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The CO SED and molecular gas properties in Early-Type Galaxies (ETGs)

The CO SED and molecular gas properties in Early-Type Galaxies (ETGs). CO. CS. HCN. S0 galaxy NGC6014. Credit: NASA/ESA. S0 galaxy NGC5866. Credit: NASA/ESA. HCO +. Estelle Bayet (University of Oxford). Collaborators : M. Bureau (Oxford), T. Davies (Oxford),

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The CO SED and molecular gas properties in Early-Type Galaxies (ETGs)

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  1. The CO SED and molecular gas properties in Early-Type Galaxies (ETGs) CO CS HCN S0 galaxy NGC6014. Credit: NASA/ESA S0 galaxy NGC5866. Credit: NASA/ESA HCO+ Estelle Bayet (University of Oxford) Collaborators : M. Bureau (Oxford), T. Davies (Oxford), A. Crockers (USA) + SAURON and ATLAS3D teams

  2. I. Observations: so far… so good!  review of detections  first results

  3. I. Observations: so far… so good!  review of detections  first results II. Models: so far… not that good!  results  limitations

  4. I. Observations: so far… so good!  review of detections  first results II. Models: so far… not that good!  results  limitations III. Conclusions and Perspective

  5. I. Observations: - 22 % (56/259) of the volume limited sample of ATLAS3D ETGs are gas-rich ETGs (Young et al. 2010) i.e. with clear detection of CO(1-0) and CO(2-1) (CO(2-1) isalso from Welsch and Sage 2003)

  6. I. Observations: - 22 % (56/259) of the volume limited sample of ATLAS3D ETGs are gas-rich ETGs (Young et al. 2010) i.e. with clear detection of CO(1-0) and CO(2-1) (CO(2-1) isalso from Welsch and Sage 2003) - 32 %(18/56) of the galaxies in this sample of gas-rich ETGs have been chosen for an observational follow-up in 13CO(1-0), 13CO(2-1), HCN(1-0) and HCO+(1-0) lines (Krips et al. 2010, Crocker et al. 2011)

  7. Extracted from Crocker et al 2011 12CO(1-0) 12CO(2-1) 13CO(1-0) 13CO(2-1) HCN(1-0) HCO+(1-0)

  8. Extracted from Crocker et al 2011 12CO(1-0) 12CO(2-1) 13CO(1-0) 13CO(2-1) HCN(1-0) HCO+(1-0)

  9. Extracted from Crocker et al 2011 12CO(1-0) 12CO(2-1) 13CO(1-0) 13CO(2-1) HCN(1-0) HCO+(1-0)

  10. I. Observations: - 22 % (56/259) of the volume limited sample of ATLAS3D ETGs are gas-rich ETGs (Young et al. 2010) i.e. with clear detection of CO(1-0) and CO(2-1) (CO(2-1) isalso from Welsch and Sage 2003) - 32 %(18/56) of the galaxies in this sample of gas-rich ETGs have been chosen for an observational follow-up in 13CO(1-0), 13CO(2-1), HCN(1-0) and HCO+(1-0) lines (Krips et al. 2010, Crocker et al. 2011) Summary: CO (4 lines) : 100% (18/18) HCN (1 line) : 66% (12/18) HCO+ (1 line) : 55% (10/18) HCN+HCO + (2 lines) : 38% (7/18)

  11. I. Observations: - 22 % (56/259) of the volume limited sample of ATLAS3D ETGs are gas-rich ETGs (Young et al. 2010) i.e. with clear detection of CO(1-0) and CO(2-1) (CO(2-1) isalso from Welsch and Sage 2003) - 32 %(18/56) of the galaxies in this sample of gas-rich ETGs have been chosen for an observational follow-up in 13CO(1-0), 13CO(2-1), HCN(1-0) and HCO+(1-0) lines (Krips et al. 2010, Crocker et al. 2011) Summary: CO (4 lines) : 100% (18/18) I can model two HCN (1 line) : 66% (12/18) gas phases in ETGs HCO+ (1 line) : 55% (10/18) (CO and a denser and HCN+HCO + (2 lines) : 38% (7/18) warmer gas)

  12. I. Observations: Extracted from Crocker et al 2011 Paglione et al. (2001)’s spirals NGC1266 NGC1266 NGC1266 R21 GMCs in M31 Brouillet et al. (2005) Gao & Solomon (2004)’s spirals R10 - Correlated - ETGs lower than - Exceptions: AGN - ½ have bigger R10 SB: less dense gas driving chemistry than R21 gas thinner in ETGs or lot of 13CO or not enough HCO+ effect of global TK and n(H2)? due to low - Exceptions ionisation rate?

  13. II. Models :

  14. II. Models : Theory LVG model (van der Tak et al. 2007)  averaged gas physical properties TK , <σv> and density are uniform Line of sight - 0D model - Spherical geometry - Equation of statistical equilibrium + level population - collision rates - Velocity = FWHM of our observations - TK and density uniform Radiation intensity = fo(S;escape probabilities of a photon emitted by the molecular transition) ONE MOLECULE (X) ONLY !! 3 (4) parameters : n(H2), TK, , N(X)/Vel, (12C/13C)  TB  Amb (Kkms-1)

  15. II. Models : In practise - Extract the FWHM

  16. II. Models : In practise - Extract the FWHM - Make grids of models for all the molecules and all the velocities: e.g (n(H2), TK, N(12CO))=(103-107 cm-3, 10-250 K, 1010-1020 cm-2) for velocities ranging from 60 to 430 kms-1

  17. II. Models : In practise - Extract the FWHM - Make grids of models for all the molecules and all the velocities: e.g (n(H2), TK, N(13CO))=(103-107 cm-3, 10-250 K, 1010-1020 cm-2) for velocities ranging from 60 to 430 kms-1

  18. II. Models : In practise - Extract the FWHM - Make grids of models for all the molecules and all the velocities: e.g (n(H2), TK, N(HCN)=(103-107 cm-3, 10-250 K, 1010-1020 cm-2) for velocities ranging from 60 to 430 kms-1

  19. II. Models : In practise - Extract the FWHM - Make grids of models for all the molecules and all the velocities: e.g (n(H2), TK, N(HCO+)=(103-107 cm-3, 10-250 K, 1010-1020 cm-2) for velocities ranging from 60 to 430 kms-1

  20. II. Models : In practise - Extract the FWHM - Make grids of models for all the molecules and all the velocities: e.g (n(H2), TK, N(HCO+)=(103-107 cm-3, 10-250 K, 1010-1020 cm-2) for velocities ranging from 60 to 430 kms-1  ½ million models run for the 4 species investigated here

  21. II. Models : In practise - Extract the FWHM - Make grids of models for all the molecules and all the velocities: e.g (n(H2), TK, N(HCN))=(103-107 cm-3, 10-250 K, 1010-1020 cm-2) for velocities ranging from 60 to 430 kms-1  ½ million models run for the 4 species investigated here - produce programme which calculates line ratio from models and compare them to observed ones (χ2 and likelihood) TWO-components LVG CO gas component : 12CO(1-0)/13CO(1-0), 12CO(2-1)/13CO(2-1), 12CO(1-0)/12CO(2-1) HCN/HCO+ gas component: HCN(1-0)/HCO+(1-0)

  22. II. Models : In practise - Extract the FWHM - Make grids of models for all the molecules and all the velocities: e.g (n(H2), TK, N(HCN))=(103-107 cm-3, 10-250 K, 1010-1020 cm-2) for velocities ranging from 60 to 430 kms-1  ½ million models run for the 4 species investigated here - produce programme which calculates line ratio from models and compare them to observed ones (χ2 and likelihood) TWO-components LVG CO gas component : 12CO(1-0)/13CO(1-0), 12CO(2-1)/13CO(2-1), 12CO(1-0)/12CO(2-1) HCN/HCO+ gas component: HCN(1-0)/HCO+(1-0)  best models identified, not unique!!!

  23. II. Models : Results Results for NGC3605 (D=22.2 Mpc) (Spatial resol=2.2kpc) N(CO)

  24. II. Models : Results Best models as predicted by χ2

  25. II. Models : Results Best models as predicted by χ2

  26. II. Models : Results Best models as predicted by χ2

  27. II. Models : Results Best models as predicted by χ2

  28. II. Models : Results Results for NGC3605 (D=22.2 Mpc) (Spatial resol=2.2kpc) N(CO)

  29. II. Models : Results Best models as predicted by χ2

  30. II. Models : Results χ2 likelihood First CO SEDs for ETGs !!

  31. II. Models : Results χ2 likelihood First CO SEDs for ETGs !! SB: peak turnover around CO(7-6) (e.g. Bayet et al. 2006)

  32. II. Models : Results χ2 likelihood First CO SEDs for ETGs !! SB: peak turnover around CO(7-6) (e.g. Bayet et al. 2006) Mrk 231: flat (van der Werf’s talk ?)

  33. II. Models : Results χ2 likelihood First CO SEDs for ETGs !! SB: peak turnover around CO(7-6) (e.g. Bayet et al. 2006) Mrk 231: flat (van der Werf’s talk)

  34. II. Models : Results χ2 likelihood First CO SEDs for ETGs !! Need high-frequency CO and HCN/HCO+ data: Herschel, JCMT and IRAM-30m proposals SB: peak turnover around CO(7-6) (e.g. Bayet et al. 2006) Mrk 231: flat (van der Werf’s talk)

  35. NGC4710 (λ= 3mm) First CS(2-1) and CS(3-2) detections in ETGs !!  presence of dense SF gas in ETGs, even denser than the one traced by HCN !! 4/10 : both CS lines detected 3/10 : no lines detected 3/10 : detected only in CS(2-1) because of bad weather conditions at pico veleta (Davis et al., in prep). methanol CS(2-1) NGC5866 (λ= 2mm) CS(3-2) methanol

  36. II. Models : Results χ2 likelihood First CO SEDs for ETGs !! Need high-frequency CO and HCN/HCO+ data: Herschel, JCMT and IRAM-30m proposals Bright side: we have high resolution maps !!!  successful ALMA proposal on NGC4710 for HCN/HCO+(3-2) SB: peak turnover around CO(7-6) (e.g. Bayet et al. 2006) Mrk 231: flat (van der Werf’s talk)

  37. II. Models (on-going): Spatially resolved n(H2), TK, N(12CO) maps from CARMA and IRAM-PdBI reachable!!! (Topaz et al. 2012 in prep)

  38. II. Models (on-going): Spatially resolved n(H2), TK, N(12CO) maps from CARMA and IRAM-PdBI CO PVD: Optical PVD: Temperature: 12CO(2-1) / 12CO(1-0) Velocity [N II] Velocity Opacity: 12CO(2-1) / 13CO(2-1) Hα Position Position

  39. III. Conclusions and perspectives Observations : - More low resolution data at high frequency for CO and HCN/HCO+ to better constrain the model predictions

  40. III. Conclusions and perspectives Observations : - More low resolution data at high frequency for CO and HCN/HCO+ to better constrain the model predictions - new CS lines (low resolution) to analyse and derive corresponding gas properties: 1) compare with CS extragalactic nearby source sample from Bayet et al. (2010) 2) compare CO and CS ladders in ETGs  SF laws ?

  41. III. Conclusions and perspectives Observations : - More low resolution data at high frequency for CO and HCN/HCO+ to better constrain the model predictions - new CS lines (low resolution) to analyse and derive corresponding gas properties: 1) compare with CS extragalactic nearby source sample from Bayet et al. (2010) 2) compare CO and CS ladders in ETGs  SF laws ? - acquire high resolution high frequency maps in CO, HCN/HCO+ and CS Three gas phases corresponding to gas reservoir, clumps and dense SF regions, respectively in ETGS !!!

  42. III. Conclusions and perspectives Observations : - More low resolution data at high frequency for CO and HCN/HCO+ to better constrain the model predictions - new CS lines (low resolution) to analyse and derive corresponding gas properties: 1) compare with CS extragalactic nearby source sample from Bayet et al. (2010) 2) compare CO and CS ladders in ETGs  SF laws ? - acquire high resolution high frequency maps in CO, HCN/HCO+ and CS Three gas phases corresponding to gas reservoir, clumps and dense SF regions, respectively in ETGS !!! Models : - Develop models more specific to ETGs: 1) taking into account high metallicity and α-elements enhancement (Bayet et al. 2011 in prep)

  43. Variation with respect to the metallicity (high) (Bayet et al. 2011, in prep) Variation with respect to three scenarios of α–elements enhancements (Bayet et al. 2011, in prep)

  44. III. Conclusions and perspectives Observations : - More low resolution data at high frequency for CO and HCN/HCO+ to better constrain the model predictions - new CS lines (low resolution) to analyse and derive corresponding gas properties: 1) compare with CS extragalactic nearby source sample from Bayet et al. (2010) 2) compare CO and CS ladders in ETGs  SF laws ? - acquire high resolution high frequency maps in CO, HCN/HCO+ and CS Three gas phases corresponding to gas reservoir, clumps and dense SF regions, respectively in ETGS !!! Models : - Develop models more specific to ETGs: 1) taking into account high metallicity and α-elements enhancement (Bayet et al. 2011 in prep) 2) what is the impact of the UV-upturn on the chemistry?

  45. PDR model (UCL_PDR) (Bayet et al. 2012 in prep)

  46. III. Conclusions and perspectives Observations : - More low resolution data at high frequency for CO and HCN/HCO+ to better constrain the model predictions - new CS lines (low resolution) to analyse and derive corresponding gas properties: 1) compare with CS extragalactic nearby source sample from Bayet et al. (2010) 2) compare CO and CS ladders in ETGs  SF laws ? - acquire high resolution high frequency maps in CO, HCN/HCO+ and CS Three gas phases corresponding to gas reservoir, clumps and dense SF regions, respectively in ETGS !!! Models : - Develop models more specific to ETGs: 1) taking into account high metallicity and α-elements enhancement (Bayet et al. 2011 in prep) 2) what is the impact of the UV-upturn on the chemistry?

  47. Thank you !!!

  48. II. Models : Results Results for NGC3605 (D=22.2 Mpc) (Spatial resol=2.2kpc)

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