A half-ring of ionized circumstellar material trapped in the magnetosphere of a white dwarf merger remnant
Fuente:
arXiv
Enregistré dans:
| Auteurs principaux: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Publié: |
2025
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866915788767625216 |
|---|---|
| author | Cristea, Andrei A. Caiazzo, Ilaria Cunningham, Tim Raymond, John C. Vennes, Stephane Kawka, Adela Desai, Aayush Miller, David R. Hermes, J. J. Fuller, Jim Heyl, Jeremy van Roestel, Jan Burdge, Kevin B. Rodriguez, Antonio C. Pelisoli, Ingrid Gänsicke, Boris T. Szkody, Paula Kenyon, Scott J. Vanderbosch, Zach Drake, Andrew Ferrario, Lilia Wickramasinghe, Dayal Karambelkar, Viraj R. Justham, Stephen Pakmor, Ruediger El-Badry, Kareem Prince, Thomas Kulkarni, S. R. Graham, Matthew J. Masci, Frank J. Groom, Steven L. Purdum, Josiah Dekany, Richard Bellm, Eric C. |
| author_facet | Cristea, Andrei A. Caiazzo, Ilaria Cunningham, Tim Raymond, John C. Vennes, Stephane Kawka, Adela Desai, Aayush Miller, David R. Hermes, J. J. Fuller, Jim Heyl, Jeremy van Roestel, Jan Burdge, Kevin B. Rodriguez, Antonio C. Pelisoli, Ingrid Gänsicke, Boris T. Szkody, Paula Kenyon, Scott J. Vanderbosch, Zach Drake, Andrew Ferrario, Lilia Wickramasinghe, Dayal Karambelkar, Viraj R. Justham, Stephen Pakmor, Ruediger El-Badry, Kareem Prince, Thomas Kulkarni, S. R. Graham, Matthew J. Masci, Frank J. Groom, Steven L. Purdum, Josiah Dekany, Richard Bellm, Eric C. |
| contents | Many white dwarfs are observed in compact double white dwarf binaries and, through the emission of gravitational waves, a large fraction are destined to merge. The merger remnants that do not explode in a Type Ia supernova are expected to initially be rapidly rotating and highly magnetized. We here present our discovery of the variable white dwarf ZTF J200832.79+444939.67, hereafter ZTF J2008+4449, as a likely merger remnant showing signs of circumstellar material without a stellar or substellar companion. The nature of ZTF J2008+4449 as a merger remnant is supported by its physical properties: hot ($35,500\pm300$ K) and massive ($1.12\pm0.03$ M$_\odot$), the white dwarf is rapidly rotating with a period of $\approx$ 6.6 minutes and likely possesses exceptionally strong magnetic fields ($\sim$ 400-600 MG) at its surface. Remarkably, we detect a significant period derivative of $(1.80\pm0.09)\times10^{-12}$ s/s, indicating that the white dwarf is spinning down, and a soft X-ray emission that is inconsistent with photospheric emission. As the presence of a mass-transferring stellar or brown dwarf companion is excluded by infrared photometry, the detected spin down and X-ray emission could be tell-tale signs of a magnetically driven wind or of interaction with circumstellar material, possibly originating from the fallback of gravitationally bound merger ejecta or from the tidal disruption of a planetary object. We also detect Balmer emission, which requires the presence of ionized hydrogen in the vicinity of the white dwarf, showing Doppler shifts as high as $\approx$ 2000 km s$^{-1}$. The unusual variability of the Balmer emission on the spin period of the white dwarf is consistent with the trapping of a half ring of ionised gas in the magnetosphere of the white dwarf. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2507_13850 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | A half-ring of ionized circumstellar material trapped in the magnetosphere of a white dwarf merger remnant Cristea, Andrei A. Caiazzo, Ilaria Cunningham, Tim Raymond, John C. Vennes, Stephane Kawka, Adela Desai, Aayush Miller, David R. Hermes, J. J. Fuller, Jim Heyl, Jeremy van Roestel, Jan Burdge, Kevin B. Rodriguez, Antonio C. Pelisoli, Ingrid Gänsicke, Boris T. Szkody, Paula Kenyon, Scott J. Vanderbosch, Zach Drake, Andrew Ferrario, Lilia Wickramasinghe, Dayal Karambelkar, Viraj R. Justham, Stephen Pakmor, Ruediger El-Badry, Kareem Prince, Thomas Kulkarni, S. R. Graham, Matthew J. Masci, Frank J. Groom, Steven L. Purdum, Josiah Dekany, Richard Bellm, Eric C. Solar and Stellar Astrophysics High Energy Astrophysical Phenomena Many white dwarfs are observed in compact double white dwarf binaries and, through the emission of gravitational waves, a large fraction are destined to merge. The merger remnants that do not explode in a Type Ia supernova are expected to initially be rapidly rotating and highly magnetized. We here present our discovery of the variable white dwarf ZTF J200832.79+444939.67, hereafter ZTF J2008+4449, as a likely merger remnant showing signs of circumstellar material without a stellar or substellar companion. The nature of ZTF J2008+4449 as a merger remnant is supported by its physical properties: hot ($35,500\pm300$ K) and massive ($1.12\pm0.03$ M$_\odot$), the white dwarf is rapidly rotating with a period of $\approx$ 6.6 minutes and likely possesses exceptionally strong magnetic fields ($\sim$ 400-600 MG) at its surface. Remarkably, we detect a significant period derivative of $(1.80\pm0.09)\times10^{-12}$ s/s, indicating that the white dwarf is spinning down, and a soft X-ray emission that is inconsistent with photospheric emission. As the presence of a mass-transferring stellar or brown dwarf companion is excluded by infrared photometry, the detected spin down and X-ray emission could be tell-tale signs of a magnetically driven wind or of interaction with circumstellar material, possibly originating from the fallback of gravitationally bound merger ejecta or from the tidal disruption of a planetary object. We also detect Balmer emission, which requires the presence of ionized hydrogen in the vicinity of the white dwarf, showing Doppler shifts as high as $\approx$ 2000 km s$^{-1}$. The unusual variability of the Balmer emission on the spin period of the white dwarf is consistent with the trapping of a half ring of ionised gas in the magnetosphere of the white dwarf. |
| title | A half-ring of ionized circumstellar material trapped in the magnetosphere of a white dwarf merger remnant |
| topic | Solar and Stellar Astrophysics High Energy Astrophysical Phenomena |
| url | https://arxiv.org/abs/2507.13850 |