Metallicity and morphology of the cool circumgalactic medium - PowerPoint PPT Presentation

Metallicity and morphology of the cool circumgalactic medium Ting-Wen Lan Kavli Fellow In collaboration with Masataka Fukugita

Mg II doublet 1 . 0 0 . 9 residual 0 . 8 0 . 7 Circumgalactic medium 0 . 6 (CGM) 0 . 5 2796 ˚ 2803 ˚ A A 2790 2795 2800 2805 2810 rest frame wavelength ( ˚ A) Accessible from z~0.4 to 2.5 in optical regions N HI >=10 19 cm -2 How does the metallicity of the CGM evolve? What is the morphology of the CGM?

~100,000 systems Zhu and Ménard (2013)

Metal composite spectrum 1.0 0.8 0.6 0.4 0.2 0.0 1.0 0.8 0.6 0.4 0.2 0.0

Metal composite spectrum 1.0 0.8 0.6 1.0 0.4 0.2 0.98 0.0 1.0 0.8 0.6 1.0 0.4 0.2 0.98 0.0

Metal column densities as a function of redshift 15 . 5 SiII 15 . 0 log column density/cm -2 FeII log column density/ cm − 2 14 . 5 14 . 0 A tracer for volume density, n H, of the gas 13 . 5 CI 13 . 0 ZnII 12 . 5 12 . 0 A tracer for intrinsic metal abundance > 10 metal elements in total 11 . 5 1 . 0 1 . 5 2 . 0 2 . 5 redshift

Neutral hydrogen column densities as a function of redshift 21 . 0 20 . 5 log 10 N HI / cm − 2 20 . 0 19 . 5 Rao et al. (2006) Ménard et al. (2009) Matejek, Simcoe et al. (2013) Rao et al. (2017) 19 . 0 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 2 . 5 3 . 0 3 . 5 4 . 0 redshift See also Matejek, Simcoe et al. (2013)

Constraining the physical properties of gas with CLOUDY 0 . 4 0 . 4 0 . 4 z = 1 . 4 z = 1 . 4 z = 1 . 4 0 . 2 0 . 2 0 . 2 W λ 2796 > 0 . 8 ˚ W λ 2796 > 0 . 8 ˚ W λ 2796 > 0 . 8 ˚ A A A Metallicity 0 . 0 0 . 0 0 . 0 [Z/H] [Z/H] [Z/H] − 0 . 2 − 0 . 2 − 0 . 2 − 0 . 4 − 0 . 4 − 0 . 4 Metallicity based on [ZnII/HI] Metallicity based on [ZnII/HI] Metallicity based on [ZnII/HI] Constraints Input constraints Input constraints Input constraints − 0 . 6 − 0 . 6 − 0 . 6 (HI, ZnII) (HI, CI/CII) (N HI , N CI (N HI , N CI (HI, ZnII,CI/CII) (N HI , N CI N CII ) N CII ) N CII , N ZnII ) (N HI , N ZnII ) (N HI , N ZnII ) (N HI , N ZnII ) − 0 . 8 − 0 . 8 − 0 . 8 − 1 . 0 − 1 . 0 − 1 . 0 − 1 . 0 − 0 . 5 − 0 . 5 − 0 . 5 − 0 . 5 0 . 0 0 . 0 0 . 0 0 . 0 − 1 . 0 − 1 . 0 − 0 . 5 − 0 . 5 0 . 0 0 . 0 − 1 . 0 − 1 . 0 − 0 . 5 − 0 . 5 0 . 0 0 . 0 log n H [cm − 3 ] log n H [cm − 3 ] log n H [cm − 3 ] log n H [cm − 3 ] 0 . 4 0 . 2 Metallicity 0 . 0 [Z/H] − 0 . 2 − 0 . 4 W λ 2796 > 0 . 8 ˚ A z=0.9 z=1.1 z=1.4 z=1.8 z=2.0 z=2.3 − 0 . 6 z = 0 . 9 z = 1 . 1 z = 1 . 4 z = 1 . 8 z = 2 . 0 z = 2 . 3 − 0 . 8 − 1 . 0 − 0 . 5 0 . 0 − 1 . 0 − 0 . 5 0 . 0 − 1 . 0 − 0 . 5 0 . 0 − 1 . 0 − 0 . 5 0 . 0 − 1 . 0 − 0 . 5 0 . 0 − 1 . 0 − 0 . 5 0 . 0 log n H [cm − 3 ]

Metallicity evolution 1 . 0 1 . 0 0 . 5 0 . 5 ~solar metallicity Metallicity [Z/H] Metallicity [Z/H] 0 . 0 0 . 0 − 0 . 5 − 0 . 5 30 % solar metallicity − 1 . 0 − 1 . 0 − 1 . 5 − 1 . 5 DLAs (Rafelski et al. 2012) 0 . 0 0 . 0 0 . 5 0 . 5 1 . 0 1 . 0 1 . 5 1 . 5 2 . 0 2 . 0 2 . 5 2 . 5 3 . 0 3 . 0 redshift redshift

Metallicity evolution 1 . 0 1 . 0 1 . 0 0 . 5 0 . 5 ~solar metallicity 0 . 5 Metal evolution of the Universe Metallicity [Z/H] Metallicity [Z/H] Metallicity [Z/H] 0 . 0 0 . 0 0 . 0 − 0 . 5 − 0 . 5 − 0 . 5 30 % solar metallicity − 1 . 0 − 1 . 0 − 1 . 0 − 1 . 5 − 1 . 5 − 1 . 5 Damped Lyman alpha systems (Neeleman et al.) DLAs (Rafelski et al. 2012) 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 2 . 5 3 . 0 0 . 0 0 . 0 0 . 5 0 . 5 1 . 0 1 . 0 1 . 5 1 . 5 2 . 0 2 . 0 2 . 5 2 . 5 3 . 0 3 . 0 redshift redshift redshift

Gas cloud volume density ~0.3 cm -3 size of clouds ~ N H /n H ~ 30 pc

1 Covering fraction 0 . 1 Number of clouds ~ f c x area ~ 10 6 𝜏 cloud See also Chen et al (2010), 0 . 01 Lan, Ménard & Zhu (2014) Huang et al. (2015), Nielsen et al. (2013) 10 100 500 r p [kpc]

Summary 1 . 0 ~solar metallicity 0 . 5 Metal production Metallicity [Z/H] 0 . 0 Metallicity evolution − 0 . 5 30 % solar metallicity − 1 . 0 − 1 . 5 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 2 . 5 3 . 0 redshift volume density ~ 0.3 cm -3 cloud size ~ 30 pc

The CGM is clumpy, consisting of ~10 6 metal-rich clouds.