Advanced

Probabilistic fibre-to-target assignment algorithm for multi-object spectroscopic surveys

Tempel, E. ; Norberg, P. ; Tuvikene, T. ; Bensby, T. LU ; Chiappini, C. ; Christlieb, N. ; Cioni, M. R.L. ; Comparat, J. ; Davies, L. J.M. and Guiglion, G. , et al. (2020) In Astronomy and Astrophysics 635.
Abstract

Context. Several new multi-object spectrographs are currently planned or under construction that are capable of observing thousands of Galactic and extragalactic objects simultaneously. Aims. In this paper we present a probabilistic fibre-to-target assignment algorithm that takes spectrograph targeting constraints into account and is capable of dealing with multiple concurrent surveys. We present this algorithm using the 4-m Multi-Object Spectroscopic Telescope (4MOST) as an example. Methods. The key idea of the proposed algorithm is to assign probabilities to fibre-target pairs. The assignment of probabilities takes the fibre positioner's capabilities and constraints into account. Additionally, these probabilities include requirements... (More)

Context. Several new multi-object spectrographs are currently planned or under construction that are capable of observing thousands of Galactic and extragalactic objects simultaneously. Aims. In this paper we present a probabilistic fibre-to-target assignment algorithm that takes spectrograph targeting constraints into account and is capable of dealing with multiple concurrent surveys. We present this algorithm using the 4-m Multi-Object Spectroscopic Telescope (4MOST) as an example. Methods. The key idea of the proposed algorithm is to assign probabilities to fibre-target pairs. The assignment of probabilities takes the fibre positioner's capabilities and constraints into account. Additionally, these probabilities include requirements from surveys and take the required exposure time, number density variation, and angular clustering of targets across each survey into account. The main advantage of a probabilistic approach is that it allows for accurate and easy computation of the target selection function for the different surveys, which involves determining the probability of observing a target, given an input catalogue. Results. The probabilistic fibre-to-target assignment allows us to achieve maximally uniform completeness within a single field of view. The proposed algorithm maximises the fraction of successfully observed targets whilst minimising the selection bias as a function of exposure time. In the case of several concurrent surveys, the algorithm maximally satisfies the scientific requirements of each survey and no specific survey is penalised or prioritised. Conclusions. The algorithm presented is a proposed solution for the 4MOST project that allows for an unbiased targeting of many simultaneous surveys. With some modifications, the algorithm may also be applied to other multi-object spectroscopic surveys.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; ; and , et al. (More)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; and (Less)
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Instrumentation: spectrographs, Methods: statistical, Surveys, Techniques: miscellaneous
in
Astronomy and Astrophysics
volume
635
article number
A101
publisher
EDP Sciences
external identifiers
  • scopus:85092134207
ISSN
0004-6361
DOI
10.1051/0004-6361/201937228
project
4MOST - massive spectroscopic surveys of the Milky Way and the Universe
language
English
LU publication?
yes
id
8b8ec6f2-5707-409d-a87e-7989b37988eb
date added to LUP
2020-11-06 10:28:24
date last changed
2020-12-29 04:44:14
@article{8b8ec6f2-5707-409d-a87e-7989b37988eb,
  abstract     = {<p>Context. Several new multi-object spectrographs are currently planned or under construction that are capable of observing thousands of Galactic and extragalactic objects simultaneously. Aims. In this paper we present a probabilistic fibre-to-target assignment algorithm that takes spectrograph targeting constraints into account and is capable of dealing with multiple concurrent surveys. We present this algorithm using the 4-m Multi-Object Spectroscopic Telescope (4MOST) as an example. Methods. The key idea of the proposed algorithm is to assign probabilities to fibre-target pairs. The assignment of probabilities takes the fibre positioner's capabilities and constraints into account. Additionally, these probabilities include requirements from surveys and take the required exposure time, number density variation, and angular clustering of targets across each survey into account. The main advantage of a probabilistic approach is that it allows for accurate and easy computation of the target selection function for the different surveys, which involves determining the probability of observing a target, given an input catalogue. Results. The probabilistic fibre-to-target assignment allows us to achieve maximally uniform completeness within a single field of view. The proposed algorithm maximises the fraction of successfully observed targets whilst minimising the selection bias as a function of exposure time. In the case of several concurrent surveys, the algorithm maximally satisfies the scientific requirements of each survey and no specific survey is penalised or prioritised. Conclusions. The algorithm presented is a proposed solution for the 4MOST project that allows for an unbiased targeting of many simultaneous surveys. With some modifications, the algorithm may also be applied to other multi-object spectroscopic surveys.</p>},
  author       = {Tempel, E. and Norberg, P. and Tuvikene, T. and Bensby, T. and Chiappini, C. and Christlieb, N. and Cioni, M. R.L. and Comparat, J. and Davies, L. J.M. and Guiglion, G. and Koch, A. and Kordopatis, G. and Krumpe, M. and Loveday, J. and Merloni, A. and Micheva, G. and Minchev, I. and Roukema, B. F. and Sorce, J. G. and Starkenburg, E. and Storm, J. and Swann, E. and Thi, W. F. and Traven, G. and De Jong, R. S.},
  issn         = {0004-6361},
  language     = {eng},
  publisher    = {EDP Sciences},
  series       = {Astronomy and Astrophysics},
  title        = {Probabilistic fibre-to-target assignment algorithm for multi-object spectroscopic surveys},
  url          = {http://dx.doi.org/10.1051/0004-6361/201937228},
  doi          = {10.1051/0004-6361/201937228},
  volume       = {635},
  year         = {2020},
}