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Arxiv: The Lower Limit of Dynamical Black Hole Masses Detectable in Virgo Compact Stellar Systems Using the JWST/NIRSpec IFU Published: 8/4/2024 11:55:10 PM Updated: 9/10/2024 9:56:49 PM

Paper abstract: Due to observational challenges, the mass function of black holes (BH) atlower masses is poorly constrained in the local universe. Understanding theoccupation fraction of BHs in low-mass galaxies is crucial for constraining theorigins of supermassive BH seeds. Compact stellar systems (CSSs), includingultra-compact dwarf galaxies (UCDs) and compact elliptical galaxies (cEs), arepotential intermediate-mass BH hosts. Despite the difficulties posed by theirlimited spheres of influence, stellar dynamical modeling has been effective inestimating central BH masses in CSSs. Some CSSs may harbor a BH constituting upto 20% of their host stellar mass, while others might not have a central BH. Insupport of our ongoing efforts to determine the BH masses in select CSSs in theVirgo cluster using JWST/NIRSpec IFU observations and orbit-superpositiondynamical models, we create mock kinematic data mimicking the characteristicsof observed cEs/UCDs in the Virgo cluster with different BH masses. We thenconstruct a series of dynamical models using the orbit-superposition codeFORSTAND and explore the accuracy of recovering the BH mass. We find that themass of BHs comprising 1% or more of the total host stellar mass can beaccurately determined through kinematic maps featuring higher-order velocitymoments. We also assess how BH mass measurement is affected by deprojectionmethods, regularization factors, anisotropy parameters, orbit initialconditions, the absence of higher-order velocity moments, spatial resolution,and the signal-to-noise ratio.