Hong-Star

Myung Gyoon Lee(李明均)

Astronomy ProgramDept of Physics & Astronomy

Seoul National UniversityKorea

(Prof.SS Hong ISM workshop, June 17-19, 2009, SNU)

2

Today

Hong-Star

(Human beings,

POems,

Nebulae, Dust, Gas, and

STARs in Galaxies)

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Encounter

In 1978

ET?

A human being?

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Encounter1979? (his office at SNU)

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Encounter1979? (SNU)

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Encounter1990.8.15

(Palomar Obs)

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Encounter1990.8.11 (Pasadena)

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Encounter

1998.5.13

(Mt.Sorak)

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Encounter2006.11.10 (Mt.Gwanag)

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Poems:(Missing home by Jiyong Jung)

향수 (정지용 1927)

넓은 벌 동쪽 끝으로 옛이야기 지줄 대는 실개천이 휘돌아 나가고

얼룩백이 황소가 해설피 금빛 게으른 울음을 우는 곳

그곳이 차마 꿈엔들 잊힐리야

질화로에 재가 식어지면, 비인 밭에 밤바람 소리 말을 달리고

엷은 졸음에 겨운 늙으신 아버지가 짚 벼개를 돋아 고이시는 곳

그곳이 차마 꿈엔들 잊힐리야

흙에서 자란 내 마음, 파란 하늘빛( dust)이 그리워함부로 쏜 화살을 찾으러 풀 섶 이슬에 함초롬 휘적시던 곳

그곳이 차마 꿈엔들 잊힐리야

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Peoms

전설바다에 춤추는 밤 물결 같은 검은 귀밑머리 날리는 어린 누이와,

아무렇지도 않고 예쁠 것도 없는 사철 발 벗은 아내가 따가운 햇살을

등에 지고 이삭 줍던 곳

그곳이 차마 꿈엔들 잊힐리야

하늘에는 성근 별(stars), 알 수도 없는 모래성으로 발을 옮기고,서리 까마귀 우지짖고 지나가는 초라한 지붕

흐릿한 불빛에 돌아앉아 도란도란 거리는 곳

그곳이 차마 꿈엔들 잊힐리야

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Dust

Stars lose their mass during evolution.

Where is dust?

Dust in GCsSS Hong, JH Pyo, E Kim, MG Lee+ team

Were is dust in globular clusters?Dust in AGB?

Dust in dark clouds?

Dust out of GCs?

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Dust in GCsAKARI/FIS ob: 17 globular clusters

(65um,90um, 140um, 160um)

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Dust in GCsPoint sources with dust (AGB or ?)

Diffuse dust (dust clouds)

NGC 288 (K+90um+140um) NGC 7089

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Nebulae in M51

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Stars

Diverse kinds of stars in the U

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First Stars in the U

One of the key topics for coming age!

When did they form?

How did they form?

Where did they form?

How massive are they?

How can we find them?

(Bromm et al 2009, Cooke etal 2009, Sloan et al 2009)

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First pops

H, He gas

Pop III.1 stars : metal-free

Molecular clouds (gas & dust)

Pop III.2 stars: 0

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Astronomers!

Evolution of astronomers

From Life to Stars

From Stars to Galaxies

Playing with Galaxies

From Galaxies back to Stars!

From Stars back to Life?

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First forms

Stars vs globular clusters? Stars!

globular clusters vs galaxies?

Dwarf galaxies vs giant galaxies?

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First forms

Dwarf galaxies vs Globular clusters ?

Similar mass, similar luminosity

Difference? Which first?

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First forms

GCs vs galaxies?

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First forms

Dwarfs can have GCs, while GCs cannot have dwarfs!

Then dwarfs first!

How did dwarfs form?

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First forms

Dwarf galaxies vs giant galaxies?

Mostly Dwarfs!?

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How to find the first stars

(1) NIR spectroscopy for HeII 1640 emission line at z 7

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First stars in Local Universe

Very metal-poor stars in halos (EMP, UMP,HMP)

Very metal-poor galaxies

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First galaxies?

Sextans dSph (Lee et al 2003)

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First galaxies?

Star formation history

Chemical evolution – very rapid enrichment

(Lee et al 2009)

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Metal-poor stars

Galactic halo vs dSphs

Dwarf galaxies vs giant galaxies?

Dwarfs!

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I ZW 18The lowest O abundance: log(O/H)=7.2

(~0.02 Zo): chemically unevolved!

Dwarf irregular galaxy

D=18.2 Mpc (Cep&TRGB :Aloisi et al. 2007)

[Fe/H] of stars: Unknown!

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Summary

First stars in the Universe: remaining to be found.

The first star in my life was Prof.Hong.

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Hong-Star

1998.5.13 (Mt.Sorak)

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Summary

Hong-Star is the first star in Korea.

Hong-Star will be shining forever.

(you know why, by considering his mass).

Host-Star is going toward Life in the U

Hope that he enjoy a life as a human-being.