure stellar velocity dispersions (σ⋆) both with cross-correlation and direct fitting methods. These measurements are found to be in good agreement with each-other and with those in previous studies for objects in common. The CaT equivalent width is also measured. -
The Virgo Supercluster
12-1 How Far Away Is It – The Virgo Supercluster The Virgo Supercluster {Abstract – In this segment of our “How far away is it” video book, we cover our local supercluster, the Virgo Supercluster. We begin with a description of the size, content and structure of the supercluster, including the formation of galaxy clusters and galaxy clouds. We then take a look at some of the galaxies in the Virgo Supercluster including: NGC 4314 with its ring in the core, NGC 5866, Zwicky 18, the beautiful NGC 2841, NGC 3079 with is central gaseous bubble, M100, M77 with its central supermassive black hole, NGC 3949, NGC 3310, NGC 4013, the unusual NGC 4522, NGC 4710 with its "X"-shaped bulge, and NGC 4414. At this point, we have enough distant galaxies to formulate Hubble’s Law and calculate Hubble’s Red Shift constant. From a distance ladder point of view, once we have the Hubble constant, and we can measure red shift, we can calculate distance. So we add Red Shift to our ladder. Then we continue with galaxy gazing with: NGC 1427A, NGC 3982, NGC 1300, NGC 5584, the dusty NGC 1316, NGC 4639, NGC 4319, NGC 3021 with is large number of Cepheid variables, NGC 3370, NGC 1309, and 7049. We end with a review of the distance ladder now that Red Shift has been added.} Introduction [Music: Antonio Vivaldi – “The Four Seasons – Winter” – Vivaldi composed "The Four Seasons" in 1723. "Winter" is peppered with silvery pizzicato notes from the high strings, calling to mind icy rain. The ending line for the accompanying sonnet reads "this is winter, which nonetheless brings its own delights." The galaxies of the Virgo Supercluster will also bring us their own visual and intellectual delight.] Superclusters are among the largest structures in the known Universe.