Hubble Sees a "Mess of Stars" 17 August 2015

Total Page：16

File Type：pdf, Size：1020Kb

Image: Hubble sees a "mess of stars" 17 August 2015 Planetary Camera 2 (WFPC2). Provided by NASA ESA/Hubble and NASA and S. Smartt (Queen's University Belfast), Acknowledgements: Nick Rose and Flickr user penninecloud Bursts of pink and red, dark lanes of mottled cosmic dust, and a bright scattering of stars—this NASA/ESA Hubble Space Telescope image shows part of a messy barred spiral galaxy known as NGC 428. It lies approximately 48 million light- years away from Earth in the constellation of Cetus (The Sea Monster). Although a spiral shape is still just about visible in this close-up shot, overall NGC 428's spiral structure appears to be quite distorted and warped, thought to be a result of a collision between two galaxies. There also appears to be a substantial amount of star formation occurring within NGC 428—another telltale sign of a merger. When galaxies collide their clouds of gas can merge, creating intense shocks and hot pockets of gas, and often triggering new waves of star formation. NGC 428 was discovered by William Herschel in December 1786. More recently a type of supernova designated SN2013ct was discovered within the galaxy by Stuart Parker of the BOSS (Backyard Observatory Supernova Search) project in Australia and New Zealand, although it is unfortunately not visible in this image. This image was captured by Hubble's Advanced Camera for Surveys (ACS) and Wide Field and 1 / 2 APA citation: Image: Hubble sees a "mess of stars" (2015, August 17) retrieved 25 September 2021 from https://phys.org/news/2015-08-image-hubble-mess-stars.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. 2 / 2 Powered by TCPDF (www.tcpdf.org).

Copy Link

Recommended publications

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 für Radioastronomie, Auf dem Hügel 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”.
[Show full text]
Search for Gas Accretion Imprints in Voids: I. Sample Selection and Results for NGC 428
MNRAS 000,1{13 (2018) Preprint 1 November 2018 Compiled using MNRAS LATEX style file v3.0 Search for gas accretion imprints in voids: I. Sample selection and results for NGC 428 Evgeniya S. Egorova,1;2? Alexei V. Moiseev,1;2;3 Oleg V. Egorov1;2 1 Lomonosov Moscow State University, Sternberg Astronomical Institute, Universitetsky pr. 13, Moscow 119234, Russia 2 Special Astrophysical Observatory, Russian Academy of Sciences, Nizhny Arkhyz 369167, Russia 3 Space Research Institute, Russian Academy of Sciences, Profsoyuznaya ul. 84/32, Moscow 117997, Russia Accepted XXX. Received YYY; in original form ZZZ ABSTRACT We present the first results of a project aimed at searching for gas accretion events and interactions between late-type galaxies in the void environment. The project is based on long-slit spectroscopic and scanning Fabry-Perot interferometer observations per- formed with the SCORPIO and SCORPIO-2 multimode instruments at the Russian 6-m telescope, as well as archival multiwavelength photometric data. In the first paper of the series we describe the project and present a sample of 18 void galaxies with oxy- gen abundances that fall below the reference `metallicity-luminosity' relation, or with possible signs of recent external accretion in their optical morphology. To demonstrate our approach, we considered the brightest sample galaxy NGC 428, a late-type barred spiral with several morphological peculiarities. We analysed the radial metallicity dis- tribution, the ionized gas line-of-sight velocity and velocity dispersion maps together with WISE and SDSS images. Despite its very perturbed morphology, the velocity field of ionized gas in NGC 428 is well described by pure circular rotation in a thin flat disc with streaming motions in the central bar.
[Show full text]
Lopsided Spiral Galaxies: Evidence for Gas Accretion
A&A 438, 507–520 (2005) Astronomy DOI: 10.1051/0004-6361:20052631 & c ESO 2005 Astrophysics Lopsided spiral galaxies: evidence for gas accretion F. Bournaud1, F. Combes1,C.J.Jog2, and I. Puerari3 1 Observatoire de Paris, LERMA, 61 Av. de l’Observatoire, 75014 Paris, France e-mail: [email protected] 2 Department of Physics, Indian Institute of Science, Bangalore 560012, India 3 Instituto Nacional de Astrofísica, Optica y Electrónica, Calle Luis Enrique Erro 1, 72840 Tonantzintla, Puebla, Mexico Received 3 January 2005 / Accepted 15 March 2005 Abstract. We quantify the degree of lopsidedness for a sample of 149 galaxies observed in the near-infrared from the OSUBGS sample, and try to explain the physical origin of the observed disk lopsidedness. We confirm previous studies, but for a larger sample, that a large fraction of galaxies have significant lopsidedness in their stellar disks, measured as the Fourier amplitude of the m = 1 component normalised to the average or m = 0 component in the surface density. Late-type galaxies are found to be more lopsided, while the presence of m = 2 spiral arms and bars is correlated with disk lopsidedness. We also show that the m = 1 amplitude is uncorrelated with the presence of companions. Numerical simulations were carried out to study the generation of m = 1viadifferent processes: galaxy tidal encounters, galaxy mergers, and external gas accretion with subsequent star formation. These simulations show that galaxy interactions and mergers can trigger strong lopsidedness, but do not explain several independent statistical properties of observed galaxies. To explain all the observational results, it is required that a large fraction of lopsidedness results from cosmological accretion of gas on galactic disks, which can create strongly lopsided disks when this accretion is asymmetrical enough.
[Show full text]
Resonant Structure in the Disks of Spiral Galaxies, Using Phase-Reversals in Streaming Motions from 2D Hα Fabry-Perot Spectroscopy
Resonant structure in the disks of spiral galaxies, using phase-reversals in streaming motions from 2D Hα Fabry-Perot spectroscopy Joan Font (1,2), John E. Beckman (1,2,3), Benoît Epinat (4,5) Kambiz Fathi (1,6,7), Leonel Gutiérrez (1,8), Olivier Hernandez (9). 1. Instituto de Astrofísica de Canarias, c/Vía Láctea, s/n, E38205, La Laguna, Tenerife, Spain: [email protected], [email protected]. 2. Departamento de Astrofísica. Universidad de La Laguna, Tenerife, Spain. 3. Consejo Superior de Investigaciones Científicas, Spain. 4. Laboratoire d’Astrophysique de Toulouse-Tarbes. Université de Toulouse, CNRS, 14 Avenue Édouard Berlin, F-31400, Toulouse, France: [email protected]. 5. CNRS, IRAP, 9 Av. Colonel Roche, BP 44346, 31028, Toulouse, Cedex 4, France. 6. Department of Astronomy, University of Stockholm, AlbaNova, 10691, Stockholm, Sweden: [email protected]. 7. Oscar Klein Centre for Cosmoparticle Physics, Stockholm University, 10691 Stockholm, Sweden. 8. Instituto de Astronomía, Universidad Nacional Autónoma de México, Apdo. Postal 877, 22800, Ensenada B.C., México: [email protected]. 9. Département de Physique et Astronomie, Université de Montreal, CP. 6128, Succ. Centre ville, Montréal, QC H3C 3J7, Canada: [email protected]. ABSTRACT In this article we introduce a technique for finding resonance radii in a disk galaxy. We use a two-dimensional velocity field in Hα emission obtained with Fabry-Perot interferometry, derive the classical rotation curve, and subtract it off, leaving a residual velocity map. As the streaming motions should reverse sign at corotation, we detect these reversals, and plot them in a histogram against galactocentric radius, excluding points where the amplitude of the reversal is smaller than the measurement uncertainty.
[Show full text]
Making a Sky Atlas
Appendix A Making a Sky Atlas Although a number of very advanced sky atlases are now available in print, none is likely to be ideal for any given task. Published atlases will probably have too few or too many guide stars, too few or too many deep-sky objects plotted in them, wrong- size charts, etc. I found that with MegaStar I could design and make, specifically for my survey, a “just right” personalized atlas. My atlas consists of 108 charts, each about twenty square degrees in size, with guide stars down to magnitude 8.9. I used only the northernmost 78 charts, since I observed the sky only down to –35°. On the charts I plotted only the objects I wanted to observe. In addition I made enlargements of small, overcrowded areas (“quad charts”) as well as separate large-scale charts for the Virgo Galaxy Cluster, the latter with guide stars down to magnitude 11.4. I put the charts in plastic sheet protectors in a three-ring binder, taking them out and plac- ing them on my telescope mount’s clipboard as needed. To find an object I would use the 35 mm finder (except in the Virgo Cluster, where I used the 60 mm as the finder) to point the ensemble of telescopes at the indicated spot among the guide stars. If the object was not seen in the 35 mm, as it usually was not, I would then look in the larger telescopes. If the object was not immediately visible even in the primary telescope – a not uncommon occur- rence due to inexact initial pointing – I would then scan around for it.
[Show full text]
A Classical Morphological Analysis of Galaxies in the Spitzer Survey Of
Accepted for publication in the Astrophysical Journal Supplement Series A Preprint typeset using LTEX style emulateapj v. 03/07/07 A CLASSICAL MORPHOLOGICAL ANALYSIS OF GALAXIES IN THE SPITZER SURVEY OF STELLAR STRUCTURE IN GALAXIES (S4G) Ronald J. Buta1, Kartik Sheth2, E. Athanassoula3, A. Bosma3, Johan H. Knapen4,5, Eija Laurikainen6,7, Heikki Salo6, Debra Elmegreen8, Luis C. Ho9,10,11, Dennis Zaritsky12, Helene Courtois13,14, Joannah L. Hinz12, Juan-Carlos Munoz-Mateos˜ 2,15, Taehyun Kim2,15,16, Michael W. Regan17, Dimitri A. Gadotti15, Armando Gil de Paz18, Jarkko Laine6, Kar´ın Menendez-Delmestre´ 19, Sebastien´ Comeron´ 6,7, Santiago Erroz Ferrer4,5, Mark Seibert20, Trisha Mizusawa2,21, Benne Holwerda22, Barry F. Madore20 Accepted for publication in the Astrophysical Journal Supplement Series ABSTRACT The Spitzer Survey of Stellar Structure in Galaxies (S4G) is the largest available database of deep, homogeneous middle-infrared (mid-IR) images of galaxies of all types. The survey, which includes 2352 nearby galaxies, reveals galaxy morphology only minimally affected by interstellar extinction. This paper presents an atlas and classifications of S4G galaxies in the Comprehensive de Vaucouleurs revised Hubble-Sandage (CVRHS) system. The CVRHS system follows the precepts of classical de Vaucouleurs (1959) morphology, modified to include recognition of other features such as inner, outer, and nuclear lenses, nuclear rings, bars, and disks, spheroidal galaxies, X patterns and box/peanut structures, OLR subclass outer rings and pseudorings, bar ansae and barlenses, parallel sequence late-types, thick disks, and embedded disks in 3D early-type systems. We show that our CVRHS classifications are internally consistent, and that nearly half of the S4G sample consists of extreme late-type systems (mostly bulgeless, pure disk galaxies) in the range Scd-Im.
[Show full text]
ALABAMA University Libraries
THE UNIVERSITY OF ALABAMA University Libraries The Distribution of Bar and Spiral Arm Strengths in Disk Galaxies R. Buta – University of Alabama S. Vasylyev – University of Alabama H. Salo – University of Oulu, Finland E. Laurikainen – University of Oulu, Finland Deposited 06/13/2018 Citation of published version: Buta, R., Vasylyev, S., Salo, H., Laurikainen, E. (2005): The Distribution of Bar and Spiral Arm Strengths in Disk Galaxies. The Astronomical Journal, 130(2). DOI: 10.1086/431251 © 2005. The American Astronomical Society. All rights reserved. Printed in U.S.A. The Astronomical Journal, 130:506 –523, 2005 August A # 2005. The American Astronomical Society. All rights reserved. Printed in U.S.A. THE DISTRIBUTION OF BAR AND SPIRAL ARM STRENGTHS IN DISK GALAXIES R. Buta and S. Vasylyev Department of Physics and Astronomy, University of Alabama, Box 870324, Tuscaloosa, AL 35487 and H. Salo and E. Laurikainen Division of Astronomy, Department of Physical Sciences, University of Oulu, Oulu FIN-90014, Finland Received 2005 March 11; accepted 2005 April 18 ABSTRACT The distribution of bar strengths in disk galaxies is a fundamental property of the galaxy population that has only begun to be explored. We have applied the bar-spiral separation method of Buta and coworkers to derive the distribution of maximum relative gravitational bar torques, Qb, for 147 spiral galaxies in the statistically well- deﬁned Ohio State University Bright Galaxy Survey (OSUBGS) sample. Our goal is to examine the properties of bars as independently as possible of their associated spirals. We ﬁnd that the distribution of bar strength declines smoothly with increasing Qb, with more than 40% of the sample having Qb 0:1.
[Show full text]
Cloud Download
ATLAS OF GALAXIES USEFUL FOR MEASURING THE COSMOLOGICAL DISTANCE SCALE .0 o NASA SP-496 ATLAS OF GALAXIES USEFUL FOR MEASURING THE COSMOLOGICAL DISTANCE SCALE Allan Sandage Space Telescope Science Institute Baltimore, Maryland and Department of Physics and Astronomy, The Johns Hopkins University Baltimore, Maryland and John Bedke Computer Sciences Corporation Space Telescope Science Institute Baltimore, Maryland Scientific and Technical Information Division 1988 National Aeronautics and Space Administration Washington, DC Library of Congress Cataloging-in-Publication Data Sandage, Allan. Atlas of galaxies useful for measuring the cosomological distance scale. (NASA SP ; 496) Bibliography: p. 1. Cosmological distances--Measurement. 2. GalaxiesrAtlases. 3. Hubble Space Telescope. I. Bedke, John. II. Title. 111. Series. QB991.C66S36 1988 523.1'1 88 600056 For sale b_ the Superintendent of tX_uments. U S Go_ernment Printing Office. Washington. DC 20402 PREFACE A critical first step in determining distances to galaxies is to measure some property (e.g., size or luminosity) of primary objects such as stars of specific types, H II regions, and supernovae remnants that are resolved out of the general galaxy stellar content. Very few galaxies are suitable for study at such high resolution because of intense disk background light, excessive crowding by contaminating images, internal obscuration due to dust, high inclination angles, or great distance. Nevertheless, these few galaxies with accurately measurable primary distances are required to calibrate secondary distance indicators which have greater range. If telescope time is to be optimized, it is important to know which galaxies are suitable for specific resolution studies. No atlas of galaxy photographs at a scale adequate for resolution of stellar content exists that is complete for the bright galaxy sample [e.g.; for the Shapley-Ames (1932) list, augmented with listings in the Second Reference Catalog (RC2) (de Vaucouleurs, de Vaucouleurs, and Corwin, 1977); and the Uppsala Nilson (1973) catalogs].
[Show full text]
A Classical Morphological Analysis of Galaxies in the Spitzer Survey of Stellar Structure in Galaxies (S4G)
University of Louisville ThinkIR: The University of Louisville's Institutional Repository Faculty Scholarship 4-2015 A classical morphological analysis of galaxies in the Spitzer Survey of Stellar Structure in Galaxies (S4G). Ronald J. Buta University of Alabama - Tuscaloosa Kartik Sheth National Radio Astronomy Observatory E. Athanassoula Aix Marseille Universite Albert Bosma Aix Marseille Universite Johan H. Knapen Universidad de La Laguna See next page for additional authors Follow this and additional works at: https://ir.library.louisville.edu/faculty Part of the Astrophysics and Astronomy Commons Original Publication Information Buta, Ronald J., et al. "A Classical Morphological Analysis of Galaxies in the Spitzer Survey of Stellar Structures in Galaxies (S4G)." 2015. The Astrophysical Journal Supplement Series 217(2): 46 pp. This Article is brought to you for free and open access by ThinkIR: The University of Louisville's Institutional Repository. It has been accepted for inclusion in Faculty Scholarship by an authorized administrator of ThinkIR: The University of Louisville's Institutional Repository. For more information, please contact [email protected]. Authors Ronald J. Buta, Kartik Sheth, E. Athanassoula, Albert Bosma, Johan H. Knapen, Eija Laurikainen, Heikki Salo, Debra M. Elmegreen, Luis C. Ho, Dennis Zaritsky, Helene M. Courtois, Joannah Hinz, Juan Carlos Muñoz-Mateos, Taehyun Kim, Michael Regan, Dimitri A. Gadotti, Armando Gil de Paz, Jarkko Laine, Karin Menendez-Delmestre, Sebastien Comeron, Santiago Erroz-Ferrer, Mark Seibert, Trisha Mizusawa, Benne W. Holwerda, and Barry Madore This article is available at ThinkIR: The University of Louisville's Institutional Repository: https://ir.library.louisville.edu/ faculty/178 The Astrophysical Journal Supplement Series, 217:32 (46pp), 2015 April doi:10.1088/0067-0049/217/2/32 © 2015.
[Show full text]
Radio Sources in Low-Luminosity Active Galactic Nuclei
A&A 435, 521–543 (2005) Astronomy DOI: 10.1051/0004-6361:20042277 & c ESO 2005 Astrophysics Radio sources in low-luminosity active galactic nuclei IV. Radio luminosity function, importance of jet power, and radio properties of the complete Palomar sample N. M. Nagar1,2, H. Falcke3, and A. S. Wilson4 1 Kapteyn Institute, Landleven 12, 9747 AD Groningen, The Netherlands 2 Astronomy Group, Departamento de Física, Universidad de Concepción, Casilla 160-C, Concepción, Chile e-mail: [email protected] 3 ASTRON, PO Box 2, 7990 AA Dwingeloo, The Netherlands Department of Astronomy, Radboud University Nijmegen, Postbus 9010, 6500 GL Nijmegen, The Netherlands e-mail: [email protected] 4 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] Received 29 October 2004 / Accepted 5 February 2005 Abstract. We present the completed results of a high resolution radio imaging survey of all (∼200) low-luminosity active galactic nuclei (LLAGNs) and AGNs in the Palomar Spectroscopic Sample of all (∼488) bright northern galaxies. The high incidences of pc-scale radio nuclei, with implied brightness temperatures ∼>107 K, and sub-parsec jets argue for accreting black holes in ∼>50% of all LINERs and low-luminosity Seyferts; there is no evidence against all LLAGNs being mini-AGNs. The detected parsec-scale radio nuclei are preferentially found in massive ellipticals and in type 1 nuclei (i.e. nuclei with broad Hα emission). The radio luminosity function (RLF) of Palomar Sample LLAGNs and AGNs extends three orders of magnitude below, and is continuous with, that of “classical” AGNs.
[Show full text]
Molecular Gas in the Central Regions of the Latest-Type Spiral Galaxies
A&A 406, 87–103 (2003) Astronomy DOI: 10.1051/0004-6361:20030755 & c ESO 2003 Astrophysics Molecular gas in the central regions of the latest-type spiral galaxies T. Boker ¨ 1,, U. Lisenfeld2, and E. Schinnerer3, 1 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA 2 Instituto de Astrof´ısica de Andaluc´ıa (CSIC), Camino Bajo de Huetor 24, 18080 Granada, Spain e-mail: [email protected] 3 National Radio Astronomy Observatory, PO Box 0, Socorro, NM 87801, USA e-mail: [email protected] Received 11 March 2003 / Accepted 15 May 2003 Abstract. Using the IRAM 30 m telescope, we have surveyed an unbiased sample of 47 nearby spiral galaxies of very late (Scd-Sm) Hubble-type for emission in the 12CO(1−0) and (2−1) lines. The sensitivity of our data (a few mK) allows detection 7 of about 60% of our sample in at least one of the CO lines. The median detected H2 mass is 1.4 × 10 M within the central few kpc, assuming a standard conversion factor. We use the measured line intensities to complement existing studies of the molecular gas content of spiral galaxies as a function of Hubble-type and to significantly improve the statistical significance of such studies at the late end of the spiral sequence. We find that the latest-type spirals closely follow the correlation between molecular gas content and galaxy luminosity established for earlier Hubble types. The molecular gas in late-type galaxies seems to be less centrally concentrated than in earlier types.
[Show full text]
Spitzer/Infrared Array Camera Near-Infrared Features in the Outer Parts of S4G Galaxies
University of Louisville ThinkIR: The University of Louisville's Institutional Repository Faculty Scholarship 11-2014 Spitzer/Infrared Array Camera near-infrared features in the outer parts of S4G galaxies. Seppo Laine Spitzer Science Center Johan H. Knapen Universidad de La Laguna Juan Carlos Munoz-Mateos National Radio Astronomy Observatory Taehyun Kim Seoul National University Sebastien Comeron University of Oulu See next page for additional authors Follow this and additional works at: https://ir.library.louisville.edu/faculty Part of the Astrophysics and Astronomy Commons Original Publication Information Laine, Seppo, et al. "Spitzer/Infrared Array Camera Near-Infrared Features in the Outer Parts of S4G Galaxies." 2014. Monthly Notices of the Royal Astronomical Society 444(4): 3015-3039. This Article is brought to you for free and open access by ThinkIR: The University of Louisville's Institutional Repository. It has been accepted for inclusion in Faculty Scholarship by an authorized administrator of ThinkIR: The University of Louisville's Institutional Repository. For more information, please contact [email protected]. Authors Seppo Laine, Johan H. Knapen, Juan Carlos Munoz-Mateos, Taehyun Kim, Sebastien Comeron, Marie Martig, Benne W. Holwerda, E. Athanassoula, Albert Bosma, Peter H. Johansson, Santiago Erroz-Ferrer, Dimitri A. Gadotti, Armando Gil de Paz, Joannah Hinz, Jarkko Laine, Eija Laurikainen, Karin Menendez- Delmestre, Trisha Mizusawa, Michael Regan, Heikki Salo, Kartik Sheth, Mark Seibert, Ronald J. Buta, Mauricio Cisternas, Bruce G. Elmegreen, Debra M. Elmegreen, Luis C. Ho, Barry F. Madore, and Dennis Zaritsky This article is available at ThinkIR: The University of Louisville's Institutional Repository: https://ir.library.louisville.edu/ faculty/189 MNRAS 444, 3015–3039 (2014) doi:10.1093/mnras/stu1642 Spitzer/Infrared Array Camera near-infrared features in the outer parts of S4G galaxies Seppo Laine,1‹ Johan H.
[Show full text]