Identification of a Helium Donor Star in NGC 247 ULX-1
With Very Large Telescope Multi Unit Spectroscopic Explorer (MUSE) observations, we detected highly variable helium emission lines from the optical counterpart of the supersoft ultraluminous X-ray source (ULX) NGC 247 ULX-1. No Balmer lines can be seen in the source spectrum. This is the first evide...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/acc5eb |
| _version_ | 1797701144042012672 |
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| author | Changxing Zhou Hua Feng Fuyan Bian |
| author_facet | Changxing Zhou Hua Feng Fuyan Bian |
| author_sort | Changxing Zhou |
| collection | DOAJ |
| description | With Very Large Telescope Multi Unit Spectroscopic Explorer (MUSE) observations, we detected highly variable helium emission lines from the optical counterpart of the supersoft ultraluminous X-ray source (ULX) NGC 247 ULX-1. No Balmer lines can be seen in the source spectrum. This is the first evidence for the presence of a helium donor star in ULXs, consistent with a prediction that helium donor stars may be common in ULXs. The helium lines with an FWHM of about 200 km s ^−1 are likely produced on the outer accretion disk. Their strong variation implies that the central X-ray source can be significantly obscured to the outer disk. Also, a ring or a double-ring structure is revealed in the MUSE image. It is unknown whether or not it is related to the progenitor of the ULX binary. |
| first_indexed | 2024-03-12T04:31:09Z |
| format | Article |
| id | doaj.art-b3a5c9b18b56490f98e9b674145b5c30 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T04:31:09Z |
| publishDate | 2023-01-01 |
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| series | The Astrophysical Journal |
| spelling | doaj.art-b3a5c9b18b56490f98e9b674145b5c302023-09-03T10:05:25ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0194725210.3847/1538-4357/acc5ebIdentification of a Helium Donor Star in NGC 247 ULX-1Changxing Zhou0https://orcid.org/0000-0002-5954-2571Hua Feng1https://orcid.org/0000-0001-7584-6236Fuyan Bian2https://orcid.org/0000-0002-1620-0897Department of Engineering Physics, Tsinghua University , Beijing 100084, People's Republic of ChinaDepartment of Engineering Physics, Tsinghua University , Beijing 100084, People's Republic of China; Department of Astronomy, Tsinghua University , Beijing 100084, People's Republic of China ; hfeng@tsinghua.edu.cnEuropean Southern Observatory , Alonso de Córdova 3107, Casilla 19001, Vitacura, Santiago 19, Chile ; fuyan.bian@eso.orgWith Very Large Telescope Multi Unit Spectroscopic Explorer (MUSE) observations, we detected highly variable helium emission lines from the optical counterpart of the supersoft ultraluminous X-ray source (ULX) NGC 247 ULX-1. No Balmer lines can be seen in the source spectrum. This is the first evidence for the presence of a helium donor star in ULXs, consistent with a prediction that helium donor stars may be common in ULXs. The helium lines with an FWHM of about 200 km s ^−1 are likely produced on the outer accretion disk. Their strong variation implies that the central X-ray source can be significantly obscured to the outer disk. Also, a ring or a double-ring structure is revealed in the MUSE image. It is unknown whether or not it is related to the progenitor of the ULX binary.https://doi.org/10.3847/1538-4357/acc5ebUltraluminous x-ray sourcesX-ray binary starsCompanion starsHydrogen deficient starsStellar accretion disks |
| spellingShingle | Changxing Zhou Hua Feng Fuyan Bian Identification of a Helium Donor Star in NGC 247 ULX-1 The Astrophysical Journal Ultraluminous x-ray sources X-ray binary stars Companion stars Hydrogen deficient stars Stellar accretion disks |
| title | Identification of a Helium Donor Star in NGC 247 ULX-1 |
| title_full | Identification of a Helium Donor Star in NGC 247 ULX-1 |
| title_fullStr | Identification of a Helium Donor Star in NGC 247 ULX-1 |
| title_full_unstemmed | Identification of a Helium Donor Star in NGC 247 ULX-1 |
| title_short | Identification of a Helium Donor Star in NGC 247 ULX-1 |
| title_sort | identification of a helium donor star in ngc 247 ulx 1 |
| topic | Ultraluminous x-ray sources X-ray binary stars Companion stars Hydrogen deficient stars Stellar accretion disks |
| url | https://doi.org/10.3847/1538-4357/acc5eb |
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