[C II] 158  m Emission from Damped Ly  Systems Art Wolfe and Ken Nagamine UCSD UCSD

DLAS are Definition of Damped Ly  System (DLA): N(HI) > 2*10 20 cm -2 Distinguishing characteristic of DLAs : Gas is Neutral

DLAS are Definition: N(HI) > 2*10 20 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 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 unit Comoving Volume versus redshift

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 Current Visible Matter Neutral Gas at High z

HIRES 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 Thermal Pressure Chemistry Kinematics Nucleosynthesis Dust & Nucleosynthesis Nucleosynthesis

Obtaining Cooling Rates from CII* Absorption [C II] 158 micron transition dominates cooling of neutral gas in Galaxy ISM Spontaneous emission rate per atom l c =n  [CII] obtained from strength of absorption and Lyman alpha absorption Thermal equilibrium condition l c =  pe gives heating rate per atom

[C II] 158 micron Emission rates vs N(H I) Median l c = ergs s -1 H -1 for positive Detections Upper limits tend to have low N(H I) DLA l c values about 30 times lower than for Galaxy: explained by lower dust content and similar SFRs per unit area

Effect of Adding Local FUV Heating

An LBG Galaxy Associated with a DLA (Moller etal ‘02) 8.4 kpc Ly  Emission [O III] Emission CII * Absorption

[C II] contours superposed on 6.75  m Image

[C II] Flux Densities Predicted for DLAs

Predicted S 0 for DLA A 3  Alma limit for 20 hr integration time3  Alma limit for 20 hr integration time 90 % Mass range predicted for CDM Models of DLAs90 % Mass range predicted for CDM Models of DLAs M H I =m D MM H I =m D M

Tentative l c versus  v relation DLA ADLA A CDM Models predict  v = 0.6v cCDM Models predict  v = 0.6v c M=v c 3 /10GH(z)M=v c 3 /10GH(z)

DLA A S 0 impliedfor Mass predicted by l c versus  v relationS 0 implied for Mass predicted by l c versus  v relation

17 kpc 608 MHz VLBI Map of PKS

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

Alma Sensitivity for Detection of C II Emission Lower Limit for DLA forLower Limit for DLA for M H I =10 10 M sun M H I =10 10 M sun

Predicted S 0 for full Sample “Redshift Desert’’“Redshift Desert’’ CNM confirmed by absence of Si II * 1264 absorptionCNM confirmed by absence of Si II * 1264 absorption