Salvato in:
| Autore principale: | |
|---|---|
| Natura: | Preprint |
| Pubblicazione: |
2026
|
| Soggetti: | |
| Accesso online: | https://arxiv.org/abs/2603.10200 |
| Tags: |
Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
|
| _version_ | 1866917331378110464 |
|---|---|
| author | White, Nicholas E. |
| author_facet | White, Nicholas E. |
| contents | Cygnus~X-3 is a Galactic X-ray binary with a 4.8-hr orbital period operating in the ultraluminous regime. Although the system is viewed at relatively low inclination ($i\approx28^\circ$), it exhibits a deep orbital modulation. Recent IXPE observations show strong linear polarization orthogonal to the radio jet, indicating that the X-ray emission is dominated by reflection from the inner walls of a supercritical outflow funnel.
We propose a Hybrid Roche-lobe overflow (RLOF) scenario in which a massive Wolf-Rayet donor effectively fills its Roche lobe with a focused wind driving a super-Eddington accretion stream. Using a numerical synthesis of the folded light curve, we show that the modulation is reproduced when the central funnel is periodically occulted by a vertically extended, shock-heated Turbulent Wall formed by stream impact on the outer disk rim. This produces a phase lag ($Δϕ\approx0.11$) between X-ray minimum and binary conjunction, with extended attenuation by the WR wind defining a broader Suppression Region.
This geometry explains the enhanced iron-line equivalent width during X-ray minimum via a coronagraphic effect. The large radial-velocity amplitude of FeXXVI measured by XRISM ($K_{\rm obs}\approx430$ km s$^{-1}$) and its zero-crossing at $ϕ_X=0.0$ arise naturally in the stream-impact region rather than from orbital motion of the compact object.
Finally, we show that the observed secular orbital expansion ($\dot P>0$) follows directly from highly non-conservative mass transfer with inner-disk mass loss, indicating that Cygnus~X-3 is a stable, long-lived system in a supercritical accretion regime. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2603_10200 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | The Geometric Crisis in Cygnus~X-3: Limitations of Wind-Fed Accretion and the Case for Roche-Lobe Overflow White, Nicholas E. High Energy Astrophysical Phenomena Cygnus~X-3 is a Galactic X-ray binary with a 4.8-hr orbital period operating in the ultraluminous regime. Although the system is viewed at relatively low inclination ($i\approx28^\circ$), it exhibits a deep orbital modulation. Recent IXPE observations show strong linear polarization orthogonal to the radio jet, indicating that the X-ray emission is dominated by reflection from the inner walls of a supercritical outflow funnel. We propose a Hybrid Roche-lobe overflow (RLOF) scenario in which a massive Wolf-Rayet donor effectively fills its Roche lobe with a focused wind driving a super-Eddington accretion stream. Using a numerical synthesis of the folded light curve, we show that the modulation is reproduced when the central funnel is periodically occulted by a vertically extended, shock-heated Turbulent Wall formed by stream impact on the outer disk rim. This produces a phase lag ($Δϕ\approx0.11$) between X-ray minimum and binary conjunction, with extended attenuation by the WR wind defining a broader Suppression Region. This geometry explains the enhanced iron-line equivalent width during X-ray minimum via a coronagraphic effect. The large radial-velocity amplitude of FeXXVI measured by XRISM ($K_{\rm obs}\approx430$ km s$^{-1}$) and its zero-crossing at $ϕ_X=0.0$ arise naturally in the stream-impact region rather than from orbital motion of the compact object. Finally, we show that the observed secular orbital expansion ($\dot P>0$) follows directly from highly non-conservative mass transfer with inner-disk mass loss, indicating that Cygnus~X-3 is a stable, long-lived system in a supercritical accretion regime. |
| title | The Geometric Crisis in Cygnus~X-3: Limitations of Wind-Fed Accretion and the Case for Roche-Lobe Overflow |
| topic | High Energy Astrophysical Phenomena |
| url | https://arxiv.org/abs/2603.10200 |