An Aromatic Inventory of the Local Volume
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
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: -
High Resolution HI Distributions and Multi-Wavelength Analyses Of
High Resolution H I Distributions and Multi-Wavelength Analyses of Magellanic Spirals NGC 4618 and NGC 4625 Jane F. Kaczmarek1& Eric M. Wilcots University of Wisconsin Madison, Department of Astronomy, 475 N. Charter Street, Madison WI 53706 USA [email protected], [email protected] ABSTRACT We present a detailed analysis of high resolution H I observations of the Magellanic spiral galaxies NGC 4618 and NGC 4625. While the H I disk of NGC 4625 is remarkably quiescent with a nearly uniform velocity dispersion and no evidence of H I holes, there is a dynamic interplay between star formation and the distribution of neutral hydrogen in NGC 4618. We calculate the critical density for widespread star formation in each galaxy and find that star formation proceeds even where the surface density of the atomic gas is well below the critical density necessary for global star formation. There are strong spatial correlations in NGC 4618 between UV emission, 1.4 GHz radio continuum emission, and peaks in the H I column density. Despite the apparent overlap of the outer disks of the two galaxies, we find that they are kinematically distinct, indicating that NGC 4618 and NGC 4625 are not interacting. The structure of NGC 4618 and, in particular, the nature of its outer ring, are highly suggestive of an interaction, but the timing and nature of such an interaction remain unclear. Subject headings: galaxies: neutral hydrogen { galaxies: Magellanic spirals { galaxies: individual (NGC 4618 & NGC 4625) 1. Introduction arXiv:1206.4104v1 [astro-ph.CO] 19 Jun 2012 One of the more stunning revelations about the Local Group in the past few years has been the observations of the proper motions of the Magellanic Clouds showing that they are moving at significantly higher velocities than previously thought (e.g. -
Star Dust National Capital Astronomers, Inc
Star Dust National Capital Astronomers, Inc. April 10, 2010 Volume 68, Issue 8 http://capitalastronomers.org Next Meeting April 2010: Dr. David J. Thompson When: Sat. Apr. 10, 2010 NASA Goddard Space Flight Center Deputy Project Scientist Time: 7:30 pm Fermi Gamma-ray Space Telescope Where: UM Observatory Highlights from the Fermi Speaker: David Thompson, Gamma-ray Space Telescope NASA Goddard Abstract: Since August, 2008, the Fermi Gamma-ray Space Telescope has Table of Contents been scanning the sky, producing a full-sky image every three hours. The Preview of Apr. 2010 Talk 1 cosmic gamma-rays recorded by Fermi come from extreme astrophysical Spectacular Spiral 2 phenomena. Some key observations include: Octavia Occultation 3 (1) Gamma-rays from pulsars appear to come from a region well above Occultations 4 the surface of the neutron star; Arlington Planetarium 5 (2) Multiwavelength studies of blazars show that simple models of jet Calendar 5 emission are not always adequate to explain what is seen; (3) Gamma-ray bursts can exhibit strong emission at high energies even from Directions to Dinner/Meeting distant bursts, with implications for some models of quantum gravity; Members and guests are invited to (4) Cosmic-ray electrons at energies approaching 1 TeV seem to suggest join us for dinner at the Garden a local source for some of these particles. Restaurant located in the UMUC Inn & Conference Center, 3501 Biography: Dave Thompson University Blvd E. The meeting is received his PhD in physics held at the UM Astronomy from the University of Maryland Observatory on Metzerott Rd about in 1973 and almost immediately started a job at NASA Goddard halfway between Adelphi Rd and Space Flight Center with the University Blvd. -
1. Introduction
THE ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 122:109È150, 1999 May ( 1999. The American Astronomical Society. All rights reserved. Printed in U.S.A. GALAXY STRUCTURAL PARAMETERS: STAR FORMATION RATE AND EVOLUTION WITH REDSHIFT M. TAKAMIYA1,2 Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637; and Gemini 8 m Telescopes Project, 670 North Aohoku Place, Hilo, HI 96720 Received 1998 August 4; accepted 1998 December 21 ABSTRACT The evolution of the structure of galaxies as a function of redshift is investigated using two param- eters: the metric radius of the galaxy(Rg) and the power at high spatial frequencies in the disk of the galaxy (s). A direct comparison is made between nearby (z D 0) and distant(0.2 [ z [ 1) galaxies by following a Ðxed range in rest frame wavelengths. The data of the nearby galaxies comprise 136 broad- band images at D4500A observed with the 0.9 m telescope at Kitt Peak National Observatory (23 galaxies) and selected from the catalog of digital images of Frei et al. (113 galaxies). The high-redshift sample comprises 94 galaxies selected from the Hubble Deep Field (HDF) observations with the Hubble Space Telescope using the Wide Field Planetary Camera 2 in four broad bands that range between D3000 and D9000A (Williams et al.). The radius is measured from the intensity proÐle of the galaxy using the formulation of Petrosian, and it is argued to be a metric radius that should not depend very strongly on the angular resolution and limiting surface brightness level of the imaging data. It is found that the metric radii of nearby and distant galaxies are comparable to each other. -
The Metallicity-Luminosity Relationship of Dwarf Irregular Galaxies
A&A 399, 63–76 (2003) Astronomy DOI: 10.1051/0004-6361:20021748 & c ESO 2003 Astrophysics The metallicity-luminosity relationship of dwarf irregular galaxies II. A new approach A. M. Hidalgo-G´amez1,,F.J.S´anchez-Salcedo2, and K. Olofsson1 1 Astronomiska observatoriet, Box 515, 751 20 Uppsala, Sweden e-mail: [email protected], [email protected] 2 Instituto de Astronom´ıa-UNAM, Ciudad Universitaria, Apt. Postal 70 264, C.P. 04510, Mexico City, Mexico e-mail: [email protected] Received 21 June 2001 / Accepted 21 November 2002 Abstract. The nature of a possible correlation between metallicity and luminosity for dwarf irregular galaxies, including those with the highest luminosities, has been explored using simple chemical evolutionary models. Our models depend on a set of free parameters in order to include infall and outflows of gas and covering a broad variety of physical situations. Given a fixed set of parameters, a non-linear correlation between the oxygen abundance and the luminosity may be established. This would be the case if an effective self–regulating mechanism between the accretion of mass and the wind energized by the star formation could lead to the same parameters for all the dwarf irregular galaxies. In the case that these parameters were distributed in a random manner from galaxy to galaxy, a significant scatter in the metallicity–luminosity diagram is expected. Comparing with observations, we show that only variations of the stellar mass–to–light ratio are sufficient to explain the observed scattering and, therefore, the action of a mechanism of self–regulation cannot be ruled out. -
The Professor Comet's Report Early Spring – April 2012
The Professor Comet’s Report 1 Mr. Justin J McCollum (BS, MS Physics) Lab Physics Coordinator Dept. of Physics Lamar University Welcome to the comet report which is a monthly article on the observations of comets by the amateur astronomy community and comet hunters from around the world! This C/2009 P1 Garradd with article is dedicated to the latest reports of available comets for Barred Spiral Galaxy NGC 4236 observations, current state of those comets, future 14 March 2011! predictions, & projections for observations in comet astronomy! Early Spring – April 2012 The Professor Comet’s Report 2 The Current Status of the Predominant Comets for Apr 2012! Comets Designation Orbital Magnitude Trend Observation Constellations Visibility (IAU – MPC) Status Visual (Range in (Night Sky Location) Period Lat.) Garradd 2009 P1 C 7.0* - 7.5 Fading 90°N – 30°S SW region of Ursa Major moving All Night SSW towards the SE region of Lynx. Giacobini - 21P P 9 – 10 Fading Poor N/A Zinner Elongation Lost in the daytime Glare! LINEAR 2011 F1 C 11 .7* Brightening 90°N – 20°S Undergoing retrograde motion All Night between Boötes and Draco thru the late Spring. Gehrels 2 78P P 12.2* Fading 60˚N - 20˚S Moving eastwards across Taurus Early Evening and progressing along the N edge of the Hyades Star Cluster! McNaught 2011 Q2 C 12.5 Fading 70˚N – Eqn. Currently in the S central region Early Morning of Andromeda moving NE between the boundary between Andromeda & Pisces. NEAT 246P/2010 V2 P 12.3* - 13 Possible 65˚N - 60˚S Undergoing retrograde motion All Night Steadiness in the E half of the N central region of Virgo until late June. -
Astronomy Astrophysics
A&A 433, 79–86 (2005) Astronomy DOI: 10.1051/0004-6361:20034537 & c ESO 2005 Astrophysics Asymmetrical structure of ionization and kinematics in the Seyfert galaxy NGC 5033 E. Mediavilla1, A. Guijarro2, A. Castillo-Morales3 , J. Jiménez-Vicente3, E. Florido3, S. Arribas4,, B. García-Lorenzo1, and E. Battaner3 1 Instituto de Astrofísica de Canarias, Tenerife, Spain e-mail: [email protected] 2 Centro Astronómico Hispano Alemán, Almería, Spain e-mail: [email protected] 3 Dpto. Física Teórica y del Cosmos, Universidad de Granada, Spain 4 Space Telescope Science Institute, Baltimore, USA Received 18 October 2003 / Accepted 29 November 2004 Abstract. We present integral field spectroscopy of NGC 5033, a low luminosity Seyfert galaxy. The observations were made with INTEGRAL, a fiber based system operating at the WHT. The intensity map of the Hβ emission line represents a spi- ral or ring-like pattern of HII regions. On the contrary, the [OIII] intensity map morphology is markedly anisotropic. The strong morphological differences imply that the [OIII] emitters represent highly ionized gas illuminated by the central source. The [OIII] map morphology is compatible with a biconical structure of ionization induced by strong extinction in the galaxy disc that also obscures half of the spheroidal stellar bulge. We identify the spectrum corresponding to the Seyfert 1 nucleus from the presence of Hβ broad emission lines. This spectrum is located in a region where strong extinction is expected but exhibits the bluest spectral energy distribution. The Seyfert 1 nucleus seems to be offcenter with respect to the stellar rotation center. This result has been also found in other Seyfert galaxies and interpreted in terms of a past merger. -
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. -
Prime Focus After Sunset
Highlights of the April Sky. - - - 1st - - - Dusk: Mercury is 10º above the western horizon Prime Focus after sunset. Continues until the 15th. A Publication of the Kalamazoo Astronomical Society - - - 3rd - - - Dawn: Antares is 1º below April 2010 the Moon before sunrise. - - - 6th - - - Last Quarter Moon ThisThis MonthsMonths KAS EventsEvents - - - 11th - - - Dawn: Waning Crescent Moon is 5º above Jupiter. General Meeting: Friday, April 9 @ 7:00 pm th - - - 13 - - - PM: Mars is less than 2º Kalamazoo Area Math & Science Center - See Page 8 for Details from the Beehive Cluster (M44) in Cancer. Continues until the 20th. Observing Session: Saturday, April 10 @ 8:00 pm - - - 14th - - - Saturn & Orion Nebula - Kalamazoo Nature Center New Moon th Observing Session: Saturday, April 17 @ 8:00 pm - - - 15 - - - Dusk: Mercury and a very Saturn & Open Clusters - Kalamazoo Nature Center thin crescent Moon 7º to lower right of Venus. Look low on western horizon. Astronomy Day: Saturday, April 24 @ 10:00 am low on western horizon. Kalamazoo Valley Museum & Fetzer Center - See Page 3 for Details - - - 16st - - - PM: Waxing Crescent Moon is 8º above Venus. PM: Pleiades is 3.5º above the Moon/Mercury pair. InsideInside thethe Newsletter.Newsletter. .. .. - - - 21st - - - First Quarter Moon March Meeting Minutes......................... p. 2 - - - 23rd - - - PM: Venus and Pleiades fit Board Meeting Minutes......................... p. 2 within a 5º field-of-view. Astronomy Day 2010............................ p. 3 - - - 24th - - - Astronomy Day Spectacular Spiral................................... p. 4 PM: Waxing Gibbous Moon NASA Space Place.................................. p. 5 is lower right of Saturn. April Night Sky........................................ p. 6 - - - 25th - - - PM: Waxing Gibbous Moon KAS Officers & Announcements........ p. 7 is lower left of Saturn. -
Australian Sky & Telescope
TRANSIT MYSTERY Strange sights BINOCULAR TOUR Dive deep into SHOOT THE MOON Take amazing as Mercury crosses the Sun p28 Virgo’s endless pool of galaxies p56 lunar images with your smartphone p38 TEST REPORT Meade’s 25-cm LX600-ACF P62 THE ESSENTIAL MAGAZINE OF ASTRONOMY Lasers and advanced optics are transforming astronomy p20 HOW TO BUY THE RIGHT ASTRO CAMERA p32 p14 ISSUE 93 MAPPING THE BIG BANG’S COSMIC ECHOES $9.50 NZ$9.50 INC GST LPI-GLPI-G LUNAR,LUNAR, PLANETARYPLANETARY IMAGERIMAGER ANDAND GUIDERGUIDER ASTROPHOTOGRAPHY MADE EASY. Let the LPI-G unleash the inner astrophotographer in you. With our solar, lunar and planetary guide camera, experience the universe on a whole new level. 0Image Sensor:'+(* C O LOR 0 Pixel Size / &#*('+ 0Frames per second/Resolution• / • / 0 Image Format: #,+$)!&))'!,# .# 0 Shutter%,*('#(%%#'!"-,,* 0Interface: 0Driver: ASCOM compatible 0GuiderPort: 0Color or Monochrome Models (&#'!-,-&' FEATURED DEALERS: MeadeTelescopes Adelaide Optical Centre | www.adelaideoptical.com.au MeadeInstrument The Binocular and Telescope Shop | www.bintel.com.au MeadeInstruments www.meade.com Sirius Optics | www.sirius-optics.com.au The device to free you from your handbox. With the Stella adapter, you can wirelessly control your GoTo Meade telescope at a distance without being limited by cord length. Paired with our new planetarium app, *StellaAccess, astronomers now have a graphical interface for navigating the night sky. STELLA WI-FI ADAPTER / $#)'$!!+#!+ #$#)'#)$##)$#'&*' / (!-')-$*')!($%)$$+' "!!$#$)(,#%',).( StellaAccess app. Available for use on both phones and tablets. /'$+((()$!'%!#)'*")($'!$)##!'##"$'$*) stars, planets, celestial bodies and more /$,'-),',### -' ($),' /,,,$"$')*!!!()$$"%)!)!($%( STELLA is controlled with Meade’s planetarium app, StellaAccess. Available for purchase for both iOS S and Android systems. -
Dwarf Galaxy Dark Matter Density Profiles Inferred from Stellar and Gas Kinematics
ACCEPTED BY APJ Preprint typeset using LATEX style emulateapj v. 5/2/11 DWARF GALAXY DARK MATTER DENSITY PROFILES INFERRED FROM STELLAR AND GAS KINEMATICS* JOSHUA J. ADAMS1,2 , JOSHUA D. SIMON1, MAXIMILIAN H. FABRICIUS3,REMCO C. E. VAN DEN BOSCH4 , JOHN C. BARENTINE5, RALF BENDER3,6,KARL GEBHARDT5,7,GARY J. HILL 5,7,8 , JEREMY D. MURPHY9 ,R.A.SWATERS10, JENS THOMAS3,GLENN VAN DE VEN4, Accepted by ApJ ABSTRACT We present new constraints on the density profiles of dark matter (DM) halos in seven nearby dwarf galaxies from measurements of their integrated stellar light and gas kinematics. The gas kinematics of low mass galaxies frequently suggest that they contain constant density DM cores, while N-body simulations instead predict a cuspy profile. We present a data set of high resolution integral field spectroscopy on seven galaxies and measure the stellar and gas kinematics simultaneously. Using Jeans modeling on our full sample, we examine whether gas kinematics in general produce shallower density profiles than are derived from the stars. Although 2/7 galaxies show some localized differences in their rotation curves between the two tracers, estimates of the central logarithmic slope of the DM density profile, γ, are generally robust. The mean and standard deviation of the logarithmic slope for the population are γ = 0.67 0.10 when measured in the stars and γ = 0.58 0.24 when measured in the gas. We also find that the halos± are not under-concentrated at the radii of half± their maximum velocities. Finally, we search for correlations of the DM density profile with stellar velocity anisotropy and other baryonic properties. -
121012-AAS-221 Program-14-ALL, Page 253 @ Preflight
221ST MEETING OF THE AMERICAN ASTRONOMICAL SOCIETY 6-10 January 2013 LONG BEACH, CALIFORNIA Scientific sessions will be held at the: Long Beach Convention Center 300 E. Ocean Blvd. COUNCIL.......................... 2 Long Beach, CA 90802 AAS Paper Sorters EXHIBITORS..................... 4 Aubra Anthony ATTENDEE Alan Boss SERVICES.......................... 9 Blaise Canzian Joanna Corby SCHEDULE.....................12 Rupert Croft Shantanu Desai SATURDAY.....................28 Rick Fienberg Bernhard Fleck SUNDAY..........................30 Erika Grundstrom Nimish P. Hathi MONDAY........................37 Ann Hornschemeier Suzanne H. Jacoby TUESDAY........................98 Bethany Johns Sebastien Lepine WEDNESDAY.............. 158 Katharina Lodders Kevin Marvel THURSDAY.................. 213 Karen Masters Bryan Miller AUTHOR INDEX ........ 245 Nancy Morrison Judit Ries Michael Rutkowski Allyn Smith Joe Tenn Session Numbering Key 100’s Monday 200’s Tuesday 300’s Wednesday 400’s Thursday Sessions are numbered in the Program Book by day and time. Changes after 27 November 2012 are included only in the online program materials. 1 AAS Officers & Councilors Officers Councilors President (2012-2014) (2009-2012) David J. Helfand Quest Univ. Canada Edward F. Guinan Villanova Univ. [email protected] [email protected] PAST President (2012-2013) Patricia Knezek NOAO/WIYN Observatory Debra Elmegreen Vassar College [email protected] [email protected] Robert Mathieu Univ. of Wisconsin Vice President (2009-2015) [email protected] Paula Szkody University of Washington [email protected] (2011-2014) Bruce Balick Univ. of Washington Vice-President (2010-2013) [email protected] Nicholas B. Suntzeff Texas A&M Univ. suntzeff@aas.org Eileen D. Friel Boston Univ. [email protected] Vice President (2011-2014) Edward B. Churchwell Univ. of Wisconsin Angela Speck Univ. of Missouri [email protected] [email protected] Treasurer (2011-2014) (2012-2015) Hervey (Peter) Stockman STScI Nancy S.