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

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Presentation on theme: "[C II] 158  m Emission from Damped Ly  Systems Art Wolfe and Ken Nagamine UCSD UCSD."— Presentation transcript:

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

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

3 DLAS are Definition: N(HI) > 2*10 20 cm -2 Distinguishing characteristic of DLAs : Gas is Neutral Stars form out of cold gas

4 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

5 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

6 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

7 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

8 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 1335.7 absorption and Lyman alpha absorption Thermal equilibrium condition l c =  pe gives heating rate per atom

9 [C II] 158 micron Emission rates vs N(H I) Median l c =10 -26.6 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

10 Effect of Adding Local FUV Heating

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

12 [C II] contours superposed on 6.75  m Image

13 [C II] Flux Densities Predicted for DLAs

14 Predicted S 0 for DLA 2206-19A 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

15 Tentative l c versus  v relation DLA2206-19ADLA2206-19A 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)

16 DLA2206-19A S 0 impliedfor Mass predicted by l c versus  v relationS 0 implied for Mass predicted by l c versus  v relation

17 17 kpc 608 MHz VLBI Map of PKS 0458-02

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

19 Alma Sensitivity for Detection of C II Emission Lower Limit for DLA0458-02 forLower Limit for DLA0458-02 for M H I =10 10 M sun M H I =10 10 M sun

20 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


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