Download presentation
Presentation is loading. Please wait.
Published byMarybeth Fletcher Modified over 9 years ago
1
1 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Name of Meeting Location Date - Change in Slide Master Catalogs Framework Andrew Connolly Simulations Scientist September 19-20, 2013 CDP FINAL DESIGN REVIEW September 19 - 20, 2013
2
2 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Introduction to Catalogs The LSST system is complex and resembles no other system in astronomy. Simulated data can be used to identify and quantify risk associated with various aspects of the project. Engineering sensitivity studies, algorithmic optimization, informing sizing models, and interface integration and testing are all areas where simulated data can provide significant leverage.
3
3 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Introduction to Catalogs Simple analysis can be done with simple catalogs: grids of point sources, or extended sources. To analyze the system in full complexity a Universal model with realistic properties beyond what is strictly required to meet design specifications is needed. We present a model of the universe containing galaxies, stars, moving objects and variable objects that meets the requirements in the Requirements Document and is also realistic at a level that facilitates in depth analysis of algorithms and science capabilities.
4
4 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Dust Model
5
5 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Introduction to Catalogs: Galactic Structure − Stars are embedded in a dust model based on that of Amôres and Lépine (2005) − So that there is no discontinuity in the measured reddening, the 3D dust model is normalized to the Schlegel et al. (1998) maps at 100 kpc. − A realistic dust distribution is important for tests of photometric calibration, photometric redshift algorithms, stellar population modeling, among others.
6
6 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013
7
7 Galaxies
8
8 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Introduction to Catalogs: Galaxies − Positions and redshifts from Millennium (Springel et al. 2005) assuming a standard Λ-CDM cosmology − Semi-analytic baryon model from De Lucia et al. (2006) − Light cone produces 4.5x4.5 degree footprint to z=6 and samples masses from 2.5x10 9 to 10 12 M − Using UVRIK magnitudes from the DeLucia catalogs for the disk and bulge, Bruzual and Charlot (2005) SEDs are fit for each component. − Sizes (half-light radius) are assigned using the absolute-magnitude vs. half-light radius relation from Gonzalez et al. (2009) − AGNs are assigned using the Bongiorno et al. (2012) luminosity functions. For each AGN it’s host galaxy colors and stellar mass are computed from empirical relations from SDSS data. These are used with the redshift to pick a host galaxy from the galaxy catalog.
9
9 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Introduction to Catalogs: Galaxies A section of the galaxy catalog showing the density of sources
10
10 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Galactic Structure
11
11 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Introduction to Catalogs: Galactic Structure − Stars in the galaxy are drawn from a realization of the Galfast model which uses density laws from Jurić et al. (2008) and metallicity and kinematic models from Ivezić et al. (2008) and Bond et al. (2010). These were all derived from SDSS data. − SEDs are assigned using the SDSS colors from the Galfast model F, G, and K main sequence and RGB use Kurucz (1993) models White Dwarfs use Bergeron et al. (1995) models M, L, and T Dwarfs from Cushing, Bochanski, Burrows, Patterson and Hawley, and Kowalski derived from SDSS data. The galactic dust model uses that of Amôres and Lépine (2005) normalized to the Schlegel et al. (1998) results at 100 kpc. − 10% of stars are variable at a level observable by LSST including RR Ly, Cepheids, and M-dwarf flares.
12
12 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Introduction to Catalogs: Galactic Structure The density of stars from the Galfast model of the galaxy.
13
13 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Solar System Model
14
14 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Introduction to Catalogs: Solar System − The solar system model is a realization of the Grav et al. (2007) model. This is the same model used by the Pan STARRS project. − All major groups are represented: main belt, NEO, trojans, TNOs and comets − The sample is complete to V=24.5 − Each object is assigned a carbonaceous or stony composition (DeMeo et al. 2009) based on a relation to the size of its orbit based on SDSS observations. − The package oorb (Granvic et al. 2009) is used to calculate the orbit and V band magnitude which is used to derive the LSST band observations at a given point in time
15
15 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Introduction to Catalogs: Solar System The distribution of objects in the Solar System Model color coded by population
16
16 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Query Framework
17
17 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Introduction to Catalogs: Query Framework − Query – Pure python and contains the mapping from schema to python objects and hooks for connecting to the database − Measurement and Formatting – Pure python (except for astrometry routines) and contains software for calculating astrometry and photometry given a time and pointing. Also contains mappings of python objects to catalog columns and formatting for catalogs. − Extensible through python sub-classing and inheritance. − Examples of catalogs are: Inputs to PhoSim reference catalogs moving objects and simulated alert streams calibration catalogs
18
18 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Validation of Catalogs
19
19 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Cumulative star counts for fields at l=90 o Stellar number counts Star counts from Galfast (Jurić et al. 2008; solid) compared to counts from the Besançon model (Robin et al. 2003). Symbols are star counts from the SDSS catalog. Sizing models Star galaxy separation Deblending PSF modeling
20
20 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Sensitivity of n eff on Galaxy Size Distribution 2 -4 -2 0 4 Wider distribution Comparison of the effective number of galaxies for weak lensing measurements relative to the value calculated from the COSMOS data (Chang et al. 20013). Weak lensing Size distributions
21
21 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Questions?
22
22 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Galaxy Number Counts Galaxy number counts matched to observed number counts (Metcalf et al. 2010) Sizing model Star galaxy separation Weak lensing
23
23 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Galaxy Ellipticity Top panels show the comparison of the base catalog ellipticity distribution to the COSMOS distribution. Bottom panels show a distributions that are too wide and to narrow to make the requirement (left and right respectively). Weak lensing Shape measurement Shape noise
24
24 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Stellar Color Accuracy Principal color definitions from Ivezic (2004)
25
25 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Stellar Color Accuracy Principal color distributions for stars from the Galfast model relative to the mean principal colors in the SDSS photometric system Calibration
26
26 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Stellar Color Distribution Color distribution of main sequence (forward hatched) and white dwarf (backward hatched) stars for high galactic latitude fields. Calibration
27
27 FINAL DESIGN REVIEW | TUCSON, AZ | OCTOBER 21-25, 2013 Solar System Model Accuracy Distribution of interpolation error for each of the populations in the solar system model. The mean is always below 1”. The requirement is 1”. Testing the moving object pipelines
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.