Variability of the near-infrared extinction curve towards the Galactic centre
| Autor: | E. Gallego-Cano, A. T. Gallego-Calvente, Banafsheh Shahzamanian, Francisco Nogueras-Lara, Rainer Schödel, Francisco Najarro, Nadine Neumayer |
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| Přispěvatelé: | Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737, Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFISICA DE ANDALUCIA (IAA), SEV-2017-0709, Nogueras Lara, F. [0000-0002-6379-7593], Schöedel, R. [0000-0001-5404-797X], Gallego Calvente, A. T. [0000-0002-6428-8045], Shahzamanian, B. [0000-0001-6437-6806], Neumayer, N. [0000-0002-6922-2598], European Commission (EC), European Southern Observatory (ESO), Ministerio de Economía y Competitividad (MINECO), Agencia Estatal de Investigación (AEI), European Research Council, Ministerio de Educación, Cultura y Deporte (España), Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), German Research Foundation, European Research Council (ERC), La Silla Paranal Observatory, Centro de Excelencia Científica Severo Ochoa Instituto de Astrofísica de Andalucía CSIC, Deutsche Forschungsgemeinschaft (DFG), Ministerio de Educación, Cultura y Deporte (MECD) |
| Rok vydání: | 2019 |
| Předmět: |
Stellar population
Population FOS: Physical sciences Context (language use) Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Quantitative Biology::Populations and Evolution Stellar structure education 010303 astronomy & astrophysics Red clump Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics Dust extinction Physics education.field_of_study Galaxy: nucleus nucleus [Galaxy] Galaxy: center 010308 nuclear & particles physics Astronomy and Astrophysics Dust Extinction center [Galaxy] Astrophysics - Astrophysics of Galaxies Galaxy Stars Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Extinction (optical mineralogy) Astrophysics of Galaxies (astro-ph.GA) Stars: horizontal-branch horizontal-branch [Stars] Astrophysics::Earth and Planetary Astrophysics |
| Zdroj: | Astronomy and Astrophysics DIGITAL.INTA Repositorio Digital del Instituto Nacional de Técnica Aeroespacial Universidad de Alicante (UA) Instituto Nacional de Técnica Aeroespacial (INTA) Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | Due to the extreme extinction towards the Galactic centre (A(v) similar to 30 mag), its stellar population is mainly studied in the near-infrared (NIR) regime. Therefore, a proper analysis of the NIR extinction curve is necessary to fully characterise the stellar structure and population of the inner part of the galaxy. Aims. We studied the dependence of the extinction index (alpha(lambda)) in the NIR on the line of sight, wavelength, and extinction. Methods. We used the GALACTICNUCLEUS imaging survey, a high angular resolution catalogue (0.2 '') for the inner part of the Galaxy in JHK(s) and studied the spatial variation in the extinction index. We also applied two independent methods based on red clump stars to compute the extinction index between different bands and its variation with wavelength. Results. We did not detect any significant line-of-sight or extinction variation in a within the studied region in the nuclear stellar disc. The extinction index between JH and HKs differs by 0.19 +/- 0.05. We obtained mean values for the extinction indices alpha(JH)( )= 2.43 +/- 0.03 and alpha(HK), = 2.23 +/- 0.03. The dependence of the extinction index on the wavelength could explain the differences obtained for a d in the literature since it was assumed constant for the NIR regime.© ESO 2019. The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement no [614922]. This work is based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme IDs 195. B-0283 and 091. B-0418. We thank the sta ff at ESO for their great e ff orts and helpfulness. F. N.-L. acknowledges financial support from a MECD pre-doctoral contract, code FPU14/01700. F. N. acknowledges financial support through Spanish grants ESP2015-65597C4-1-R and ESP2017-86582-C4-1-R (MINECO/FEDER). We acknowledge support from the State Agency for Research of the Spanish MCIU through the Centre of Excellence Severo Ochoa Award of the Instituto de Astrofisica de Andalucia (CSIC) (SEV-2017-0709). N.N. acknowledges support from Sonderforschungsbereich SFB 881 "The Milky Way System" (subproject B8) of the German Research Foundation (DFG). |
| Databáze: | OpenAIRE |
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