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Resolving the Kinematic Structure of Multiphase Gas

Presenter : Chieh-Lin Yang

Advisor : Ting-Wen Lan

Date : 2026/08/31

Crédit:ESO/IDA/Danish 1.5 m/R. Gendler, J.-E. Ovaldsen, C. Thöne and C. Féron

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Galaxy

Crédit:ESO/IDA/Danish 1.5 m/R. Gendler, J.-E. Ovaldsen, C. Thöne and C. Féron

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Gas

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Circumgalactic Medium

https://www.rri.res.in/highlights/new-study-may-redefine-how-mass-halo-around-galaxies-measured

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https://www.rri.res.in/highlights/new-study-may-redefine-how-mass-halo-around-galaxies-measured

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https://www.rri.res.in/highlights/new-study-may-redefine-how-mass-halo-around-galaxies-measured

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Absorption Line Spectroscopy

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Mg II

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Si IV Si II

C IV Al II

Mg II

Fe II

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Si IV Si II

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Si IV Si II

10⁴ K

10⁵ K

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Low Resolution

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?

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SDSS

R ~ 2,000

N > 100,000

image Credit: David Law, https://www.sdss4.org/manga_4/

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KODIAQ DR2

R > 36,000

N = 300

https://keckobservatory.org/our-story/telescopes/

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SDSS

R ~ 2,000

N > 100,000

KODIAQ DR2

R > 36,000

N = 300

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JHU-SDSS Metal absorption catalog

KODIAQ DR2

x

174 systems

10 for detailed analysis

EW(2796)

0 1 2 3 4

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VoigtFIt

Krogager (2018)

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Number of components

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Number of components

v

Where?

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Number of components

b parameter

How wide?

v

Where?

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Number of components

b parameter

How wide?

logN

How deep?

v

Where?

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Number of components

b parameter

How wide?

logN

How deep?

v

Where?

How hot or turbulent?

How much gas/atoms?

How fast?

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0 1 2 3 4

4

0.4

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4

21

0.4

2.1

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4

21

26

0.4

2.1

4.1

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Past research

My result

0.4

2.1

4.1

Churchill et al.(2020)

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0.4

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0.4

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0.4

2.1

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0.4

2.1

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0.4

2.1

4.1

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0.4

2.1

4.1

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Conclusion

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KODIAQ DR2

R > 36000

Conclusion

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KODIAQ DR2

R > 36000

Conclusion

VoigtFit

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KODIAQ DR2

R > 36000

Conclusion

VoigtFit

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KODIAQ DR2

R > 36000

Conclusion

VoigtFit