[[C IIC II]] 158 158 m Emission from m Emission from Damped LyDamped Ly Systems Systems

Art Wolfe and Ken Nagamine Art Wolfe and Ken Nagamine UCSD UCSD

DLAS are

•Definition of Damped LySystem (DLA): N(HI) > 2*1020 cm-2

•Distinguishing characteristic of DLAs : Gas is Neutral

DLAS are

•Definition: N(HI) > 2*1020 cm-2

•Distinguishing characteristic of DLAs : Gas is Neutral

Stars form out of cold gas

•DLAs Dominate the Neutral Gas Content of the Universe at z=[0,5]

•Gas Content of DLAs at z=[3,4] Accounts for current visible Mass

•DLAs Serve as Important Neutral Gas Reservoirs for Star Formation

Relevance of DLAs for Star FormationRelevance of DLAs for Star Formation

•DLAs Dominate the Neutral Gas Content of the Universe at z=[0,5]

•Gas Content of DLAs at z=[3,4] Accounts for current visible Mass

•DLAs Serve as Important Neutral Gas Reservoirs for Star Formation

Mass per unitComoving Volume versusredshift

•DLAs Dominate the Neutral Gas Content of the Universe at z=[0,5]

•Gas Content of DLAs at z=[3,4] Accounts for current visible Mass

•DLAs Serve as Important Neutral Gas Reservoirs for Star Formation

CurrentVisibleMatter

NeutralGas atHigh z

HIRES Metal-line Velocity Profiles in DLAsHIRES Metal-line Velocity Profiles in DLAsHIRES Metal-line Velocity Profiles in DLAsHIRES Metal-line Velocity Profiles in DLAs

High-resolution spectroscopy on very large telescopes can yield quantitative information about DLAs:

• Cooling Rates

• Star formation rates.

SFRs

ThermalPressure

Chemistry

Kinematics

Nucleosynthesis

Dust & Nucleosynthesis

Nucleosynthesis

Nucleosynthesis

Obtaining Cooling Rates from CII* AbsorptionObtaining Cooling Rates from CII* Absorption

• [C II] 158 micron transition dominates cooling of neutral gas in Galaxy ISM

• Spontaneous emission rate per atom lc=n[CII] obtained from strength of 1335.7 absorption and Lyman alpha absorption

• Thermal equilibrium condition lc= pe gives heating rate per atom

2121)IH(*)IIC(

][ ~ Ahn NN

IIC ν 2121)IH(*)IIC(

][ ~ Ahn NN

IIC ν

[C II] 158 micron Emission rates vs N(H I)[C II] 158 micron Emission rates vs N(H I)

• Median lc=10-26.6 ergs s-1 H-1 for positive Detections

• Upper limits tend to have low N(H I)

• DLA lc values about 30 times lower than for Galaxy: explained by lower dust content and similar SFRs per unit area

Effect of Adding Local FUV HeatingEffect of Adding Local FUV Heating

An LBG Galaxy Associated with a DLA (Moller etal ‘02)An LBG Galaxy Associated with a DLA (Moller etal ‘02)

8.4 kpc

LyEmission [O III] Emission

CII* Absorption

[C II] contours superposed on 6.75 [C II] contours superposed on 6.75 m Imagem Image

[C II] Flux Densities Predicted for DLAs[C II] Flux Densities Predicted for DLAs

Predicted SPredicted Sνν00 for DLA 2206-19A for DLA 2206-19A

• 33 Alma limit for 20 hr Alma limit for 20 hr integration timeintegration time

• 90 % Mass range 90 % Mass range predicted for CDM predicted for CDM Models of DLAsModels of DLAs

• MMH IH I =m =mDDMM

Tentative lTentative lcc versus versus v relationv relation

• DLA2206-19ADLA2206-19A

• CDM Models predict CDM Models predict v = 0.6vv = 0.6vcc

• M=vM=vcc33/10GH(z)/10GH(z)

DLA2206-19ADLA2206-19A

• SSνν00 impliedimplied for Mass for Mass

predicted by lpredicted by lc c versus versus

v relationv relation

17 kpc17 kpc

608 MHz VLBI Map of PKS 0458-02608 MHz VLBI Map of PKS 0458-02

Single-Dish versus VLBI 21 cm Absorption profilesSingle-Dish versus VLBI 21 cm Absorption profiles for DLA 0458-02 at z=2.0394for DLA 0458-02 at z=2.0394

Alma Sensitivity for Detection of C II Alma Sensitivity for Detection of C II EmissionEmission

• Lower Limit for Lower Limit for DLA0458-02 forDLA0458-02 for

MMH IH I=10=101010 M Msunsun

Predicted SPredicted Sνν0 0 for full Sample for full Sample

• ““Redshift Desert’’Redshift Desert’’

• CNM confirmed by CNM confirmed by absence of absence of Si IISi II* * 1264 1264 absorption absorption