Bibliographic Details
| Title: |
Dynamical confirmation of a black hole in the X-ray transient Swift J1727.8-1613 |
| Authors: |
Sanchez, D. Mata, Torres, M. A. P., Casares, J., Munoz-Darias, T., Padilla, M. Armas, Yanes-Rizo, I. V. |
| Source: |
A&A 693, A129 (2025) |
| Publication Year: |
2024 |
| Collection: |
Astrophysics |
| Subject Terms: |
Astrophysics - High Energy Astrophysical Phenomena |
| More Details: |
The X-ray transient Swift J1727.8-1613 ended its 10-month discovery outburst on June of 2024, when it reached an optical brightness comparable to pre-discovery magnitudes. With the aim of performing a dynamical study, we launched an optical spectroscopy campaign with the GTC telescope. We detect the companion star and construct its radial velocity curve, yielding a binary orbital period of Porb = 10.8038 +- 0.0010 h and a radial velocity semi-amplitude of K2 = 390 +- 4 km/s. This results in a mass function of f(M1)=2.77 +- 0.09 Msun. Combined with constraints on the binary inclination, it sets a lower limit to the compact object mass of M1 > 3.12 +- 0.10 Msun, dynamically confirming the black hole nature of the accretor. Comparison of the average spectrum in the rest frame of the companion with synthetic stellar templates supports a K4V donor partially veiled (74%) by the accretion disc. A refined distance measurement of 3.7+- 0.3 kpc, together with the astrometric proper motion and the systemic velocity derived from the radial velocity curve (-181 +-4 km/s), supports a natal kick velocity of 220 +40 -50 km/s, at the upper end of the observed distribution.
Comment: 6 (+2 appendix) pages, 3 (+1) figures, 2 tables. Submitted to A&A on the 22th of August 2024, accepted on the 12th of November 2024. Updated final distance values after fixing a bug affecting the spectroscopic distance determination |
| Document Type: |
Working Paper |
| DOI: |
10.1051/0004-6361/202451960 |
| Access URL: |
http://arxiv.org/abs/2408.13310 |
| Accession Number: |
edsarx.2408.13310 |
| Database: |
arXiv |
