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--- tests:streams:results [2014/10/31 12:11] – [Spherical stellar halo] jason.sanders
+++ tests: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]]
     - [[#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====
@@ Line 34: / Line 47: @@
 === Kohei Hattori ===
+[Kohei2015]
+I use 50 randomly selected stars (without error) from the leading or trailing streams.
+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
+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|}}
+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|}}
+[Kohei2014]
 I selected in total 200 stars (without error) from the leading or trailing streams.
 I assume that the potential is flattened logarithmic potential and fit the data to derive the parameters $(q,v_0)$.
@@ Line 40: / Line 73: @@
 {{:tests:streams:pal5_kohei_hattori_200stars_without_error.jpg?200|}}
-acceleration at Pal 5: $3.16 \pm 0.068 \;pc/Myr^2$
+acceleration at Pal 5:
+$3.168 \pm 0.06 \;pc/Myr^2$ (for all 200 stars)
+$3.299 \pm 0.04 \;pc/Myr^2$ (for 100 stars in leading stream)
+$2.670 \pm 0.20 \;pc/Myr^2$ (for 100 stars in trailing stream)
 === Jo Bovy ===
@@ Line 68: / Line 107: @@
 {{ :tests:streams:sergey_pal5_mcmc.png?200 |}}
+==Jason Sanders==
+I attempted to fit the potential with the location of the progenitor known and no errors. I used only 30 stars. I fitted both a logarithmic potential (just two parameters circular velocity Vc and flattening q) and the full potential used for the simulation with all parameters bar the halo parameters held fixed.
+{{:tests:streams:jls_pal5_truepot.png?300|}}
+{{:tests:streams:pal5_noerrors_logarithmic_vcq.png?300|}}
+{{:tests:streams:pal5_noerrors_logarithmic_acc.png?300|}}
+The blue histogram is the acceleration at Pal5 distribution using the logarithmic and green is using the correct potential form. The red line shows the true value.
 ==== The Via Lactea challenge ====
@@ Line 146: / 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.
+===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====