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http://hdl.handle.net/2445/119792
Title: | The First Simultaneous X-Ray/Radio Detection of the First Be/BH System MWC 656 |
Author: | Ribó Gomis, Marc Munar i Adrover, Pere Paredes i Poy, Josep Maria Marcote Martin, Benito Iwasawa, Kazushi Moldón Vara, Francisco Javier Casares, J. Migliari, Simone Paredes Fortuny, Xavier |
Keywords: | Forats negres (Astronomia) Estels binaris de raigs X Black holes (Astronomy) X-ray binaries |
Issue Date: | 1-Feb-2017 |
Publisher: | Institute of Physics (IOP) |
Abstract: | MWC 656 is the first known Be/black hole (BH) binary system. Be/BH binaries are important in the context of binary system evolution and sources of detectable gravitational waves because they are possible precursors of coalescing neutron star/BH binaries. X-ray observations conducted in 2013 revealed that MWC 656 is a quiescent high-mass X-ray binary (HMXB), opening the possibility to explore X-ray/radio correlations and the accretion/ejection coupling down to low luminosities for BH HMXBs. Here we report on a deep joint Chandra/VLA observation of MWC 656 (and contemporaneous optical data) conducted in 2015 July that has allowed us to unambiguously identify the X-ray counterpart of the source. The X-ray spectrum can be fitted with a power law with Γ ~ 2, providing a flux of sime4 × 10−15 erg cm−2 s−1 in the 0.5-8 keV energy range and a luminosity of LX sime 3 × 1030 erg s−1 at a 2.6 kpc distance. For a 5 M⊙ BH this translates into sime5 × 10−9 LEdd. These results imply that MWC 656 is about 7 times fainter in X-rays than it was two years before and reaches the faintest X-ray luminosities ever detected in stellar-mass BHs. The radio data provide a detection with a peak flux density of 3.5 ± 1.1 μJy beam−1. The obtained X-ray/radio luminosities for this quiescent BH HMXB are fully compatible with those of the X-ray/radio correlations derived from quiescent BH low-mass X-ray binaries. These results show that the accretion/ejection coupling in stellar-mass BHs is independent of the nature of the donor star. |
Note: | Reproducció del document publicat a: https://doi.org/10.3847/2041-8213/835/2/L33 |
It is part of: | Astrophysical Journal Letters, 2017, vol. 835, num. 2 |
URI: | http://hdl.handle.net/2445/119792 |
Related resource: | https://doi.org/10.3847/2041-8213/835/2/L33 |
ISSN: | 2041-8205 |
Appears in Collections: | Articles publicats en revistes (Institut de Ciències del Cosmos (ICCUB)) Articles publicats en revistes (Física Quàntica i Astrofísica) |
Files in This Item:
File | Description | Size | Format | |
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667758.pdf | 1.04 MB | Adobe PDF | View/Open |
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