ly- alpha morphology-density r elation @ high-z

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Yuichi Matsuda (NAOJ)松田有一（国立天文台）

Ly-alpha morphology-density

relation @ high-z

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1) Subaru / S-Cam survey shows a hint of Ly-alpha morphology-density relation at high-z.

2) Current observations are limited to extremely bright Ly-alpha blobs.

3) TMT will be able to study the morphology of the circum galactic medium of more normal galaxies at high-z.

Summary

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Ly-alpha imaging of the CGM• Lya imaging is a promising way to see the 2D

morphology of the gaseous structure around high-z galaxies (Chris Martin’s talk).

Dekel et al. (2009), van de Voort et al. (2011)

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Subaru Telescope + Suprime-Cam + Narrow-band filter 8.2 m 27’ x 34’ 21 x 17 cm R ~ 80

http://www.naoj.org/

Subaru / S-Cam Lya Survey at z=3 2.4 sq deg deep Lya imaging survey (Yamada+12) 12 pointings (SSA22 + 6 surrounding fields, Subaru Deep Field,

GOODS-N, Subaru-XMM Deep Survey Fields) 1-sigma Lya surface brightness~10-18 erg s-1 cm-2 arcsec-2 2200 Lya emitters (Yamada+12) 14 giant (>100kpc) Lya nebulae (Matsuda+11)

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2.4 sq deg deep Lya imaging survey (Yamada+12) 12 pointings (SSA22 + 6 surrounding fields, Subaru Deep Field,

GOODS-N, Subaru-XMM Deep Survey Fields) 1-sigma Lya surface brightness~10-18 erg s-1 cm-2 arcsec-2 2200 Lya emitters (Yamada+12) 14 giant (>100kpc) Lya blobs (Matsuda+11)

300kpc

Subaru / S-Cam Lya Survey at z=3

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The areas of blobs are measured above a threshold of 1.4x10-18

erg/s/cm2/arcsec2.

The circles have diameters of the major axis of the Lya blobs.

300kpc

Filamentary & Spherical Lya blobs

Covering Factor0

0.51

1.52

2.53

3.54

4.5

20-25%25-30%30-35%35-40%40-45%45-50%50-55%

Filamentary Spherical

20 25 30 35 40 45 50 55(%)

N

S S

S

S

S

F

FF F

F F

F

F

F


Faucher-Giguere+11200 kpc 200 kpc

Matsuda+11

ObservationSimulation

Spherical?

Covering Factor ~60%


Faucher-Giguere+11200 kpc 200 kpc

Matsuda+11

Filamentary?

ObservationSimulation

Covering Factor ~20%

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2.4 sq deg deep Lya imaging survey (Yamada+12) 12 pointings (SSA22 + 6 surrounding fields, Subaru Deep Field,

GOODS-N, Subaru-XMM Deep Survey Fields) 1-sigma Lya surface brightness~10-18 erg s-1 cm-2 arcsec-2 2200 Lyman-alpha emitters (Yamada+12) 14 giant (>100kpc) Lyman-alpha nebulae (Matsuda+11)


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-0.5 1 30%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

SphericalFilamentary

Frac

tion

Surface Over Density of Lya Emitters(<5 Mpc)

Field Protocluster

Lya Morphology Density Relation?

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Local Morphology Density Relation

Dressler 80Fr

actio

n

Surface Density of galaxies

S + Irr

E + S0

Field Cluster

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• Filamentary Lya blobs may relate to disc galaxy formation via cold streams in the field.

• Spherical Lya blobs may relate elliptical galaxy formation in hot haloes in proto-cluster.

-0.5 1 30%

10%20%30%40%50%60%70%80%90%

100%SphericalFilamentary

Frac

tion

Over Density


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• Current observations are limited to extremely bright Lya blobs (only 14 sources!!).

• It is difficult to study the Lya morphologies of fainter normal galaxies individually.

-0.5 1 30%

10%20%30%40%50%60%70%80%90%

100%SphericalFilamentary

Frac

tion

Over Density


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20”150kpc

High LowLAE surface density (5 Mpc/h smoothing)

Stacking analysis of 2200 LAEs

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The Lya radial profile of the field LAEs has a steeper slope.

Do the field LAEs (and LBGs) also have filamentary CGM structure?

If so, TMT will be able to detect the Lya emitting filaments around LAEs and LBGs.

8m 10hrs

30m 10hrs

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1) Subaru / S-Cam survey shows a hint of Ly-alpha morphology-density relation at high-z.

2) Current observations are limited to extremely bright Lya sources.

3) TMT will be able to study the morphology of the circum galactic medium of more normal galaxies at high-z.

Summary

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Conclusion

• Ly-alpha imaging is a promising way to study gaseous structure around high-z galaxies.

• Subaru / S-Cam survey shows a hint of Ly-

alpha morphology-density relation at high-z but the survey is limited to extreme cases.

• TMT will be able to observe the gaseous structure around more normal galaxies.

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1) Subaru / Suprime-Cam survey at z=3 shows a hint of Lyman-alpha morphology density relation.

2) Filamentary Lya nebulae are found in the field, while spherical nebulae are dominant in overdense regions.

3) Filamentary nebulae may relate to disc formation via cold streams in the field while the spherical nebulae may relate to spheroid formation in hot haloes in the proto-cluster.

Summary

Radial profile of stacked Lya image of 92 LBGs at z=2-3

Surface brightness threshold ~10-19 erg s-1 cm-2 arcsec-2

Lya

All UV-continuum selected galaxies at z=2-3 have diffuse extended Lya halos

Current survey threshold

Steidel+1120”

150kpc

But the data are from galaxy over-densities

What determines Lya spatial extent?

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Study Lya halos using 2128 LAEs at z=3.1 as a function of environment and UV luminosity (Matsuda+12)

LAE

surfa

ce d

ensit

y (5

Mpc

/h sm

ooth

ing)

Low

H

igh

Bright FaintCentral UV Luminosity

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Future Subaru HSC Survey• Hyper Suprime-Cam (1.5 deg diameter)• Subaru Strategic Program (300 nts in 5yrs)• Survey starts from Spring 2014• Including Deep z=2-7 Lya imaging in ~30 sq deg• http://www.naoj.org/Projects/HSC/surveyplan.html

Subaru Telescope + Hyper Suprime-Cam + Narrow-band filter 8.2 m 90 arcmin diameter 60 cm diameter

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Exponential fitting

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Bright 　　　　　　　　　　　　　　　　　　　　　　　　　　　　 FaintCentral UV luminosity

20”150kpc

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Expo

nenti

al sc

ale

leng

th

Low HighLAE surface density

(5 Mpc/h smoothing)

Faint 　　　　　　　 BrightCentral UV luminosity

Exponential fitting

ly- alpha morphology-density r elation @ high-z

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