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LSST school workshop: Getting ready to do science with LSST data
Improved Point Source Detection in Crowded Fields using Probabilistic Cataloging (8938) - Mardi 13 juin 2017 11:50 - 12:15

Improved Point Source Detection in Crowded Fields using Probabilistic Cataloging

Cataloging is challenging in crowded fields because sources are extremely covariant with their neighbors and blending makes even the number of sources ambiguous. We present the first optical probabilistic catalog, cataloging a crowded (~0.1 sources per pixel brighter than 22nd magnitude in F606W) Sloan Digital Sky Survey r band image from M2. Probabilistic cataloging returns an ensemble of catalogs inferred from the image and thus can capture source-source covariance and deblending ambiguities. By comparing to a traditional catalog of the same image and a Hubble Space Telescope catalog of the same region, we show that our catalog ensemble better recovers sources from the image. It goes more than a magnitude deeper than the traditional catalog while having a lower false discovery rate brighter than 20th magnitude. We also present an algorithm for reducing this catalog ensemble to a condensed catalog that is similar to a traditional catalog, except it explicitly marginalizes over source-source covariances and nuisance parameters. We show that this condensed catalog has a similar completeness and false discovery rate to the catalog ensemble. Future telescopes will be more sensitive, and thus more of their images will be crowded. Probabilistic cataloging performs better than existing software in crowded fields and so should be considered when creating photometric pipelines in the Large Synoptic Survey Telescope era.

Mr. Stephen PORTILLO (Harvard-Smithsonian Center for Astrophysics)

Toutes les vidéos de l'évenement LSST school workshop: Getting ready to do science with LSST data (35 videos)

00:57:52.63

2017-06-12

09:05 - 10:30 : Point sources and astrometry

00:19:33.76

2017-06-12

11:00 - 11:30 : Point sources and astrometry (cont.)

00:53:58.55

2017-06-12

11:30 - 12:30 : Extended sources and galaxy photometry

00:42:27.54

2017-06-12

14:00 - 15:00 : Extended sources and galaxy photometry (cont.)

00:40:20.86

2017-06-12

15:00 - 15:30 : Image differencing

01:21:04.24

2017-06-12

16:00 - 17:30 : Image differencing (cont.)

00:47:16.06

2017-06-13

09:20 - 10:00 : PSF parameter estimation

00:39:50.93

2017-06-13

09:20 - 10:00 : Efficient multi-band deblending

00:36:08.77

2017-06-13

11:10 - 11:50 : LSST DM Processing of Crowded Fields

00:24:52.80

2017-06-13

11:50 - 12:15 : Improved Point Source Detection in Crowded Fields using Probabili...

00:35:12.33

2017-06-13

14:00 - 14:45 : Hyper Suprime-Cam Subaru Strategic Program

00:47:18.80

2017-06-13

14:45 - 15:30 : HSC data meets LSST code

00:30:32.70

2017-06-13

16:00 - 16:40 : Photometry extraction and validation using the HSC pipeline of HS...

00:49:15.71

2017-06-13

16:40 - 17:20 : Reprocessing CFHT data with the LSST DM software stack

00:39:19.51

2017-06-13

17:20 - 18:00 : Reprocessing CFHT Deep fields with the stack

00:33:20.11

2017-06-14

09:00 - 09:30 : Joint astrometry

00:29:58.54

2017-06-14

09:30 - 10:00 : Creating DCR-matched templates for image differencing

00:32:01.48

2017-06-14

10:00 - 10:30 : Advances in astronomical image processing - Solving the problems ...

00:32:11.88

2017-06-14

11:00 - 11:30 : LSST DM stack image differencing on CFHT images

00:34:11.44

2017-06-14

14:00 - 14:35 : Dark Energy Survey - Status, Science, and Algorithmic Advancement...

00:32:37.68

2017-06-14

14:35 - 15:10 : Forward Global Calibration of the Dark Energy Survey [remote pres...

00:36:19.72

2017-06-14

15:10 - 15:45 : Photometric Calibration: lessons from CFHTLS

00:24:44.83

2017-06-14

16:10 - 16:40 : PHOTOMETRYPIPELINE: An automated pipeline for calibrated photomet...

00:27:32.14

2017-06-15

09:00 - 09:30 : LSST Data Management Overview

00:41:45.78

2017-06-15

09:30 - 10:10 : What LSST Will Deliver: Images, Catalogs, Alerts, Services

00:33:17.41

2017-06-15

10:10 - 10:40 : Qserv: A distributed shared-nothing database for the LSST catalog

00:31:42.47

2017-06-15

11:10 - 11:40 : Scaling cloud for LSST catalog at IN2P3

00:44:12.37

2017-06-15

11:40 - 12:20 : LHC experiments : Petabytes to papers

00:34:58.27

2017-06-15

12:20 - 12:50 : Exploring Spark and MongoDb for LSST

00:40:06.94

2017-06-15

14:00 - 14:40 : Euclid - An update on the mission and its processing plan

00:32:55.31

2017-06-15

14:40 - 15:20 : The Dark Energy Survey Data Management System [remote presentatio...

00:33:43.47

2017-06-15

15:50 - 16:20 : Weak Lensing Data processing for the CFHTLenS and KiDS surveys [r...

00:35:11.10

2017-06-15

16:20 - 17:00 : Lessons from a Large Survey: The First Decade of Pan-STARRS Obser...

00:16:24.21

2017-06-15

17:00 - 17:10 : CosmoHub demonstration [spontaneous contribution]

00:04:11.44

2017-06-15

17:10 - 17:20 : Workshop: Wrap up

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