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Dimitri Gadotti (Max Planck Institute for Astrophysics – Garching) MAGPOP Network Meeting What can we learn from imaging and spectroscopy of well-resolved galaxies? 1. The BUDDA code: - from bulge/disk decomposition to multi-component decomposition 2. Dating secular evolution: - the ages of bars 3. On bars and haloes: - inferring halo properties from bar properties
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The BUDDA Code (de Souza, Gadotti & dos Anjos 2004) BUlge/Disk Decomposition Analysis (http://www.mpa-garching.mpg.de/~dimitri/budda.html) 2D (Image Fitting) reliable results (de Jong 1995) for galaxies with different components (constraints from PA and ellipticity) discrepancies among 1D fits can be as large as 100% (Baggett, Baggett & Anderson 1998) Bulge (Sérsic 1968) Disk (Freeman 1970) Residual Images (sub-structures) Dimitri Gadotti (MPA – Garching)
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A Structural Analysis of 51 Early-Type Galaxies R-band images Structural parameters Inner disks in ~ 1/3 of Es merger signature (see Burstein et al. 2001) ? direct image residual image NGC 1052 (E4 – Sey2) Dimitri Gadotti (MPA – Garching)
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IC 1459 direct image residual image A Structural Analysis of 51 Early-Type Galaxies Classified as E3 (RC3) but has a disk! It’s an S0! Also a LINER… Wrong morphological classification in ~ 1/3 of Es and S0s Dimitri Gadotti (MPA – Garching)
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NGC 1291 Residual Images and Sub-Structures NGC 2217 NGC 4314 (B band – Steward Obs.) (Gadotti & de Souza 2006) NGC 5850 (Ks – Kitt Peak) (Gadotti & de Souza 2005, 2006) Dimitri Gadotti (MPA – Garching)
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Residual Images and Sub-Structures Dimitri Gadotti (MPA – Garching)
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The New BUDDA: Generalized Ellipses PureBoxy Disky (e.g., Athanassoula et al. 1990) Boxy Es emit strongly in radio/X-ray, are more luminous & massive, and show slow rotation compared to disky Es (e.g., Bender et al. 1989) Different formation histories (Naab & Burkert 2003) ? Dimitri Gadotti (MPA – Garching)
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The New BUDDA: Edge-on Disks van der Kruit & Searle (1981) Dimitri Gadotti (MPA – Garching)
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The New BUDDA: Double Exponential Disks Truncation (Freeman 1970 type II - e.g., Pohlen 2002) Anti-truncation (Erwin, Beckman & Pohlen 2005) Origin: bars, spirals, interactions…??? ? 3-5 h 0 Dimitri Gadotti (MPA – Garching)
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The New BUDDA: Four Components Central Source Moffat (1969) profile: fits better seeing effects (see Trujillo et al. 2001a,b) Bar Sérsic profile n=1: late-type bars n=0.5-1: early-type bars Dimitri Gadotti (MPA – Garching)
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The New BUDDA: Four Components AGN DiskBar Bulge Dimitri Gadotti (MPA – Garching)
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Bars and Secular Evolution Bars are to a large extent shaping the physical properties of galaxies (see Kormendy & Kennicutt 2004) : - creating rings & spirals arms - attenuating metallicity & color gradients - fueling AGN & central star formation - building bulges
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Questions -When did the first bars appear? -How fast bars drive gas to the center? -For how long a bar modifies the evolution of its host galaxy? -What is the fraction of pseudo-bulge stars? -Are bars really recurrent? Dimitri Gadotti (MPA – Garching)
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Estimating the Ages of Bars (see Gadotti & de Souza 2005) y x σzσz - Thin bars ↔ recently-formed; thick bars ↔ evolved - Measure the stellar vertical velocity dispersion Dimitri Gadotti (MPA – Garching)
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Spectroscopy - 14 face-on barred galaxies: Kitt Peak (2.3m) & La Silla (1.5m) - Diversified sample: morphology, AGN and environment Dimitri Gadotti (MPA – Garching)
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Espectros NGC 4608 NGC 5850 NGC 4394 NGC 4579
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Gauss-Hermite series (van der Marel & Franx 93) K0III stars Determining the LOSVDs Dimitri Gadotti (MPA – Garching)
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Radial Profiles of σ z r σzσz r σzσz Young bar Old bar Central drop in σ z (inner disk?) Dimitri Gadotti (MPA – Garching)
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Clear Cases Dimitri Gadotti (MPA – Garching)
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Let’s Quantify -σ Z,bar : at 50%-60% of bar semi-major length - σ Z : difference to σ Z in the disk at same distance -Young bars: σ Z,bar ~ 30 Km/s and σ Z ~ 5 Km/s -Old bars: σ Z,bar ~ 100 Km/s and σ Z ~ 40 Km/s -Statistical tests indicate different populations at the 98% confidence level Dimitri Gadotti (MPA – Garching)
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Some Results -AGN activity seems to be found preferentially in young bars (timescale for AGN fueling is short): -2/8 (25%) of old bars have AGN, but 3/5 (60%) of young bars show activity -Better bar x AGN correlation with young bars! -Bar recurrence may be more frequent in late-type galaxies: -7/8 (88%) of old bars are early-type, but only 2/5 (40%) of young bars are early-type Dimitri Gadotti (MPA – Garching)
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On Bars and Haloes Previous studies concluded that haloes are against bars (Ostriker & Peebles 1973) Using live haloes the truth is the opposite (Athanassoula & Misiriotis 2002; see also Athanassoula 2003) ! Angular momentum transfer between halo and disk makes stronger bars Depends on halo properties like mass and velocity distribution MH | MD Dimitri Gadotti (MPA – Garching)
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On Bars and Haloes J and Ks near-infrared observations at the Cananea 2.1-m telescope Compare the properties of N-body models and real barred galaxies N-body simulations MH | MD Dimitri Gadotti (MPA – Garching)
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On Bars and Haloes MH | MD N-body simulations Dimitri Gadotti (MPA – Garching)
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On Bars and Haloes MH | MD Real galaxies Dimitri Gadotti (MPA – Garching)
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On Bars and Haloes Real galaxiesN-body simulations Dimitri Gadotti (MPA – Garching)
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