DOCSLIB.ORG

Observing Galaxies in Pegasus 01 October 2015 23:07

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Observing Galaxies in Pegasus 01 October 2015 23:07 Observing galaxies in Pegasus 01 October 2015 23:07 Context As you look towards Pegasus you are looking below the galactic plane under the Orion spiral arm of our galaxy. The Perseus-Pisces supercluster wall of galaxies runs through this constellation. It stretches from RA 3h +40 in Perseus to 23h +10 in Pegasus and is around 200 million light years away. It includes the Pegasus I group noted later this document. The constellation is well placed from mid summer to late autumn. Pegasus is a rich constellation for galaxy observing. I have observed 80 galaxies in this constellation. Relatively bright galaxies This section covers the galaxies that were visible with direct vision in my 16 inch or smaller scopes. This list will therefore grow over time as I have not yet viewed all the galaxies in good conditions at maximum altitude in my 16 inch scope! NGC 7331 MAG 9 This is the stand out galaxy of the constellation. It is similar to our milky way. Around it are a number of fainter NGC galaxies. I have seen the brightest one, NGC 7335 in my 10 inch scope with averted vision. I have seen NGC 7331 in my 25 x 100mm binoculars. NGC 7814 - Mag 10 ? Not on observed list ? This is a very lovely oval shaped galaxy. By constellation Page 1 NGC 7332 MAG 11 / NGC 7339 MAG 12 These galaxies are an isolated bound pair about 67 million light years away. NGC 7339 is the fainter of the two galaxies at the eyepiece. I have seen NGC 7332 in my 25 x 100mm binoculars. NGC 7217 MAG 10 - Not showing on list! I rated this as bright (2 star) when I observed it in my 10 inch scope and noted it was larger than NGC 7177 (see below). By constellation Page 2 NGC 7457 MAG 10 I could see this at low power in my 14 inch scope. NGC 7177 MAG 11 I found this hard to locate but it could be seen with direct vision in my 10 inch scope. By constellation Page 3 NGC 7743 MAG 11 This was visible at low power in my 10 inch scope. NGC 7469 MAG 12 The core of this galaxy was just visible with direct vision in my 14 inch scope. I could not see IC 5283 nearby! By constellation Page 4 NGC 7311 MAG 12 This was quite easy to see with direct vision in my 16 inch scope. Other special galaxies and galaxy groups of note I have set out below a selection of observed galaxies and galaxy groups of note in the constellation. The Pegasus I group is a relatively bright group of about 13 galaxies at a distance of 180 million light years. I have observed NGC 7619 and NGC 7626 which look like car headlights in the fog! I have also seen NGC 7623 and NGC 7611 with my 10 inch scope. By constellation Page 5 The Stephens quintet is a very famous group of five faint small galaxies visible in the same FOV. All five were just visible in my 16 inch scope. 7320 is 40 million light years away. The other are between 200 and 300 million light years away. NGC 7479 This is the other mag 10 galaxy in Pegasus. It is 105 million light years away. It is of note as its structure can be seen in larger scopes. However when I observed it in my 14 inch scope I needed averted vision to pick it up. This might have been a reflection of its relatively low declination. NGC 7385 group It is a rare to be able to see five galaxies in one field of view. Five galaxies (7383 / 7385 / 7386 / 7387 / 7389) in this group were visible with averted vision in my 16 inch scope with the 7mm eyepiece which gives a 0.3 degrees FOV. This group is between 300 and 350 million light years away. NGC 1 & 2 The first entry in the NGC catalogue is NGC 1. I observed NGC 1 with my 16 inch scope. NGC 2 is next to it but I could not pick it up in my 16 inch scope. NGC 7673 & NGC 7677 are a faint pair of galaxies. NGC 7677 was by far the faintest and was only just visible with averted vision in my 14 inch scope. NGC 7769 and NGC 7771 are a faint pair of galaxies. NGC 7771 was very tough to pick out even with averted vision with my 10 inch scope. I could not see NGC 7770, a fainter galaxy in this field in my 10 inch scope. NGC 7465 was just visible with averted vision in my 10 inch scope. I could not see NGC 7463 or NGC 7464. By constellation Page 6 Full list of observed galaxies in Pegasus ref1 SIZE SHAPE Visual mag Comments MLY surf_brt INSTRUM _scale ness ENT NGC large oval 1 9.5 Brecon Star Party 48 13.3 25 x 100B 7331 NGC small thin 1 11.1 Brecon Star Party 53 12.6 25 x 100B 7332 oval NGC small oval 1 11.2 Just visible in 20mm. Better with averted vision. 49 13.0 Skywatch 7177 er 10 inch NGC small oval 1 11.2 Lovely oval galaxy, picked up in 24mm eyepiece 36 13.6 Darkstar 7457 14 inch NGC very circular 1 11.5 Small faint oval galaxy. 76 13.6 Skywatch 7743 small er 10 inch NGC very circular 1 12.3 Bright core - small - Just visible with direct vision 216 12.7 Darkstar 7469 small 14 inch NGC very oval 1 12.5 Oval object 199 12.6 Meade 16 7311 small inch NGC small oval <0.5 10.6 Faint averted oval glow 46 13.2 Meade 7814 90mm NGC small circular <0.5 10.9 Another go at this given its a good night. Quite large 106 13.4 Skywatch 7479 and elongated. Better with averted vision and better in er 10 inch 12.5mm lens. No arms just a long barrel to me. NGC very circular <0.5 11.1 Brighter of a great double set of galaxies. A third NGC 169 12.9 Skywatch 7619 small 7611 is just visible. Oval in shape. er 10 inch NGC small oval <0.5 11.3 Tough small galaxy 33 13.9 Darkstar 7741 14 inch NGC very circular <0.5 11.6 Easy enough to find but on the faint side. Better with 74 12.7 Skywatch 7742 small averted vision. It is possible in 12.5mm er 10 inch NGC very oval <0.5 11.7 Really tough even with averted vision tonight. Only 108 12.9 Skywatch 7448 small appearing occasionally. er 10 inch NGC small thin <0.5 11.8 Toughest of the night. Really only fleeting glimpses with 96 12.9 Skywatch 7817 oval averted vision! er 10 inch NGC very circular <0.5 11.8 Oval galaxy. Small but easy to spot with averted vision 88 13.2 Skywatch 7454 small er 10 inch NGC very circular <0.5 11.8 Low sbr spiral galaxy - relatively easy with AV - In a 153 13.1 Darkstar 7678 small triangle of stars 14 inch NGC very oval <0.5 12.0 Very tough low sbr galaxy 231 14.0 Skywatch 7753 small er 10 inch NGC 16 very oval <0.5 12.0 Found relatively easily tonight. Still faint and best with 136 12.4 Skywatch small averted vision. er 10 inch NGC 23 very oval <0.5 12.0 Faint but visible readily with averted vision. 206 13.0 Skywatch small er 10 inch NGC very circular <0.5 12.0 Slightly extended glow 231 13.2 Darkstar 7042 small 14 inch NGC very circular <0.5 12.0 Oval diffuse object 1 of 5 348 12.8 Meade 16 7385 small inch NGC very circular <0.5 12.0 One of a pair in the same FOV. This one is brighter 190 12.9 Skywatch 7769 small than 7771. er 10 inch NGC 14 very circular <0.5 12.1 Faint averted glow 0 13.9 Darkstar small 14 inch NGC very oval <0.5 12.1 Very small faint oval shaped object 181 13.3 Skywatch 7711 small er 10 inch NGC very circular <0.5 12.1 Small faint galaxy. Pretty tough one to confirm sighting. 81 13.3 Skywatch 7280 small er 10 inch NGC very circular <0.5 12.1 Very small ,very faint galaxy. 75 12.8 Skywatch 7625 small er 10 inch NGC very circular <0.5 12.2 Very faint oval galaxy. 227 12.6 Skywatch 7550 small er 10 inch NGC very slither <0.5 12.2 Only just with averted vision 56 13.0 Skywatch 7339 small er 10 inch NGC very circular <0.5 12.3 small faint circular galaxy 0 14.3 Meade 16 7490 small inch NGC very circular <0.5 12.3 Oval diffuse object 2 of 5 323 12.8 Meade 16 By constellation Page 7 NGC very circular <0.5 12.3 Oval diffuse object 2 of 5 323 12.8 Meade 16 7386 small inch NGC very circular <0.5 12.3 Nice oval galaxy west of a triangle of stars 365 13.1 Darkstar 7768 small 14 inch NGC very oval <0.5 12.3 One of a pair in the same FOV. This one is fainter than 191 13.1 Skywatch 7771 small 7769. Could not positively identify 7770. er 10 inch NGC very circular <0.5 12.4 Faint galaxy visible with averted vision 389 13.1 Darkstar 7720 small 14 inch NGC very circular <0.5 12.4 Very small faint oval shaped object 180 13.2 Skywatch 7722 small er 10 inch NGC very circular <0.5 12.4 Small faint circular galaxy.
Load more

Recommended publications
  • Midterm Results the Milky Way in the Infrared
    3/2/10 Lecture 13 : Midterm Results The Interstellar Medium and Cosmic Recycling A2020 Prof. Tom Megeath The Milk The Milky Way in the Infrared Way from Above (artist conception) The Milky Way appears to have a bar and four spiral arms. Star formation and hot blue stars concentrated in arms. View from the Earth: Edge On Infrared light penetrates the clouds and shows the entire galaxy 1 3/2/10 NGC 7331: the Milky Way’s Twins The Interstellar Medium The space between the stars is not empty, but filled with a very low density of matter in the form of: •Atomic hydrogen •Ionized hydrogen •Molecular Hydrogen •Cosmic Rays •Dust grains •Many other molecules (water, carbon monoxide, formaldehyde, methanol, etc) •Organic molecules like polycyclic aromatic hydrocarbons How do we know the gas is there? Review: Kirchoff Laws Remainder of the Lecture Foreground gas cooler, absorption 1. How we observe and study the interstellar medium 2. The multiwavelength Milky Way Absorbing gas hotter, 3. Cosmic Recycling emission lines (and (or cooler blackbody) blackbody) If foreground gas and emitting blackbody the same temperature: perfect blackbody (no lines) Picture from Nick Strobel’s astronomy notes: www.astronomynotes.com 2 3/2/10 Observing the ISM through Absorption Lines • We can determine the composition of interstellar gas from its absorption lines in the spectra of stars • 70% H, 28% He, 2% heavier elements in our region of Milky Way Picture from Nick Strobel’s astronomy notes: www.astronomynotes.com Emission Lines Emission Line Nebula M27 Emitted by atoms and ions in planetary and HII regions.
    [Show full text]
  • The X-Ray Emission of Local Luminous Infrared Galaxies⋆
    A&A 535, A93 (2011) Astronomy DOI: 10.1051/0004-6361/201117420 & c ESO 2011 Astrophysics The X-ray emission of local luminous infrared galaxies M. Pereira-Santaella1, A. Alonso-Herrero1, M. Santos-Lleo2, L. Colina1, E. Jiménez-Bailón3, A. L. Longinotti4, G. H. Rieke5,M.Ward6, and P. Esquej1 1 Departamento de Astrofísica, Centro de Astrobiología, CSIC/INTA, Carretera de Torrejón a Ajalvir, km 4, 28850 Torrejón de Ardoz, Madrid, Spain e-mail: [email protected] 2 XMM-Newton Science Operation Centre, European Space Agency, 28691 Villanueva de la Cañada, Madrid, Spain 3 Instituto de Astronomía, Universidad Nacional Autónoma de México, Apartado Postal 70-264, 04510 Mexico DF, México 4 MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, NE80-6011, Cambridge, MA 02139, USA 5 Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA 6 Department of Physics, Durham University, South Road, Durham, DH1 3LE, UK Received 6 June 2011 / Accepted 5 September 2011 ABSTRACT We study the X-ray emission of a representative sample of 27 local luminous infrared galaxies (LIRGs). The median IR luminosity of our sample is log LIR/L = 11.2, therefore the low-luminosity end of the LIRG class is well represented. We used new XMM-Newton data as well as Chandra and XMM-Newton archive data. The soft X-ray (0.5–2 keV) emission of most of the galaxies (>80%), including LIRGs hosting a Seyfert 2 nucleus, is dominated by star-formation-related processes. These LIRGs follow the star-formation rate (SFR) versus soft X-ray luminosity correlation observed in local starbursts.
    [Show full text]
  • Infrared Spectroscopy of Nearby Radio Active Elliptical Galaxies
    The Astrophysical Journal Supplement Series, 203:14 (11pp), 2012 November doi:10.1088/0067-0049/203/1/14 C 2012. The American Astronomical Society. All rights reserved. Printed in the U.S.A. INFRARED SPECTROSCOPY OF NEARBY RADIO ACTIVE ELLIPTICAL GALAXIES Jeremy Mould1,2,9, Tristan Reynolds3, Tony Readhead4, David Floyd5, Buell Jannuzi6, Garret Cotter7, Laura Ferrarese8, Keith Matthews4, David Atlee6, and Michael Brown5 1 Centre for Astrophysics and Supercomputing Swinburne University, Hawthorn, Vic 3122, Australia; [email protected] 2 ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) 3 School of Physics, University of Melbourne, Melbourne, Vic 3100, Australia 4 Palomar Observatory, California Institute of Technology 249-17, Pasadena, CA 91125 5 School of Physics, Monash University, Clayton, Vic 3800, Australia 6 Steward Observatory, University of Arizona (formerly at NOAO), Tucson, AZ 85719 7 Department of Physics, University of Oxford, Denys, Oxford, Keble Road, OX13RH, UK 8 Herzberg Institute of Astrophysics Herzberg, Saanich Road, Victoria V8X4M6, Canada Received 2012 June 6; accepted 2012 September 26; published 2012 November 1 ABSTRACT In preparation for a study of their circumnuclear gas we have surveyed 60% of a complete sample of elliptical galaxies within 75 Mpc that are radio sources. Some 20% of our nuclear spectra have infrared emission lines, mostly Paschen lines, Brackett γ , and [Fe ii]. We consider the influence of radio power and black hole mass in relation to the spectra. Access to the spectra is provided here as a community resource. Key words: galaxies: elliptical and lenticular, cD – galaxies: nuclei – infrared: general – radio continuum: galaxies ∼ 1. INTRODUCTION 30% of the most massive galaxies are radio continuum sources (e.g., Fabbiano et al.
    [Show full text]
  • Winter Constellations
    Winter Constellations *Orion *Canis Major *Monoceros *Canis Minor *Gemini *Auriga *Taurus *Eradinus *Lepus *Monoceros *Cancer *Lynx *Ursa Major *Ursa Minor *Draco *Camelopardalis *Cassiopeia *Cepheus *Andromeda *Perseus *Lacerta *Pegasus *Triangulum *Aries *Pisces *Cetus *Leo (rising) *Hydra (rising) *Canes Venatici (rising) Orion--Myth: Orion, the great ​ ​ hunter. In one myth, Orion boasted he would kill all the wild animals on the earth. But, the earth goddess Gaia, who was the protector of all animals, produced a gigantic scorpion, whose body was so heavily encased that Orion was unable to pierce through the armour, and was himself stung to death. His companion Artemis was greatly saddened and arranged for Orion to be immortalised among the stars. Scorpius, the scorpion, was placed on the opposite side of the sky so that Orion would never be hurt by it again. To this day, Orion is never seen in the sky at the same time as Scorpius. DSO’s ● ***M42 “Orion Nebula” (Neb) with Trapezium A stellar ​ ​ ​ nursery where new stars are being born, perhaps a thousand stars. These are immense clouds of interstellar gas and dust collapse inward to form stars, mainly of ionized hydrogen which gives off the red glow so dominant, and also ionized greenish oxygen gas. The youngest stars may be less than 300,000 years old, even as young as 10,000 years old (compared to the Sun, 4.6 billion years old). 1300 ly. ​ ​ 1 ● *M43--(Neb) “De Marin’s Nebula” The star-forming ​ “comma-shaped” region connected to the Orion Nebula. ● *M78--(Neb) Hard to see. A star-forming region connected to the ​ Orion Nebula.
    [Show full text]
  • 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.
    [Show full text]
  • Radio Identification and Continuum Spectra of Decameter-Wavelength
    Astronomy Reports, Vol. 47, No. 2, 2003, pp. 110–118. Translated from Astronomicheski˘ı Zhurnal, Vol. 80, No. 2, 2003, pp. 130–139. Original Russian Text Copyright c 2003 by Verkhodanov, Verkhodanova, Andernach. Radio Identification and Continuum Spectra of Decameter-Wavelength Sources O.V. Verkhodanov1, N. V. Verkhodanova1,andH.Andernach2 1Special Astrophysical Observatory, Russian Academy of Sciences, Nizhni ˘ı Arkhyz, Karachaevo-Cherkesskaya Republic, 357169 Russia 2University of Guanajuato, Department of Astronomy, Apdo Postal 144, Guanajuato, GTO, CP36000, Mexico´ Received March 22, 2002; in final form, June 26, 2002 Abstract—The paper describes a method for the radio identification of decameter-wavelength sources based on their continuum spectra and analysis of their coordinates in relatively large error boxes sur- rounding a specified position on the sky. The distribution of continuum spectra and identifications in other wavelength ranges are analyzed for the resulting radio catalog. Using identifications with the FIRST and NVSS surveys, the statistics of the spectral index–size and spectral index–fluxdensity distributions for steep-spectrum sources have been studied, and a catalog of ultrasteep-spectrum (α<−1.2) decameter- wavelength sources has been compiled. c 2003MAIK “Nauka/Interperiodica”. 1. INTRODUCTION 40 × 40cosecδ window obtained from a cross iden- tification with the CATS database [7]. We addressed The catalog of 1822 radio sources obtained with this problem via interactive processing of the radio the UTR telescope (Kharkov) by Braude et al.[1–5] spectra [8] obtained through a cross-identification at 10, 12.6, 14.7, 16.7, 20, and 25 MHz covers about of the UTR objects with sources from the CATS 30% of the sky and is the lowest-frequency catalog database using a 40 identification window.
    [Show full text]
  • Multicolor Surface Photometry of Lenticular Galaxies
    The Astronomical Journal, 129:630–646, 2005 February # 2005. The American Astronomical Society. All rights reserved. Printed in U.S.A. MULTICOLOR SURFACE PHOTOMETRY OF LENTICULAR GALAXIES. I. THE DATA Sudhanshu Barway School of Studies in Physics, Pandit Ravishankar Shukla University, Raipur 492010, India; [email protected] Y. D. Mayya Instituto Nacional de Astrofisı´ca, O´ ptica y Electro´nica, Apdo. Postal 51 y 216, Luis Enrique Erro 1, 72000 Tonantzintla, Pue., Mexico; [email protected] Ajit K. Kembhavi Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune 411007, India; [email protected] and S. K. Pandey1 School of Studies in Physics, Pandit Ravishankar Shukla University, Raipur 492010, India; [email protected] Receivedv 2003 Auggust 13; accepted 2004 October 20 ABSTRACT We present multicolor surface and aperture photometry in the B, V, R,andK0 bands for a sample of 34 lenticular galaxies from the Uppsala General Catalogue. From surface photometric analysis, we obtain radial profiles of surface brightness, colors, ellipticity, position angle, and the Fourier coefficients that describe the departure of isophotal shapes from a purely elliptical form; we find the presence of dust lanes, patches, and ringlike structure in several galaxies in the sample. We obtain total integrated magnitudes and colors and find that these are in good agreement with the values from the Third Reference Catalogue. Isophotal colors are correlated with each other, following the sequence expected for early-type galaxies. The color gradients in lenticular galaxies are more negative than the corresponding gradients in elliptical galaxies. There is a good correlation between BÀVand BÀR color gradients, and the mean gradients in the BÀV, BÀR,andVÀK0 colors are À0:13 Æ 0:06, À0:18 Æ 0:06, and À0:25 Æ 0:11 mag dexÀ1 in radius, respectively.
    [Show full text]
  • Active Galactic Nuclei and Their Neighbours
    CCD Photometric Observations of Active Galactic Nuclei and their Neighbours by Traianou Efthalia A dissertation submitted in partial fulfillment of the requirements for the degree of Ptychion (Physics) in Aristotle University of Thessaloniki September 2016 Supervisor: Manolis Plionis, Professor To my loved ones Many thanks to: Manolis Plionis for accepting to be my thesis adviser. ii TABLE OF CONTENTS DEDICATION :::::::::::::::::::::::::::::::::: ii LIST OF FIGURES ::::::::::::::::::::::::::::::: v LIST OF TABLES :::::::::::::::::::::::::::::::: ix LIST OF APPENDICES :::::::::::::::::::::::::::: x ABSTRACT ::::::::::::::::::::::::::::::::::: xi CHAPTER I. Introduction .............................. 1 II. Active Galactic Nuclei ........................ 4 2.1 Early History of AGN’s ..................... 4 2.2 AGN Phenomenology ...................... 7 2.2.1 Seyfert Galaxies ................... 7 2.2.2 Low Ionization Nuclear Emission-Line Regions(LINERS) 10 2.2.3 ULIRGS ........................ 11 2.2.4 Radio Galaxies .................... 12 2.2.5 Quasars or QSO’s ................... 14 2.2.6 Blazars ......................... 15 2.3 The Unification Paradigm .................... 16 2.4 Beyond the Unified Model ................... 18 III. Research Goal and Methodology ................. 21 3.1 Torus ............................... 21 3.2 Ha Balmer Line ......................... 23 3.3 Galaxy-Galaxy Interactions ................... 25 3.4 Our Aim ............................. 27 iii IV. Observations .............................. 29 4.1 The Telescope
    [Show full text]
  • The Bright Galaxies NGC 1068 (M 77), NGC 2146, NGC 3079, NGC 4826 (M 64), and NGC 7469 F
    A&A 493, 525–538 (2009) Astronomy DOI: 10.1051/0004-6361:200810655 & c ESO 2009 Astrophysics CI and CO in nearby galaxy centers The bright galaxies NGC 1068 (M 77), NGC 2146, NGC 3079, NGC 4826 (M 64), and NGC 7469 F. P. Israel Sterrewacht Leiden, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands e-mail: [email protected] Received 22 July 2008 / Accepted 5 November 2008 ABSTRACT Aims. We study the physical properties and amount of molecular gas in the central regions of galaxies with active nuclei. Methods. Maps and measurements of the J = 1−0, J = 2−1, J = 3−2, J = 4−3 12CO, the J = 1−0, J = 2−1, and J = 3−2 13CO lines in the central arcminute squared of NGC 1068, NGC 2146, NGC 3079, NGC 4826, and NGC 7469, as well as 492 GHz CI maps in three of these are used to model the molecular gas clouds in these galaxies. Results. Bright CO concentrations were detected and mapped in all five objects. In all cases, the observed lines could be fitted with two distinct gas components. The physical condition of the molecular gas is found to differ from galaxy to galaxy. Rather high kinetic temperatures of 125−150 K occur in NGC 2146 and NGC 3079. Very high densities of 0.3−1.0 × 105 cm−3 occur in NGC 2146, NGC 3079, and NGC 7469. The CO to H2 conversion factor X is typically an order of magnitude less than the “standard” value in the solar neighborhood.
    [Show full text]
  • Arxiv:1809.03080V1
    DRAFT VERSION SEPTEMBER 11, 2018 Typeset using LATEX twocolumn style in AASTeX62 Polar Dust, Nuclear Obscuration and IR SED Diversity in Type-1 AGNs ∗ JIANWEI LYU (吕建伟 )1 AND GEORGE H. RIEKE1 1 Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA (Received 2018 May 15; Revised 2018 August 29; Accepted 2018 September 8) Submitted to ApJ ABSTRACT Despite the hypothesized similar face-on viewing angles, the infrared emission of type-1 AGNs has diverse spectral energy distribution (SED) shapes that deviate substantially from the well-characterized quasar tem- plates. Motivated by the commonly-seen UV-optical obscuration and the discovery of parsec-scale mid-IR polar dust emission in some nearby AGNs, we develop semi-empirical SED libraries for reddened type-1 AGNs built on the quasar intrinsic templates, assuming low-level extinction caused by an extended distribution of large dust grains. We demonstrate that this model can reproduce the nuclear UV-to-IR SED and the strong mid-IR polar dust emission of NGC 3783, the type-1 AGN with the most relevant and robust observational constraints. In addition, we compile 64 low-z Seyfert-1 nuclei with negligible mid-IR star formation contamination and satisfactorily fit the individual IR SEDs as well as the composite UV to mid-IR composite SEDs. Given the success of these fits, we characterize the possible infrared SED of AGN polar dust emission and utilize a simple but effective strategy to infer its prevalence among type-1 AGNs. The SEDs of high-z peculiar AGNs, including the extremely red quasars, mid-IR warm-excess AGNs, and hot dust-obscured galaxies, can be also reproduced by our model.
    [Show full text]
  • 2014 Observers Challenge List
    2014 TMSP Observer's Challenge Atlas page #s # Object Object Type Common Name RA, DEC Const Mag Mag.2 Size Sep. U2000 PSA 18h31m25s 1 IC 1287 Bright Nebula Scutum 20'.0 295 67 -10°47'45" 18h31m25s SAO 161569 Double Star 5.77 9.31 12.3” -10°47'45" Near center of IC 1287 18h33m28s NGC 6649 Open Cluster 8.9m Integrated 5' -10°24'10" Can be seen in 3/4d FOV with above. Brightest star is 13.2m. Approx 50 stars visible in Binos 18h28m 2 NGC 6633 Open Cluster Ophiuchus 4.6m integrated 27' 205 65 Visible in Binos and is about the size of a full Moon, brightest star is 7.6m +06°34' 17h46m18s 2x diameter of a full Moon. Try to view this cluster with your naked eye, binos, and a small scope. 3 IC 4665 Open Cluster Ophiuchus 4.2m Integrated 60' 203 65 +05º 43' Also check out “Tweedle-dee and Tweedle-dum to the east (IC 4756 and NGC 6633) A loose open cluster with a faint concentration of stars in a rich field, contains about 15-20 stars. 19h53m27s Brightest star is 9.8m, 5 stars 9-11m, remainder about 12-13m. This is a challenge obJect to 4 Harvard 20 Open Cluster Sagitta 7.7m integrated 6' 162 64 +18°19'12" improve your observation skills. Can you locate the miniature coathanger close by at 19h 37m 27s +19d? Constellation star Corona 5 Corona Borealis 55 Trace the 7 stars making up this constellation, observe and list the colors of each star asterism Borealis 15H 32' 55” Theta Corona Borealis Double Star 4.2m 6.6m .97” 55 Theta requires about 200x +31° 21' 32” The direction our Sun travels in our galaxy.
    [Show full text]
  • 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.
    [Show full text]