ALMA-IMF Core Working Group, October 8 2020

Connection:
https://ufl.zoom.us/j/96368629056?pwd=c1JmbWN6Rll0ZkNjYzJZamtXZFdmUT09

Attendees: Fred, Yohan, Jeff, Amy, Nathalie, Sasha, Gemma, Allison, Roberto, Patricio, Nichol, Adam, Thomas, Leo, Alex, HongLi, Fabrice, Sylvain, Timea, Tapas, Quang, Ant
Not attending: Fabien

For memory:
Minutes from our last telecon
Members and their main interests


Agenda:

1. News on core extraction by Yohan and Fabien

• Detailed analysis of W43-MM2&3 data → Recipe for detailed CMF papers:
  

Detection: “denoised” images not corrected by the PB shape
W43-MM2MM3_1mm_cohe_sm_sk06.fits
W43-MM2MM3_3mm_cohe_sm_sk05.fits

Measurements: original images, PB-corrected
W43-MM2MM3_1mm_bsens.fits
W43-MM2MM3_1mm_cleanest.fits
W43-MM2MM3_3mm_bsens.fits
W43-MM2MM3_3mm_cleanest.fits
→ Final extraction to be done with getsf and GExt2D.

Question to Sasha: is it possible to spare time and not measure cores’ parameters on the W43-MM2MM3_1mm_cohe_sm_sk06.fits and W43-MM2MM3_3mm_cohe_sm_sk06.fits maps? Answer: Sure!

• Presentation of FlufiCarp by Yohan:
  

To do this analysis, I am using the automatic procedures I developed. They are available on GitHub (private for now) but I can give you access if you want. These scripts can be run no matter the region, the software or its version and allow catalogs comparison, analysis, post-selection, mass calculation with a temperature map and CMFs drawing. Feel free to contact me if you are interested in using these scripts for your own region.

Here is the GitHub link : https://github.com/Yohan-Pouteau/FlufiCarp
Please only circulate this link between consortium members

1. Temperature estimates with PPMAP

• The PPMAP Tdust image used to estimate Tdust of cores in W43-MM2&3
  

Figure: Over-plotting the 1mm contours and the bsens sources (ellipses). Sources in red are potential hot cores with Sint (bsens) /Sint (cleanest)>1.4. 

Questions to Alex:
→ why is the PPMAP coverage smaller than the 1mm ALMA coverage? Some cores fall outside the Tdust map… 
Answer: image cropped to avoid edge effect, filtering will solve this issue.

→ why such squared regions? 
Answer: edge effects as well, not present anymore in the new image

→ A couple of cores lie over the cold (10K) artefact created when fitting a modified blackbody toward pixels whose the 3mm emission is largely contaminated by free-free emission. Is there a method to ignore the 3mm image when fitting the SED of these pixels?
Answer: Alex could substitute a model wo 3mm to the black rounded artefact on the image
Adam: To mitigate/remove the free-free emission, we could in the future use the H41alpha image or VLA emission.

Question to Fabrice/Nathalie:
→ Do you confirm the “hot core” nature of the red sources?

• Jeff’s evaluation of the filtering scales of the datasets used by PPMAP 
  

Jeff’s presentation from last week.
Comments?

* Max recov. scale = ~0.6 x \lambda/Lmin         See equation nº6.1 (p53) in https://www.iram.fr/IRAMFR/ARC/documents/cycle1/alma-technical-handbook.pdf

• Impact of these filtering scales on the PPMAP results by Alex
  

Improvements by making 2 steps:

• Herschel-only Tdust map [at which resolution?] →  very clean map
  
• Spatial filter (60’’, 30’’) to Herschel data + ALMA + other images
  

issues: negative areas in filtered images are not fitted by PPMAP and thus create blanked pixels in the Tdust resulting image
optical thickness to be treated (70 micron, 1mm?)

1. Other estimations of the core temperature

• Investigating thermometers like CH3OH, CH3CN, CH3CCH lines? 
  

Timea and Nathalie started but it is too complex to apply our knowledge to get a better estimate of the core temperature.
[This information cannot be used for the 1st mass estimates we’ll make but we can expect publishing  more corrected core temperature and thus mass measurements in the future.]

• What is the status of Brian’s efforts to analyze and collect ammonia data? He will be invited next week.
  

• Fred and Nathalie should soon (next week?) present the proxy proposed for the protostellar luminosity, using the line contamination from COMs.