SLIDE 1
How does the metallicity of the CGM evolve? What is the morphology of the CGM?
Circumgalactic medium (CGM)
2790 2795 2800 2805 2810 rest frame wavelength ( ˚ A) 0.5 0.6 0.7 0.8 0.9 1.0 residual 2796 ˚ A 2803 ˚ A Mg II doublet
Metallicity and morphology of the cool circumgalactic medium - - PowerPoint PPT Presentation
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
SLIDE 2
SLIDE 3
~100,000 systems
Zhu and Ménard (2013)
SLIDE 4
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
SLIDE 5
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
1.0 0.98 1.0 0.98
SLIDE 6
1.0 1.5 2.0 2.5
redshift
11.5 12.0 12.5 13.0 13.5 14.0 14.5 15.0 15.5
log column density/cm−2
SiII FeII
CI ZnII
Metal column densities as a function of redshift
> 10 metal elements in total
A tracer for intrinsic metal abundance A tracer for volume density, nH, of the gas
log column density/cm-2
SLIDE 7
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 redshift 19.0 19.5 20.0 20.5 21.0
log10 NHI/cm−2
Rao et al. (2006) Ménard et al. (2009) Matejek, Simcoe et al. (2013) Rao et al. (2017) See also Matejek, Simcoe et al. (2013)
Neutral hydrogen column densities as a function of redshift
SLIDE 8
−1.0 −0.5 0.0
log nH [cm−3] (NHI, NCI
NCII)
−1.0 −0.5 0.0 −0.8 −0.6 −0.4 −0.2 0.0 0.2 0.4
[Z/H]
Metallicity based on [ZnII/HI]
Wλ2796 > 0.8 ˚ A z = 1.4
Input constraints
(NHI, NZnII)
−1.0 −0.5 0.0
(NHI, NCI
NCII, NZnII)
(HI, ZnII,CI/CII)
−1.0 −0.5 0.0
log nH [cm−3] (NHI, NCI
NCII)
−1.0 −0.5 0.0 −0.8 −0.6 −0.4 −0.2 0.0 0.2 0.4
[Z/H]
Metallicity based on [ZnII/HI]
Wλ2796 > 0.8 ˚ A z = 1.4
Input constraints
(NHI, NZnII)
(HI, CI/CII)
−1.0 −0.5 0.0 −0.8 −0.6 −0.4 −0.2 0.0 0.2 0.4
[Z/H]
Metallicity based on [ZnII/HI]
Wλ2796 > 0.8 ˚ A z = 1.4
Input constraints
(NHI, NZnII)
−1.0 −0.5 0.0
log nH [cm−3]
Metallicity
Constraining the physical properties of gas with CLOUDY (HI, ZnII)
−1.0 −0.5 0.0 −0.8 −0.6 −0.4 −0.2 0.0 0.2 0.4
[Z/H] z = 0.9 Wλ2796 > 0.8 ˚ A
−1.0 −0.5 0.0
z = 1.1
−1.0 −0.5 0.0
z = 1.4
−1.0 −0.5 0.0
z = 1.8
log nH [cm−3]
−1.0 −0.5 0.0
z = 2.0
−1.0 −0.5 0.0
z = 2.3
Metallicity
z=0.9 z=1.1 z=1.4 z=1.8 z=2.0 z=2.3
Constraints
−1.0 −0.5 0.0
log nH [cm−3]
SLIDE 9
0.0 0.5 1.0 1.5 2.0 2.5 3.0 redshift −1.5 −1.0 −0.5 0.0 0.5 1.0 Metallicity [Z/H] 0.0 0.5 1.0 1.5 2.0 2.5 3.0 redshift −1.5 −1.0 −0.5 0.0 0.5 1.0 Metallicity [Z/H]
DLAs (Rafelski et al. 2012)
~solar metallicity 30 % solar metallicity
Metallicity evolution
SLIDE 10
0.0 0.5 1.0 1.5 2.0 2.5 3.0 redshift −1.5 −1.0 −0.5 0.0 0.5 1.0 Metallicity [Z/H] 0.0 0.5 1.0 1.5 2.0 2.5 3.0 redshift −1.5 −1.0 −0.5 0.0 0.5 1.0 Metallicity [Z/H]
Damped Lyman alpha systems (Neeleman et al.)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 redshift −1.5 −1.0 −0.5 0.0 0.5 1.0 Metallicity [Z/H]
~solar metallicity 30 % solar metallicity
DLAs (Rafelski et al. 2012)
Metal evolution of the Universe
Metallicity evolution
SLIDE 11
size of clouds ~ NH /nH ~ 30 pc
~0.3 cm-3
Gas cloud volume density
SLIDE 12
10 100 500 0.01 0.1 1
rp [kpc] Covering fraction
Lan, Ménard & Zhu (2014)
Number of clouds ~
fc x area 𝜏cloud
~ 106
See also Chen et al (2010), Huang et al. (2015), Nielsen et al. (2013)
SLIDE 13
Summary
0.0 0.5 1.0 1.5 2.0 2.5 3.0 redshift −1.5 −1.0 −0.5 0.0 0.5 1.0 Metallicity [Z/H]
~solar metallicity
30 % solar metallicity Metal production
Metallicity evolution volume density ~ 0.3 cm-3 cloud size ~ 30 pc
SLIDE 14
The CGM is clumpy, consisting of ~106 metal-rich clouds.
SLIDE 15