A Hidden Friend for the Galactic Center Black Hole, Sgr A*
Publikation: Bidrag til tidsskrift › Letter › Forskning › fagfællebedømt
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A Hidden Friend for the Galactic Center Black Hole, Sgr A*. / Naoz, Smadar; Will, Clifford M.; Ramirez-Ruiz, Enrico; Hees, Aurelien; Ghez, Andrea M.; Do, Tuan.
I: Astrophysical Journal Letters, Bind 888, Nr. 1, 8, 01.01.2020.Publikation: Bidrag til tidsskrift › Letter › Forskning › fagfællebedømt
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T1 - A Hidden Friend for the Galactic Center Black Hole, Sgr A*
AU - Naoz, Smadar
AU - Will, Clifford M.
AU - Ramirez-Ruiz, Enrico
AU - Hees, Aurelien
AU - Ghez, Andrea M.
AU - Do, Tuan
PY - 2020/1/1
Y1 - 2020/1/1
N2 - The hierarchical nature of galaxy formation suggests that a supermassive black hole binary could exist in our galactic center. We propose a new approach to constraining the possible orbital configuration of such a binary companion to the galactic center black hole Sagittarius A* (Sgr A*) through the measurement of stellar orbits. Focusing on the star S0-2, we show that requiring its orbital stability in the presence of a companion to Sgr A* yields stringent constraints on the possible configurations of such a companion. Furthermore, we show that precise measurements of time variations in the orbital parameters of S0-2 could yield stronger constraints. Using existing data on S0-2 we derive upper limits on the binary black hole separation as a function of the companion mass. For the case of a circular orbit, we can rule out a 10(5) M companion with a semimajor axis greater than 170 au or 0.8 mpc. This is already more stringent than bounds obtained from studies of the proper motion of Sgr A*. Including other stars orbiting the galactic center should yield stronger constraints that could help uncover the presence of a companion to Sgr A*. We show that a companion can also affect the accretion process, resulting in a variability that may be consistent with the measured infrared flaring timescales and amplitudes. Finally, if such a companion exists, it will emit gravitational wave radiation, potentially detectable with the Laser Interferometer Space Antenna (LISA).
AB - The hierarchical nature of galaxy formation suggests that a supermassive black hole binary could exist in our galactic center. We propose a new approach to constraining the possible orbital configuration of such a binary companion to the galactic center black hole Sagittarius A* (Sgr A*) through the measurement of stellar orbits. Focusing on the star S0-2, we show that requiring its orbital stability in the presence of a companion to Sgr A* yields stringent constraints on the possible configurations of such a companion. Furthermore, we show that precise measurements of time variations in the orbital parameters of S0-2 could yield stronger constraints. Using existing data on S0-2 we derive upper limits on the binary black hole separation as a function of the companion mass. For the case of a circular orbit, we can rule out a 10(5) M companion with a semimajor axis greater than 170 au or 0.8 mpc. This is already more stringent than bounds obtained from studies of the proper motion of Sgr A*. Including other stars orbiting the galactic center should yield stronger constraints that could help uncover the presence of a companion to Sgr A*. We show that a companion can also affect the accretion process, resulting in a variability that may be consistent with the measured infrared flaring timescales and amplitudes. Finally, if such a companion exists, it will emit gravitational wave radiation, potentially detectable with the Laser Interferometer Space Antenna (LISA).
KW - Supermassive black holes
KW - Astrophysical black holes
KW - Galactic center
KW - the Milky Way physics
KW - Gravitation
KW - Gravitational waves
KW - Gravitational wave sources
KW - the Milky Way
KW - Milky Way dynamics
KW - STELLAR ORBITS
KW - BINARY
KW - MODEL
KW - VARIABILITY
KW - HYPERVELOCITY
KW - PARSEC
KW - STARS
KW - MILKY
KW - MASS
KW - DISCOVERY
U2 - 10.3847/2041-8213/ab5e3b
DO - 10.3847/2041-8213/ab5e3b
M3 - Letter
VL - 888
JO - The Astrophysical Journal Letters
JF - The Astrophysical Journal Letters
SN - 2041-8205
IS - 1
M1 - 8
ER -
ID: 247937988