학술논문
An Unbiased CO Survey Toward the Northern Region of the Small Magellanic Cloud with the Atacama Compact Array. II. CO Cloud Catalog
Document Type
Working Paper
Author
Ohno, Takahiro; Tokuda, Kazuki; Konishi, Ayu; Matsumoto, Takeru; Sewiło, Marta; Kondo, Hiroshi; Sano, Hidetoshi; Tsuge, Kisetsu; Zahorecz, Sarolta; Goto, Nao; Neelamkodan, Naslim; Wong, Tony; Fukushima, Hajime; Takekoshi, Tatsuya; Muraoka, Kazuyuki; Kawamura, Akiko; Tachihara, Kengo; Fukui, Yasuo; Onishi, Toshikazu
Source
Subject
Language
Abstract
The nature of molecular clouds and their statistical behavior in subsolar metallicity environments are not fully explored yet. We analyzed data from an unbiased CO($J$ = 2-1) survey at the spatial resolution of ~2 pc in the northern region of the Small Magellanic Cloud with the Atacama Compact Array to characterize the CO cloud properties. A cloud-decomposition analysis identified 426 spatially/velocity-independent CO clouds and their substructures. Based on the cross-matching with known infrared catalogs by Spitzer and Herschel, more than 90% CO clouds show spatial correlations with point sources. We investigated the basic properties of the CO clouds and found that the radius--velocity linewidth ($R$-$\sigma_{v}$) relation follows the Milky Way-like power-low exponent, but the intercept is ~1.5 times lower than that in the Milky Way. The mass functions ($dN/dM$) of the CO luminosity and virial mass are characterized by an exponent of ~1.7, which is consistent with previously reported values in the Large Magellanic Cloud and in the Milky Way.
Comment: 18 pages, 9 figures. Accepted for publication in The Astrophysical Journal
Comment: 18 pages, 9 figures. Accepted for publication in The Astrophysical Journal