Internal calibration of Gaia BP/RP low-resolution spectra

Context. The full third Gaia data release will provide, for the first time, the calibrated spectra obtained with the blue and red Gaia slitless spectrophotometers (BP and RP, respectively). Gaia is a very complex mission and cannot be considered as a single instrument, but rather as many instruments...

Descripción completa

Detalles Bibliográficos
Autores: Carrasco, J. M., Weiler, Michael, Jordi, Carme, Fabricius, Claus, Angeli, G. de, Evans, D.W., Leeuwen, Fred van, Riello, Marco, Montegriffo, P.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/260657
Acceso en línea:http://hdl.handle.net/10261/260657
Access Level:acceso abierto
Palabra clave:Instrumentation: spectrographs
Space vehicles: instruments
Techniques: spectroscopic
Galaxies: general
Stars: general
id ES_09c27f92eec175195a6cbbbd2d2baafa
oai_identifier_str oai:digital.csic.es:10261/260657
network_acronym_str ES
network_name_str España
repository_id_str
dc.title.none.fl_str_mv Internal calibration of Gaia BP/RP low-resolution spectra
title Internal calibration of Gaia BP/RP low-resolution spectra
spellingShingle Internal calibration of Gaia BP/RP low-resolution spectra
Carrasco, J. M.
Instrumentation: spectrographs
Space vehicles: instruments
Techniques: spectroscopic
Galaxies: general
Stars: general
title_short Internal calibration of Gaia BP/RP low-resolution spectra
title_full Internal calibration of Gaia BP/RP low-resolution spectra
title_fullStr Internal calibration of Gaia BP/RP low-resolution spectra
title_full_unstemmed Internal calibration of Gaia BP/RP low-resolution spectra
title_sort Internal calibration of Gaia BP/RP low-resolution spectra
dc.creator.none.fl_str_mv Carrasco, J. M.
Weiler, Michael
Jordi, Carme
Fabricius, Claus
Angeli, G. de
Evans, D.W.
Leeuwen, Fred van
Riello, Marco
Montegriffo, P.
author Carrasco, J. M.
author_facet Carrasco, J. M.
Weiler, Michael
Jordi, Carme
Fabricius, Claus
Angeli, G. de
Evans, D.W.
Leeuwen, Fred van
Riello, Marco
Montegriffo, P.
author_role author
author2 Weiler, Michael
Jordi, Carme
Fabricius, Claus
Angeli, G. de
Evans, D.W.
Leeuwen, Fred van
Riello, Marco
Montegriffo, P.
author2_role author
author
author
author
author
author
author
author
dc.contributor.none.fl_str_mv Ministerio de Ciencia, Innovación y Universidades (España)
University of Cambridge
Agenzia Spaziale Italiana
Istituto Nazionale di Astrofisica
Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]
dc.subject.none.fl_str_mv Instrumentation: spectrographs
Space vehicles: instruments
Techniques: spectroscopic
Galaxies: general
Stars: general
topic Instrumentation: spectrographs
Space vehicles: instruments
Techniques: spectroscopic
Galaxies: general
Stars: general
description Context. The full third Gaia data release will provide, for the first time, the calibrated spectra obtained with the blue and red Gaia slitless spectrophotometers (BP and RP, respectively). Gaia is a very complex mission and cannot be considered as a single instrument, but rather as many instruments. The two lines of sight with wide fields of view introduce strong variations of the observations across the large focal plane with more than one hundred different detectors. The main challenge when facing Gaia spectral calibration is that no lamp spectra or flat fields are available during the mission. Also, the significant size of the line spread function with respect to the dispersion of the prisms produces alien photons contaminating neighbouring positions of the spectra. This makes the calibration special and different from standard approaches. Aims. This work gives a detailed description of the internal calibration model for the spectrophotometric data used to obtain the content of the Gaia catalogue. The main purpose of the internal calibration is to bring all the epoch spectra onto a common flux and pixel (pseudo-wavelength) scale, taking into account variations over the focal plane and with time, producing a mean spectrum from all the observations of the same source. Methods. In order to describe all observations on a common mean flux and pseudo-wavelength scale, we constructed a suitable representation of the internally calibrated mean spectra via basis functions, and we described the transformation between non-calibrated epoch spectra and calibrated mean spectra via a discrete convolution, parametrising the convolution kernel to recover the relevant coefficients. Results. The model proposed here for the internal calibration of the Gaia spectrophotometric observations is able to combine all observations into a mean instrument to allow the comparison of different sources and observations obtained with different instrumental conditions along the mission and the generation of mean spectra from a number of observations of the same source. We derived a calibration model that can handle the self-calibrating nature of the problem. The output of this model provides the internal mean spectra, not as a sampled function (flux and wavelength), but as a linear combination of basis functions, although sampled spectra can easily be derived from them.
publishDate 2021
dc.date.none.fl_str_mv 2021
2022
2022
2022
dc.type.none.fl_str_mv info:eu-repo/semantics/article
http://purl.org/coar/resource_type/c_6501
Publisher's version
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/260657
url http://hdl.handle.net/10261/260657
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv #PLACEHOLDER_PARENT_METADATA_VALUE#
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/RTI2018-095076-B-C21
http://doi.org/10.1051/0004-6361/202141249
Sí
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv Springer Nature
publisher.none.fl_str_mv Springer Nature
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
repository.name.fl_str_mv
repository.mail.fl_str_mv
_version_ 1869403124655980544
spelling Internal calibration of Gaia BP/RP low-resolution spectraCarrasco, J. M.Weiler, MichaelJordi, CarmeFabricius, ClausAngeli, G. deEvans, D.W.Leeuwen, Fred vanRiello, MarcoMontegriffo, P.Instrumentation: spectrographsSpace vehicles: instrumentsTechniques: spectroscopicGalaxies: generalStars: generalContext. The full third Gaia data release will provide, for the first time, the calibrated spectra obtained with the blue and red Gaia slitless spectrophotometers (BP and RP, respectively). Gaia is a very complex mission and cannot be considered as a single instrument, but rather as many instruments. The two lines of sight with wide fields of view introduce strong variations of the observations across the large focal plane with more than one hundred different detectors. The main challenge when facing Gaia spectral calibration is that no lamp spectra or flat fields are available during the mission. Also, the significant size of the line spread function with respect to the dispersion of the prisms produces alien photons contaminating neighbouring positions of the spectra. This makes the calibration special and different from standard approaches. Aims. This work gives a detailed description of the internal calibration model for the spectrophotometric data used to obtain the content of the Gaia catalogue. The main purpose of the internal calibration is to bring all the epoch spectra onto a common flux and pixel (pseudo-wavelength) scale, taking into account variations over the focal plane and with time, producing a mean spectrum from all the observations of the same source. Methods. In order to describe all observations on a common mean flux and pseudo-wavelength scale, we constructed a suitable representation of the internally calibrated mean spectra via basis functions, and we described the transformation between non-calibrated epoch spectra and calibrated mean spectra via a discrete convolution, parametrising the convolution kernel to recover the relevant coefficients. Results. The model proposed here for the internal calibration of the Gaia spectrophotometric observations is able to combine all observations into a mean instrument to allow the comparison of different sources and observations obtained with different instrumental conditions along the mission and the generation of mean spectra from a number of observations of the same source. We derived a calibration model that can handle the self-calibrating nature of the problem. The output of this model provides the internal mean spectra, not as a sampled function (flux and wavelength), but as a linear combination of basis functions, although sampled spectra can easily be derived from them.Authors at the ICCUB were supported by the Spanish Ministry of Science, Innovation and University (MICIU/FEDER, UE) through grant RTI2018-095076-B-C21, and the Institute of Cosmos Sciences University of Barcelona (ICCUB, Unidad de Excelencia “María de Maeztu”) through grant CEX2019-000918-M. Authors at the Institute of Astronomy of the University of Cambridge were supported by the United Kingdom Science and Technology Facilities Council (STFC) and the United Kingdom Space Agency (UKSA) through the following grants to the University of Cambridge: ST/K000756/1, ST/N000641/1 and ST/S000089/1. Authors at INAF were supported by the Agenzia Spaziale Italiana (ASI) through contracts I/037/08/0, I/058/10/0, 2014-025-R.0, 2014-025-R.1.2015 and 2018-24-HH.0 to the Italian Istituto Nazionale di Astrofisica (INAF), and INAF.Springer NatureMinisterio de Ciencia, Innovación y Universidades (España)University of CambridgeAgenzia Spaziale ItalianaIstituto Nazionale di AstrofisicaConsejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]2022202220212022info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501Publisher's versioninfo:eu-repo/semantics/publishedVersionhttp://hdl.handle.net/10261/260657reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Inglés#PLACEHOLDER_PARENT_METADATA_VALUE#info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/RTI2018-095076-B-C21http://doi.org/10.1051/0004-6361/202141249Síinfo:eu-repo/semantics/openAccessoai:digital.csic.es:10261/2606572026-05-22T06:33:51Z
score 15,811543

Similares en LA Referencia