User Tools

Site Tools

Trace:
tests:streams:challenges

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:challenges [2015/08/29 18:32] – cmateu_astrosen.unam.mxtests:streams:challenges [2022/10/24 12:26] (current) – external edit 127.0.0.1
Line 33: Line 33:
        * *.obs.* are convolved observable coordinates and error bars. The 11 columns are: apparent V magnitude, RA, dec, parallax, parallax error, proper motion in RA, PM_{RA} error, PM in dec, PM_{dec} error, RV, RV error.        * *.obs.* are convolved observable coordinates and error bars. The 11 columns are: apparent V magnitude, RA, dec, parallax, parallax error, proper motion in RA, PM_{RA} error, PM in dec, PM_{dec} error, RV, RV error.
   * [[http://user.astro.columbia.edu/~robyn/SphericalIsochrone.GaiaOnly/SphericalIsochrone.GaiaOnly.20streams.tgz|SphericalIsochrone.GaiaOnly.20streams.tgz]] --- subset of 20 streams convolved with Gaia errors, same naming convention/columns as above   * [[http://user.astro.columbia.edu/~robyn/SphericalIsochrone.GaiaOnly/SphericalIsochrone.GaiaOnly.20streams.tgz|SphericalIsochrone.GaiaOnly.20streams.tgz]] --- subset of 20 streams convolved with Gaia errors, same naming convention/columns as above
-  * [[http://user.astro.columbia.edu/~robyn/SphericalIsochrone.GaiaOnly/SphericalIsochone.GaiaOnly.subsample.tgz|SphericalIsochone.GaiaOnly.subsample.tgz]] --- for exploratory plotting purposes, two files containing 1/20th of the stars in each progenitor with full 6D coordinates, concatenated into one big list (~10MB), with (.cxv) and without (.txv) errors. +  * [[http://user.astro.columbia.edu/~robyn/SphericalIsochrone.GaiaOnly/SphericalIsochrone.GaiaOnly.subsample.tgz|SphericalIsochrone.GaiaOnly.subsample.tgz]] --- for exploratory plotting purposes, two files containing 1/20th of the stars in each progenitor with full 6D coordinates, concatenated into one big list (~10MB), with (.cxv) and without (.txv) errors. 
   * [[http://user.astro.columbia.edu/~robyn/SphericalIsochrone.GaiaOnly/SphericalIsochone.GaiaOnly.sub.info|SphericalIsochone.GaiaOnly.sub.info]] --- for each progenitor, lists the ID number, number of stars with full measured 6D positions (i.e. the number of rows in each of the data files in .All and .20streams), and number included in .subsample.   * [[http://user.astro.columbia.edu/~robyn/SphericalIsochrone.GaiaOnly/SphericalIsochone.GaiaOnly.sub.info|SphericalIsochone.GaiaOnly.sub.info]] --- for each progenitor, lists the ID number, number of stars with full measured 6D positions (i.e. the number of rows in each of the data files in .All and .20streams), and number included in .subsample.
   * [[http://user.astro.columbia.edu/~robyn/SphericalIsochrone.GaiaOnly/SphericalIsochrone.progs.info|SphericalIsochrone.progs.info]] --- information about the progenitors of the streams: ID#, *total* number of [RGB] stars in the original progenitor, time since infall in Myr, log luminosity in solar units, log *total* mass (stars+dark matter) in solar masses, scale radius in kpc, velocity dispersion in km/s, orbital apocenter radius in kpc, and orbital circularity [=L/L_circ(E)].   * [[http://user.astro.columbia.edu/~robyn/SphericalIsochrone.GaiaOnly/SphericalIsochrone.progs.info|SphericalIsochrone.progs.info]] --- information about the progenitors of the streams: ID#, *total* number of [RGB] stars in the original progenitor, time since infall in Myr, log luminosity in solar units, log *total* mass (stars+dark matter) in solar masses, scale radius in kpc, velocity dispersion in km/s, orbital apocenter radius in kpc, and orbital circularity [=L/L_circ(E)].
Line 159: Line 159:
  
   * $M_{Halo} = 1.81194\times 10^{12}\,M_{\odot}$   * $M_{Halo} = 1.81194\times 10^{12}\,M_{\odot}$
-  * $R_{Halo} = 32260\,pc$+  * $r_{Halo} = 32260\,pc$
   * $q_z = 0.8140$   * $q_z = 0.8140$
   * $M_{Pal5}(t=-4 Gyr) = 31090\,M_{\odot}$   * $M_{Pal5}(t=-4 Gyr) = 31090\,M_{\odot}$
   * $M_{Pal5}(t=today) = 13150\,M_{\odot}$   * $M_{Pal5}(t=today) = 13150\,M_{\odot}$
   * $d_{Sun} = 23190\,pc$   * $d_{Sun} = 23190\,pc$
-  * $V_C(R_{Sun}) = 249.01\,km/s$ +  * $V_C(r_{Sun}) = 249.01\,km/s$ 
-  * $V_C(R_{Pal5}) = 247.84\,km/s$ +  * $V_C(r_{Pal5}) = 247.84\,km/s$ 
-  * $V_C(R_{Halo}) = 251.99\,km/s$ +  * $V_C(r_{Halo}) = 251.99\,km/s$ 
-  * $a(R_{Sun}, 0, 0) = 7.95\,pc/Myr^2$ +  * $a(r_{Sun}, 0, 0) = 7.95\,pc/Myr^2$ 
-  * $a(R_{Pal5}) = a(7816 pc, 240 pc, 16640 pc) = 3.51\,pc/Myr^2$ +  * $a(r_{Pal5}) = a(7816 pc, 240 pc, 16640 pc) = 3.51\,pc/Myr^2$ 
-  * $a(R_{Halo}, 0, 0) = 2.06\,pc/Myr^2$+  * $a(r_{Halo}, 0, 0) = 2.06\,pc/Myr^2$
      
 == Functional form of the potential components == == Functional form of the potential components ==
Line 175: Line 175:
 Flattened NFW halo: Flattened NFW halo:
  
-  * $\Phi_{Halo}(R, z) = -\frac{GM}{\sqrt{R^2+\frac{z^2}{q_z^2}}}\ln\left(1+\frac{\sqrt{R^2+\frac{z^2}{q_z^2}}}{R_{Halo}} \right)$+  * $\Phi_{Halo}(R, z) = -\frac{GM}{\sqrt{R^2+\frac{z^2}{q_z^2}}}\ln\left(1+\frac{\sqrt{R^2+\frac{z^2}{q_z^2}}}{r_{Halo}} \right)$
  
 Jaffe bulge: Jaffe bulge:
  
-  * $\Phi_{Bulge} = \frac{GM_{Bulge}}{b_{bulge}}\ln{\frac{R}{R+b_{bulge}}$+  * $\Phi_{Bulge}(r) = \frac{GM_{Bulge}}{b_{bulge}}\ln{\frac{r}{r+b_{bulge}}$
   * $M_{Bulge} = 3.4\times 10^{10}\,M_\odot$   * $M_{Bulge} = 3.4\times 10^{10}\,M_\odot$
   * $b_{Bulge} = 700.0\,pc$   * $b_{Bulge} = 700.0\,pc$
Line 185: Line 185:
 Miyamoto-Nagai disk: Miyamoto-Nagai disk:
  
-  * $\Phi_{Disk} = -\frac{GM_{Disk}}{\sqrt{R^2+\left(a_{Disk}+\sqrt{z^2+b_{Disk}^2}\right)^2}}$+  * $\Phi_{Disk}(r) = -\frac{GM_{Disk}}{\sqrt{R^2+\left(a_{Disk}+\sqrt{z^2+b_{Disk}^2}\right)^2}}$
   * $M_{Disk} = 1.0\times 10^{11}\,M_{\odot}$   * $M_{Disk} = 1.0\times 10^{11}\,M_{\odot}$
   * $a_{Disk} = 6500\,pc$   * $a_{Disk} = 6500\,pc$
Line 224: Line 224:
 The dataset is based on a dark matter N-body simulation populated with stars. The simulation used is the Aquarius A halo (Springel et al. 2008). The Cooper et al 2010 method has been used to populate the halo with stars. This uses the semi-analytical model Galform to predict star formation occurring in each subhalo. The stellar mass is then tagged onto the most bound 1% dark matter particles in the corresponding haloes in the N-body simulation at the appropriate times. These tagged dark matter particles can be located in the final snapshot to track where the stellar mass ends up. The dataset is based on a dark matter N-body simulation populated with stars. The simulation used is the Aquarius A halo (Springel et al. 2008). The Cooper et al 2010 method has been used to populate the halo with stars. This uses the semi-analytical model Galform to predict star formation occurring in each subhalo. The stellar mass is then tagged onto the most bound 1% dark matter particles in the corresponding haloes in the N-body simulation at the appropriate times. These tagged dark matter particles can be located in the final snapshot to track where the stellar mass ends up.
  
-==== Stream catalogue ====+=== Stream catalogue ===
  
 10 streams extracted from the Aquarius A-2 simulation. These have been visually selected as extended, coherent objects in the process of disruption. Each stream is made up by a random subset of the particles that were once a member of the progenitor satellite. In each case while the majority of particles will either be in the satellite or in the stream structure, however, a notable fraction may be completely disassociated. 10 streams extracted from the Aquarius A-2 simulation. These have been visually selected as extended, coherent objects in the process of disruption. Each stream is made up by a random subset of the particles that were once a member of the progenitor satellite. In each case while the majority of particles will either be in the satellite or in the stream structure, however, a notable fraction may be completely disassociated.
Line 236: Line 236:
 Streams have been populated with one red KIII giant per 40 solar masses (Helmi et al. 2011; Marigo et al. 2008), with M_V = 1, V-I = 1. The sample includes stars with G band > 20, which would be outside of the Gaia limits. Removing these stars eliminates several of the streams. Streams have been populated with one red KIII giant per 40 solar masses (Helmi et al. 2011; Marigo et al. 2008), with M_V = 1, V-I = 1. The sample includes stars with G band > 20, which would be outside of the Gaia limits. Removing these stars eliminates several of the streams.
  
-==halo star catalogue==+===Halo star catalogue===
  
 This is the whole stellar halo catalogue based on the Aquarius A-2 simulation. Details about how the catalogue is constructed can be found in Cooper et al. (2010). The catalogue includes all the accreted particles in the stellar halo. It is the parent catalogue used to make the 10 streams in the stream catalogue above. Again the Sun has been placed at 8 kpc with a velocity of (0,220,0)km/s, All positions/velocities are given in heliocentric coordinates. Files are in ASCII format, with the first line giving the number of objects in the file. Notice each object, instead of being a single star, is a particle that represents a single stellar population. The following data files are available:  This is the whole stellar halo catalogue based on the Aquarius A-2 simulation. Details about how the catalogue is constructed can be found in Cooper et al. (2010). The catalogue includes all the accreted particles in the stellar halo. It is the parent catalogue used to make the 10 streams in the stream catalogue above. Again the Sun has been placed at 8 kpc with a velocity of (0,220,0)km/s, All positions/velocities are given in heliocentric coordinates. Files are in ASCII format, with the first line giving the number of objects in the file. Notice each object, instead of being a single star, is a particle that represents a single stellar population. The following data files are available: 
Line 247: Line 247:
  
  
-==complete mock catalogue of individual halo stars==+===Complete mock catalogue of individual halo stars===
  
 Each particle in the halo star catalogue above represents a stellar population instead of individual stars. We have further sampled these particles into individual stars and details about the sampling can be found in  Each particle in the halo star catalogue above represents a stellar population instead of individual stars. We have further sampled these particles into individual stars and details about the sampling can be found in 
 [[ttp://adsabs.harvard.edu/abs/2014arXiv1406.2320L | Lowing et al. (2014)]]. A complete mock catalogue containing all the stars in the accreted stellar halo is available at http://galaxy-catalogue.dur.ac.uk:8080/StellarHalo, as a public SQL database. This catalogue contains useful observed properties of stars such as their magnitudes in five SDSS bands and effective temperature. [[ttp://adsabs.harvard.edu/abs/2014arXiv1406.2320L | Lowing et al. (2014)]]. A complete mock catalogue containing all the stars in the accreted stellar halo is available at http://galaxy-catalogue.dur.ac.uk:8080/StellarHalo, as a public SQL database. This catalogue contains useful observed properties of stars such as their magnitudes in five SDSS bands and effective temperature.
  
-==Error-convolved mock catalogue of individual halo stellar tracers==+===Error-convolved mock catalogue of individual halo stellar tracers===
 (NEW-Aug 2015) (NEW-Aug 2015)
  
Line 258: Line 258:
 extracted from the Lowing et al. 2015 mock catalogues explained in the previous subsection. extracted from the Lowing et al. 2015 mock catalogues explained in the previous subsection.
  
-//Error prescriptions://  Proper motion and radial velocity errors have been simulated with Gaia error prescriptions as of Jun-2015 in [[ https://github.com/mromerog/Gaia-errors | Merce Romero’s Gaia error code]]. Photometric distance errors of 20% and 7% have been simulated for K giants and RR Lyrae stars respectively (these precisions are achievable using Gaia data for photometric distance measurements). The simulation of observables includes the effect of extinction, based on the 3D reddennig map from Drimmel et al. (2003). +//Error prescriptions://  Proper motion and radial velocity errors have been simulated with Gaia error prescriptions as of Jun-2015 in [[ https://github.com/mromerog/Gaia-errors | Merce Romero’s Gaia error code]]. Photometric distance errors of 20% and 7% have been simulated for K giants and RR Lyrae stars respectively (these precisions are achievable using Gaia data for photometric distance measurements). The simulation of observables includes the effect of extinction, based on the 3D reddennig map from Drimmel et al. (2003). The Sun has been placed at X=8 kpc with a velocity of (0,220,0)km/s.
  
 The SQL queries used to extract the stars are provided as part of each file’s header.  The SQL queries used to extract the stars are provided as part of each file’s header. 
Line 285: Line 285:
 We also provide analogous catalogues for Andreea Font's LJMU Gas-Dynamical Simulations (see [[#gas-dynamical_challenge|Gas-dynamical Challenge]]). We also provide analogous catalogues for Andreea Font's LJMU Gas-Dynamical Simulations (see [[#gas-dynamical_challenge|Gas-dynamical Challenge]]).
  
-====realizations of tracers obeying the Eddington formula with two integrals of motion and NFW potential====+===Realizations of tracers obeying the Eddington formula with two integrals of motion and NFW potential===
  
 The full phase space distribution of a tracer population bound to an idealized dark matter halo potential can be obtained from the Eddington formula, assuming a particular parameterization of the distribution function (DF). We have approximated the potential of Aquairus halo A using a spherical NFW fit to its dark matter density profile and randomly sampled N points from a corresponding DF having two integrals of motion (binding energy and angular momentum), assuming a simple form for the tracer density and velocity anisotropy. The full phase space distribution of a tracer population bound to an idealized dark matter halo potential can be obtained from the Eddington formula, assuming a particular parameterization of the distribution function (DF). We have approximated the potential of Aquairus halo A using a spherical NFW fit to its dark matter density profile and randomly sampled N points from a corresponding DF having two integrals of motion (binding energy and angular momentum), assuming a simple form for the tracer density and velocity anisotropy.
Line 347: Line 347:
 Here are two mock catalogues for K giant stars in two Haloes from Andreea Font's LJMU Gas-Dynamical simulations (Font et al. in prep). We have used the same methods as for the [[#error-convolved_mock_catalogue_of_individual_halo_stellar_tracers|Error-convolved mock catalogue of individual halo stellar tracers]]: i.e. Ben Lowing's code (2015) to resample star particles into individual stars, Xue et al. (2014) criteria to select K giant stars and the same error prescriptions (described below). Here are two mock catalogues for K giant stars in two Haloes from Andreea Font's LJMU Gas-Dynamical simulations (Font et al. in prep). We have used the same methods as for the [[#error-convolved_mock_catalogue_of_individual_halo_stellar_tracers|Error-convolved mock catalogue of individual halo stellar tracers]]: i.e. Ben Lowing's code (2015) to resample star particles into individual stars, Xue et al. (2014) criteria to select K giant stars and the same error prescriptions (described below).
  
-//Error prescriptions://  Proper motion and radial velocity errors have been simulated with Gaia error prescriptions as of Jun-2015 in [[ https://github.com/mromerog/Gaia-errors | Merce Romero’s Gaia error code]]. Photometric distance errors of 20% have been simulated for K giants (e.g. Xue et al. 2014). The simulation of observables includes the effect of extinction, based on the 3D reddennig map from Drimmel et al. (2003). +//Error prescriptions://  Proper motion and radial velocity errors have been simulated with Gaia error prescriptions as of Jun-2015 in [[ https://github.com/mromerog/Gaia-errors | Merce Romero’s Gaia error code]]. Photometric distance errors of 20% have been simulated for K giants (e.g. Xue et al. 2014). The simulation of observables includes the effect of extinction, based on the 3D reddennig map from Drimmel et al. (2003). The Sun has been placed at X=8 kpc with a velocity of (0,220,0)km/s.
  
 The SQL queries used to extract the stars are provided as part of each file’s header.  The SQL queries used to extract the stars are provided as part of each file’s header. 
tests/streams/challenges.1440873172.txt.gz · Last modified: 2022/10/24 12:26 (external edit)