SgrA${}^{\ast }$ spin and mass estimates through the detection of an extremely large mass-ratio inspiral

Abstract

Estimating the spin of $\mathrm{Sgr}{\mathrm{A}}^{\ast }$ is one of the current challenges we face in understanding the center of our Galaxy. In the present work, we show that detecting the gravitational waves (GWs) emitted by a brown dwarf inspiraling around $\mathrm{Sgr}{\mathrm{A}}^{\ast }$ will allow us to measure the mass and the spin of $\mathrm{Sgr}{\mathrm{A}}^{\ast }$ with unprecedented accuracy. Such systems are known as extremely large mass-ratio inspirals (XMRIs) and are expected to be abundant and loud sources in our galactic center. We consider XMRIs with a fixed orbital inclination and different spins of $\mathrm{Sgr}{\mathrm{A}}^{\ast }$ ($s$) between 0.1 and 0.9. For both cases, we obtain the number of circular and eccentric XMRIs expected to be detected by space-borne GW detectors like LISA and TianQin. We find that if the orbit is eccentric, then we expect to always have several XMRIs in band while for almost circular XMRIs, we only expect to have one source in band if $\mathrm{Sgr}{\mathrm{A}}^{\ast }$ is highly spinning. We later perform a Fisher matrix analysis to show that by detecting a single XMRI the mass of $\mathrm{Sgr}{\mathrm{A}}^{\ast }$ can be determined with an accuracy of the order $10^{-2}{\text{M}}_{\odot }$, while the spin can be measured with an accuracy between $10^{-7}$ and $10^{-4}$ depending on the orbital parameters of the XMRI.

arXiv comment7 pages, 2 figures, 1 table

References in corpus (33)

• On the variation of the Initial Mass Function
• TianQin: a space-borne gravitational wave detector
• First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way
• Monitoring stellar orbits around the Massive Black Hole in the Galactic Center
• Measuring Distance and Properties of the Milky Way's Central Supermassive Black Hole with Stellar Orbits
• Science with the space-based interferometer LISA. V: Extreme mass-ratio inspirals
• First Sagittarius A* Event Horizon Telescope Results. VI: Testing the Black Hole Metric
• Detection, Measurement and Gravitational Radiation
• LISA Capture Sources: Approximate Waveforms, Signal-to-Noise Ratios, and Parameter Estimation Accuracy
• First Sagittarius A* Event Horizon Telescope Results. V. Testing Astrophysical Models of the Galactic Center Black Hole
• Science with the space-based interferometer eLISA. I: Supermassive black hole binaries
• First Sagittarius A* Event Horizon Telescope Results. III: Imaging of the Galactic Center Supermassive Black Hole
• The TianQin project: current progress on science and technology
• First Sagittarius A* Event Horizon Telescope Results. II. EHT and Multi-wavelength Observations, Data Processing, and Calibration
• First Sagittarius A* Event Horizon Telescope Results. IV. Variability, Morphology, and Black Hole Mass
• Strong mass segregation around a massive black hole
• LISA detections of massive black hole inspirals: parameter extraction errors due to inaccurate template waveforms
• On strong mass segregation around a massive black hole: Implications for lower-frequency gravitational-wave astrophysics
• Science with the TianQin observatory: Preliminary result on extreme-mass-ratio inspirals
• The distribution of old stars around the Milky Way's central black hole I: Star counts
• The impact of realistic models of mass segregation on the event rate of extreme-mass ratio inspirals and cusp re-growth
• The distribution of stars around the Milky Way's black hole III: Comparison with simulations
• Gravitational waves from stars orbiting the Sagittarius A* black hole
• X-MRIs: Extremely Large Mass-Ratio Inspirals
• Gravitational waves from bodies orbiting the Galactic Center black hole and their detectability by LISA
• On the Radii of Brown Dwarfs Measured with AKARI Near-Infrared Spectroscopy
• The role of the supermassive black hole spin in the estimation of the EMRI event rate
• Detecting Gravitational-waves from Extreme Mass Ratio Inspirals using Convolutional Neural Networks
• Improved gravitational radiation time-scales: significance for LISA and LIGO-Virgo sources
• Expectations for extreme-mass-ratio bursts from the Galactic Centre
• Improved gravitational radiation time-scales II: spin-orbit contributions and environmental perturbations
• The three body first post-Newtonian effects on the secular dynamics of a compact binary near a spinning supermassive black hole
• Models of mass segregation at the Galactic centre

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• Constructing a gravitational wave analysis pipeline for extremely large mass ratio inspirals