Repository logo

Infoscience

  • English
  • French
Log In
Logo EPFL, École polytechnique fédérale de Lausanne

Infoscience

  • English
  • French
Log In
  1. Home
  2. Academic and Research Output
  3. Journal articles
  4. Strong Lens Time Delay Challenge. Ii. Results Of Tdc1
 
research article

Strong Lens Time Delay Challenge. Ii. Results Of Tdc1

Liao, Kai
•
Treu, Tommaso
•
Marshall, Phil
Show more
2015
The Astrophysical Journal

We present the results of the first strong lens time delay challenge. The motivation, experimental design, and entry level challenge are described in a companion paper. This paper presents the main challenge, TDC1, which consisted of analyzing thousands of simulated light curves blindly. The observational properties of the light curves cover the range in quality obtained for current targeted efforts (e.g., COSMOGRAIL) and expected from future synoptic surveys (e.g., LSST), and include simulated systematic errors. Seven teams participated in TDC1, submitting results from 78 different method variants. After describing each method, we compute and analyze basic statisticsmeasuring accuracy (or bias) A, goodness of fit chi(2), precision P, and success rate f. For some methods we identify outliers as an important issue. Other methods show that outliers can be controlled via visual inspection or conservative quality control. Several methods are competitive, i.e., give vertical bar A vertical bar < 0.03, P < 0.03, and chi(2) < 1.5, with some of the methods already reaching sub-percent accuracy. The fraction of light curves yielding a time delay measurement is typically in the range f = 20%-40%. It depends strongly on the quality of the data: COSMOGRAIL-quality cadence and light curve lengths yield significantly higher f than does sparser sampling. Taking the results of TDC1 at face value, we estimate that LSST should provide around 400 robust time-delay measurements, each with P < 0.03 and vertical bar A vertical bar < 0.01, comparable to current lens modeling uncertainties. In terms of observing strategies, we find that A and f depend mostly on season length, while P depends mostly on cadence and campaign duration.

  • Details
  • Metrics
Type
research article
DOI
10.1088/0004-637X/800/1/11
Web of Science ID

WOS:000349236900011

Author(s)
Liao, Kai
Treu, Tommaso
Marshall, Phil
Fassnacht, Christopher D.
Rumbaugh, Nick
Dobler, Gregory
Aghamousa, Amir
Bonvin, Vivien  
Courbin, Frederic  
Hojjati, Alireza
Show more
Date Issued

2015

Publisher

American Astronomical Society

Published in
The Astrophysical Journal
Volume

800

Issue

1

Start page

11

Subjects

gravitational lensing: strong

•

methods: data analysis

Editorial or Peer reviewed

REVIEWED

Written at

EPFL

EPFL units
LASTRO  
Available on Infoscience
May 29, 2015
Use this identifier to reference this record
https://infoscience.epfl.ch/handle/20.500.14299/114605
Logo EPFL, École polytechnique fédérale de Lausanne
  • Contact
  • infoscience@epfl.ch

  • Follow us on Facebook
  • Follow us on Instagram
  • Follow us on LinkedIn
  • Follow us on X
  • Follow us on Youtube
AccessibilityLegal noticePrivacy policyCookie settingsEnd User AgreementGet helpFeedback

Infoscience is a service managed and provided by the Library and IT Services of EPFL. © EPFL, tous droits réservés