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--- tests:astropars [2015/06/11 08:51] – glennvdv
+++ tests:astropars [2022/10/24 12:10] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
 ====== Stellar parameters ======
-[[tests:astroparsII|tests:astroparsII]]
+The purpose of these exercises is to simulate finding astrophysical parameters from Gaia data, and addressing scientific problems through this. Our main focus is on using the low resolution BP/RP data for this, but we can  include the information from astrometry and possibly also high-resolution RVS data. The exact aim depends on which challenges are suggested and which are popular.
-[[tests:astroparsIII|tests:astroparsIII]]
+In Gaia Challenge II, this package was organized by Rene Andrae and Kester Smith
+In Gaia Challenge III, this package is organized by Melissa Ness and Kester Smith
-The purpose of these exercises is to simulate finding astrophysical parameters from Gaia data. We will focus on using the low resolution BP/RP data for this, but will include the information from astrometry and possibly also high-resolution RVS data. The exact aim depends on which challenges are suggested and which are popular. There may arise some constraints  connected to our ability to simulate particular datasets.
+[[tests:astropars:astroparsII|Second workshop]] astrophysical parameters
+[[tests:astropars:astroparsIII|Third workshop]] astrophysical parameters
-Package is organized by Rene Andrae and Kester Smith
@@ Line 21: / Line 21: @@
 === Default Data Package ===
-**NOTE: updated 14/10/2014**
-There was an error in the first version of this data set. Please download the new version.
-Here is the first set of mock data.
-This has been made as follows;
-  *  Obtain a sample of objects from the Gaia Universe Model Snapshot catalogue. Coordinates are l,b=0,80 (so a sparse halo field). There are just over 2000 objects.
-  * Use Gog to produce BP,RP, RVS spectra. Note: there are few RVS spectra
-  * Gog results are held in the file gums_0_80_v1.dat. Data include position, proper motion, parallax, Radial velocity, Gaia band fluxes, and basic astrophysical parameters.
-  * BP, RP and RVS spectra are in separate files (identify with the sourceId included in the filename) The columns are wavelength,flux, error
-  * BP,RP wavelengths are currently in 'pseudo-wavelengths' (~pixel numbers). I will try to provide an approximate true wavelength scale soon.
-  * I will provide a mean instrument model (line spread function + sensitivity function) soon.
-In the meantime, please have a look at this data and let me have any comments re: ease of use (or more likely the opposite), any suggestions  etc etc.
-The data set is in the mpia public ftp site (mpia-hd.mpg.de), in pub/smith/gaiachallenge, name gums_0_80_v1.tar
-Also available;
-  *  bprpWavelengths.dat , which are the wavelengths in nm
-  *  bprpTransmission.dat , which is the total transmission function (column 1: bp, column 2: rp)
-  *  bprpLsfs.tar , a set of LSFs, one for each pixel. The wavelengths are indicated in the filename. The offsets are in pixel coordinates.
@@ Line 47: / Line 31: @@
-=== Challenges ===
-== Challenge 1 ==
-Two datasets are available from the mpia public ftp site (mpia-hd.mpg.de), in
-pub/smith/gaiachallenge/andrae, name andraeChallengeV1.tar.
-Unpack the tar archive to obtain;
- * nominal-grid-MARCS.csv  - basic APs and noise-free spectra for the a grid of known stars
- * test-data-MARCS-reduced.csv - basic data (position,astrometry,photometry) fro a set of test sources
- * test-spectra/* - files containing noisy  BP/RP data for the test data.
-The challenge is to estimate the APs (Teff, logg, Fe/H, AV) for the test spectra.
-== Challenge 2 ==
-Set of reference spectra supplied by Paula Jofre.
-These are available at the MPIA anonymous ftp site. cd to
-pub/smith/gaiachallenge/jofre and pick up the tar file.
-The file contains bp and rp spectra for 32 stars, plus the file jofre_v1.dat
-which contains the positions, astrometry, photometry, RV and VsinI for each source.
-**UPDATE** Also available jofre_v1_rvs.dat, containing rvs spectra for all stars.
-This sample has been selected from observations taken with high resolution from the
-Ground. These stars are candidates to be reference stars for Gaia in the near
-future.  The high-resolution spectra were then convolved and transformed to BP-RP
-spectra using GOG.  The challenge is to try to determine their parameters, in a
-totally blind way, and then we can during the workshop compare with high-resolution
-ground based analyses.
-== Challenge 3a ==
-Data for several **moving groups** was run through GOG. The results are available on
-the ftp site in directory murphy in file movingGroupsKnown.tar
-The challenge is just to look at the data!
-// From: Andy Casey //
-See how	well the working group can recover astrophysical parameters for a sample of N (where N is ~"large") stars. The spectra could be interpolated from	model spectra, doppler shifted,	  resampled and convolved with some profile	which would roughly represent the Gaia RVS, and	with noise + jitter   added. Making it a blind test would be much more fun.
-// From: Andy Casey //
-Fitting low-resolution BP/RP spectra and high-resolution (AMBRE grid from Gaia-ESO, not RVS from Gaia) spectra simultaneously. Does it outperform fitting each individually? High-resolution model grid is from MARCS and BP/RP are provided in MARCS, too.
-// From: Maria Bergemann //
-the performance
-of our new Bayesian pipeline [[http://adsabs.harvard.edu/abs/2014MNRAS.443..698S |(Schoenrich & Bergemann 2013)]] on the Mock Gaia photometry+RVS+parallax
-data samples.
-// From: Simon Murphy //
-Finding	*new* young moving groups in the solar neighbourhood (<1 kpc say) using
-a combination of BP,RP photometry, astrometry and RVS velocities.
-// From: Kester Smith //
-Identify the red clump.
-// From: Kester Smith //
-Identify the blue horizontal branch.
-// From: Kester Smith //
-identify extreme metallicity stars (ultra low, or very high alpha enhanced, or some other extreme)
-// From: Rene //
-validation of HR diagram: do all relevant types of stars exist in test data? do they end up in the right region of the HRD?
-=== Useful references ===
-  * CU8 APSIS: [[http://adsabs.harvard.edu/abs/2013A%26A...559A..74B|Bailer-Jones et al. (2013)]], [[http://adsabs.harvard.edu/abs/2012MNRAS.426.2463L|Liu et al. (2012)]]
-  * Combining photometry, spectroscopy & astrometry: [[http://adsabs.harvard.edu/abs/2011MNRAS.411..435B|Bailer-Jones (2011)]], [[http://adsabs.harvard.edu/abs/2014MNRAS.443..698S |Schoenrich & Bergemann (2013)]]
-  * Gaia Object Generator (GOG): [[http://adsabs.harvard.edu/abs/2014A%26A...566A.119L|Luri et al. (2014)]]
-  * Gaia Universe Model Snapshot (GUMS): [[http://adsabs.harvard.edu/abs/2012A%26A...543A.100R|Robin et al. (2012)]]
-  * Benchmark stars: [[http://adsabs.harvard.edu/abs/2014A%26A...564A.133J|Jofre et al. (2014)]], [[http://adsabs.harvard.edu/abs/2014A%26A...566A..98B|Blanco-Cuaresma et al. (2014)]]
-  * Conversion to Gaia magnitudes: [[http://adsabs.harvard.edu/abs/2010A%26A...523A..48J|Jordi et al. (2010)]]
-  * Extinction laws: [[http://adsabs.harvard.edu/abs/1989ApJ...345..245C|Cardelli et al. (1989)]], [[http://adsabs.harvard.edu/abs/1999PASP..111...63F|Fitzpatrick (1999)]]