Discovery of the Tadpole Molecular Cloud near the Galactic Nucleus

In this paper, we report the discovery of an isolated, peculiar compact cloud with a steep velocity gradient at 2.′6 northwest of Sgr A*. This “Tadpole” molecular cloud is unique owing to its characteristic head-tail structure in the position–velocity space. By tracing the CO J = 3–2 intensity peak...

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Bibliographic Details
Main Authors: Miyuki Kaneko, Tomoharu Oka, Hiroki Yokozuka, Rei Enokiya, Shunya Takekawa, Yuhei Iwata, Shiho Tsujimoto
Format: Article
Language:English
Published: IOP Publishing 2023-01-01
Series:The Astrophysical Journal
Subjects:
Online Access:https://doi.org/10.3847/1538-4357/aca66a
Description
Summary:In this paper, we report the discovery of an isolated, peculiar compact cloud with a steep velocity gradient at 2.′6 northwest of Sgr A*. This “Tadpole” molecular cloud is unique owing to its characteristic head-tail structure in the position–velocity space. By tracing the CO J = 3–2 intensity peak in each velocity channel, we noticed that the kinematics of the Tadpole can be well reproduced by a Keplerian motion around a point-like object with a mass of 1 × 10 ^5 M _⊙ . Changes in line intensity ratios along the orbit are consistent with the Keplerian orbit model. The spatial compactness of the Tadpole and absence of bright counterparts in other wavelengths indicate that the object could be an intermediate-mass black hole.
ISSN:1538-4357