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Mg II & C IV Absorption Kinematics vs. Stellar Kinematics in Galaxies

Mg II & C IV Absorption Kinematics vs. Stellar Kinematics in Galaxies. Chris Churchill (Penn State). J. Charlton J. Ding J. Masiero D. Schneider. B. Jannuzi R. Mellon J. Rigby. M. Dickinson M. Pettini A. Shapley C. Steidel. Extended Gaseous “Envelopes” and Galaxy Formation.

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Mg II & C IV Absorption Kinematics vs. Stellar Kinematics in Galaxies

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  1. Mg II & C IV Absorption Kinematics vs. Stellar Kinematics in Galaxies Chris Churchill (Penn State) J. Charlton J. Ding J. Masiero D. Schneider B. Jannuzi R. Mellon J. Rigby M. Dickinson M. Pettini A. Shapley C. Steidel

  2. Extended Gaseous “Envelopes” and Galaxy Formation The gas came first; but are the extended metal enriched “halos” near galaxies intergalactic in origin or reprocessed galactic gas? Clues (areas of study) include: • High Velocity Clouds in Milky Way • Quasar Absorption Lines IGM accretion? Intragroup material? Fountain material? Satellite accretion? Same Questions… Must compare to galaxy’s dynamical behavior and environment… What is connection between gas properties and galaxy properties…? Comparing kinematics of stars and kinematics of gas a first step… Comparing kinematics of various ionization conditions a second step…

  3. Mg II 2796 Transitions (rest—frame velocity space) (CWC & Vogt 2001)

  4. Mg II 2796 Transitions and Host Galaxies (CWC 2001)

  5. Simple Kinematic Models of Absorbing Gas from Galaxies Absorption kinematics is offset in the direction of stellar roatation compared to the galaxy’s systemic velocity Absorption kinematics is symmetric about the galaxy’s systemic velocity Halo/infall + Rotating/disk produces both signatures in single profile

  6. Q0827+243 Q1038+064 Q1148+387 (Steidel et al. 2002) Mg II kinematics traces the stellar kinematics in 4 of 5 galaxies observed to date. A symmetric infalling “halo” appears rare- there is no symmetry about the galaxy’s systemic velocity.

  7. Mg II 2796 Kinematics – CIV Strengths The velocity spread of Mg II gas is predictor of CIV absorption strength and kinematics… In Lyman limits systems (LLSs) the more distributed the low ionization phase is in velocity, the stronger is the total absorption strength of the higher ionization gas. However, the C IV does not arise in the same physical parcels of gas- the gas is multiphase in its ionization conditions. (aside): Damped Ly-a systems (DLAs) exhibit average kinematics, average C IV absorption strengths, but the largest Mg II absorption strengths. (CWC et al. 2000)

  8. Kinematics: Mg II 2796 and C IV 1548, 1550 (CWC et al. 2000)

  9. The Q1206+459 Multiple System: Multiphase Ionization The C IV, N V, and O VI arise in a separate ionization ionization phase- models of Mg II clouds cannot produce higher ionization absorption… WIYN image of Q1206 field shows four galaxies… Group environment absorbers, or galaxy hosted absorbers? STIS/HST (CWC & Charlton 1999; Ding et al. 2002)

  10. Mg II 2796 Kinematics + C IV 1548 Kinematics Case 1: high velocity Mg II clouds appear to have C IV trace them in discreet fashion; though ionization conditions are multiphase Case 2: Evidence for ionization gradients, where C IV / Mg II ratio changes across profile Case 3: Where is the C IV? Case 4: Where is the Mg II? Case 5: All cases combined! What about the galaxy kinematics in these cases? How do they stack up in velocity space?

  11. Q0827+243 Q1038+064 Q1148+387 FOS/HST spectra: they lack the resolution to discern the C IV kinematics… CIV 1548,1550 CIV 1548,1550

  12. Kinematics: Stellar, Mg II 2796, and C IV 1548, 1551 Mg II traces stellar kinematics yet is difficult to explain as extended disk rotation (at 72 kpc impact parameter!). C IV traces Mg II kinematics but has strongest component at galaxy’s systemic velocity, as highlighted in l1551. What physical entity is giving rise to this C IV component? (CWC et al. 2002, in prep)

  13. Concluding Remarks • C IV absorption strengths correlate with Mg II kinematic spreads. • Mg II kinematics consistent with stellar kinematics extended. “Disk” or co-rotating halo kinematics? No signature of symmetric, infalling halo component. • C IV kinematics does not correspond to Mg II kinematics in all cases. Galaxy-like C IV corona with adiabatic cooling, infalling Mg II cloudlets? (1999) Gas coupled to galaxy/stars, no simple IGM accretion; implications for intragroup HVCs? Many Mg II clouds have multiphase ionization in velocity space; but bulk of C IV absorption may not be aligned in velocity with Mg II. Are we seeing high ionization C IV-only “high velocity clouds” or C IV “coronae” strongly coupled to the galaxy systemic velocity. What are the affects of satellite galaxies and merger histories? Future 25 galaxies with stellar rotation curves (spirals) and stellar velocity dispersions (ellipticals). Collect C IV kinematics with COS on HST.

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