The Fate of Binaries in the Galactic Center: The Mundane and the Exotic

Stephan, Alexander P.; Naoz, Smadar; Ghez, A. M.; Morris, Mark; Ciurlo, Anna; Do, Tuan; Breivik, Katelyn; Coughlin, Scott; Rodriguez, Carl L.

doi:10.3847/1538-4357/ab1e4d

Cited by 87 publications

(119 citation statements)

References 87 publications

(117 reference statements)

Supporting

Mentioning

111

Contrasting

Order By: Relevance

“…This is compatible with the expected binary fraction 30 , based on dynamical simulations 29 and taking into account the physical characteristics of the Galactic Centre. In the most likely scenario 29 for the merger hypothesis, the original binaries would have been formed in the last major star formation event at the Galactic Centre (4-6 Myr ago 22 ). Therefore, the binary merger hypothesis offers a compelling explanation for the origin of the population of G objects for several reasons: (1) it fits well with the three-body dynamics that are necessarily at play in a dense stellar environment; (2) it is compatible with the observed wide range of G-object eccentricities 27 ; and (3) it fits well with the known star formation history and observed stellar population.…”

supporting

confidence: 88%

“…However, it is unclear whether this process can produce sufficiently massive stars to account for the S stars (typically 10-30 M ¤ 20 ). The new star resulting from a merger can appear to be from a few Myr to several Gyr younger, depending on the merging circumstances 29 . Even if the G objects cannot account for the origin of the S stars, they are possibly connected to them.…”

Section: Flux Measurementsmentioning

confidence: 99%

“…They would consequently not contribute substantially to the observed population of G objects. We use binary merger rates 29 and the initial mass function 22 . Given the absence of continuum emission, we assume the G objects come from only the lowmass part of the population.…”

Section: Binary Fraction Estimatementioning

confidence: 99%

“…=^_`a 0 (1) where N B is the number of binaries and N m the number of low-mass stars. We should expect about 10% of all binary systems to have merged within a few million years from a given star formation event in the Galactic Centre 29 . Also, 20%-25% of the initial binary population will have evaporated within the first few million years.…”

Section: Binary Fraction Estimatementioning

confidence: 99%

“…Assuming the binary merger hypothesis, we have used the number of observed G objects to estimate the required binary fraction 29 in the central 0.1 pc, obtaining a lower limit of about 5% for low-mass stars (Methods section 'Binary fraction estimate'). This is compatible with the expected binary fraction 30 , based on dynamical simulations 29 and taking into account the physical characteristics of the Galactic Centre. In the most likely scenario 29 for the merger hypothesis, the original binaries would have been formed in the last major star formation event at the Galactic Centre (4-6 Myr ago 22 ).…”

mentioning

confidence: 99%

See 4 more Smart Citations

A population of dust-enshrouded objects orbiting the Galactic black hole

Ciurlo

Campbell

Morris

et al. 2020

Nature

Self Cite

View full text Add to dashboard Cite

Nature volume 577, pages337-340 (2020) https://www.nature.com/articles/s41586-019-1883-yThe central 0.1 parsecs of the Milky Way host a supermassive black hole identified with the position of the radio and infrared source Sagittarius A* (refs 1,2 ), a cluster of young, massive stars (the S stars 3 ) and various gaseous features 4,5 . Recently, two unusual objects have been found to be closely orbiting Sagittarius A*: the so-called G sources, G1 and G2. These objects are unresolved (having a size on the order of 100 astronomical units, except at periapse where the tidal interaction with the black hole stretches them along the orbit) and they show both thermal dust emission and line emission from ionized gas 6-10 . G1 and G2 have generated attention because they appear to be tidally interacting with the supermassive Galactic black hole, possibly enhancing its accretion activity. No broad consensus has yet been reached concerning their nature: the G objects show the characteristics of gas and dust clouds but display the dynamical properties of stellar-mass objects. Here we report observations of four additional G objects, all lying within 0.04 parsecs of the black hole, and forming a class that is probably unique to this environment. The widely varying orbits derived for the six G objects demonstrate that they were commonly but separately formed.We used near-infrared (NIR) spectro-imaging data obtained over the past 13 years 11 at the W. M. Keck Observatory with the OSIRIS integral field spectrometer 12 , coupled with laser guide star adaptive optics wave front corrections 13 . OSIRIS data-cubes have two spatial dimensions -about 3 arcsec × 2 arcsec surrounding Sgr A* with a plate-scale of 35 mas-and one wavelength dimension -covering the Kn3 band, 2.121-2.229 µm, with a spectral resolution of R ≈ 3,800. We selected 24 datacubes based on image-quality and signal-to-noise ratio; see Methods section 'Observations'. These cubes were processed through the OSIRIS pipeline 14 . We also removed the stellar continua to isolate emission features associated with interstellar gas (Methods section 'Continuum subtraction'). The reduced data-cubes were analysed with a 3D visualization tool, OsrsVol 15 , that simultaneously displays all dimensions of the data-cube. This helps disentangle the many features of this crowded region, which are often superimposed in the spatial dimension but are separable in the wavelength dimension (Fig. 1).Analysing the data with OsrsVol as well as conventional 2D and 1D tools, we identify four new compact objects in Brackett-γ line emission (Brγ; 2.1661 µm rest wavelength) that consistently appear in the data across the observed timeline. In addition to Brγ, all four objects show two [Fe III] emission lines (at 2.1457 µm and 2.2184 µm; ref. 16 ).

show abstract

supporting

confidence: 88%

Section: Flux Measurementsmentioning

confidence: 99%