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The HERACLES View of the H -To-HI Ratio in Galaxies
The HERACLES View of the H2-to-HI Ratio in Galaxies Adam Leroy (NRAO, Hubble Fellow) Fabian Walter, Frank Bigiel, the HERACLES and THINGS teams The Saturday Morning Summary • Star formation rate vs. gas relation on ~kpc scales breaks apart into: A relatively universal CO-SFR relation in nearby disks Systematic environmental scalings in the CO-to-HI ratio • The CO-to-HI ratio is a strong function of radius, total gas, and stellar surface density correlated with ISM properties: dust-to-gas ratio, pressure harder to link to dynamics: gravitational instability, arms • Interpretation: the CO-to-HI ratio traces the efficiency of GMC formation Density and dust can explain much of the observed behavior heracles Fabian Walter Erik Rosolowsky MPIA UBC Frank Bigiel Eva Schinnerer UC Berkeley THINGS plus… MPIA Elias Brinks Antonio Usero Gaelle Dumas U Hertfordshire OAN, Madrid MPIA Erwin de Blok Andreas Schruba Helmut Wiesemeyer U Cape Town IRAM … MPIA Rob Kennicutt Axel Weiss Karl Schuster Cambridge MPIfR IRAM Barry Madore Carsten Kramer Karin Sandstrom Carnegie IRAM MPIA Michele Thornley Daniela Calzetti Kelly Foyle Bucknell UMass MPIA Collaborators The HERA CO-Line Extragalactic Survey First maps Leroy et al. (2009) • IRAM 30m Large Program to map CO J = 2→1 line • Instrument: HERA receiver array operating at 230 GHz • 47 galaxies: dwarfs to starbursts and massive spirals -2 • Very wide-field (~ r25) and sensitive (σ ~ 1-2 Msun pc ) NGS The HI Nearby Galaxy Survey HI Walter et al. (2008), AJ Special Issue (2008) • VLA HI maps of 34 galaxies: -
The Puzzling Nature of Dwarf-Sized Gas Poor Disk Galaxies
Dissertation submitted to the Department of Physics Combined Faculties of the Astronomy Division Natural Sciences and Mathematics University of Oulu Ruperto-Carola-University Oulu, Finland Heidelberg, Germany for the degree of Doctor of Natural Sciences Put forward by Joachim Janz born in: Heidelberg, Germany Public defense: January 25, 2013 in Oulu, Finland THE PUZZLING NATURE OF DWARF-SIZED GAS POOR DISK GALAXIES Preliminary examiners: Pekka Heinämäki Helmut Jerjen Opponent: Laura Ferrarese Joachim Janz: The puzzling nature of dwarf-sized gas poor disk galaxies, c 2012 advisors: Dr. Eija Laurikainen Dr. Thorsten Lisker Prof. Heikki Salo Oulu, 2012 ABSTRACT Early-type dwarf galaxies were originally described as elliptical feature-less galax- ies. However, later disk signatures were revealed in some of them. In fact, it is still disputed whether they follow photometric scaling relations similar to giant elliptical galaxies or whether they are rather formed in transformations of late- type galaxies induced by the galaxy cluster environment. The early-type dwarf galaxies are the most abundant galaxy type in clusters, and their low-mass make them susceptible to processes that let galaxies evolve. Therefore, they are well- suited as probes of galaxy evolution. In this thesis we explore possible relationships and evolutionary links of early- type dwarfs to other galaxy types. We observed a sample of 121 galaxies and obtained deep near-infrared images. For analyzing the morphology of these galaxies, we apply two-dimensional multicomponent fitting to the data. This is done for the first time for a large sample of early-type dwarfs. A large fraction of the galaxies is shown to have complex multicomponent structures. -
Radio Continuum and CO Emission in Star-Forming Galaxies
A&A 385, 412–424 (2002) Astronomy DOI: 10.1051/0004-6361:20020140 & c ESO 2002 Astrophysics Radio continuum and CO emission in star-forming galaxies M. Murgia1,A.Crapsi1,2, L. Moscadelli3, and L. Gregorini1,4 1 Istituto di Radioastronomia del CNR, Via Gobetti 101, 40129, Bologna, Italy 2 Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125, Firenze, Italy 3 Osservatorio Astronomico di Cagliari, Loc. Poggio dei Pini, Strada 54, 09012 Capoterra (CA), Italy 4 Dipartimento di Fisica, Universit`a di Bologna, Via B. Pichat 6/2, 40127 Bologna, Italy Received 30 October 2001 / Accepted 23 January 2002 Abstract. We combine the radio continuum images from the NRAO VLA Sky Survey with the CO-line observations from the extragalactic CO survey of the Five College Radio Astronomy Observatory to study the relationship between molecular gas and the star formation rate within the disks of 180 spiral galaxies at 4500 resolution. We find a tight correlation between these quantities. On average, the ratio between the radio continuum and the CO emission is constant, within a factor of 3, both inside the same galaxy and from galaxy to galaxy. The mean star formation efficiency deduced from the radio continuum corresponds to convert 3.5% of the available molecular gas into stars on a time scale of 108 yr and depends weakly on general galaxy properties, such as Hubble type or nuclear activity. A comparison is made with another similar analysis performed using the Hα luminosity as star formation indicator. The overall agreement we find between the two studies reinforces the use of the radio luminosity as star formation rate indicator not only on global but also on local scales. -
Arxiv:Astro-Ph/0309446V1 16 Sep 2003 N Necocigmlclrcod(..Mk38 Eke Al
The Neutral ISM in Starburst Galaxies ASP Conference Series, Vol. xxx, 2003 S. Aalto, S. H¨uttemeister, A. Pedlar Extragalactic water masers in bright IRAS sources A. Tarchi1,2, C. Henkel3, A.B. Peck4, N. Nagar5, L. Moscadelli2, and K.M. Menten3 1Instituto di Radioastronomia, CNR, Bologna, Italy 2Osservatorio Astronomico di Cagliari, Capoterra (CA), Italy 3MPIfR, Bonn, Germany 4Harvard-Smithsonian CfA, SMA Project, Hilo, HI, USA 5Kapteyn Astronomical Institute, Groningen, the Netherlands Abstract. We report the results of a search for 22 GHz water maser emission in IRAS-bright galaxies, using the 100-m Effelsberg telescope. In particular, we present the details of four new maser detections (IC 342, NGC 2146, NGC 3556, and Arp 299) and follow-up interferometric stud- ies. A comparison between water maser detection rates derived in the present study and those in previous similar surveys is also presented. 1. Introduction To date, there is evidence for a total of three distinct classes of extragalactic H2O masers: i) H2O megamasers (with isotropic luminosities Liso > 10 L⊙) associated with accretion disks in active galaxies (e.g. NGC 4258, Miyoshi et al. 1995) ii) H2O megamasers resulting from an interaction between the nuclear radio jet and an encroaching molecular cloud (e.g. Mrk 348, Peck et al. 2001, 2003) iii) weaker H2O masers, the ‘kilomasers’ (with Liso < 10 L⊙), often associated with prominent star forming regions in large scale galactic disks, and, thus far arXiv:astro-ph/0309446v1 16 Sep 2003 found in galaxies containing bright IRAS (Infrared Astronomical Satellite) point sources (e.g. NGC 2146, Tarchi et al. -
Hubble Sights Galaxy Stuck in the Middle 30 April 2018
Hubble sights galaxy stuck in the middle 30 April 2018 from Earth in the constellation of Camelopardalis (the Giraffe). Camelopardalis contains many other interesting deep-sky objects, including the open cluster NGC 1502, the elegant Kemble's Cascade asterism, and the starburst galaxy NGC 2146. Provided by NASA Credit: ESA/Hubble & NASA, A. Fillipenko This pretty, cloud-like object may not look much like a galaxy—it lacks the well-defined arms of a spiral galaxy, or the reddish bulge of an elliptical—but it is in fact something known as a lenticular galaxy. Lenticular galaxies sit somewhere between the spiral and elliptical types; they are disk-shaped, like spirals, but they no longer form large numbers of new stars and thus contain only aging populations of stars, like ellipticals. NGC 2655's core is extremely luminous, resulting in its additional classification as a Seyfert galaxy: a type of active galaxy with strong and characteristic emission lines. This luminosity is thought to be produced as matter is dragged onto the accretion disk of a supermassive black hole sitting at the center of NGC 2655. The structure of NGC 2655's outer disk, on the other hand, appears calmer, but it is oddly shaped. The complex dynamics of the gas in the galaxy suggest that it may have had a turbulent past, including mergers and interactions with other galaxies. NGC 2655 is located about 80 million light-years 1 / 2 APA citation: Hubble sights galaxy stuck in the middle (2018, April 30) retrieved 28 September 2021 from https://phys.org/news/2018-04-hubble-sights-galaxy-stuck-middle.html This document is subject to copyright. -
Highlights and Discoveries from the Chandra X-Ray Observatory1
Highlights and Discoveries from the Chandra X-ray Observatory1 H Tananbaum1, M C Weisskopf2, W Tucker1, B Wilkes1 and P Edmonds1 1Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138. 2 NASA/Marshall Space Flight Center, ZP12, 320 Sparkman Drive, Huntsville, AL 35805. Abstract. Within 40 years of the detection of the first extrasolar X-ray source in 1962, NASA’s Chandra X-ray Observatory has achieved an increase in sensitivity of 10 orders of magnitude, comparable to the gain in going from naked-eye observations to the most powerful optical telescopes over the past 400 years. Chandra is unique in its capabilities for producing sub-arcsecond X-ray images with 100-200 eV energy resolution for energies in the range 0.08<E<10 keV, locating X-ray sources to high precision, detecting extremely faint sources, and obtaining high resolution spectra of selected cosmic phenomena. The extended Chandra mission provides a long observing baseline with stable and well-calibrated instruments, enabling temporal studies over time-scales from milliseconds to years. In this report we present a selection of highlights that illustrate how observations using Chandra, sometimes alone, but often in conjunction with other telescopes, have deepened, and in some instances revolutionized, our understanding of topics as diverse as protoplanetary nebulae; massive stars; supernova explosions; pulsar wind nebulae; the superfluid interior of neutron stars; accretion flows around black holes; the growth of supermassive black holes and their role in the regulation of star formation and growth of galaxies; impacts of collisions, mergers, and feedback on growth and evolution of groups and clusters of galaxies; and properties of dark matter and dark energy. -
The Outermost Hii Regions of Nearby Galaxies
THE OUTERMOST HII REGIONS OF NEARBY GALAXIES by Jessica K. Werk A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Astronomy and Astrophysics) in The University of Michigan 2010 Doctoral Committee: Professor Mario L. Mateo, Co-Chair Associate Professor Mary E. Putman, Co-Chair, Columbia University Professor Fred C. Adams Professor Lee W. Hartmann Associate Professor Marion S. Oey Professor Gerhardt R. Meurer, University of Western Australia Jessica K. Werk Copyright c 2010 All Rights Reserved To Mom and Dad, for all your love and encouragement while I was taking up space. ii ACKNOWLEDGMENTS I owe a deep debt of gratitude to a long list of individuals, institutions, and substances that have seen me through the last six years of graduate school. My first undergraduate advisor in Astronomy, Kathryn Johnston, was also my first Astronomy Professor. She piqued my interest in the subject from day one with her enthusiasm and knowledge. I don’t doubt that I would be studying something far less interesting if it weren’t for her. John Salzer, my next and last undergraduate advisor, not only taught me so much about observing and organization, but also is responsible for convincing me to go on in Astronomy. Were it not for John, I’d probably be making a lot more money right now doing something totally mind-numbing and soul-crushing. And Laura Chomiuk, a fellow Wesleyan Astronomy Alumnus, has been there for me through everything − problem sets and personal heartbreak alike. To know her as a friend, goat-lover, and scientist has meant so much to me over the last 10 years, that confining my gratitude to these couple sentences just seems wrong. -
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. -
Stsci Newsletter: 2011 Volume 028 Issue 02
National Aeronautics and Space Administration Interacting Galaxies UGC 1810 and UGC 1813 Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) 2011 VOL 28 ISSUE 02 NEWSLETTER Space Telescope Science Institute We received a total of 1,007 proposals, after accounting for duplications Hubble Cycle 19 and withdrawals. Review process Proposal Selection Members of the international astronomical community review Hubble propos- als. Grouped in panels organized by science category, each panel has one or more “mirror” panels to enable transfer of proposals in order to avoid conflicts. In Cycle 19, the panels were divided into the categories of Planets, Stars, Stellar Rachel Somerville, [email protected], Claus Leitherer, [email protected], & Brett Populations and Interstellar Medium (ISM), Galaxies, Active Galactic Nuclei and Blacker, [email protected] the Inter-Galactic Medium (AGN/IGM), and Cosmology, for a total of 14 panels. One of these panels reviewed Regular Guest Observer, Archival, Theory, and Chronology SNAP proposals. The panel chairs also serve as members of the Time Allocation Committee hen the Cycle 19 Call for Proposals was released in December 2010, (TAC), which reviews Large and Archival Legacy proposals. In addition, there Hubble had already seen a full cycle of operation with the newly are three at-large TAC members, whose broad expertise allows them to review installed and repaired instruments calibrated and characterized. W proposals as needed, and to advise panels if the panelists feel they do not have The Advanced Camera for Surveys (ACS), Cosmic Origins Spectrograph (COS), the expertise to review a certain proposal. Fine Guidance Sensor (FGS), Space Telescope Imaging Spectrograph (STIS), and The process of selecting the panelists begins with the selection of the TAC Chair, Wide Field Camera 3 (WFC3) were all close to nominal operation and were avail- about six months prior to the proposal deadline. -
The Cosmic Web! What Does Our Universe Look Like on the Largest Scale?
Lecture III The Cosmic Web! what does our Universe look like on the largest scale? aurorasimionescu.wordpress.com/teaching “Large-scale structure” refers to spatial scales larger than single galaxies: superclusters, clusters, groups, filaments, walls, voids What structure is our own Galaxy embedded in? The Local Group What structure is our own Galaxy embedded in? The Virgo Supercluster: a ~ 60 Mpc flattened structure, centered on the Virgo Cluster; the Local Group is at the outskirts. We are falling towards Virgo with ~ 300 km/s, and will get there in about 10 - 15 Gyr What structure is our own Galaxy embedded in? The Laniakea Supercluster find locations where peculiar velocity flows diverge, rather than defining structures based on galaxy number overdensity R. Brent Tully et al. Nature 513, 71 (2014) Redshift surveys To map and quantify the LSS (and compare with theoretical predictions), we need redshift surveys: mapping the 3-D distribution of galaxies in space (2D position on the sky plus redshift used as distance indicator) The 2dF (2 degree Field) redshift survey done with the 3.9-m Anglo-Australian telescope from 1997-2002 – Redshifts of ~ 250,000 galaxies with B < 19.5 mag, covering 5% of the sky reaching to z ~ 0.3 The Sloan Digital Sky Survey (SDSS) done with a dedicated 2.5-m telescope at Apache Point Observatory in New Mexico – Multicolor imaging to r ~ 23 mag, and spectra of galaxies down to r < 17.5 mag, reaching to z ~ 0.7; final data release covers 35% of sky and spectra from 3 million objects The 2dF Galaxy Redshift Survey How do we quantify Large-Scale Structure? If galaxies are clustered, they are “correlated”. -
Astrophysics in 2006 3
ASTROPHYSICS IN 2006 Virginia Trimble1, Markus J. Aschwanden2, and Carl J. Hansen3 1 Department of Physics and Astronomy, University of California, Irvine, CA 92697-4575, Las Cumbres Observatory, Santa Barbara, CA: ([email protected]) 2 Lockheed Martin Advanced Technology Center, Solar and Astrophysics Laboratory, Organization ADBS, Building 252, 3251 Hanover Street, Palo Alto, CA 94304: ([email protected]) 3 JILA, Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder CO 80309: ([email protected]) Received ... : accepted ... Abstract. The fastest pulsar and the slowest nova; the oldest galaxies and the youngest stars; the weirdest life forms and the commonest dwarfs; the highest energy particles and the lowest energy photons. These were some of the extremes of Astrophysics 2006. We attempt also to bring you updates on things of which there is currently only one (habitable planets, the Sun, and the universe) and others of which there are always many, like meteors and molecules, black holes and binaries. Keywords: cosmology: general, galaxies: general, ISM: general, stars: general, Sun: gen- eral, planets and satellites: general, astrobiology CONTENTS 1. Introduction 6 1.1 Up 6 1.2 Down 9 1.3 Around 10 2. Solar Physics 12 2.1 The solar interior 12 2.1.1 From neutrinos to neutralinos 12 2.1.2 Global helioseismology 12 2.1.3 Local helioseismology 12 2.1.4 Tachocline structure 13 arXiv:0705.1730v1 [astro-ph] 11 May 2007 2.1.5 Dynamo models 14 2.2 Photosphere 15 2.2.1 Solar radius and rotation 15 2.2.2 Distribution of magnetic fields 15 2.2.3 Magnetic flux emergence rate 15 2.2.4 Photospheric motion of magnetic fields 16 2.2.5 Faculae production 16 2.2.6 The photospheric boundary of magnetic fields 17 2.2.7 Flare prediction from photospheric fields 17 c 2008 Springer Science + Business Media. -
00E the Construction of the Universe Symphony
The basic construction of the Universe Symphony. There are 30 asterisms (Suites) in the Universe Symphony. I divided the asterisms into 15 groups. The asterisms in the same group, lay close to each other. Asterisms!! in Constellation!Stars!Objects nearby 01 The W!!!Cassiopeia!!Segin !!!!!!!Ruchbah !!!!!!!Marj !!!!!!!Schedar !!!!!!!Caph !!!!!!!!!Sailboat Cluster !!!!!!!!!Gamma Cassiopeia Nebula !!!!!!!!!NGC 129 !!!!!!!!!M 103 !!!!!!!!!NGC 637 !!!!!!!!!NGC 654 !!!!!!!!!NGC 659 !!!!!!!!!PacMan Nebula !!!!!!!!!Owl Cluster !!!!!!!!!NGC 663 Asterisms!! in Constellation!Stars!!Objects nearby 02 Northern Fly!!Aries!!!41 Arietis !!!!!!!39 Arietis!!! !!!!!!!35 Arietis !!!!!!!!!!NGC 1056 02 Whale’s Head!!Cetus!! ! Menkar !!!!!!!Lambda Ceti! !!!!!!!Mu Ceti !!!!!!!Xi2 Ceti !!!!!!!Kaffalijidhma !!!!!!!!!!IC 302 !!!!!!!!!!NGC 990 !!!!!!!!!!NGC 1024 !!!!!!!!!!NGC 1026 !!!!!!!!!!NGC 1070 !!!!!!!!!!NGC 1085 !!!!!!!!!!NGC 1107 !!!!!!!!!!NGC 1137 !!!!!!!!!!NGC 1143 !!!!!!!!!!NGC 1144 !!!!!!!!!!NGC 1153 Asterisms!! in Constellation Stars!!Objects nearby 03 Hyades!!!Taurus! Aldebaran !!!!!! Theta 2 Tauri !!!!!! Gamma Tauri !!!!!! Delta 1 Tauri !!!!!! Epsilon Tauri !!!!!!!!!Struve’s Lost Nebula !!!!!!!!!Hind’s Variable Nebula !!!!!!!!!IC 374 03 Kids!!!Auriga! Almaaz !!!!!! Hoedus II !!!!!! Hoedus I !!!!!!!!!The Kite Cluster !!!!!!!!!IC 397 03 Pleiades!! ! Taurus! Pleione (Seven Sisters)!! ! ! Atlas !!!!!! Alcyone !!!!!! Merope !!!!!! Electra !!!!!! Celaeno !!!!!! Taygeta !!!!!! Asterope !!!!!! Maia !!!!!!!!!Maia Nebula !!!!!!!!!Merope Nebula !!!!!!!!!Merope