tests:streams:challenges
Differences
This shows you the differences between two versions of the page.
Both sides previous revisionPrevious revisionNext revision | Previous revision | ||
tests:streams:challenges [2015/08/29 06:06] – cmateu_astrosen.unam.mx | tests: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:// | * [[http:// | ||
- | * [[http:// | + | * [[http:// |
* [[http:// | * [[http:// | ||
* [[http:// | * [[http:// | ||
Line 159: | Line 159: | ||
* $M_{Halo} = 1.81194\times 10^{12}\, | * $M_{Halo} = 1.81194\times 10^{12}\, | ||
- | * $R_{Halo} = 32260\,pc$ | + | * $r_{Halo} = 32260\,pc$ |
* $q_z = 0.8140$ | * $q_z = 0.8140$ | ||
* $M_{Pal5}(t=-4 Gyr) = 31090\, | * $M_{Pal5}(t=-4 Gyr) = 31090\, | ||
* $M_{Pal5}(t=today) = 13150\, | * $M_{Pal5}(t=today) = 13150\, | ||
* $d_{Sun} = 23190\,pc$ | * $d_{Sun} = 23190\,pc$ | ||
- | * $V_C(R_{Sun}) = 249.01\, | + | * $V_C(r_{Sun}) = 249.01\, |
- | * $V_C(R_{Pal5}) = 247.84\, | + | * $V_C(r_{Pal5}) = 247.84\, |
- | * $V_C(R_{Halo}) = 251.99\, | + | * $V_C(r_{Halo}) = 251.99\, |
- | * $a(R_{Sun}, 0, 0) = 7.95\, | + | * $a(r_{Sun}, 0, 0) = 7.95\, |
- | * $a(R_{Pal5}) = a(7816 pc, 240 pc, 16640 pc) = 3.51\, | + | * $a(r_{Pal5}) = a(7816 pc, 240 pc, 16640 pc) = 3.51\, |
- | * $a(R_{Halo}, 0, 0) = 2.06\, | + | * $a(r_{Halo}, 0, 0) = 2.06\, |
| | ||
== 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, | + | * $\Phi_{Halo}(R, |
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_{Bulge} = 3.4\times 10^{10}\, | ||
* $b_{Bulge} = 700.0\,pc$ | * $b_{Bulge} = 700.0\,pc$ | ||
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_{Disk} = 1.0\times 10^{11}\, | ||
* $a_{Disk} = 6500\,pc$ | * $a_{Disk} = 6500\,pc$ | ||
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, | 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, | ||
Line 247: | Line 247: | ||
- | ==complete | + | ===Complete |
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:// | [[ttp:// | ||
- | ==Error-convolved mock catalogue of individual halo stellar tracers (NEW-Aug 2015)== | + | ===Error-convolved mock catalogue of individual halo stellar tracers=== |
+ | (NEW-Aug 2015) | ||
These are Gaia observable K giant and RR Lyrae stars from the Aquarius A2 halo, | These are Gaia observable K giant and RR Lyrae stars from the Aquarius A2 halo, | ||
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:// | + | //Error prescriptions:// |
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 284: | Line 285: | ||
We also provide analogous catalogues for Andreea Font's LJMU Gas-Dynamical Simulations (see [[# | We also provide analogous catalogues for Andreea Font's LJMU Gas-Dynamical Simulations (see [[# | ||
- | ==realizations | + | ===Realizations |
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 344: | Line 345: | ||
Use a series of gas-dynamical simulations of Milky Way-type galaxies to retrieve the potential. | Use a series of gas-dynamical simulations of Milky Way-type galaxies to retrieve the potential. | ||
- | 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 Aquarius | + | 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' |
- | //Error prescriptions:// | + | //Error prescriptions:// |
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 352: | Line 353: | ||
* [[ https:// | * [[ https:// | ||
- | * [[ https:// | + | * [[ https:// |
* Catalogue file structure: | * Catalogue file structure: | ||
*Av, V, Gmag, Grvs : V-band extinction, V-band, G and Grvs apparent magnitudes | *Av, V, Gmag, Grvs : V-band extinction, V-band, G and Grvs apparent magnitudes | ||
Line 363: | Line 364: | ||
* [[ https:// | * [[ https:// | ||
* Progenitor info file structure: | * Progenitor info file structure: | ||
- | * IDstream, TreeID: progenitor ID, TreeID (Aquarius native | + | * IDstream, TreeID: progenitor ID, TreeID (alternative |
* infallZ, | * infallZ, | ||
* NKIII_all, NKIII_G20 : total number and Gaia observable (G<20) number of K giants stars in progenitor | * NKIII_all, NKIII_G20 : total number and Gaia observable (G<20) number of K giants stars in progenitor | ||
These are provisional files provided for Gaia Challenge purposes (potential | These are provisional files provided for Gaia Challenge purposes (potential | ||
- | fitting and stream finding challenges). The final set for all five haloes will be published in Mateu et al. in prep. | + | fitting and stream finding challenges). The final set for all haloes will be published in Mateu et al. in prep. |
==Publication policy== | ==Publication policy== |
tests/streams/challenges.1440828418.txt.gz · Last modified: 2022/10/24 12:26 (external edit)