User Tools

Site Tools


tests:streams:results

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revisionPrevious revision
Next revision
Previous revision
tests:streams:results [2015/09/01 12:06] – [The new Palomar 5 challenge] khattoritests:streams:results [2022/10/24 12:26] (current) – external edit 127.0.0.1
Line 14: Line 14:
     - [[#the_old_palomar_5_challenge|The old Palomar 5 challenge]]     - [[#the_old_palomar_5_challenge|The old Palomar 5 challenge]]
     - [[#spherical_halo_challenge|Spherical Halo Challenge]]     - [[#spherical_halo_challenge|Spherical Halo Challenge]]
-===== 1. Gaia Challenge 2014 =====+===== 1. Gaia Challenge 2014-2015 ===== 
 + 
 + 
 +==== Finding streams in the halo ==== 
 + 
 +===  Paola Re Fiorentin & Alessandro Spagna === 
 + 
 +We selected all the stream stellar particles within 3 kpc of the Sun from Robyn Sanderson's data set and applied the random errors expected for FGK dwarfs as estimated by [[http://adsabs.harvard.edu/abs/2015arXiv150803736R| Re Fiorentin et al. 2015]]. 
 + 
 +{{ :tests:streams:spagna_figura10b.png?600 |}} 
 + 
 +Here, we present the resulting Lxy vs. Lz distribution of the "expected" local streams found using the "true" values (bottom panel),  the final Gaia catalog (middle panel), and the current ground based surveys (top panel). 
 + 
  
 ====The new Palomar 5 challenge==== ====The new Palomar 5 challenge====
Line 38: Line 51:
 I assumed the correct parameters for disc and bulge potential as well as the correct scale length for the halo potential.  I assumed the correct parameters for disc and bulge potential as well as the correct scale length for the halo potential. 
 I model the orbital energy distribution in each tail as a Gaussian distribution and  I model the orbital energy distribution in each tail as a Gaussian distribution and 
-run an emcee code to derive the posterior distribution of $(M/(10^{10}M_\odot), q_z)$. +run an emcee code to derive the posterior distribution of $(M/(10^{12}M_\odot), q_z)$. 
  
  
 {{:tests:streams:bothlt_n50_5e3_1e4_120min_line-triangle_two_params.png?200|}} {{:tests:streams:bothlt_n50_5e3_1e4_120min_line-triangle_two_params.png?200|}}
 +
 +The results for $(M/(10^{12}M_\odot), q_z, R_{Halo})$:
 +
 +A sample of 50 stars:
 +{{:tests:streams:from0000_line-triangle_three_params.png?200|}}
 +
 +Another different sample of 50 stars and the histogram of acceleration at Pal5 for this sample:
 +{{:tests:streams:from3000_line-triangle_three_params.png?200|}}
 +{{:tests:streams:hist_acc_kohei.png?200|}}
  
  
Line 171: Line 193:
 The red lines show the true values. The black dots and lines are for the error-free data. The green dots and lines are with errors. The blue lines show lines of constant acceleration at r = 4.2, 13, 20 kpc.  The red lines show the true values. The black dots and lines are for the error-free data. The green dots and lines are with errors. The blue lines show lines of constant acceleration at r = 4.2, 13, 20 kpc. 
  
 +
 +===Kohei Hattori===
 +[Kohei2015]
 +I use 50 randomly selected stars (without error) from a single stream. I model the orbital energy distribution in the stream (without distinguishing leading and trailing streams) as a Gaussian distribution and run an emcee code to derive the posterior distribution of $(\log_{10} M/M_\odot, \log_{10} b/{\rm kpc})$.
 +
 +Results for Stream #41
 +{{:tests:streams:kohei_isochrone41_line-triangle_two_params.png?200|}}
 +{{:tests:streams:isochrone41_posterior_kohei.png?200|}}
 +
 +Results for Stream #79
 +{{:tests:streams:kohei_isochrone79_line-triangle_two_params.png?200|}}
 +
 +Results for Stream #111
 +{{:tests:streams:kohei_isochrone111_line-triangle_two_params.png?200|}}
 +
 +Why b is overestimated in some cases? [e.g., #41]
 +{{:tests:streams:sphericalisochrone_radius_energy.png?200|}}
 ====Finding streams in the halo challenge==== ====Finding streams in the halo challenge====
  
tests/streams/results.1441109211.txt.gz · Last modified: 2022/10/24 12:26 (external edit)