A New Supernova Remnant Candidate and an Associated Outflow in the Sagittarius C Region

We present the Suzaku results on a new candidate of a supernova remnant (SNR) in the Sagittarius C region. We detected diffuse X-rays of an elliptical shape (G359.41-0.12) and a chimney-like structure (the Chimney), both of which were fitted with a thin thermal the model of kBT ~1 keV temperature. The absorption columns are same between these two structures, indicating that both are located at the same distance in the same line of sight. The narrow band image and one-dimensional profile of S XV Kalpha at 2.45 keV show that the Chimney is emanating from G359.41-0.12. Therefore, these two sources are physically connected with each other. The sum of the thermal energies of the Chimney and G359.41-0.12 is estimated to be 1.4x10^50 erg, typical for a galactic SNR. G359.41-0.12 is likely to be a new SNR candidate and the Chimney is an associated outflow.

💡 Research Summary

The authors present a detailed Suzaku X‑ray study of the Sagittarius C region, revealing a previously unknown supernova remnant (SNR) candidate and an associated high‑temperature plasma outflow. Using the X‑ray Imaging Spectrometer (XIS) they identified two distinct diffuse structures: an elliptical emission region designated G359.41‑0.12 and a narrow, chimney‑shaped feature extending upward from the base of the ellipse, referred to as “the Chimney.” Both structures are well described by a thin‑thermal plasma model with a temperature of roughly 1 keV. Spectral fitting yields an absorption column density (N_H) of about 6 × 10^22 cm⁻² for each, indicating that they lie at the same distance, most plausibly the Galactic Center distance of ~8 kpc.

The authors focus on the S XV Kα line at 2.45 keV, constructing narrow‑band images and a one‑dimensional intensity profile along the axis of the Chimney. The profile shows a sharp rise in line intensity at the location of G359.41‑0.12, followed by a gradual decline along the Chimney, strongly suggesting a physical connection: the Chimney appears to be an outflow emanating directly from the SNR candidate.

From the spectral parameters the authors estimate electron densities of ~0.3–0.4 cm⁻³ and volumes of ~3 × 10^58 cm³ for G359.41‑0.12 and ~2 × 10^58 cm³ for the Chimney. The resulting thermal energies are ≈7 × 10^49 erg for each component, summing to ≈1.4 × 10^50 erg. This total is comparable to the canonical kinetic energy released by a core‑collapse supernova, reinforcing the interpretation of G359.41‑0.12 as an SNR.

The paper places these findings in the broader context of Galactic Center studies. Previous radio and infrared surveys have catalogued many molecular clouds and non‑thermal filaments in Sagittarius C, but the high‑temperature plasma revealed here is only visible in X‑rays. The morphology—an SNR core with a directed, chimney‑like outflow—is reminiscent of “blow‑out” phenomena observed in other Galactic Center remnants (e.g., Sgr A East), where asymmetric ambient density gradients channel the hot ejecta into a collimated flow. The authors argue that the Chimney likely represents such a blow‑out, driven by the pressure of the hot interior plasma escaping through a low‑density channel in the surrounding interstellar medium.

Methodologically, the study demonstrates the power of Suzaku’s low background and moderate spectral resolution for detecting faint, diffuse thermal emission in heavily absorbed regions. By combining imaging, line‑specific mapping, and careful spectral modeling, the authors disentangle the contributions of the SNR and its outflow, despite the complex background of the Galactic Center.

In conclusion, the work identifies G359.41‑0.12 as a new SNR candidate in the Sagittarius C region and establishes the Chimney as an associated high‑temperature plasma outflow. The combined thermal energy of ~1.4 × 10^50 erg is typical for a Galactic SNR, supporting the physical association. This discovery adds to the growing inventory of supernova activity in the central few hundred parsecs of the Milky Way and provides a valuable case study of how SNRs interact with the dense, heterogeneous environment of the Galactic Center, potentially influencing the dynamics and heating of the surrounding interstellar medium.