CPLUOS Astrophysics team meeting

Monday 27 Sept 2021, 16:30 → 17:55 Asia/Seoul

물리학과

https://uos-ac-kr.zoom.us/j/8264902652

16:30 → 17:45 COSMOLOGY

16:30 Dr.Sangnam Park's Report - FDM_Offset

Speaker: Sangnam Park

16:45 Hyeonmo's report - CDM Halo Evolution for Gadget2 Simulation

Speaker: Hyeonmo Koo (University of Seoul)

• Particle Number Graph Comparison
  • Particle Number 20000
  • Particle Number 40000
• First Evolution
  • 0.538 ≒ Particle Number 20000 > Particle Number 40000 > Particle Number 60000 > Particle Number 80000 > Particle Number 100000 > Particle Number 120000 > Particle Number 140000 > Particle Number 160000 > Particle Number 180000 > Particle Number 200000 ≒ 0.534

17:00 Young's report. FoF and MST algorithm

Speaker: Young Ju

• Added lots of noise into the random data set.
• Original cluster is 50 cluster and each of cluster have 100 galaxies.
  • 5000, 8000, 10000 noise added.
• For MGS, more than 3 members
  • 570 / 140 for 10 members / 54 for 20 members
  • 646 / 296 for 10 members / 117 for 20 members
  • 616 / 357 for 10 members / 157 for 20 members
• For DBSCAN, more than 3 members
  • 40 / 39 for 10 members / 39 for 20 members
  • 103 / 94 for 10 members / 39 for 20 members
  • 167 / 148 for 10 members / 66 for 20 members
  • The results of DBSCAN is similar to MGS, but there is one notable thing that the DBSCAN merger with other cluster while MGS nearly consists original cluster.
• For MST, more than 3 members
  • 228 / 57 for 10 members / 30 for 20 members
  • 59 / 6 for 10 members / 2 for 20 members
  • 27 / 1 for 10 members / 1 for 20 members
• For Hierarchial clustering, more than 3 members
  • 226 / 55 for 10 members / 28 for 20 members
  • 59 / 6 for 10 members / 2 for 20 members
  • 27 / 1 for 10 members / 1 for 20 members

17:15 CHOA(Cosmology of High-Order Statistics)

Speaker: Se Yeon Hwang

• Observation data SDSS-Ⅲ DR12 CMASS
• Observation data SDSS-Ⅲ DR12 CMASS ↔ Pinocchio1 (same parameter with CMASS)
• Pinocchio2 (same parameter with Abacus) ↔ Abacus (N-body simulation)
• Pinocchio1 (same parameter with CMASS)
  • Box size = 1500(Mpc/h)
  • rsd(2,3,4-point)
  • Cosmological parameter : same as BOSS CMASS
  • Cosmological parameter used in Pinocchio
    • Omegamatter = 0.307
    • OmegaLambda = 0.692
    • OmegaBaryon = 0.048
    • h = 0.677
    • sigma8 = 0.828
• Pinocchio2 (same parameter with Abacus)
  • Box size = 1100(Mpc/h)
  • rsd(2,3,4-point)
  • Cosmological parameter : same as Abacus(Planck 2015)
  • Cosmological parameter used in Pinocchio
    • Omegamatter = 0.314
    • OmegaLambda = 0.686
    • OmegaBaryon = 0.049
    • h = 0.6726
    • sigma8 = 0.830
• 2pcf, better : Pinocchio1 (same parameter with CMASS) < Pinocchio2 (same parameter with Abacus) < Abacus (N-body simulation)
• 2pcf, chi square : Abacus < Pinocchio with abacus parameter < Pinocchio with CMASS parameter
• 3pcf, chi square : Pinocchio with abacus parameter < Abacus < Pinocchio with CMASS parameter
• 4pcf, chi square : Pinocchio with abacus parameter < Abacus < Pinocchio with CMASS parameter

17:30 Dr.Sabiu's Report - 21cm paper referee report

Speaker: Dr Cristiano Sabiu (University of Seoul)

slides

• Started writing paper
  • 1. Introduction
    • a. 21cm - EoR -
    • b. Fuzzy Dark Matter / Axion
  • 2. Modeling
    • a. 21cmFAST -
      • i. Pots of 21cm Temperature / Snapshots / Lightcones
      • ii. Nuisance (astrophysical) parameters
    • b. AxionCAMB
      • i. Pots of initial P(k)
  • 3. Rionization History
• Referee Report
  • Editor : "I have received the reviewer's report on your above submission to The Astrophysical Journal, and is appended below. As you will see, the reviewer thinks that your manuscript is interesting and that it will merit publication once you have addressed the issues raised in the report."
  • Reviewer : This paper introduces a new way to probe the ultra light axion mass with future 21cm observations using convolution neural networks. I think this is an interesting idea, but many important aspects are lacking in this work and should be explored in order for it to be relevant for future observations.
    • 1. The authors vary some of the astrophysical parameters but set the cosmology to be fixed in their simulations. They should explore varying the cosmological parameters to explore these degeneracies with the axion mass. They should also include the neutrino mass in their simulations.
    • 2. The effect of the non-linear density field should be included (and Fig. 1 should be updated correspondingly).
    • 3. Foreground contamination should be added (with its amplitude varied) in the simulations. In sum, I believe that this article should not be published in its current form. The presentation of the machine learning technique is interesting, but it still needs work to be used as a practical tool for cosmology.

17:45 → 17:55 Discussion