Resolved astrometric orbits of ten O-type binaries

Bouquin, J.-B. Le; Sana, H.; Gosset, Éric; Becker, M. De; Duvert, G.; Absil, Olivier; Anthonioz, F.; Berger, J.‐P.; Ertel, S.; Grellmann, R.; Guieu, S.; Kervella, P.; Rabus, M.; Willson, Matthew

doi:10.1051/0004-6361/201629260

Cited by 46 publications

(45 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Therefore, HD 167971 appears as a binary system (SB-T) in the near-infrared interferometric data. Figure 1 presents the best-fit orbit of T around the SB reported by Le Bouquin et al (2017). This solution is in agreement with previous estimates reported by the light-curve analyses of Blomme et al (2007) and Ibanoglu et al (2013).…”

Section: Introductionsupporting

confidence: 89%

A VLBI study of the wind-wind collision region in the massive multiple HD 167971

Sánchez-Bermúdez

Alberdi

Schödel

et al. 2019

A&A

View full text Add to dashboard Cite

Context. Colliding winds in massive binaries are able to accelerate particles up to relativistic speeds as the result of the interaction between the winds of the different stellar components. HD 167971 exhibits this phenomenology which makes it a strong radio source. Aims. We aim at characterizing the morphology of the radio emission and its dependence on the orbital motion, traced independently by NIR-interferometry, of the spectroscopic binary and the tertiary component that conforms HD 167971. Methods. We analyze 2006 and 2016 very long baseline interferometric data at C and X bands. We complement our analysis with a geometrical model of the wind-wind collision region, and with an astrometric description of the system. Results. We confirm that the detected non-thermal radio emission is associated with the wind-wind collision region of the spectroscopic binary and the tertiary component in HD 167971. The wind-wind collision region changes orientation in agreement with the orbital motion of the tertiary around the spectroscopic binary. The total intensity also changes between the two observing epochs in a way inversely proportional to the separation between the SB and T, with a negative-steep spectral index typical of an optically thin synchrotron emission possibly steepened by an inverse Compton cooling effect. The wind-wind collision bow-shock shape and its position with respect to the stars indicates that the wind momentum from the spectroscopic binary is stronger than that of the tertiary. Finally, the astrometric solution derived for the stellar system and the wind-wind collision region is consistent with independent Gaia data.

show abstract

Section: Introductionsupporting

confidence: 89%

A VLBI study of the wind-wind collision region in the massive multiple HD 167971

Sánchez-Bermúdez

Alberdi

Schödel

et al. 2019

A&A

View full text Add to dashboard Cite

show abstract

“…As already mentioned by several authors, low eccentricities are surprising for such long-period binary systems (e.g., Neilson et al 2015;Le Bouquin et al 2017). The contribution of the primary component to the circularization timescale may be computed as (Zahn 1977;Khaliullin & Khaliullina 2010)…”

Section: Full Set Of Primary Rvs Elementmentioning

confidence: 86%

The long-period massive binary HD 54662 revisited

Mossoux

Mahy

Rauw

2018

A&A

View full text Add to dashboard Cite

Context. HD 54662 is an O-type binary star belonging to the CMa OB1 association. Because of its long-period orbit, this system is an interesting target to test the adiabatic wind shock model. Aims. The goal of this study is to improve our knowledge of the orbital and stellar parameters of HD 54662 and to analyze its X-ray emission to test the theoretical scaling of X-ray emission with orbital separation for adiabatic wind shocks. Methods. We applied a spectral disentangling code to a set of optical spectra to determine the radial velocities and the individual spectra of the primary and secondary stars. The orbital solution of the system was established and the reconstructed individual spectra were analyzed by means of the CMFGEN model atmosphere code. We fitted two X-ray spectra using a Markov Chain Monte Carlo algorithm and compared these spectra to the emission expected from adiabatic shocks. Results. We determine an orbital period of 2103.4 days, a surprisingly low orbital eccentricity of 0.11, and a mass ratio m 2 /m 1 of 0.84. Combined with the orbital inclination inferred in a previous astrometric study, we obtain surprisingly low masses of 9.7 and 8.2 M . From the disentangled primary and secondary spectra, we infer O6.5 spectral types for both stars, of which the primary is about two times brighter than the secondary. The softness of the X-ray spectra for the two observations, the very small variation of best-fitting spectral parameters, and the comparison of the X-ray-to-bolometric luminosity ratio with the canonical value for O-type stars allow us to conclude that X-ray emission from the wind interaction region is quite low and that the observed emission is rather dominated by the intrinsic emission from the stars. We cannot confirm the runaway status previously attributed to HD 54662 by computing the peculiar radial and tangential velocities. We find no X-ray emission associated with the bow shock detected in the infrared. Conclusions. The lack of hard X-ray emission from the wind-shock region suggests that the mass-loss rates are lower than expected and/or that the pre-shock wind velocities are much lower than the terminal wind velocities. The bow shock associated with HD 54662 possibly corresponds to a wind-blown arc created by the interaction of the stellar winds with the ionized gas of the CMa OB1 association rather than by a large differential velocity between the binary and the surrounding interstellar medium.

show abstract

“…Its orbit was resolved using the Very Large Telescope Interferometer (VLTI) and its first astrometric solution was determined by Le Bouquin et al (2017). According to this recent ephemeris, our observation corresponds to orbital phase φ = 0.37.…”

Section: The Starsmentioning

confidence: 99%

X-ray study of bow shocks in runaway stars

Becker

Valle

Romero

et al. 2017

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

Massive runaway stars produce bow shocks through the interaction of their winds with the interstellar medium, with the prospect for particle acceleration by the shocks. These objects are consequently candidates for non-thermal emission. Our aim is to investigate the X-ray emission from these sources. We observed with XMM-Newton a sample of 5 bow shock runaways, which constitutes a significant improvement of the sample of bow shock runaways studied in X-rays so far. A careful analysis of the data did not reveal any X-ray emission related to the bow shocks. However, X-ray emission from the stars is detected, in agreement with the expected thermal emission from stellar winds. On the basis of background measurements we derive conservative upper limits between 0.3 and 10 keV on the bow shocks emission. Using a simple radiation model, these limits together with radio upper limits allow us to constrain some of the main physical quantities involved in the non-thermal emission processes, such as the magnetic field strength and the amount of incident infrared photons. The reasons likely responsible for the non-detection of non-thermal radiation are discussed. Finally, using energy budget arguments, we investigate the detectability of inverse Compton X-rays in a more extended sample of catalogued runaway star bow shocks. From our analysis we conclude that a clear identification of non-thermal X-rays from massive runaway bow shocks requires one order of magnitude (or higher) sensitivity improvement with respect to present observatories.

show abstract

Resolved astrometric orbits of ten O-type binaries

Cited by 46 publications

References 48 publications

A VLBI study of the wind-wind collision region in the massive multiple HD 167971

A VLBI study of the wind-wind collision region in the massive multiple HD 167971

The long-period massive binary HD 54662 revisited

X-ray study of bow shocks in runaway stars

Contact Info

Product

Resources

About