Suchergebnisse

The GALANTE optical photometric survey is observing the northern Galactic plane and some adjacent regions using seven narrow- and intermediate-filters, covering a total of 1618 deg2. The survey has been designed with multiple exposure times and at least two different air masses per field to maximize its photometric dynamic range, comparable to that of Gaia, and ensure the accuracy of its photometric calibration. The goal is to reach at least 1 per cent accuracy and precision in the seven bands for all stars brighter than AB magnitude 17 while detecting fainter stars with lower values of the signal-to-noise ratio. The main purposes of GALANTE are the identification and study of extinguished O+B+WR stars, the derivation of their extinction characteristics, and the cataloguing of F and G stars in the solar neighbourhood. Its data will be also used for a variety of other stellar studies and to generate a high-resolution continuum-free map of the Hα emission in the Galactic plane. We describe the techniques and the pipeline that are being used to process the data, including the basis of an innovative calibration system based on Gaia DR2 and 2MASS photometry. © 2021 The Author(s). ; JMA, GH, and HGE acknowledge support from the Spanish Government Ministerio de Ciencia through grant PGC2018-095 049-B-C22. EJA and AL-G acknowledge support from the Spanish Government Ministerio de Ciencia through grant PGC2018-095 049-B-C21 and from the State Agency for Research of the Spanish Government Ministerio de Ciencia through the 'Center of Excellence Severo Ochoa' award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709). The GALANTE team at the Centro de Astrobiología acknowledges financial support from the Science and Operations Department of the European Space Agency – Contract Number 4 000 126 507. RHB acknowledges support from the ESAC Faculty Visitor Program. Funding for OAJ, UPAD, and CEFCA has been provided by the Governments of Spain and Aragón through the Fondo de Inversiones de Teruel; the Aragonese Government through the Research Groups E96, E103, and E16_17R; the Spanish Government Ministerio de Ciencia, Innovación y Universidades (MCIU/AEI/FEDER, UE) with grantPGC2018-097 585-B-C21; the Spanish Ministerio de Economía y Competitividad (MINECO/FEDER, UE) with grants AYA2015-66 211-C2-1-P, AYA2015-66 211-C2-2, AYA2012-30 789, and ICTS-2009-14; and the European FEDER funding with grants FCDD10-4E-867 and FCDD13-4E-2685. PRTC acknowledges financial support from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) process number 2018/05 392-8 and CNPq process number 310 041/2018-0. The main source of data for this paper is the JAST80 telescope at the Observatorio Astrofísico de Javalambre, Teruel, Spain (owned, managed, and operated by the Centro de Estudios de Física del Cosmos de Aragón). As detailed in this paper, the initial part of the reduction and astrometric calibration was done by the OAJ Data Processing and Archiving Unit (UPAD) and the main part of the reduction and calibration was done at the Centro de Astrobiología. In addition to the JAST80 data, two other types of data products have been used as sources for the catalogue generation and calibration: [1] from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC; https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. [2] From the Two Micron All Sky Survey (2MASS), which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation, where the word 'National' refers to the United States of America. No optically reflecting surface with a size larger than the height of the tallest of the authors was required to write this paper. ; Peer reviewed

In this paper, we analyse how to extract the physical properties from the GALANTE photometry of a stellar sample. We propose a direct comparison between the observational colours (photometric bands normalized to the 515 nm central wavelength) and the synthetic colours derived from different stellar libraries. We use the reduced χ2 as the figure of merit for selecting the best fitting between both colour sets. The synthetic colours of the Next Generation Spectral Library (NGSL) provide a valuable sample for testing the uncertainty and precision of the stellar parameters derived from observational data. Reddening, as an extrinsic stellar physical parameter becomes a crucial variable for accounting for the errors and bias in the derived estimates: the higher the reddenings, the larger the errors and uncertainties in the derived parameters. NGSL colours also enable us to compare different theoretical stellar libraries for the same set of physical parameters, where we see how different catalogues of models can provide very different solutions in a, sometimes, non-linear way. This peculiar behaviour makes us to be cautious with the derived physical parameters obtained from GALANTE photometry without previous detailed knowledge of the theoretical libraries used to this end. In addition, we carry out the experiment of deriving physical stellar parameters from some theoretical libraries, using some other libraries as observational data. In particular, we use the Kurucz and Coelho libraries, as input observational data, to derive stellar parameters from Coelho + TLUSTY and Kurucz + TLUSTY stellar libraries, respectively, for different photometric errors and colour excesses.© 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society ; We thank the Centro de Estudios de F´ısica del Cosmos de Aragon´ (CEFCA) team in Teruel and Javalambre for supporting us in this project, giving us the opportunity to use non-J-PLUS useful nights to develop the GALANTE survey. We also want to recognize the work of the NGSL team (Gregg et al. 2006; Heap & Lindler 2016) whose observational catalogue has been of great help for our work. This research made use of PYTHON (http://www.python.org); NUMPY (van der Walt, Colbert & Varoquaux 2011); SCIPY (Jones et al. 2001); and MATPLOTLIB (Hunter 2007), a suite of open-source PYTHON modules that provides a framework for creating scientific plots. We also acknowledge the use of STILTS and TOPCAT tools (Taylor 2005). AL-G, EJA, and JMA acknowledge support from the Spanish Government Ministerio de Ciencia, Innovacion y Universidades ´ though grants AYA2013-40 611-P and AYA2016-75 931-C2-1/2-P. AL-G and EJA also acknowledge support from the State Agency for Research of the Spanish MCIU through the 'Center of Excellence Severo Ochoa' award for the Instituto de Astrof´ısica de Andaluc´ıa (SEV-2017-0709). ; Peer reviewed