Geometric Correction for Wind Accretion in Binary Systems
The Bondi–Hoyle–Lyttleton (BHL) accretion model is widely used to describe how a compact object accretes material from a companion's stellar wind in binary systems. However, its standard implementation becomes inaccurate when the wind velocity ( v _w ) is comparable to or less than the orbital...
Saved in:
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/ada953 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850214663988445184 |
|---|---|
| author | Emilio Tejeda Jesús A. Toalá |
| author_facet | Emilio Tejeda Jesús A. Toalá |
| author_sort | Emilio Tejeda |
| collection | DOAJ |
| description | The Bondi–Hoyle–Lyttleton (BHL) accretion model is widely used to describe how a compact object accretes material from a companion's stellar wind in binary systems. However, its standard implementation becomes inaccurate when the wind velocity ( v _w ) is comparable to or less than the orbital velocity ( v _o ), predicting nonphysical accretion efficiencies above unity. This limits its applicability to systems with low wind-to-orbital velocity ratios ( w = v _w / v _o ≤ 1), such as symbiotic systems. We revisit the implementation of the BHL model and introduce a geometric correction factor that accounts for the varying orientation of the accretion cylinder relative to the wind direction. This correction ensures physically plausible accretion efficiencies ( η ≤ 1) for all w in circular orbits. Our new implementation naturally predicts the flattening of the accretion efficiency observed in numerical simulations for w < 1, without the need for ad hoc adjustments. We also peer into the implications of our prescription for the less-explored case of eccentric orbits, highlighting the key role of the geometric correction factor in shaping the accretion process. We compare our predictions with numerical simulations, finding good agreement for a wide range of parameters. Applications to the symbiotic star R Aqr and the X-ray binary LS 5039 are presented. This improved implementation offers a more accurate description of wind accretion in binary systems, with implications for stellar evolution, population synthesis, and observational data interpretation. |
| format | Article |
| id | doaj-art-439494f05a144f76bbf252cc1f04e48c |
| institution | OA Journals |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj-art-439494f05a144f76bbf252cc1f04e48c2025-08-20T02:08:49ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-01980222610.3847/1538-4357/ada953Geometric Correction for Wind Accretion in Binary SystemsEmilio Tejeda0https://orcid.org/0000-0001-9936-6165Jesús A. Toalá1https://orcid.org/0000-0002-5406-0813SECIHTI—Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo , Ciudad Universitaria, 58040 Morelia, Mich., Mexico ; emilio.tejeda@umich.mxInstituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México , Morelia 58089, Mich., MexicoThe Bondi–Hoyle–Lyttleton (BHL) accretion model is widely used to describe how a compact object accretes material from a companion's stellar wind in binary systems. However, its standard implementation becomes inaccurate when the wind velocity ( v _w ) is comparable to or less than the orbital velocity ( v _o ), predicting nonphysical accretion efficiencies above unity. This limits its applicability to systems with low wind-to-orbital velocity ratios ( w = v _w / v _o ≤ 1), such as symbiotic systems. We revisit the implementation of the BHL model and introduce a geometric correction factor that accounts for the varying orientation of the accretion cylinder relative to the wind direction. This correction ensures physically plausible accretion efficiencies ( η ≤ 1) for all w in circular orbits. Our new implementation naturally predicts the flattening of the accretion efficiency observed in numerical simulations for w < 1, without the need for ad hoc adjustments. We also peer into the implications of our prescription for the less-explored case of eccentric orbits, highlighting the key role of the geometric correction factor in shaping the accretion process. We compare our predictions with numerical simulations, finding good agreement for a wide range of parameters. Applications to the symbiotic star R Aqr and the X-ray binary LS 5039 are presented. This improved implementation offers a more accurate description of wind accretion in binary systems, with implications for stellar evolution, population synthesis, and observational data interpretation.https://doi.org/10.3847/1538-4357/ada953Binary starsStellar accretionStellar windsHigh mass x-ray binary starsSymbiotic binary stars |
| spellingShingle | Emilio Tejeda Jesús A. Toalá Geometric Correction for Wind Accretion in Binary Systems The Astrophysical Journal Binary stars Stellar accretion Stellar winds High mass x-ray binary stars Symbiotic binary stars |
| title | Geometric Correction for Wind Accretion in Binary Systems |
| title_full | Geometric Correction for Wind Accretion in Binary Systems |
| title_fullStr | Geometric Correction for Wind Accretion in Binary Systems |
| title_full_unstemmed | Geometric Correction for Wind Accretion in Binary Systems |
| title_short | Geometric Correction for Wind Accretion in Binary Systems |
| title_sort | geometric correction for wind accretion in binary systems |
| topic | Binary stars Stellar accretion Stellar winds High mass x-ray binary stars Symbiotic binary stars |
| url | https://doi.org/10.3847/1538-4357/ada953 |
| work_keys_str_mv | AT emiliotejeda geometriccorrectionforwindaccretioninbinarysystems AT jesusatoala geometriccorrectionforwindaccretioninbinarysystems |