Статья

A Noninteracting Galactic Black Hole Candidate in a Binary System with a Main-sequence Star

Sukanya ChakrabartiDepartment of Physics and Astronomy, University of Alabama, Huntsville, 301 North Sparkman Drive, Huntsville, USA; [email protected]Joshua D. SimonCarnegie ObservatoriesPeter CraigSchool of Physics and Astronomy, Rochester Institute of Technology, 1 Lomb Memorial Drive, Rochester, NY 14623, USAHenrique ReggianiObservatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101, USATimothy D. BrandtDepartment of Physics, University of California, Santa Barbara, Santa Barbara, CA 93106, USAPuragra GuhathakurtaUniversity of California Santa Cruz, UCO/Lick Observatory, 1156 High Street, Santa Cruz, CA 95064, USAPaul A. DalbaDepartment of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064, USAEvan N. KirbyDepartment of Physics and Astronomy, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556, USAPhilip ChangDepartment of Physics, University of Wisconsin-Milwaukee, 3135 North Maryland Avenue, Milwaukee, WI 53211, USADaniel HeyInstitute for Astronomy, University of Hawai’i, Honolulu, HI 96822, USAAlessandro SavinoDepartment of Astronomy, University of California, Berkeley, Berkeley, CA, 94720, USAMarla GehaDepartment of Astronomy, Yale University, 52 Hillhouse Avenue, New Haven, CT 06520, USAI. B. ThompsonObservatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101, USA

2023en

ABI

Аннотация

Abstract We describe the discovery of a solar neighborhood ( d = 468 pc) binary system with a main-sequence sunlike star and a massive noninteracting black hole candidate. The spectral energy distribution of the visible star is described by a single stellar model. We derive stellar parameters from a high signal-to-noise Magellan/MIKE spectrum, classifying the star as a main-sequence star with T eff = 5972 K, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <mml:mi>g</mml:mi> <mml:mo>=</mml:mo> <mml:mn>4.54</mml:mn> </mml:math> , and M = 0.91 M ⊙ . The spectrum shows no indication of a second luminous component. To determine the spectroscopic orbit of the binary, we measured the radial velocities of this system with the Automated Planet Finder, Magellan, and Keck over four months. We show that the velocity data are consistent with the Gaia astrometric orbit and provide independent evidence for a massive dark companion. From a combined fit of our spectroscopic data and the astrometry, we derive a companion mass of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>11.39</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1.31</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>1.51</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> M ⊙ . We conclude that this binary system harbors a massive black hole on an eccentric ( e = 0.46 ± 0.02), 185.4 ± 0.1 day orbit. These conclusions are independent of El-Badry et al., who recently reported the discovery of the same system. A joint fit to all available data yields a comparable period solution but a lower companion mass of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>9.32</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.21</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.22</mml:mn> </mml:mrow> </mml:msubsup> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>⊙</mml:mo> </mml:mrow> </mml:msub> </mml:math> . Radial velocity fits to all available data produce a unimodal solution for the period that is not possible with either data set alone. The combination of both data sets yields the most accurate orbit currently available.

Перевод пока недоступен

Идентификаторы

DOI: 10.3847/1538-3881/accf21

Цитирования и источники

Цитирований: 4Использованных источников: 0

Показатели — AkademScholar