Distribution of Galaxies 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 Astronomía Extragaláctica y Cosmología Observacional Depto. de Astronomía (UGto)

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

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

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

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

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]

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 Venati dwarves (stellar overdensity on SDSS data) [Belokurov et al. 2006, ApJ 647, L111; y Zucker et al. 2006a, ApJ 643, 103]

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

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-G115 05 23 35.0 –69 45 22 SBm -18.5 49 650 x 550 –0.6 7. SMC NGC 292 00 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-G030 01 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-G220 06 41 37.0 –50 57 58 dSph(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-G004 02 39 59.0 –34 26 57 dSph(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

The Local Universe: the Andromeda system NGC 185 NGC 147

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

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

The Local Universe: The Local Group of Galaxies

The Local Universe: The Local Group of Galaxies

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

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  1012 M 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  1012 M and tcol = tH ≈ 14 Ga RLG  1.2 Mpc

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

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

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

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

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

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]

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

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

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

z = λo – λe = H0  d λe c  600 Mpc

 4 Gpc The “Observable Universe”

Age of the Universe Quasars