@article{17c678f12ff140e5a706d7874da5099e,
title = "The Bubble Nebula NGC 7635-Testing the wind-blown bubble theory",
abstract = "We present a multiwavelength study of the iconic Bubble Nebula (NGC 7635) and its ionizing star BD+60{\"i} -{\"i} 2522. We obtained XMM-Newton EPIC X-ray observations to search for extended X-ray emission as in other similar wind-blown bubbles around massive stars. We also obtained San Pedro M{\'a}rtir spectroscopic observations with the Manchester Echelle Spectrometer to study the dynamics of the Bubble Nebula. Although our EPIC observations are deep, we do not detect extended X-ray emission from this wind-blown bubble. On the other hand, BD+60{\"i} -{\"i} 2522 is a bright X-ray source similar to other O stars. We used the stellar atmosphere code PoWR to characterize BD+60{\"i} -{\"i} 2522 and found that this star is a young O-Type star with stellar wind capable of producing a wind-blown bubble that in principle could be filled with hot gas. We discussed our findings in line with recent numerical simulations proposing that the Bubble Nebula has been formed as the result of the fast motion of BD+60{\"i} -{\"i} 2522 through the medium. Our kinematic study shows that the Bubble Nebula is composed by a series of nested shells, some showing blister-like structures, but with little signatures of hydrodynamical instabilities that would mix the material producing diffuse X-ray emission as seen in other wind-blown bubbles. Its morphology seems to be merely the result of projection effects of these different shells.",
keywords = "H ii regions, ISM: bubbles, X-rays: individual: NGC 7635, BD+602522, X-rays: stars",
author = "Toal{\'a}, {J. A.} and Guerrero, {M. A.} and H. Todt and L. Sabin and Oskinova, {L. M.} and Chu, {Y. H.} and G. Ramos-Larios and G{\'o}mez-Gonz{\'a}lez, {V. M.A.}",
note = "Funding Information: 2STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Funding Information: The authors thank the referee for a useful report that improved the presentation of this paper. This work is based on observations obtained with XMM–Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA. The NOT data presented were obtained with ALFOSC and FIES, which are provided by the Instituto de As-trof{\'i}sica de Andaluc{\'i}a (IAA-CSIC) under a joint agreement with the University of Copenhagen and NOTSA. This paper makes use of observations carried out at the Observatorio Astron{\'o}mico Nacional on the Sierra San Pedro M{\'a}rtir (OAN-SPM), Baja California, Mexico. We thank the daytime and night support staff at the OAN-SPM for facilitating and helping obtain our observations. JAT, MAG, and HT are funded by UNAM DGAPA PAPIIT projects IA100318 and IA100720. GRL acknowledges support from Fundaci{\'o}n Marcos Moshinsky, CONACyT, and PRODEP (Mexico). MAG acknowledges support of the grants AYA 2014-57280-P and PGC2018-102184-B-I00 of the Spanish Ministerio de Ciencia, Innovaci{\'o}n y Universidades, cofunded with FEDER funds. LS is supported by Direcci{\'o}n General de Asuntos del Personal Acad{\'e}mico, Universidad Nacional Aut{\'o}noma de M{\'e}xico project IN101819. Publisher Copyright: {\textcopyright} 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.",
year = "2020",
month = may,
day = "14",
doi = "10.1093/mnras/staa752",
language = "English (US)",
volume = "495",
pages = "3041--3051",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "3",
}