@article{d58f978db0ae44b7a825401fb8ad1cbe,
title = "Colliding winds in and around the stellar group IRS 13E at the galactic centre",
abstract = "IRS 13E is an enigmatic compact group of massive stars located in projection only 3.6 arcsec away from Sgr A∗. This group has been suggested to be bounded by an intermediate-mass black hole (IMBH). We present a multiwavelength study of the group and its interplay with the environment. Based on Chandra observations, we find the X-ray spectrum of IRS 13E can be well characterized by an optically thin thermal plasma. The emission peaks between two strongly mass-losing Wolf-Rayet stars of the group. These properties can be reasonably well reproduced by simulated colliding winds of these two stars. However, this scenario underpredicts the X-ray intensity in outer regions. The residual emission likely results from the ram-pressure confinement of the IRS 13E group wind by the ambient medium and is apparently associated with a shell-like warm gas structure seen in Pa α and in ALMA observations. These latter observations also show strongly peaked thermal emission with unusually large velocity spread between the two stars. These results indicate that the group is colliding with the bar of the dense cool gas mini-spiral around Sgr A∗. The extended X-ray morphology of IRS 13E and its association with the bar further suggest that the group is physically much farther away than the projected distance from Sgr A∗. The presence of an IMBH, while favourable to keep the stars bound together, is not necessary to explain the observed stellar and gas properties of IRS 13E.",
keywords = "Galaxy: centre, Hydrodynamics, Stars: Wolf-Rayet, Stars: winds, outflows, X-rays: general",
author = "{Daniel Wang}, Q. and Jun Li and Russell, {Christopher M.P.} and Jorge Cuadra",
note = "Funding Information: We thank the referee for constructive comments, which helped to improve the presentation of the paper. QDW is grateful to the financial support and hospitality that he received in the Instituto de Astrof{\'i}sica at Pontificia Universidad Cat{\'o}lica de Chile, where part of this work was performed, as well as the Fulbright U.S. Scholar Program for a fellowship. Support for this work was provided by the National Aeronautics and Space Administration through Chandra Award Number GO9-20023X issued by the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of the National Aeronautics Space Administration under contract NAS8-03060, and by the ADAP grant NNX17AL67G. JL acknowledges support by the China Scholarship Council (No. 201706040153) for the study at University of Massachusetts, Amherst. CMPR acknowledges support from FONDECYT grant 3170870. CMPR and JC acknowledge support from CONICYT project Basal AFB-170002, and from the Max Planck Society through a 'Partner Group' grant. Resources supporting this work were provided by the NASA High-End Computing Program through the NASA Advanced Supercomputing Division at Ames Research Center. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2016.1.00870.S. ALMA is a partnership of European Space Agency (representing its member states), National Science Fundation of the United States and National Institute of National Sciences of Japan, together with National Rearch Concil of Canada, Minister of Science and Technology and Academic Sinica Institute of Astronomy and Astrophyscsi of Taiwan, and Korea Astronomy and Space Institute (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. Funding Information: We thank the referee for constructive comments, which helped to improve the presentation of the paper. QDW is grateful to the financial support and hospitality that he received in the Instituto de Astrof{\'i}sica at Pontificia Universidad Cat{\'o}lica de Chile, where part of this work was performed, as well as the Fulbright U.S. Scholar Program for a fellowship. Support for this work was provided by the National Aeronautics and Space Administration through Chandra Award Number GO9-20023X issued by the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of the National Aeronautics Space Administration under contract NAS8-03060, and by the ADAP grant NNX17AL67G. JL acknowledges support by the China Scholarship Council (No. 201706040153) for the study at University of Massachusetts, Amherst. CMPR acknowledges support from FONDECYT grant 3170870. CMPR and JC acknowledge support from CONICYT project Basal AFB-170002, and from the Max Planck Society through a {\textquoteleft}Partner Group{\textquoteright} grant. Resources supporting this work were provided by the NASA High-End Computing Program through the NASA Advanced Supercomputing Division at Ames Research Center. Publisher Copyright: {\textcopyright} 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society",
year = "2020",
month = feb,
day = "1",
doi = "10.1093/mnras/stz3624",
language = "English",
volume = "492",
pages = "2481--2496",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
number = "2",
}