07 February 2019

Discussing the paper mccourt2018-characteritsticscale-coldgas.pdf

Present : EF, PL, FL, AL, AVG, TR

21 February 2019

Edith's agenda :

- Last time, many of us were away. We started to discuss the paper by McCourt et al. 2018 MNRAS 473, 5407 but we had so many open questions that we said we would continue next thursday. So I hope that those who were not there will have gone through the paper, deeply enough, before we meet and that Pierre L. will be willing to trigger the discussion again follwing his PhD work.

- Some of us also suggested that we discuss the paper by Latif et al 2011 A&A 532, A66 on Lyman alpha emission of the first galaxies. If time allows we could also start dig into it.

- I would like to review the papers in preparation under MIST, who is in charge of them and the foreseen timescale, but more importantly if there is any serious problem to face :

• Andrew: Self-irradiated molecular shocks (with Benjamin, Guillaume, me, …)
• Pierre L. : (1) CO formation in 2D MHD simulations (with Benjamin and others) / (2) statistical observables of turbulent dissipation (with Thibaud, me and others)
• Francois B. : non Gaussian PDF of Q/I and U/I (and/or E and B modes) in Planck (with Pierre L., me, others…)
• Pierre HB: small scale CO structure across the extreme velocity shear in Polaris (with Andrew, me, …)
• Edith : (1) Comparison of CH+ and Lyman alpha in one high redshift starburst galaxy, (with Benjamin,Alba, …) / (2) the Cycle 4 ALMA results on CH+ in high-z starbursts (with Benjamin and Alba , …)
• Alba : Lensing models of high-z starbursts (with me and others)
• Thibaud: too early?

Pierre HB :

• the first paper will focus on the comparison of the line profiles of CO and isotopologues accross the shear; and the analysis of the excitation is still in progress. I plan to converge on this by March 6th;
• an undergraduate (M1) student has started a short numerical project: he will work on simulating the CO spectra from the simulations; we started with the simple calculations made by Pierre L.; the project will be to apply this to 3D cubes using simple prescriptions;
• another undergraduate (M1) student will make an internship on this project, starting 20th of May, for at least 2 months, perhaps (I will have make an interview tomorrow). In case the student makes good impression, could we make the internship for 3 months, in which case we would have to pay him (~500 euros per month).
• I need an account on Totoro to work on the 3D cubes;
• With Edith, we have been discussing the possibility to start an APEX project in the Chameleon based on the H2 detections in Ingalls et al 2011; deadline should be around March 31st. This would be the first step towards ALMA observations. Schedule would be: APEX obs before fall 2019; ALMA cycle 8 (deadline: mid-april 2020), observations sept2020-sept2021;

30 April 2020 Paris-Durham (PD) 50 km/s shock into WNM.

To initialise PD we run a time evolution of a parcel of gas at density n=0.1 cm-3, irradiated with an ISRF G0=1, and cosmic ray rate zeta=10^-16 s-1.

This is the chemical evolution of that parcel, showing the electron fraction reaching ~10^-2.

This is the temperature evolution of that parcel, reaching T~10^4 K.

Using the result of the above runs as the input (chemical abundances, temperature) for PD, here is a 50 km/s shock. This is the temperature and hydrogen density profile.

For comparison with mappings (Sutherland and Dopita 2017), several models were run. This is the temperature profiles of the PD shock (black), mappings with most basic settings (blue), basic + cosmic ray rate zeta=10^-17 s-1 (orange), basic + UV field (Mathis field, 9.50918E+09 phots/cm^2/s), basic + dust calculation.

Here are the electron density profiles.

Here are the hydrogen density profiles.