Chandra/LETGS Studies of the Collisional Plasma in 4U 1626–67
We present an analysis of \chandra/LETGS observations of the ultracompact X-ray binary (UCXB) 4U 1626$-$67, continuing our project to analyze the existing Chandra gratings data of this interesting source. The extremely low mass, hydrogen-depleted donor star provides a unique opportunity to...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
American Astronomical Society
2022
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| Online Access: | https://hdl.handle.net/1721.1/141431 |
| _version_ | 1826214288970219520 |
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| author | Hemphill, Paul B Schulz, Norbert S Marshall, Herman L Chakrabarty, Deepto |
| author2 | MIT Kavli Institute for Astrophysics and Space Research |
| author_facet | MIT Kavli Institute for Astrophysics and Space Research Hemphill, Paul B Schulz, Norbert S Marshall, Herman L Chakrabarty, Deepto |
| author_sort | Hemphill, Paul B |
| collection | MIT |
| description | We present an analysis of \chandra/LETGS observations of the ultracompact
X-ray binary (UCXB) 4U 1626$-$67, continuing our project to analyze the
existing
Chandra gratings data of this interesting source. The extremely low mass,
hydrogen-depleted donor star provides a unique opportunity to study the
properties and structure of the metal-rich accreted plasma. There are strong,
double-peaked emission features of OVII-VIII and Ne IX-X, but no other
identified emission lines are detected. Our spectral fit simultaneously
models the emission line profiles and the plasma parameters, using a
two-temperature collisionally-ionized plasma. Based on our line profile
fitting, we constrain the inclination of the system to 25--60$^{\circ}$ and
the inner disk radius to $\sim$1500 gravitational radii, in turn constraining
the donor mass to $\lesssim$0.026 M_sun, while our plasma modeling confirms
previous reports of high neon abundance in the source, establishing a Ne/O
ratio in the system of $0.47 \pm 0.04$, while simultaneously estimating a
very low Fe/O ratio of $0.0042 \pm 0.0008$ and limiting the Mg/O ratio to
less than 1% by number. We discuss these results in light of previous work. |
| first_indexed | 2024-09-23T16:03:14Z |
| format | Article |
| id | mit-1721.1/141431 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T16:03:14Z |
| publishDate | 2022 |
| publisher | American Astronomical Society |
| record_format | dspace |
| spelling | mit-1721.1/1414312023-01-11T21:53:25Z Chandra/LETGS Studies of the Collisional Plasma in 4U 1626–67 Hemphill, Paul B Schulz, Norbert S Marshall, Herman L Chakrabarty, Deepto MIT Kavli Institute for Astrophysics and Space Research We present an analysis of \chandra/LETGS observations of the ultracompact X-ray binary (UCXB) 4U 1626$-$67, continuing our project to analyze the existing Chandra gratings data of this interesting source. The extremely low mass, hydrogen-depleted donor star provides a unique opportunity to study the properties and structure of the metal-rich accreted plasma. There are strong, double-peaked emission features of OVII-VIII and Ne IX-X, but no other identified emission lines are detected. Our spectral fit simultaneously models the emission line profiles and the plasma parameters, using a two-temperature collisionally-ionized plasma. Based on our line profile fitting, we constrain the inclination of the system to 25--60$^{\circ}$ and the inner disk radius to $\sim$1500 gravitational radii, in turn constraining the donor mass to $\lesssim$0.026 M_sun, while our plasma modeling confirms previous reports of high neon abundance in the source, establishing a Ne/O ratio in the system of $0.47 \pm 0.04$, while simultaneously estimating a very low Fe/O ratio of $0.0042 \pm 0.0008$ and limiting the Mg/O ratio to less than 1% by number. We discuss these results in light of previous work. 2022-03-31T13:00:38Z 2022-03-31T13:00:38Z 2021 2022-03-31T12:47:18Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/141431 Hemphill, Paul B, Schulz, Norbert S, Marshall, Herman L and Chakrabarty, Deepto. 2021. "Chandra/LETGS Studies of the Collisional Plasma in 4U 1626–67." Astrophysical Journal, 920 (2). en 10.3847/1538-4357/AC0ADE Astrophysical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Astronomical Society The American Astronomical Society |
| spellingShingle | Hemphill, Paul B Schulz, Norbert S Marshall, Herman L Chakrabarty, Deepto Chandra/LETGS Studies of the Collisional Plasma in 4U 1626–67 |
| title | Chandra/LETGS Studies of the Collisional Plasma in 4U 1626–67 |
| title_full | Chandra/LETGS Studies of the Collisional Plasma in 4U 1626–67 |
| title_fullStr | Chandra/LETGS Studies of the Collisional Plasma in 4U 1626–67 |
| title_full_unstemmed | Chandra/LETGS Studies of the Collisional Plasma in 4U 1626–67 |
| title_short | Chandra/LETGS Studies of the Collisional Plasma in 4U 1626–67 |
| title_sort | chandra letgs studies of the collisional plasma in 4u 1626 67 |
| url | https://hdl.handle.net/1721.1/141431 |
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