The Globular Group Frameworks of Ellipticals and Spirals.


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The Globular Group Frameworks of Ellipticals and Spirals Duncan A. Forbes Place for Astronomy and Supercomputing, Swinburne College Partners Jean Brodie (Lick Observatory) Carl Grillmair (JPL/SIRTF) John Huchra (Harvard-Smithsonian) Markus Kissler-Patig (ESO)
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The Globular Cluster Systems of Ellipticals and Spirals Duncan A. Forbes Center for Astrophysics & Supercomputing, Swinburne University

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Collaborators Jean Brodie (Lick Observatory) Carl Grillmair (JPL/SIRTF) John Huchra (Harvard-Smithsonian) Markus Kissler-Patig (ESO) Soeren Larsen (Lick Observatory)

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Milky Way Bulge Clusters The inward metal-rich GCs are: roundly circulated comparable metallicity to lump stars comparative speed scattering to lump stars take after the lump pivot  Bulge GCs (Minniti 1995). A comparable circumstance exists for M31

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Milky Way Globular Cluster System 4 sub-populaces: Metal-rich (~50) Bulge (R GC < 5 kpc) Thick plate (R GC > 5 kpc) Metal-poor (~100) Old Halo (prograde) Young Halo (retrograde) Young radiance + 4 Sgr smaller person GCs = Sandage clamor

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Metallicities Number of metal-rich GCs scale with the lump Forbes, Larsen & Brodie 2001

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Spiral versus Elliptical GC Systems Numbers, S N Luminosities Metallicities Abundances Sizes Ages Kinematics Spatial Distribution

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 = 0.2% Number for each unit Starlight McLaughlin (1999) proposed an all inclusive GC arrangement effectiveness  = M GC/M gas + M stars = 0.26 % M gas = current Xray gas mass

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 = 0.1% Blue Globular Clusters for each unit Starlight Halo GCs in the MW, M31 and M104 take after the general pattern.

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 = 0.1% Red Globular Clusters for every unit Starlight Bulge GCs in the MW, M31 and M104 take after the general pattern.

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The Elliptical Galaxy Formally Known as The Local Group Merging the Local Group globular bunches N = 700 +/ - 125 M V (matured) = – 20.9 S N = 3.0 +/ - 0.5 Universal iridescence capacity

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Luminosities A Universal Globular Cluster Luminosity Function M V  Ellipticals –7.33 +/ - 0.04 1.36 +/ - 0.03 Spirals –7.46 +/ - 0.08 1.21 +/ - 0.05 Even better assention if blue GCLF utilized ? Ho = 74 +/ - 7 km/s/Mpc GCLF Ho = 72 +/ - 8 km/s/Mpc HST Key Project Harris 2000

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Metallicities Previously …... Harris 2000

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Metallicities Recent improvements Use of Schlegel etal 1998 instead of Burstein & Heiles 1984. ( commonly bluer by  A V = 0.1 ) Use of Kissler-Patig etal 1998 for V-I  [Fe/H] in view of Keck spectra of NGC 1399. ( red GCs more metal-poor by 0.5 dex )

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Metallicities All huge cosmic systems (with lumps) uncover a comparable bimodal metallicity dispersion. All universes ( M V < –15 ), uncover a populace of GCs with [Fe/H] ~ –1.5. The WLM system has one GC, [Fe/H] = –1.52 age = 14.8 Gyrs (Hodge et al. 1999).

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Metallicity versus Galaxy Mass Blue GCs <2.5  V–I ~ mass ? V–I = 0.93 Pregalactic ? Red GCs ~4  V–I ~ mass Forbes, Larsen & Brodie 2001

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Metallicity versus Galaxy Mass Red GC connection has comparable incline to cosmic system shading connection. Red GCs and cosmic system stars shaped in the same star development occasion. Forbes, Larsen & Brodie 2001

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Color - Color Galaxy and GC hues from the same perception. In a few cosmic systems the red GCs and field stars have the same metallicity and age  vaporous development. Additionally NGC 5128 (Harris et al. 1999) Forbes & Forte 2001

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Galaxies Abundances High Resolution [Mg/Fe] = +0.3 Milky Way Low Resolution [Mg/Fe] = 0.0 MW, M31, M81 NGC 1399, NGC 4472 SNII versus SNIa, IMF, SFR ? Terlevich & Forbes 2001

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Sizes For Sp  S0  E  cD the GCs uncover a size–colour pattern. The blue GCs are bigger by ~20%. This pattern exists for a scope of cosmic systems and galactocentric radii . Larsen et al. 2001

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Ages Assume: blue GCs in ellipticals are old (15 Gyrs) and metal-poor ([Fe/H = –1.5) and V–I = 0.2 [Fe/H] Age V–I 15 Gyrs 0.92 –1.5 13 Gyrs 1.12 –0.5  Age = 2 Gyrs, ie like the MW old radiance and lump GCs

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Kinematics In the Milky Way V/ for the lump GCs (0.87) is more prominent than for the corona (0.24). In M49 the metal-rich GCs have V/ not as much as V/ for the metal-poor GCs (Bridges 2001). Need to concentrate more titan ellipticals.

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Spatial Distribution The surface thickness profiles of GC frameworks uncover an internal consistent thickness `core’ with a force law decrease in the external parts. The measure of inward center of the GC framework changes with host system iridescence. Forbes et al. 1996

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Spatial Distribution In Ellipticals: Red GCs are halfway focused, frequently have comparative azimuthal and thickness profiles (and shading) to the `bulge’ light. Blue GCs are more developed. Connected with the corona ? (Does the blue GC thickness profile take after the X-beam gas profile ?) Blue Red Ellipticals Halo `Bulge’ Disk ? Spirals Halo Bulge Disk

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Spiral versus Elliptical GC Systems Numbers, S N Luminosities Metallicities Abundances Sizes Ages Kinematics Spatial Distribution

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Formation Timeline Blue GCs structure in metal-poor gas with next to zero learning of potential well. Radiance development. Regular to all cosmic systems. 15 Gyrs Clumpy breakdown of generally vaporous parts structure metal-rich red GCs and `bulge’ stars. Synchronous star arrangement occasion. 13 Gyrs Field mergers of Sp + Sp  E, with S N ~ 3. Presently Time

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Conclusion The blue (metal-poor) and red (metal-rich) GCs seen in Ellipticals, Spirals and Dwarf Galaxies are basically the same thing. Seyfert 1 versus Seyfert 2

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