Detailed analysis of multi-line molecular distributions in the Seyfert galaxy NGC 1068: Possible effect of the AGN outflow to the starburst ring

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Okubo, Hiroma, Saito, Toshiki, Takano, Shuro, Kuno, Nario, Taniguchi, Akio, Nakajima, Taku, Harada, Nanase, Mawatari, Ken
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912439935696896
author Okubo, Hiroma
Saito, Toshiki
Takano, Shuro
Kuno, Nario
Taniguchi, Akio
Nakajima, Taku
Harada, Nanase
Mawatari, Ken
author_facet Okubo, Hiroma
Saito, Toshiki
Takano, Shuro
Kuno, Nario
Taniguchi, Akio
Nakajima, Taku
Harada, Nanase
Mawatari, Ken
contents We apply principal component analysis (PCA) to the integrated intensity maps of 13 molecular lines of the nearby type-2 Seyfert galaxy NGC 1068 obtained by Atacama Large Millimeter/sub-millimeter Array (ALMA) to objectively visualize the features of its center, (1) within a radius of about 2 kpc ($\sim$ 27".5; hereafter the "overall region") and (2) the ring shaped starburst region between 750 pc ($\sim$ 10") and 2 kpc ($\sim$ 27".5) of the galaxy (hereafter the "SB ring region"). PCA is a powerful unsupervised machine learning technique that extracts key information through dimensionality reduction. The PCA results for the overall region have a possibility to reconstruct a map representing the approximate H$_2$ column density and difference of volume density and/or chemical composition between the circumnuclear disk (CND) and the starburst ring (SB ring). Additionally, the PCA results for the SB ring region have a possibility to reconstruct a map representing the approximate H$_2$ column density and distinction between starburst dominated region and shock dominated region. Furthermore, the PCA results for the SB ring region indicate a possible interaction between the Active Galactic Nucleus (AGN) outflow and gas in the SB ring. Although further investigation is required, we suggest that the AGN outflow interacts with gas in the SB ring, as this feature is consistent with the direction of the AGN outflow and is contributed by CN, C$_2$H and HCN, which are known to be enhanced by the AGN outflow. These results demonstrate that PCA can effectively extract features even for galaxies with complex structures, such as AGN + SB ring. This study also implies that PCA has the potential to uncover previously unrecognized phenomena by visualizing latent structures in multi-line data.
format Preprint
id arxiv_https___arxiv_org_abs_2506_15999
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Detailed analysis of multi-line molecular distributions in the Seyfert galaxy NGC 1068: Possible effect of the AGN outflow to the starburst ring
Okubo, Hiroma
Saito, Toshiki
Takano, Shuro
Kuno, Nario
Taniguchi, Akio
Nakajima, Taku
Harada, Nanase
Mawatari, Ken
Astrophysics of Galaxies
We apply principal component analysis (PCA) to the integrated intensity maps of 13 molecular lines of the nearby type-2 Seyfert galaxy NGC 1068 obtained by Atacama Large Millimeter/sub-millimeter Array (ALMA) to objectively visualize the features of its center, (1) within a radius of about 2 kpc ($\sim$ 27".5; hereafter the "overall region") and (2) the ring shaped starburst region between 750 pc ($\sim$ 10") and 2 kpc ($\sim$ 27".5) of the galaxy (hereafter the "SB ring region"). PCA is a powerful unsupervised machine learning technique that extracts key information through dimensionality reduction. The PCA results for the overall region have a possibility to reconstruct a map representing the approximate H$_2$ column density and difference of volume density and/or chemical composition between the circumnuclear disk (CND) and the starburst ring (SB ring). Additionally, the PCA results for the SB ring region have a possibility to reconstruct a map representing the approximate H$_2$ column density and distinction between starburst dominated region and shock dominated region. Furthermore, the PCA results for the SB ring region indicate a possible interaction between the Active Galactic Nucleus (AGN) outflow and gas in the SB ring. Although further investigation is required, we suggest that the AGN outflow interacts with gas in the SB ring, as this feature is consistent with the direction of the AGN outflow and is contributed by CN, C$_2$H and HCN, which are known to be enhanced by the AGN outflow. These results demonstrate that PCA can effectively extract features even for galaxies with complex structures, such as AGN + SB ring. This study also implies that PCA has the potential to uncover previously unrecognized phenomena by visualizing latent structures in multi-line data.
title Detailed analysis of multi-line molecular distributions in the Seyfert galaxy NGC 1068: Possible effect of the AGN outflow to the starburst ring
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2506.15999