Defensa digital: repositorio de publicaciones de Defensa iberoamericanas

Español
Português

Está en:  › Datos de registro

A detailed non-LTE analysis of LB-1: Revised parameters and surface abundances

Identificadores del recurso

Astronomy and Astrophysics 634: L7 (2020)

0004-6361

https://www.aanda.org/articles/aa/full_html/2020/02/aa37318-19/aa37318-19.html

http://hdl.handle.net/20.500.12666/384

10.1051/0004-6361/201937318

1432-0746

http://dx.doi.org/10.13039/501100000271

http://dx.doi.org/10.13039/501100011033

http://dx.doi.org/10.13039/501100003329

Procedencia

(Digital.INTA - Repositorio institucional del INTA)

Ficha

Título:: A detailed non-LTE analysis of LB-1: Revised parameters and surface abundances
Tema:: Techniques: spectroscopic; Binaries; Spectroscopic; Stars; Black Holes; Abundances; Fundamental Parameters; Early Type
Descripción:: Context. It has recently been proposed that LB-1 is a binary system at 4 kpc consisting of a B-type star of 8 M-circle dot and a massive stellar black hole (BH) of 70 M-circle dot. This finding challenges our current theories of massive star evolution and formation of BHs at solar metallicity. Aims. Our objective is to derive the effective temperature, surface gravity, and chemical composition of the B-type component in order to determine its nature and evolutionary status and, indirectly, to constrain the mass of the BH. Methods. We use the non-LTE stellar atmosphere code FASTWIND to analyze new and archival high-resolution data. Results. We determine (T-eff, log g) values of (14& x2006;000 +/- 500 K, 3.50 +/- 0.15 dex) that, combined with the Gaia parallax, imply a spectroscopic mass, from log g, of 3.2(-1.9)(+2.1) M(circle dot)3.2-1.9+2.1M circle dot$ 3.2<^>{+2.1}_{-1.9}\,M_\odot $ and an evolutionary mass, assuming single star evolution, of 5.2(-0.6)(+0.3) M(circle dot)5.2-0.6+0.3M circle dot$ 5.2<^>{+0.3}_{-0.6}\,M_\odot $. We determine an upper limit of 8 km s(-1) for the projected rotational velocity and derive the surface abundances; we find the star to have a silicon abundance below solar, and to be significantly enhanced in nitrogen and iron and depleted in carbon and magnesium. Complementary evidence derived from a photometric extinction analysis and Gaia yields similar results for T-eff and log g and a consistent distance around 2 kpc. Conclusions. We propose that the B-type star is a slightly evolved main sequence star of 3-5 M-circle dot with surface abundances reminiscent of diffusion in late B/A chemically peculiar stars with low rotational velocities. There is also evidence for CN-processed material in its atmosphere. These conclusions rely critically on the distance inferred from the Gaia parallax. The goodness of fit of the Gaia astrometry also favors a high-inclination orbit. If the orbit is edge-on and the B-type star has a mass of 3-5 M-circle dot, the mass of the dark companion would be 4-5 M-circle dot, which would be easier to explain with our current stellar evolutionary models.; We thank R.-P. Kudritzki for his interesting suggestions for improvement of the first version of this Letter. We thank J. Hernandez for his help with Gaia DR2 data. S-SD, DJL, AdB, AHD and JMA acknowledges support from the Spanish Government Ministerio de Ciencia, Innovacion y Universidades through grants PGC2018-095 049-B-C22 and PGC-2018-091 3741-B-C22. JIGH acknowledges financial support from the Spanish Ministry of Science, Innovation and Universities (MICIU) under the 2013 Ramon y Cajal program RYC-2013-14875. JIGH and CAP acknowledge financial support from the Spanish Ministry project MICIU AYA2017-86389-P. SJS acknowledges funding from STFC Grant ST/P000312/1. Based on observations made with the Telescopio Nationale Galileo (TNG) and the Gran Telescopio Canarias (GTC), installed at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, in the island of La Palma. This research has made use of the Keck Observatory Archive (KOA), which is operated by the W. M. Keck Observatory and the NASA Exoplanet Science Institute (NExScI), under contract with the National Aeronautics and Space Administration. Guoshoujing Telescope (the Large Sky Area Multi-Object Fiber Spectroscopic Telescope LAMOST) is a National Major Scientific Project built by the Chinese Academy of Sciences. Funding for the project has been provided by the National Development and Reform Commission. LAMOST is operated and managed by the National Astronomical Observatories, Chinese Academy of Sciences; With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737).; Peer review
Idioma:: English
Relación:: info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/AYA2017-86389-P/ES/ESPECTROSCOPIA DE ALTA RESOLUCION ORIENTADA AL ESTUDIO DE EXOTIERRAS Y LA FORMACION DE LA VIA LACTEA. EXPLOTACION CIENTIFICA DE ESPRESSO Y HORS/; info:eu-repo/grantAgreement/MINECO//RYC-2013-14875; info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PGC2018-095049-B-C22; info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PGC2018-0913741-B-C22
Autor/Productor:: Simón Díaz, S.; Maíz Apellániz, J.; Lennon, D. J.; González Hernández, J. I.; Allende Prieto, C.; Castro, N.; De Burgos, A.; Dufton, P. L.; Herrero, A.; Toledo Padrón, B.; Smartt, S. J.
Editor:: EDP Sciences
Otros colaboradores/productores:: Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737; Simón Díaz, S. [0000-0003-1168-3524]; Maíz Apellániz, J. [0000-0003-0825-3443]; Lennon, D. J. [0000-0003-3063-4867]; González Hernández, J. I. [0000-0002-0264-7356]; Castro, N. [0000-0003-0521-473X]; De Burgos, A. [0000-0003-4729-0722]; Herrero, A. [0000-0001-8768-2179]; Toledo Padrón, B. [0000-0002-8194-215X]; Smartt, S. J. [0000-0002-8229-1731]; Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); Science and Technology Facilities Council (STFC)
Derechos:: Attribution-NonCommercial-NoDerivatives 4.0 International; © ESO 2020; https://creativecommons.org/licenses/by-nc-nd/4.0/; info:eu-repo/semantics/openAccess
Fecha:: 2021-04-14T13:16:37Z; 2020-01-31
Tipo de recurso:: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; http://purl.org/coar/resource_type/c_6501
Formato:: application/pdf

oai_dc

Descargar XML

<?xml version="1.0" encoding="UTF-8" ?>

< oai_dc:dc schemaLocation =" http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd " >
1. < dc:title > A detailed non-LTE analysis of LB-1: Revised parameters and surface abundances </ dc:title >
2. < dc:creator > Simón Díaz, S. </ dc:creator >
3. < dc:creator > Maíz Apellániz, J. </ dc:creator >
4. < dc:creator > Lennon, D. J. </ dc:creator >
5. < dc:creator > González Hernández, J. I. </ dc:creator >
6. < dc:creator > Allende Prieto, C. </ dc:creator >
7. < dc:creator > Castro, N. </ dc:creator >
8. < dc:creator > De Burgos, A. </ dc:creator >
9. < dc:creator > Dufton, P. L. </ dc:creator >
10. < dc:creator > Herrero, A. </ dc:creator >
11. < dc:creator > Toledo Padrón, B. </ dc:creator >
12. < dc:creator > Smartt, S. J. </ dc:creator >
13. < dc:contributor > Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737 </ dc:contributor >
14. < dc:contributor > Simón Díaz, S. [0000-0003-1168-3524] </ dc:contributor >
15. < dc:contributor > Maíz Apellániz, J. [0000-0003-0825-3443] </ dc:contributor >
16. < dc:contributor > Lennon, D. J. [0000-0003-3063-4867] </ dc:contributor >
17. < dc:contributor > González Hernández, J. I. [0000-0002-0264-7356] </ dc:contributor >
18. < dc:contributor > Castro, N. [0000-0003-0521-473X] </ dc:contributor >
19. < dc:contributor > De Burgos, A. [0000-0003-4729-0722] </ dc:contributor >
20. < dc:contributor > Herrero, A. [0000-0001-8768-2179] </ dc:contributor >
21. < dc:contributor > Toledo Padrón, B. [0000-0002-8194-215X] </ dc:contributor >
22. < dc:contributor > Smartt, S. J. [0000-0002-8229-1731] </ dc:contributor >
23. < dc:contributor > Agencia Estatal de Investigación (AEI) </ dc:contributor >
24. < dc:contributor > Ministerio de Economía y Competitividad (MINECO) </ dc:contributor >
25. < dc:contributor > Science and Technology Facilities Council (STFC) </ dc:contributor >
26. < dc:subject > Techniques: spectroscopic </ dc:subject >
27. < dc:subject > Binaries </ dc:subject >
28. < dc:subject > Spectroscopic </ dc:subject >
29. < dc:subject > Stars </ dc:subject >
30. < dc:subject > Black Holes </ dc:subject >
31. < dc:subject > Abundances </ dc:subject >
32. < dc:subject > Fundamental Parameters </ dc:subject >
33. < dc:subject > Early Type </ dc:subject >
34. < dc:description > Context. It has recently been proposed that LB-1 is a binary system at 4 kpc consisting of a B-type star of 8 M-circle dot and a massive stellar black hole (BH) of 70 M-circle dot. This finding challenges our current theories of massive star evolution and formation of BHs at solar metallicity. Aims. Our objective is to derive the effective temperature, surface gravity, and chemical composition of the B-type component in order to determine its nature and evolutionary status and, indirectly, to constrain the mass of the BH. Methods. We use the non-LTE stellar atmosphere code FASTWIND to analyze new and archival high-resolution data. Results. We determine (T-eff, log g) values of (14& x2006;000 +/- 500 K, 3.50 +/- 0.15 dex) that, combined with the Gaia parallax, imply a spectroscopic mass, from log g, of 3.2(-1.9)(+2.1) M(circle dot)3.2-1.9+2.1M circle dot$ 3.2<^>{+2.1}_{-1.9}\,M_\odot $ and an evolutionary mass, assuming single star evolution, of 5.2(-0.6)(+0.3) M(circle dot)5.2-0.6+0.3M circle dot$ 5.2<^>{+0.3}_{-0.6}\,M_\odot $. We determine an upper limit of 8 km s(-1) for the projected rotational velocity and derive the surface abundances; we find the star to have a silicon abundance below solar, and to be significantly enhanced in nitrogen and iron and depleted in carbon and magnesium. Complementary evidence derived from a photometric extinction analysis and Gaia yields similar results for T-eff and log g and a consistent distance around 2 kpc. Conclusions. We propose that the B-type star is a slightly evolved main sequence star of 3-5 M-circle dot with surface abundances reminiscent of diffusion in late B/A chemically peculiar stars with low rotational velocities. There is also evidence for CN-processed material in its atmosphere. These conclusions rely critically on the distance inferred from the Gaia parallax. The goodness of fit of the Gaia astrometry also favors a high-inclination orbit. If the orbit is edge-on and the B-type star has a mass of 3-5 M-circle dot, the mass of the dark companion would be 4-5 M-circle dot, which would be easier to explain with our current stellar evolutionary models. </ dc:description >
35. < dc:description > We thank R.-P. Kudritzki for his interesting suggestions for improvement of the first version of this Letter. We thank J. Hernandez for his help with Gaia DR2 data. S-SD, DJL, AdB, AHD and JMA acknowledges support from the Spanish Government Ministerio de Ciencia, Innovacion y Universidades through grants PGC2018-095 049-B-C22 and PGC-2018-091 3741-B-C22. JIGH acknowledges financial support from the Spanish Ministry of Science, Innovation and Universities (MICIU) under the 2013 Ramon y Cajal program RYC-2013-14875. JIGH and CAP acknowledge financial support from the Spanish Ministry project MICIU AYA2017-86389-P. SJS acknowledges funding from STFC Grant ST/P000312/1. Based on observations made with the Telescopio Nationale Galileo (TNG) and the Gran Telescopio Canarias (GTC), installed at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, in the island of La Palma. This research has made use of the Keck Observatory Archive (KOA), which is operated by the W. M. Keck Observatory and the NASA Exoplanet Science Institute (NExScI), under contract with the National Aeronautics and Space Administration. Guoshoujing Telescope (the Large Sky Area Multi-Object Fiber Spectroscopic Telescope LAMOST) is a National Major Scientific Project built by the Chinese Academy of Sciences. Funding for the project has been provided by the National Development and Reform Commission. LAMOST is operated and managed by the National Astronomical Observatories, Chinese Academy of Sciences; With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737). </ dc:description >
36. < dc:description > Peer review </ dc:description >
37. < dc:date > 2021-04-14T13:16:37Z </ dc:date >
38. < dc:date > 2021-04-14T13:16:37Z </ dc:date >
39. < dc:date > 2020-01-31 </ dc:date >
40. < dc:type > info:eu-repo/semantics/article </ dc:type >
41. < dc:type > info:eu-repo/semantics/publishedVersion </ dc:type >
42. < dc:type > http://purl.org/coar/resource_type/c_6501 </ dc:type >
43. < dc:identifier > Astronomy and Astrophysics 634: L7 (2020) </ dc:identifier >
44. < dc:identifier > 0004-6361 </ dc:identifier >
45. < dc:identifier > https://www.aanda.org/articles/aa/full_html/2020/02/aa37318-19/aa37318-19.html </ dc:identifier >
46. < dc:identifier > http://hdl.handle.net/20.500.12666/384 </ dc:identifier >
47. < dc:identifier > 10.1051/0004-6361/201937318 </ dc:identifier >
48. < dc:identifier > 1432-0746 </ dc:identifier >
49. < dc:identifier > http://dx.doi.org/10.13039/501100000271 </ dc:identifier >
50. < dc:identifier > http://dx.doi.org/10.13039/501100011033 </ dc:identifier >
51. < dc:identifier > http://dx.doi.org/10.13039/501100003329 </ dc:identifier >
52. < dc:language > eng </ dc:language >
53. < dc:relation > info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/AYA2017-86389-P/ES/ESPECTROSCOPIA DE ALTA RESOLUCION ORIENTADA AL ESTUDIO DE EXOTIERRAS Y LA FORMACION DE LA VIA LACTEA. EXPLOTACION CIENTIFICA DE ESPRESSO Y HORS/ </ dc:relation >
54. < dc:relation > info:eu-repo/grantAgreement/MINECO//RYC-2013-14875 </ dc:relation >
55. < dc:relation > info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PGC2018-095049-B-C22 </ dc:relation >
56. < dc:relation > info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PGC2018-0913741-B-C22 </ dc:relation >
57. < dc:rights > Attribution-NonCommercial-NoDerivatives 4.0 International </ dc:rights >
58. < dc:rights > © ESO 2020 </ dc:rights >
59. < dc:rights > https://creativecommons.org/licenses/by-nc-nd/4.0/ </ dc:rights >
60. < dc:rights > info:eu-repo/semantics/openAccess </ dc:rights >
61. < dc:format > application/pdf </ dc:format >
62. < dc:publisher > EDP Sciences </ dc:publisher >
</ oai_dc:dc >