TY - JOUR

T1 - On the possible orbital motion of Sgr A* in the smooth potential of the Milky Way

AU - Nikiforov, Igor I.

AU - Veselova, Angelina V.

N1 - Funding Information: Acknowledgements We thank the anonymous referee for a very helpful report. I.I.N. acknowledges support from the Russian Foundation for Basic Research, Grant No. 18-02-00552. Publisher Copyright: © 2020 National Astronomical Observatories, CAS and IOP Publishing Ltd. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2020/12

Y1 - 2020/12

N2 - The modern accuracy of measurements allows the residual/peculiar (Galactocentric) velocity of the supermassive black hole (SMBH) in our Galaxy, Sgr A*, on the order of several kilometers per second. We integrate possible orbits of the SMBH along with the surrounding nuclear stellar cluster (NSC) for a barred model of the Galaxy using modern constraints on the components of the SMBH Galactocentric velocity. Is is shown that the range of oscillations of the SMBH + NSC in a regular Galactic field in the plane of the Galaxy allowed by these constraints strongly depends on the set of central components of the Galactic potential. If the central components are represented only by a bulge/bar, for a point estimate of the SMBH Galactocentric velocity, the oscillation amplitude does not exceed 7 pc in the case that a classical bulge is present and reaches 25 pc if there is no bulge; with SMBH velocity components within the 2σ significance level, the amplitude can reach 15 and 50 pc, respectively. However, when taking into account the nuclear stellar disk (NSD), even in the absence of a bulge, the oscillation amplitude is only 5 pc for the point estimate of the SMBH velocity, and 10 pc for the 2σ significance level. Thus, the possible oscillations of the SMBH + NSC complex from the confirmed components of the Galaxy's potential are mostly limited by the NSD, and even taking into account the uncertainty of the mass of the latter, the oscillation amplitude can hardly exceed 13 pc = 6'.

AB - The modern accuracy of measurements allows the residual/peculiar (Galactocentric) velocity of the supermassive black hole (SMBH) in our Galaxy, Sgr A*, on the order of several kilometers per second. We integrate possible orbits of the SMBH along with the surrounding nuclear stellar cluster (NSC) for a barred model of the Galaxy using modern constraints on the components of the SMBH Galactocentric velocity. Is is shown that the range of oscillations of the SMBH + NSC in a regular Galactic field in the plane of the Galaxy allowed by these constraints strongly depends on the set of central components of the Galactic potential. If the central components are represented only by a bulge/bar, for a point estimate of the SMBH Galactocentric velocity, the oscillation amplitude does not exceed 7 pc in the case that a classical bulge is present and reaches 25 pc if there is no bulge; with SMBH velocity components within the 2σ significance level, the amplitude can reach 15 and 50 pc, respectively. However, when taking into account the nuclear stellar disk (NSD), even in the absence of a bulge, the oscillation amplitude is only 5 pc for the point estimate of the SMBH velocity, and 10 pc for the 2σ significance level. Thus, the possible oscillations of the SMBH + NSC complex from the confirmed components of the Galaxy's potential are mostly limited by the NSD, and even taking into account the uncertainty of the mass of the latter, the oscillation amplitude can hardly exceed 13 pc = 6'.

KW - Dynamics

KW - Galaxy: center

KW - Galaxy: fundamental parameters

KW - Galaxy: kinematics

UR - http://www.scopus.com/inward/record.url?scp=85100107774&partnerID=8YFLogxK

U2 - 10.1088/1674-4527/20/12/212

DO - 10.1088/1674-4527/20/12/212

M3 - Article

AN - SCOPUS:85100107774

VL - 20

JO - Research in Astronomy and Astrophysics

JF - Research in Astronomy and Astrophysics

SN - 1674-4527

IS - 12

M1 - 212

ER -