March 2008 Newsletter
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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. -
Radio Sources in Low-Luminosity Active Galactic Nuclei
A&A 392, 53–82 (2002) Astronomy DOI: 10.1051/0004-6361:20020874 & c ESO 2002 Astrophysics Radio sources in low-luminosity active galactic nuclei III. “AGNs” in a distance-limited sample of “LLAGNs” N. M. Nagar1, H. Falcke2,A.S.Wilson3, and J. S. Ulvestad4 1 Arcetri Observatory, Largo E. Fermi 5, Florence 50125, Italy 2 Max-Planck-Institut f¨ur Radioastronomie, Auf dem H¨ugel 69, 53121 Bonn, Germany e-mail: [email protected] 3 Department of Astronomy, University of Maryland, College Park, MD 20742, USA Adjunct Astronomer, Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA e-mail: [email protected] 4 National Radio Astronomy Observatory, PO Box 0, Socorro, NM 87801, USA e-mail: [email protected] Received 23 January 2002 / Accepted 6 June 2002 Abstract. This paper presents the results of a high resolution radio imaging survey of all known (96) low-luminosity active galactic nuclei (LLAGNs) at D ≤ 19 Mpc. We first report new 2 cm (150 mas resolution using the VLA) and 6 cm (2 mas resolution using the VLBA) radio observations of the previously unobserved nuclei in our samples and then present results on the complete survey. We find that almost half of all LINERs and low-luminosity Seyferts have flat-spectrum radio cores when observed at 150 mas resolution. Higher (2 mas) resolution observations of a flux-limited subsample have provided a 100% (16 of 16) detection rate of pc-scale radio cores, with implied brightness temperatures ∼>108 K. The five LLAGNs with the highest core radio fluxes also have pc-scale “jets”. -
April Constellations of the Month
April Constellations of the Month Leo Small Scope Objects: Name R.A. Decl. Details M65! A large, bright Sa/Sb spiral galaxy. 7.8 x 1.6 arc minutes, magnitude 10.2. Very 11hr 18.9m +13° 05’ (NGC 3623) high surface brighness showing good detail in medium sized ‘scopes. M66! Another bright Sb galaxy, only 21 arc minutes from M65. Slightly brighter at mag. 11hr 20.2m +12° 59’ (NGC 3627) 9.7, measuring 8.0 x 2.5 arc minutes. M95 An easy SBb barred spiral, 4 x 3 arc minutes in size. Magnitude 10.5, with 10hr 44.0m +11° 42’ a bright central core. The bar and outer ring of material will require larger (NGC 3351) aperature and dark skies. M96 Another bright Sb spiral, about 42 arc minutes east of M95, but larger and 10hr 46.8m +11° 49’ (NGC 3368) brighter. 6 x 4 arc minutes, magnitude 10.1. Located about 48 arc minutes NNE of M96. This small elliptical galaxy measures M105 only 2 x 2.1 arc minutes, but at mag. 10.3 has very high surface brightness. 10hr 47.8m +12° 35’ (NGC 3379) Look for NGC 3384! (110NGC) and NGC 3389 (mag 11.0 and 12.2) which form a small triangle with M105. NGC 3384! 10hr 48.3m +12° 38’ See comment for M105. The brightest galaxy in Leo, this Sb/Sc spiral galaxy shines at mag. 9.5. Look for NGC 2903!! 09hr 32.2m +21° 30’ a hazy patch 11 x 4.7 arc minutes in size 1.5° south of l Leonis. -
Astronomy 2008 Index
Astronomy Magazine Article Title Index 10 rising stars of astronomy, 8:60–8:63 1.5 million galaxies revealed, 3:41–3:43 185 million years before the dinosaurs’ demise, did an asteroid nearly end life on Earth?, 4:34–4:39 A Aligned aurorae, 8:27 All about the Veil Nebula, 6:56–6:61 Amateur astronomy’s greatest generation, 8:68–8:71 Amateurs see fireballs from U.S. satellite kill, 7:24 Another Earth, 6:13 Another super-Earth discovered, 9:21 Antares gang, The, 7:18 Antimatter traced, 5:23 Are big-planet systems uncommon?, 10:23 Are super-sized Earths the new frontier?, 11:26–11:31 Are these space rocks from Mercury?, 11:32–11:37 Are we done yet?, 4:14 Are we looking for life in the right places?, 7:28–7:33 Ask the aliens, 3:12 Asteroid sleuths find the dino killer, 1:20 Astro-humiliation, 10:14 Astroimaging over ancient Greece, 12:64–12:69 Astronaut rescue rocket revs up, 11:22 Astronomers spy a giant particle accelerator in the sky, 5:21 Astronomers unearth a star’s death secrets, 10:18 Astronomers witness alien star flip-out, 6:27 Astronomy magazine’s first 35 years, 8:supplement Astronomy’s guide to Go-to telescopes, 10:supplement Auroral storm trigger confirmed, 11:18 B Backstage at Astronomy, 8:76–8:82 Basking in the Sun, 5:16 Biggest planet’s 5 deepest mysteries, The, 1:38–1:43 Binary pulsar test affirms relativity, 10:21 Binocular Telescope snaps first image, 6:21 Black hole sets a record, 2:20 Black holes wind up galaxy arms, 9:19 Brightest starburst galaxy discovered, 12:23 C Calling all space probes, 10:64–10:65 Calling on Cassiopeia, 11:76 Canada to launch new asteroid hunter, 11:19 Canada’s handy robot, 1:24 Cannibal next door, The, 3:38 Capture images of our local star, 4:66–4:67 Cassini confirms Titan lakes, 12:27 Cassini scopes Saturn’s two-toned moon, 1:25 Cassini “tastes” Enceladus’ plumes, 7:26 Cepheus’ fall delights, 10:85 Choose the dome that’s right for you, 5:70–5:71 Clearing the air about seeing vs. -
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. -
What's in This Issue?
A JPL Image of surface of Mars, and JPL Ingenuity Helicioptor illustration. July 11th at 4:00 PM, a family barbeque at HRPO!!! This is in lieu of our regular monthly meeting.) (Monthly meetings are on 2nd Mondays at Highland Road Park Observatory) This is a pot-luck. Club will provide briskett and beverages, others will contribute as the spirit moves. What's In This Issue? President’s Message Member Meeting Minutes Business Meeting Minutes Outreach Report Asteroid and Comet News Light Pollution Committee Report Globe at Night SubReddit and Discord BRAS Member Astrophotos ARTICLE: Astrophotography with your Smart Phone Observing Notes: Canes Venatici – The Hunting Dogs Like this newsletter? See PAST ISSUES online back to 2009 Visit us on Facebook – Baton Rouge Astronomical Society BRAS YouTube Channel Baton Rouge Astronomical Society Newsletter, Night Visions Page 2 of 23 July 2021 President’s Message Hey everybody, happy fourth of July. I hope ya’ll’ve remembered your favorite coping mechanism for dealing with the long hot summers we have down here in the bayou state, or, at the very least, are making peace with the short nights that keep us from enjoying both a good night’s sleep and a productive observing/imaging session (as if we ever could get a long enough break from the rain for that to happen anyway). At any rate, we figured now would be as good a time as any to get the gang back together for a good old fashioned potluck style barbecue: to that end, we’ve moved the July meeting to the Sunday, 11 July at 4PM at HRPO. -
Classification of Galaxies Using Fractal Dimensions
UNLV Retrospective Theses & Dissertations 1-1-1999 Classification of galaxies using fractal dimensions Sandip G Thanki University of Nevada, Las Vegas Follow this and additional works at: https://digitalscholarship.unlv.edu/rtds Repository Citation Thanki, Sandip G, "Classification of galaxies using fractal dimensions" (1999). UNLV Retrospective Theses & Dissertations. 1050. http://dx.doi.org/10.25669/8msa-x9b8 This Thesis is protected by copyright and/or related rights. It has been brought to you by Digital Scholarship@UNLV with permission from the rights-holder(s). You are free to use this Thesis in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/ or on the work itself. This Thesis has been accepted for inclusion in UNLV Retrospective Theses & Dissertations by an authorized administrator of Digital Scholarship@UNLV. For more information, please contact [email protected]. INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. -
Understanding the H2/HI Ratio in Galaxies 3
Mon. Not. R. Astron. Soc. 394, 1857–1874 (2009) Printed 6 August 2021 (MN LATEX style file v2.2) Understanding the H2/HI Ratio in Galaxies D. Obreschkow and S. Rawlings Astrophysics, Department of Physics, University of Oxford, Keble Road, Oxford, OX1 3RH, UK Accepted 2009 January 12 ABSTRACT galaxy We revisit the mass ratio Rmol between molecular hydrogen (H2) and atomic hydrogen (HI) in different galaxies from a phenomenological and theoretical viewpoint. First, the local H2- mass function (MF) is estimated from the local CO-luminosity function (LF) of the FCRAO Extragalactic CO-Survey, adopting a variable CO-to-H2 conversion fitted to nearby observa- 5 1 tions. This implies an average H2-density ΩH2 = (6.9 2.7) 10− h− and ΩH2 /ΩHI = 0.26 0.11 ± · galaxy ± in the local Universe. Second, we investigate the correlations between Rmol and global galaxy properties in a sample of 245 local galaxies. Based on these correlations we intro- galaxy duce four phenomenological models for Rmol , which we apply to estimate H2-masses for galaxy each HI-galaxy in the HIPASS catalog. The resulting H2-MFs (one for each model for Rmol ) are compared to the reference H2-MF derived from the CO-LF, thus allowing us to determine the Bayesian evidence of each model and to identify a clear best model, in which, for spi- galaxy ral galaxies, Rmol negatively correlates with both galaxy Hubble type and total gas mass. galaxy Third, we derive a theoretical model for Rmol for regular galaxies based on an expression for their axially symmetric pressure profile dictating the degree of molecularization. -
Cold Gas in Galaxies a Concise HI Perspective
Cold Gas in Galaxies a concise HI perspective Marc Verheijen Galaxy Formation, 18-22 July 2011 - Durham Characteristics of HI imaging data A limited number of 21cm aperture synthesis imaging telescopes. array dishes Tsys BLmin BLmax configuration " EVLA 27x 25m 35 K 35 m 36 km Y zoomable 1.3” WSRT 14x 25m 27 K 36 m 2.7 km EW moveable 15” GMRT 30x 45m 73 K 100 m 25 km Y fixed 2” ATCA 6x 22m 22 K 31 m 6.0 km EW zoomable 6” Field-of-view : 20’ ! 40’ FWHM Useful resolutions : 5”! 45” x few km s-1 19 22 -2 Column density sensitivities : NHI !10 !10 atoms cm 6 HI mass limits : MHI !10 Msun at D=10 Mpc Maximum redshifts : Z<0.25 Galaxy Formation, 18-22 July 2011 - Durham major HI imaging surveys Targeted Surveys of selected samples: • WHISP (350) northern spirals with F>100 mJy • VIVA (53) SFR-selected Virgo spirals • UMa (85) Ursa Major group with MB< -18.5 • THINGS (34) HI follow-up of SINGS sample • LittleTHINGS (42) Local dIm and BCDs • FIGGS (47) Faint Irregular galaxies • ATLAS3D (166) HI follow-up of northern early-types • HALOGAS (22) the deepest HI survey of spirals • VLA-ANGST (36) HI follow-up of HST/ACS survey Blind Surveys of different environments: • Coma (WSRT) • Perseus-Pisces (VLA) • Ursa Major (VLA) • CVn (WSRT) Galaxy Formation, 18-22 July 2011 - Durham HI science topics • Galactic and galaxy structure & kinematics. - the ISM, warps, lopsidedness, rotation curves, angular momentum, non-circular motions... • Accretion and depletion of gas onto galaxies. -
A Search For" Dwarf" Seyfert Nuclei. VII. a Catalog of Central Stellar
TO APPEAR IN The Astrophysical Journal Supplement Series. Preprint typeset using LATEX style emulateapj v. 26/01/00 A SEARCH FOR “DWARF” SEYFERT NUCLEI. VII. A CATALOG OF CENTRAL STELLAR VELOCITY DISPERSIONS OF NEARBY GALAXIES LUIS C. HO The Observatories of the Carnegie Institution of Washington, 813 Santa Barbara St., Pasadena, CA 91101 JENNY E. GREENE1 Department of Astrophysical Sciences, Princeton University, Princeton, NJ ALEXEI V. FILIPPENKO Department of Astronomy, University of California, Berkeley, CA 94720-3411 AND WALLACE L. W. SARGENT Palomar Observatory, California Institute of Technology, MS 105-24, Pasadena, CA 91125 To appear in The Astrophysical Journal Supplement Series. ABSTRACT We present new central stellar velocity dispersion measurements for 428 galaxies in the Palomar spectroscopic survey of bright, northern galaxies. Of these, 142 have no previously published measurements, most being rela- −1 tively late-type systems with low velocity dispersions (∼<100kms ). We provide updates to a number of literature dispersions with large uncertainties. Our measurements are based on a direct pixel-fitting technique that can ac- commodate composite stellar populations by calculating an optimal linear combination of input stellar templates. The original Palomar survey data were taken under conditions that are not ideally suited for deriving stellar veloc- ity dispersions for galaxies with a wide range of Hubble types. We describe an effective strategy to circumvent this complication and demonstrate that we can still obtain reliable velocity dispersions for this sample of well-studied nearby galaxies. Subject headings: galaxies: active — galaxies: kinematics and dynamics — galaxies: nuclei — galaxies: Seyfert — galaxies: starburst — surveys 1. INTRODUCTION tors, apertures, observing strategies, and analysis techniques. -
Near-Infrared Structure of Fast and Slow Rotating Disk Galaxies
Draft version August 18, 2018 A Preprint typeset using LTEX style emulateapj v. 5/2/11 NEAR-INFRARED STRUCTURE OF FAST AND SLOW ROTATING DISK GALAXIES Andrew Schechtman-Rook1, Matthew A. Bershady1 Draft version August 18, 2018 ABSTRACT We investigate the stellar disk structure of six nearby edge-on spiral galaxies using high-resolution JHKs-band images and 3D radiative transfer models. To explore how mass and environment shape −1 spiral disks, we selected galaxies with rotational velocities between 69 < Vrot < 245 km sec , and two with unusual morphologies. We find a wide diversity of disk structure. Of the fast-rotating −1 (Vrot > 150 km sec ) galaxies, only NGC 4013 has the super-thin+thin+thick nested disk structure seen in NGC 891 and the Milky Way, albeit with decreased oblateness, while NGC 1055, a disturbed massive spiral galaxy, contains disks with hz . 200 pc. NGC 4565, another fast-rotator, contains a prominent ring at a radius ∼5 kpc but no super-thin disk. Despite these differences, all fast-rotating galaxies in our sample have inner truncations in at least one of their disks. These truncations lead to Freeman Type II profiles when projected face-on. Slow-rotating galaxies are less complex, lacking inner disk truncations and requiring fewer disk components to reproduce their light distributions. Super-thin disk components in undisturbed disks contribute ∼ 25% of the total Ks-band light, up to that of the thin-disk contribution. The presence of super-thin disks correlates with infrared flux ratios; galaxies with super-thin disks have fKs /f60µm ≤ 0.12 for integrated light, consistent with super- thin disks being regions of on-going star-formation. -
Revealing Hidden Substructures in the $ M {BH} $-$\Sigma $ Diagram
Draft version November 14, 2019 A Typeset using L TEX twocolumn style in AASTeX63 Revealing Hidden Substructures in the MBH –σ Diagram, and Refining the Bend in the L–σ Relation Nandini Sahu,1,2 Alister W. Graham2 And Benjamin L. Davis2 — 1OzGrav-Swinburne, Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, VIC 3122, Australia 2Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, VIC 3122, Australia (Accepted 2019 October 22, by The Astrophysical Journal) ABSTRACT Using 145 early- and late-type galaxies (ETGs and LTGs) with directly-measured super-massive black hole masses, MBH , we build upon our previous discoveries that: (i) LTGs, most of which have been 2.16±0.32 alleged to contain a pseudobulge, follow the relation MBH ∝ M∗,sph ; and (ii) the ETG relation 1.27±0.07 1.9±0.2 MBH ∝ M∗,sph is an artifact of ETGs with/without disks following parallel MBH ∝ M∗,sph relations which are offset by an order of magnitude in the MBH -direction. Here, we searched for substructure in the MBH –(central velocity dispersion, σ) diagram using our recently published, multi- component, galaxy decompositions; investigating divisions based on the presence of a depleted stellar core (major dry-merger), a disk (minor wet/dry-merger, gas accretion), or a bar (evolved unstable 5.75±0.34 disk). The S´ersic and core-S´ersic galaxies define two distinct relations: MBH ∝ σ and MBH ∝ 8.64±1.10 σ , with ∆rms|BH = 0.55 and 0.46 dex, respectively. We also report on the consistency with the slopes and bends in the galaxy luminosity (L)–σ relation due to S´ersic and core-S´ersic ETGs, and LTGs which all have S´ersic light-profiles.