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Astronomía Extragaláctica y Cosmología Observacional

Depto. de Astronomía (UGto). Astronomía Extragaláctica y Cosmología Observacional. Lecture 3 Distribution of Galaxies. The Local Universe the Milky-Way system the Andromeda system the Local Group of Galaxies the Local Supercluster the nearby superclusters.

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Astronomía Extragaláctica y Cosmología Observacional

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  1. Depto. de Astronomía (UGto) Astronomía Extragaláctica y Cosmología Observacional Lecture 3 Distribution of Galaxies • The Local Universe • the Milky-Way system • the Andromeda system • the Local Group of Galaxies • the Local Supercluster • the nearby superclusters

  2. The Local Universe: Distribution of Galaxies • Small scale: • Galaxies are not distributed at random • Concentrations of galaxies may be groups, clusters, superclusters or filaments • Regions with the lowest densities of galaxies are called voids Distribution of 14650 galaxies of the catalogs UGC, ESO and MCG http://www.eso.org/~mhilker/Gallery/gallery_lect.html

  3. The Local Universe: Distribution of Galaxies Milky-Way Distribution of 1 600 000 galaxies from 2MASS catalog

  4. Dwarf satellites Globular Clusters (R > 20 kpc) • The Local Universe: the Milky-Way system [Faber & Gallagher 1979, ARAA 17, 135*] [W. Harris 1999, in Globular Clusters*]

  5. For dSph LeoI dSph Scl dSph Car dSph LeoII dSph Dra dSph Phe dIrr UMi dSph Sex dSph • The Local Universe: the Milky-Way and its satellites Milky Way (2MASS) SMC LMC

  6. The Local Universe: the Milky-Way and its closest satellites Sag DEG CMa dwarf • Sagitarius DEG (found by stellar • brightness density investigations) [R. Ibata, G. Gilmore & M. Irwin 1994, Nature 370, 6486] • Canis Majoris dwarf (found in • 2MASS data – asymetries in red • giant population) [Martin et al. 2004, MNRAS 348, 12]

  7. The Local Universe: the Milky-Way and its closest satellites UMa dw • Ursa Majoris dwarf (overdensity of red stars in the SDSS) Boo dw CVn dw [Willman et al. 2005, ApJ 626, 85] • Bootes & Canis Venatidwarves • (stellar overdensity on SDSS data) [Belokurov et al. 2006, ApJ 647, L111; y Zucker et al. 2006a, ApJ 643, 103]

  8. The Local Universe: the Milky-Way and its closest satellites • UMa II dwarf • (found on SDSS data, Subaru) [Zucker et al. 2006b, ApJ 650, L41] • Leo T dwarf (transition) • (found on SDSS data, INT) [Irwin et al. 2007, ApJ 656, L13] Leo T dw

  9. The Local Universe: the Milky-Way system • Galaxy Alias Position (J2000.0) Type MV D(kpc) Size(’) [Fe/H] • Milky Way 17 45 39.9 –29 00 28 S(B)bc -20.9 8.5 21600 • 1. CMa dwarf1--- 07 15 –28 Irr(p) -14.0 8 720 • 2. Vir SS2--- 12 24 +00 Irr(p) 9 30 x 10 –1.9 • 3. Sag DEG3--- 18 55 03.0 –30 28 42 dSph(7p) -13.8 24 450 x 216 –0.5/–1.0 • 4. UMa II4 --- 08 51 30.0 +63 07 48 dSph(5) -3.8 30 –1.3 • 5. Coma dwarf9 --- 12 26 59.0 +23 54 15 dSph(5) -3.7 44 • 6. LMC ESO 056-G11505 23 35.0 –69 45 22SBm-18.5 49 650 x 550 –0.6 • 7. SMC NGC 29200 52 49.0 –72 49 43 Im -17.1 58 280 x 160 –1.2 • 8. Boo dwarf5 --- 14 00 06.0 +14 30 00 dSph(3p) -5.8 60 13 x 8.7 • 9. UMi dwarf DDO 199 15 09 10.0 +67 12 52 dSph(5) -8.9 69 41 x 26 –1.9/–2.2 • 10. Draco dwarf DDO 208 17 20 12.0 +57 54 55 dSph(3) -8.6 76 51 x 31 –2.0 • 11. Sculptor dwarf ESO 351-G03001 00 09.0 –33 42 33 dSph(3p) -9.8 78 39.8 x 30.9 –1.5/–1.8 • 12. Sextans dwarf --- 10 13 03.0 –01 36 53 dSph(4) -9.5 86 30 x 12 –1.9/–1.7 • 13. Carina dwarf ESO 206-G22006 41 37.0 –50 57 58dSph(4) -9.4 87 3.5 x 15.5 –1.8/–2.0 • 14. UMa dwarf6 --- 10 34 53.0 +51 55 12 dSph -6.8 100 –2.0 • 15. Fornax dwarf ESO 356-G00402 39 59.0 –34 26 57dSph(3) -13.1 131 12 x 10.2 –1.2/–1.3 • 16. Hercules dwarf9 --- 16 31 02.0 +12 47 30 dSph(5) -6.0 140 • 17. CVn II dwarf9 --- 12 57 10.0 +34 19 15 dSph(3) -4.8 150 • 18. Leo IV9 --- 11 32 57.0 –00 32 00 dSph(2) -5.1 160 • 19. CVn dwarf7 --- 13 28 03.5 +33 33 21 dSph(4) -7.9 220 8.4 x 5 • 16. Leo II DDO 93 11 13 29.0 +22 09 17 dSph(0) -10.1 230 12 x 11 –1.6/–1.9 • 17. Leo I Regulus, DDO 74 10 08 27.0 +12 18 27 dSph(3) -11.9 251 9.8 x 7.4 –1.4/–1.5 • 18. Phoenix dwarf ESO 245-G007 01 51 06.0 –44 26 41 dIrr/dSph -9.8 390 4.9 x 4.1 –1.9 • 19. Leo T8 --- 09 34 53.4 +17 03 05 dIrr/dSph -7.1 420 4.2 x 4.2 –1.6 • 3 Ibata et al. 1994, Nature 370, 6486 7 Zucker et al. 2006a, ApJ 643, 103 • 1 Martin et al. 2004, MNRAS 348, 12 4 Zucker et al. 2006b, ApJ 650, L41 • 6 Willman et al. 2005, ApJ 626, 85 9 Belokurov et al. 2007, ApJ 654, 897 • 2 Duffau et al. 2005, ApJ 636, L97 8 Irwin et al. 2007, ApJ 656, L13 • 5 Belokurov et al. 2006, ApJ 647, L111

  10. M33 • The Local Universe: the Andromeda system M32 M31 M110 NGC 185 NGC 147

  11. The Local Universe: the Andromeda system [Van den Bergh 2006, AJ 132, 1571]

  12. The Local Universe: the distant members (?) of the LG Galaxy Alias Position (J2000.0) Type MV D(kpc) Size(’) [Fe/H] Distant satellites 1. N6822 Irr -16.0 0.50 2. LeoA DDO 69 dIrr -11.5 0.69 3. Cetus dwarf dSph -10.1 0.78 4. Tucana dwarf dSph -9.6 0.87 -1.7 5. WLM DDO 221 Irr -14.4 0.95 -1.5 6. Aquarius dwarf DDO 210 Irr -10.9 0.95 7. Sag DIG dIrr -12.0 1.18 8. Gr8 DDO 155 dIrr -10.2 1.20 9. UKS 2323-326 UGCA 438 dIrr Antlia-Sextans Group 10. NGC 3109 Irr 1.30 11. Antlia dSph -10.8 1.30 -1.8 12. Sex A dIrr -14.2 1.30 -1.9 13. Sex B dIrr -13.8 1.30 -1.2

  13. The Local Universe: The Local Group of Galaxies

  14. The Local Universe: The Local Group of Galaxies

  15. The Local Universe: The Local Group of Galaxies [van den Bergh 1999, A&AR 9, 273]

  16. The Local Universe: The Local Group of Galaxies • Virial mass: MLG ≈ (7.5/G) <σ>2 RH = (7.5/G) (61 km/s)2 (350 kpc)  2.3  1012M • Zero-velocity surface radius: • radius beyond which galaxies participate in the Hubble expansion (or distance from which a free-falling body, beginning at rest, would take the age of the Universe to reach the center) [Lynden-Bell 1981, Observatory 101, 111] tcol = ¼ √ (3π / 2Gρ) = ¼ √ (2 π2 R3 / GM)  R3 = (8/ π2) GM tcol2 • considering: MLG = 2.3  1012M and tcol = tH ≈ 14 Ga RLG  1.2 Mpc

  17. The Local Universe: The Local Group of Galaxies [van den Bergh 1999, A&AR 9, 273] [van den Bergh 2000, PASP 112, 529] 

  18. The Local Universe: The vicinity of the LG Antlia- Sextans Maffei Sculptor [Karachentsev et al. 2004, AJ 127, 2031]

  19. The Local Universe: The vicinity of the LG H0 = 72 km s-1 Mpc-1 IC 342 M81 M31 CnV I NGC 253 M83 CenA [Karachentsev et al. 2005, AJ 129, 178] 

  20. The Local Universe: The Local Supercluster • discovery of the Local Supercluster [G. de Vaucouleurs 1953, AJ 58, 30]

  21. The Local Universe: The Local Supercluster [Sparke & Gallagher III, Galaxies in the Universe: an Introduction*] [B. Tully 1982, ApJ 257, 389] 

  22. The Local Universe: Nearby Superclusters • the Coma-Leo Supercluster [Gregory & Thompson 1978, ApJ 222, 784 ] • the Perseus-Pisces Supercluster [Wegner, Haynes & Giovanelli 1993, AJ 105, 1251]

  23. The Local Universe [Fairall 1998, Large Scale Structures in the Universe*]

  24. The Local Universe [M. Hudson 1993, MNRAS 265, 43]

  25. The Local • Universe  300 Mpc http://www.atlasoftheuniverse.com/

  26. z = λo – λe = H0 d λe c  600 Mpc

  27.  4 Gpc The “Observable Universe”

  28. Age of the Universe Quasars

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