DOCSLIB.ORG

Chapter 1 Inventory of the Local Universe

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Chapter 1 Inventory of the Local Universe Chapter 1 Inventory of the Local Universe 1 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE 1.1 The major types of galaxies: Hubble-Sandage system Hubble-Sandage Tuning Fork: Kormendy & Bender, ApJ 464, L119 (1996), revised for ellipticals. Other classification schemes: e.g. de Vaucouleurs (1959), van den Bergh (1960/66), Yerkes (Morgan, 1957 ff) 2 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Primary classification criteria of commonly used Hubble-Sandage system: Bulge-to-disk ratio (S0/Sa: 5 to 0.3, Sb: 1 to 0.1, Sc/Irr: 0.2 to 0) Opening angle of spiral arms (Sa: 0 to 10, Sb: 5 to 20, Sc: 10 to 30 degrees) Bars Physical parameters varying along the Hubble-Sandage system: Stellar mass M increases from irregulars (108M ) to ellipticals (1012M ) Specific Angular Momentum J=M of baryons increases from ellipticals to spirals Mean age increases from irregulars through spirals to ellipticals (B-V increases from 0.3 to 1.0, mass-to-light M=LB ratio increases from about 2 to 10) Mean stellar density of spheroids increases with decreasing spheroid luminosity Mean surface brightness of disks increases with luminosity cold gas content increases along Hubble sequence (fraction of baryonic mass: 0 in E/S0, 0.1 to 0.3 in Sa to Sc, up to 0.9 in Irr) hot gas content only significant in massive E (few percent of baryonic mass) 3 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Examples for Normal Galaxies: Elliptical (E) Galaxies: The ellipticals M 84 (right) and M 86 (middle) in the Virgo cluster (NOAO). 4 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Lenticular (S0) Galaxies: NGC 3115: S0-galaxy NGC 4371: SB0-galaxy 5 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Spiral (Sa) Galaxies: M 104 (Sombrero), Sa-galaxy NGC 3223: Sa-galaxy (P.Barthel, VLT) 6 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Spiral (Sb) Galaxies: M 31 (Andromeda): Sb-galaxy M 81: Sb-galaxy 7 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Spiral (Sc) Galaxies: M 51: Sc-galaxy M 101: Sc-galaxy courtesy: C. Gossl,¨ Wendelstein Observatory, USM courtesy: C. Gossl,¨ Wendelstein Observatory, USM 8 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Barred-Spiral (SBa) Galaxies: M 83 (Southern Pinwheel): SBa-galaxy 9 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Barred-Spiral (SBb) Galaxies: NGC 2523: SBb-galaxy M 95: SBb-galaxy 10 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Barred-Spiral (SBc) Galaxies: NGC 613: SBc-galaxy NGC 1365: SBc-galaxy 11 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Irregular (Irr) Galaxies: LMC: Irr-galaxy SMC: Irr-galaxy 12 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Milkyway, Sbc galaxy (all-sky projection in optical) 13 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Milkyway, Sbc-galaxy (all sky projection in near IR, COBE satellite) 14 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Luminosities of Bulges and Disks bulge luminosity γ = total luminosity Yoshizawa, Wakamatsu A&A 44, 363 (1975) the Hubble sequence is primarily a bulge sequence ! 15 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE 1.2 Important other galaxy types not contained in the Hubble- Sandage system: dwarf galaxies: dE: dwarf ellipticals or dwarf spheroidals, similar to E but of low luminosity and low surface brightness BCD: Blue Compact Dwarfs, concentrated starburst, faint old stellar components cD-galaxies: Yerkes classification for “extra (c) large and diffuse (D)” galaxies, found in the centers of clusters and groups low surface brightness (LSB) galaxies: mostly luminous but very low surface brightness disk galaxies active galaxies: radio galaxies; galaxies with unusual nuclear emission lines and/or extreme nuclear luminosity (QuasiStellarObjects-QSOs, Seyfert galaxies) and/or with powerful non-thermal radio emission (radio galaxies, quasars) interacting, merging and starbursting galaxies (IRAS mergers, ULIRGs, i.e. Ultra- Luminous Infra-Red Galaxies) 16 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Dwarf galaxies Leo 1 (MV = 12), dwarf elliptical (dwarf spheroidal) companion of Milky Way − 17 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE NGC 205 (MV = 16:3), dwarf elliptical companion of M31 (NOAO) − 18 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Blue Compact Dwarf (BCD) NGC 1705, blue: blue continuum, green: red continuum, red: Hα (G. Meurer) 19 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Active galaxies NGC 7742, a Seyfert galaxy 20 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE NGC 383 (= 3C31), a radio galaxy, blue: optical, red: radio (A. Bridle) 21 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE The currently most distant object known, a quasar at redshift 5.8 (April 2000, Sloan Digitial Sky Survey) 22 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Interacting, merging and starbursting galaxies Interacting galaxy pair. Note that spiral disks are not optically thick! 23 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Cartwheel galaxy 24 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Antenna galaxies 25 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE M 82, a starburst galaxy, white/brown: stellar light and dust, red: hot expanding gas in Hα (Subaru telescope) 26 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Various evolutionary steps of spiral-spiral mergers 27 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Luminosity and surface brightness bias see: Mihalas / Binney: Galactic Astronomy 28 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Galaxies at non-optical wavelengths Spirals in ultraviolett (dominated by massive stars) and visual (average population), Ultraviolet Imaging Telescope, Astro mission. Note: Redshifted spirals observed in the optical will show rest-frame UV morphology! 29 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Dwarf irregular NGC 2915 yellow: optical blue: HI 30 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE optical M81-group HI 31 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE NGC 2300 group (black&white = optical, blue/pink = X-rays) 32 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Milkyway (Sbc-galaxy) in different wavebands 33 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE 1.3 Luminosity Functions of Galaxies Schechter (ApJ 203, p297, 1976) proposed a global fitting function for all galaxies (indi- vidual types do not follow the Schechter-function) L L α L Φ = Φ exp − L ∗ L L ∗ ∗ ∗ typical values (averaged over large volumes) 10 2 LB; 10 LB; h− ∗ ' or: MB; 19:5 + 5 log h ∗ ' − 3 3 Φ 0:01Mpc− h ∗ ' α 1 1:3 (see Peebles 1993) ' − · · · − H0 L with: h = and MB = 2:5 log + 5:48 100km=s LB; Mpc − 34 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Galaxy luminosity function in the Virgo cluster (Binggeli et al. (1985), AJ 90, 1759 35 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Φ L dL is the number density of galaxies with luminosities in the range (L; L + dL) L (strong∗ variation of Φ depending on environment) ∗ averaged luminosity per volume: 1 L L j = Z L Φ d = Γ(α + 2)Φ L L L ∗ ∗ 0 ∗ ∗ 8 L j 10 ) ' Mpc3 M 9 M Using 10 yields a mass density of ρ 10 3 Ω 0:004 L ' ∗ ' Mpc ) ∗ ' 36 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE see: Thomas: ESO Astrophysics Symposia (1999) 37 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Luminosity Function Φ(M) versus Absolute Blue Magnitude MBT Binggeli, Sandage, Tammann: ARAA 26 (1988) 38 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE 1.4 Basic Components of Galaxies Spheroid (bulge): metal poor to super metal rich, generally old stars; surface brighness profile I(r) follows roughly a de Vaucouleurs law: 0:25 3:33((r=re) 1) I = Ie10− − re = half light radius − Disk: metal rich stars, strong rotation, stars show a wide range of ages, Sa and later types show star formation, HI, H2-gas, molecular clouds, dust, hot gas (heating by star formation and supernovae); surface brighness profile I(r) follows exponential law: r=ro I = Ioe− ro = disk scale length − Baryonic halo: metal poor stars with little/no rotation and a wide variety of orbits (only detected in Milky Way); globular clusters, X-ray gas (prominent in ellipticals), low density HI/HII-gas Dark halo: dominating mass outside of 10kpc, total mass in dark matter 5 to 10 times larger than baryonic mass, dark halo (maybe) slightly flattened 39 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE 1.5 Kinematics of Spirals, Tully-Fisher-Relation Rotation curves of spiral galaxies are flat, because of dark matter. see: van Albada et al. ApJ 295, 305 (1985) 2 2 2 2 @Φ Φ = Φhalo + Φdisc v = v + v (v = r ) ) c c;halo c;disc c @r 40 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE The circular speeds vcirc of spiral galaxies are closely correlated with their luminosities (Tully-Fisher-relation (1977, A&A 54, 661)): L v3:::4 ∼ (The power depends on the wavelength of L, because of changing M=L, star formation etc.) From the virial theorem, v2 M , and the identity L Σr2 one obtains: ∼ r ∼ 2 M − 4 1 L v Σ− ∼ L 2 M − 1 Evidently, the observed Tully-Fisher relation implies: L Σ− const. Indeed, most · ' M bright spirals have similar mass-to-light ratios and surface brightnesses: L const and Σ const (the latter is called the “Freeman law”). ∼ ∼ Dwarf spirals and irregulars deviate from the Tully-Fisher relation because their bary- onic densities are lower and dark matter contributes significantly to the mass within the luminous part of the galaxies. The Tully-Fisher relation is an important distance indicator at low redshifts (z < 0:1) and can serve as an indicator for spiral galaxy evolution at higher redshifts. 41 CHAPTER 1. INVENTORY OF THE LOCAL UNIVERSE Tully-Fisher relation top: local calibrators middle: Ursa major cluster bottom: Virgo cluster i WR = 2vcirc vcirc can be deduced from HI observations; correction for incli- nation from flattening of optical image.
Load more

Recommended publications
  • Disk Mass and Disk Heating in the Spiral Galaxy NGC 3223?
    A&A 576, A57 (2015) Astronomy DOI: 10.1051/0004-6361/201425279 & c ESO 2015 Astrophysics Disk mass and disk heating in the spiral galaxy NGC 3223? G. Gentile1;2, C. Tydtgat1;3, M. Baes1, G. De Geyter1, M. Koleva1, G. W. Angus2, W. J. G. de Blok4;5;6, W. Saftly1, and S. Viaene1 1 Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281, 9000 Gent, Belgium e-mail: [email protected] 2 Department of Physics and Astrophysics, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium 3 Department of Solid State Sciences, Krijgslaan 281, 9000 Gent, Belgium 4 Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo, The Netherlands 5 Astrophysics, Cosmology and Gravity Centre, Department of Astronomy, University of Cape Town, Private Bag X3, 7701 Rondebosch, South Africa 6 Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen, The Netherlands Received 5 November 2014 / Accepted 11 February 2015 ABSTRACT We present the stellar and gaseous kinematics of an Sb galaxy, NGC 3223, with the aim of determining the vertical and radial stellar velocity dispersion as a function of radius, which can help to constrain disk heating theories. Together with the observed NIR photometry, the vertical velocity dispersion is also used to determine the stellar mass-to-light (M=L) ratio, typically one of the largest uncertainties when deriving the dark matter distribution from the observed rotation curve. We find a vertical-to-radial velocity dispersion ratio of σz/σR = 1:21 ± 0:14, significantly higher than expectations from known correlations, and a weakly-constrained Ks-band stellar M=L ratio in the range 0.5–1.7, which is at the high end of (but consistent with) the predictions of stellar population synthesis models.
    [Show full text]
  • Dark Energy and Extending the Geodesic Equations of Motion: Connecting the Galactic and Cosmological Length Scales
    General Relativity and Gravitation (2011) DOI 10.1007/s10714-010-1043-z RESEARCHARTICLE A. D. Speliotopoulos Dark energy and extending the geodesic equations of motion: connecting the galactic and cosmological length scales Received: 23 May 2010 / Accepted: 16 June 2010 c The Author(s) 2010 Abstract Recently, an extension of the geodesic equations of motion using the Dark Energy length scale was proposed. Here, we apply this extension to analyz- ing the motion of test particles at the galactic scale and longer. A cosmological check of the extension is made using the observed rotational velocity curves and core sizes of 1,393 spiral galaxies. We derive the density profile of a model galaxy using this extension, and with it, we calculate σ8 to be 0.73±0.12; this is within +0.049 experimental error of the WMAP value of 0.761−0.048. We then calculate R200 to be 206±53 kpc, which is in reasonable agreement with observations. Keywords Dark energy, Galactic density profile, Density fluctuations, Extensions of the geodesic equations of motion, Galactic rotation curves 1 Introduction In a previous paper [1], we constructed an extension of the geodesic equations of motion (GEOM). This construction is possible because with the discovery of +0.82 −30 3 Dark Energy, ΛDE = (7.21−0.84) × 10 g/cm [2; 3; 4], there is now a length 1/2 scale, λDE = c/(ΛDEG) , associated with the universe. As this length scale is also not associated with the mass of any known particle, this extension does not violate various statements of the equivalence principle.
    [Show full text]
  • Nuclear Activity in Circumnuclear Ring Galaxies
    International Journal of Astronomy and Astrophysics, 2016, 6, 219-235 Published Online September 2016 in SciRes. http://www.scirp.org/journal/ijaa http://dx.doi.org/10.4236/ijaa.2016.63018 Nuclear Activity in Circumnuclear Ring Galaxies María P. Agüero1, Rubén J. Díaz2,3, Horacio Dottori4 1Observatorio Astronómico de Córdoba, UNCand CONICET, Córdoba, Argentina 2ICATE, CONICET, San Juan, Argentina 3Gemini Observatory, La Serena, Chile 4Instituto de Física, UFRGS, Porto Alegre, Brazil Received 23 May 2016; accepted 26 July 2016; published 29 July 2016 Copyright © 2016 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract We have analyzed the frequency and properties of the nuclear activity in a sample of galaxies with circumnuclear rings and spirals (CNRs), compiled from published data. From the properties of this sample a typical circumnuclear ring can be characterized as having a median radius of 0.7 kpc (mean 0.8 kpc, rms 0.4 kpc), located at a spiral Sa/Sb galaxy (75% of the hosts), with a bar (44% weak, 37% strong bars). The sample includes 73 emission line rings, 12 dust rings and 9 stellar rings. The sample was compared with a carefully matched control sample of galaxies with very similar global properties but without detected circumnuclear rings. We discuss the relevance of the results in regard to the AGN feeding processes and present the following results: 1) bright companion galaxies seem
    [Show full text]
  • 190 Index of Names
    Index of names Ancora Leonis 389 NGC 3664, Arp 005 Andriscus Centauri 879 IC 3290 Anemodes Ceti 85 NGC 0864 Name CMG Identification Angelica Canum Venaticorum 659 NGC 5377 Accola Leonis 367 NGC 3489 Angulatus Ursae Majoris 247 NGC 2654 Acer Leonis 411 NGC 3832 Angulosus Virginis 450 NGC 4123, Mrk 1466 Acritobrachius Camelopardalis 833 IC 0356, Arp 213 Angusticlavia Ceti 102 NGC 1032 Actenista Apodis 891 IC 4633 Anomalus Piscis 804 NGC 7603, Arp 092, Mrk 0530 Actuosus Arietis 95 NGC 0972 Ansatus Antliae 303 NGC 3084 Aculeatus Canum Venaticorum 460 NGC 4183 Antarctica Mensae 865 IC 2051 Aculeus Piscium 9 NGC 0100 Antenna Australis Corvi 437 NGC 4039, Caldwell 61, Antennae, Arp 244 Acutifolium Canum Venaticorum 650 NGC 5297 Antenna Borealis Corvi 436 NGC 4038, Caldwell 60, Antennae, Arp 244 Adelus Ursae Majoris 668 NGC 5473 Anthemodes Cassiopeiae 34 NGC 0278 Adversus Comae Berenices 484 NGC 4298 Anticampe Centauri 550 NGC 4622 Aeluropus Lyncis 231 NGC 2445, Arp 143 Antirrhopus Virginis 532 NGC 4550 Aeola Canum Venaticorum 469 NGC 4220 Anulifera Carinae 226 NGC 2381 Aequanimus Draconis 705 NGC 5905 Anulus Grahamianus Volantis 955 ESO 034-IG011, AM0644-741, Graham's Ring Aequilibrata Eridani 122 NGC 1172 Aphenges Virginis 654 NGC 5334, IC 4338 Affinis Canum Venaticorum 449 NGC 4111 Apostrophus Fornac 159 NGC 1406 Agiton Aquarii 812 NGC 7721 Aquilops Gruis 911 IC 5267 Aglaea Comae Berenices 489 NGC 4314 Araneosus Camelopardalis 223 NGC 2336 Agrius Virginis 975 MCG -01-30-033, Arp 248, Wild's Triplet Aratrum Leonis 323 NGC 3239, Arp 263 Ahenea
    [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]
  • Ngc Catalogue Ngc Catalogue
    NGC CATALOGUE NGC CATALOGUE 1 NGC CATALOGUE Object # Common Name Type Constellation Magnitude RA Dec NGC 1 - Galaxy Pegasus 12.9 00:07:16 27:42:32 NGC 2 - Galaxy Pegasus 14.2 00:07:17 27:40:43 NGC 3 - Galaxy Pisces 13.3 00:07:17 08:18:05 NGC 4 - Galaxy Pisces 15.8 00:07:24 08:22:26 NGC 5 - Galaxy Andromeda 13.3 00:07:49 35:21:46 NGC 6 NGC 20 Galaxy Andromeda 13.1 00:09:33 33:18:32 NGC 7 - Galaxy Sculptor 13.9 00:08:21 -29:54:59 NGC 8 - Double Star Pegasus - 00:08:45 23:50:19 NGC 9 - Galaxy Pegasus 13.5 00:08:54 23:49:04 NGC 10 - Galaxy Sculptor 12.5 00:08:34 -33:51:28 NGC 11 - Galaxy Andromeda 13.7 00:08:42 37:26:53 NGC 12 - Galaxy Pisces 13.1 00:08:45 04:36:44 NGC 13 - Galaxy Andromeda 13.2 00:08:48 33:25:59 NGC 14 - Galaxy Pegasus 12.1 00:08:46 15:48:57 NGC 15 - Galaxy Pegasus 13.8 00:09:02 21:37:30 NGC 16 - Galaxy Pegasus 12.0 00:09:04 27:43:48 NGC 17 NGC 34 Galaxy Cetus 14.4 00:11:07 -12:06:28 NGC 18 - Double Star Pegasus - 00:09:23 27:43:56 NGC 19 - Galaxy Andromeda 13.3 00:10:41 32:58:58 NGC 20 See NGC 6 Galaxy Andromeda 13.1 00:09:33 33:18:32 NGC 21 NGC 29 Galaxy Andromeda 12.7 00:10:47 33:21:07 NGC 22 - Galaxy Pegasus 13.6 00:09:48 27:49:58 NGC 23 - Galaxy Pegasus 12.0 00:09:53 25:55:26 NGC 24 - Galaxy Sculptor 11.6 00:09:56 -24:57:52 NGC 25 - Galaxy Phoenix 13.0 00:09:59 -57:01:13 NGC 26 - Galaxy Pegasus 12.9 00:10:26 25:49:56 NGC 27 - Galaxy Andromeda 13.5 00:10:33 28:59:49 NGC 28 - Galaxy Phoenix 13.8 00:10:25 -56:59:20 NGC 29 See NGC 21 Galaxy Andromeda 12.7 00:10:47 33:21:07 NGC 30 - Double Star Pegasus - 00:10:51 21:58:39
    [Show full text]
  • ¼¼Çwªâðw¦¹Á¼ºëw£Àêëw ˆ†‰€ «ÆÊ¿Àäàww«¸ÂÀ ‰‡‡Œ†ˆ‰†‰Œ
    ¼¼ÇwªÂÐw¦¹Á¼ºËw£ÀÊËw II - C ll r l 400 e e l G C k i 200 r he Dec. P.A. w R.A. Size Size Chart N a he ss d l Object Type Con. Mag. Class t NGC Description l AS o o sc e s r ( h m ) max min No. C a ( ' ) ( ) sc R AAS e r e M C T e B H H x x NGC 3511 GALXY CRT 11 03.4 -23 05 11 6 m 2.1 m 76 SBc vF,vL,mE 98 x x NGC 3513 GALXY CRT 11 03.8 -23 15 11.5 2.9 m 2.4 m 75 SBb vF,vL,mE 98 IC 2627 GALXY CRT 11 09.9 -23 44 12 2.6 m 2.1 m SBbc eF,L,R,stell N 98 NGC 3573 GALXY CEN 11 11.3 -36 53 12.3 3.6 m 1 m 4 Sa eF,S,R,glbM,3 st 11 f 98 NGC 3571 GALXY CRT 11 11.5 -18 17 12.1 3 m 0.9 m 94 SBa pF,pL,iF,bM 98 B,pL,E,vsmbMN,2 B st x NGC 3585 GALXY HYA 11 13.3 -26 45 9.9 5.2 m 3.1 m 107 Elliptical 98 tri NGC 3606 GALXY HYA 11 16.3 -33 50 12.4 1.5 m 1.4 m Elliptical eF,S,R,gbM 98 x x x NGC 3621 GALXY HYA 11 18.3 -32 49 9.7 12.4 m 5.7 m 159 SBcd cB,vL,E 160,am 4 st 98 NGC 3673 GALXY HYA 11 25.2 -26 44 11.5 3.7 m 2.4 m 70 SBb F,vL,gvlbM,*7 s 6' 98 PK 283+25.1 PLNNB HYA 11 26.7 -34 22 12.1 188 s 174 s 98 x NGC 3693 GALXY CRT 11 28.2 -13 12 13 3.4 m 0.7 m 85 Sb cF,S,E,gbM 98 NGC 3706 GALXY CEN 11 29.7 -36 24 11.3 3.1 m 1.8 m 78 E-SO pB,cS,R,psmbM 98 NGC 3717 GALXY HYA 11 31.5 -30 19 11.2 6.2 m 1 m 33 Sb pB,S,mE,*13 att 98 «ÆÊ¿ÀÄÀww«¸ÂÀ ¼¼ÇwªÂÐw¦¹Á¼ºËw£ÀÊËw II - C ll r l 400 e e l G C k i 200 r he Dec.
    [Show full text]
  • Galaxy Groups and Clouds in the Local (Z~ 0.01) Universe
    Mon. Not. R. Astron. Soc. 000, 1–26 (XXX) Printed 5 June 2018 (MN LATEX style file v2.2) Galaxy groups and clouds in the Local (z ∼ 0.01) universe Dmitry Makarov1,2,3⋆, Igor Karachentsev1,2 1Special Astrophysical Observatory, Nizhniy Arkhyz, Karachai-Cherkessia 369167, Russia 2Universit´ede Lyon, Universit´eLyon 1, CNRS/IN2P3, Institut de Physique Nucl´eaire de Lyon, Villeurbanne, France 3Isaac Newton Institute of Chile, SAO Branch, Russia Accepted 2010 November 23. Received 2010 November 23; in original form 2010 August 01 ABSTRACT We present an all-sky catalogue of 395 nearby galaxy groups revealed in the Local Supercluster and its surroundings. The groups and their associations are identified ◦ −1 among 10914 galaxies at |b| > 15 with radial velocities VLG < 3500 km s . Our group finding algorithm requires the group members to be located inside their zero- velocity surface. Hereby, we assume that individual galaxy masses are proportional to their total K-band luminosities, M/LK =6 M⊙/L⊙. The sample of our groups, where each group has n > 4 members, is characterized by the following medians: mean projected radius hRi = 268 kpc, radial velocity dis- −1 11 persion σV =74 km s , K-band luminosity LK =1.210 L⊙, virial and projected 12 12 masses Mvir =2.410 and Mp =3.310 M⊙, respectively. Accounting for measure- ment error reduces the median masses by 30 per cent. For 97 per cent of identified groups the crossing time does not exceed the cosmic time, 13.7 Gyr, having the median at 3.8 Gyr. We examine different properties of the groups, in particular, of the known nearby groups and clusters in Virgo and Fornax.
    [Show full text]
  • The Star Formation History of Seyfert 2 Nuclei
    Mon. Not. R. Astron. Soc. 355, 273Ð296 (2004) doi:10.1111/j.1365-2966.2004.08321.x The star formation history of Seyfert 2 nuclei R. Cid Fernandes,1 Q. Gu,2 J. Melnick,3 E. Terlevich,4 R. Terlevich,4 D. Kunth,5 R. Rodrigues Lacerda1 and B. Joguet5 1Departamento de F«õsica, CFM, Universidade Federal de Santa Catarina, PO Box 476, Florianopolis« 88040-900, SC, Brazil 2Department of Astronomy, Nanjing University, Nanjing 210093, China 3European Southern Observatory, Alonso de Cordova 3107, Santiago, Chile 4Instituto Nacional de Astrof`õsica, Optica y Electronica,` Tonantzintla, Puebla, Mexico« 5Institut d’Astrophysique de Paris, 98bis Boulevard Arago, 75014 Paris, France Accepted 2004 August 13. Received 2004 July 25; in original form 2004 February 16 ABSTRACT We present a study of the stellar populations in the central ∼200 pc of a large and homogeneous sample comprising 79 nearby galaxies, most of which are Seyfert 2s. The star formation history of these nuclei is reconstructed by means of state-of-the-art population synthesis modelling of their spectra in the 3500Ð5200 Å interval. A quasar-like featureless continuum (FC) is added to the models to account for possible scattered light from a hidden active galactic nucleus (AGN). We find the following. (1) The star formation history of Seyfert 2 nuclei is remarkably heterogeneous: young starbursts, intermediate-age and old stellar populations all appear in significant and widely varying proportions. (2) A significant fraction of the nuclei show a strong FC component, but this FC is not always an indication of a hidden AGN: it can also betray the presence of a young, dusty starburst.
    [Show full text]
  • Constraining Dark Matter Halo Profiles and Galaxy Formation Models Using Spiral Arm Morphology
    The Astrophysical Journal, 645:1012–1023, 2006 July 10 # 2006. The American Astronomical Society. All rights reserved. Printed in U.S.A. CONSTRAINING DARK MATTER HALO PROFILES AND GALAXY FORMATION MODELS USING SPIRAL ARM MORPHOLOGY. I. METHOD OUTLINE Marc S. Seigar,1 James S. Bullock,1 Aaron J. Barth,1 and Luis C. Ho2 Received 2006 January 9; accepted 2006 March 22 ABSTRACT We investigate the use of spiral arm pitch angles as a probe of disk galaxy mass profiles. We confirm our previous result that spiral arm pitch angles (P) are well correlated with the rate of shear (S ) in disk galaxy rotation curves by using a much larger sample (51 galaxies) than used previously (17 galaxies). We use this correlation to argue that imaging data alone can provide a powerful probe of galactic mass distributions out to large look-back times. In contrast to previous work, we show that observed spiral arm pitch angles are similar when measured in the optical (at 0.4 m) and the near-infrared (at 2.1 m) with a mean difference of 2N3 Æ 2N7. This is then used to strengthen the known correlation between P and S using B-band images. We then use two example galaxies to demonstrate how an inferred shear rate coupled with a bulge-disk decomposition model and a Tully-Fisher–derived velocity normali- zation can be used to place constraints on a galaxy’s baryon fraction and dark matter halo profile. We show that ESO 582-G12, a galaxy with a high shear rate (slightly declining rotation curve) at 10 kpc, favors an adiabatically contracted halo, with high initial NFW concentration (cvir > 16) and a high fraction of halo baryons in the form of stars (15%–40%).
    [Show full text]
  • Andromeda - Daughter of Cassiopeia
    May 18 2021 Andromeda - Daughter of Cassiopeia Observed: No Object Her Type Mag Alias/Notes IC 5372 Non-Existent IC 1530 Non-Existent NGC 19 Non-Existent NGC 44 Non-Existent NGC 6 Non-Existent NGC 67A Non-Existent IC 1539 Non-Existent NGC 70 NGC 82 Non-Existent NGC 85B Non-Existent NGC 537 Non-Existent IC 1665 Non-Existent Single Star NGC 317 Non-Existent IC 1580 Non-Existent Single Star NGC 162 Non-Existent STAR IC 24 Non-Existent Single Star NGC 90 Non-Existent IC 1547 Non-Existent NGC 85A Non-Existent IC 240 Non-Existent NGC 999 NGC 846 Non-Existent NGC 847 IC 1737 Non-Existent IC 1707 Non-Existent IC 1545 Non-Existent IC 1538 Non-Existent Sub Total: 24 Observed: Yes Object Her Type Mag Alias/Notes C 410 Nebula 16 Cluster+Nebula in M31 Close to G280 G 87 Globular 15.6 IC 1541 Glxy 15.5 CGCG 478-55 PGC 1287 IC 1540 Glxy SBb 14.9 UGC 186 MCG 4-1-50 CGCG 478-54 PGC 1276 IC 1536 Glxy E/S0 15.4 MCG 8-1-32 MK 939 CGCG 549-28 PGC 949 IC 1535 Glxy S 15.1 UGC 131 MCG 8-1-30 CGCG 549-26 PGC 922 IC 1534 Glxy S0 14.8 UGC 125 MCG 8-1-28 CGCG 549-25 5ZW6 PGC 910 IC 1525 Glxy SBb 13 UGC 12883 MCG 8-1-16 CGCG 548-20 CGCG 549-11 IRAS 23567+4636 PGC 73150 IC 239 Glxy SAB(rs)cd 11.8 UGC 2080 MCG 6-6-65 CGCG 523-71 IRAS 2333+3845 PGC 9899 IC 179 Glxy E 13.6 UGC 1475 MCG 6-5-75 CGCG 522-101 PGC 7581 IC 178 Glxy Sab 14.1 UGC 1456 MCG 6-5-70 CGCG 522-94 IRAS 1559+3625 PGC 7488 IC 65 Glxy SAB(s)bc 13.6 UGC 625 MCG 8-3-5 CGCG 551-4 IRAS 580+4724 PGC 3635 IC 46 Glxy S0? 14.8 CGCG 479-63 KARA32 PGC 2575 IC 45 Glxy Pec 15.4 UGC 449 MCG 5-2-39 CGCG 500-73 PGC 2537
    [Show full text]
  • Dark and Luminous Matter in Bright Spiral Galaxies
    Dark and Luminous Matter in Bright Spiral Galaxies DISSERTATION Presented in Partial Ful¯llment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Susan Alice Joan Kassin ***** The Ohio State University 2004 Dissertation Committee: Approved by Professor Richard Pogge, Adviser Professor Bradley Peterson Adviser Astronomy Graduate Program Professor Christopher Kochanek Professor Jay Frogel ABSTRACT I present photometrically calibrated images and surface photometry in the B; V; R; J; H; and K-bands of 26, and in the g, r, and K-bands of 5 nearby bright o (BT < 12:5 mag) spiral galaxies with inclinations between 30{65 degrees spanning the Hubble Sequence from Sa to Scd. Data are from The Ohio State University Bright Spiral Galaxy Survey, the Two Micron All Sky Survey, and the Sloan Digital Sky Survey Second Data Release. Radial surface brightness pro¯les are extracted, and integrated magnitudes are measured from the pro¯les. Axis ratios, position angles, and scale lengths are measured from the near-infrared. A 1-dimensional bulge/disk decomposition is performed on galaxies with a non-negligable bulge component. Radial stellar mass distributions are estimated by applying color-M=L relations derived from spectrophotometric spiral galaxy evolution models to the photometry. When available, radial gas masses are added to the radial stellar mass distributions to produce radial baryonic mass distributions. For each galaxy, a rotation curve due to its radial baryonic mass distribution is calculated, taking into account both the bulge and disk components when necessary. All of the galaxies have high-quality ii rotation curves available in the literature which allows us to calculate radial dark matter distributions for each galaxy by comparison with the baryonic mass rotation curves.
    [Show full text]