Search Publications
A kinematic analysis of the giant molecular complex W3: Possible evidence for cloud-cloud collisions that triggered OB star clusters in W3 Main and W3(OH)
Bieging, John H.; Tachihara, Kengo; Fukui, Yasuo +6 more
W3 is one of the most outstanding regions of high-mass star formation in the outer solar circle, and includes two active star-forming clouds: W3 Main and W3(OH). Based on a new analysis of the
Q-band line survey observations toward a carbon-chain-rich clump in the Serpens South region
Lai, Shih-Ping; Liu, Sheng-Yuan; Nakamura, Fumitaka +17 more
We have conducted Q-band (30-50 GHz) line survey observations toward a carbon-chain emission peak in the Serpens South cluster-forming region with the extended Q-band (eQ) receiver installed on the Nobeyama 45 m radio telescope. Approximately 180 lines have been detected, including tentative detection, and these lines are attributed to 52 molecule…
KAgoshima Galactic Object survey with Nobeyama 45 m telescope by Mapping in Ammonia lines (KAGONMA): Discovery of parsec-scale CO depletion in the Canis Major star-forming region
Shimajiri, Yoshito; Sunada, Kazuyoshi; Omodaka, Toshihiro +6 more
In observational studies of infrared dark clouds, the number of detections of CO freeze-out on to dust grains (CO depletion) at the pc scale is extremely limited, and the conditions for its occurrence are, therefore, still unknown. We report a new object where pc-scale CO depletion is expected. As part of the Kagoshima Galactic Object survey with …
CO multi-line imaging of nearby galaxies (COMING). XII. CO-to-H2 conversion factor and dust-to-gas ratio
Kobayashi, Masato I. N.; Kuno, Nario; Miyamoto, Yusuke +8 more
We simultaneously measured the spatially resolved CO-to-H2 conversion factor (αCO) and dust-to-gas ratio (DGR) in nearby galaxies on a kiloparsec scale. In this study, we used 12CO(J = 1-0) data obtained by the Nobeyama 45 m radio telescope with H I and dust mass surface densities. We obtained the values of global …
Cosmic-ray-driven enhancement of the C0/CO abundance ratio in W 51 C
Yamagishi, Mitsuyoshi; Kaneda, Hidehiro; Shimonishi, Takashi +5 more
We examine spatial variations of the C0$/$CO abundance ratio (XC/CO) in the vicinity of the γ-ray supernova remnant W 51 C, based on [C I] (3P1-3P0), 12CO(1-0), and 13CO(1-0) observations with the ASTE and Nobeyama 45 m telescopes. We find that XC/CO…
Twisted magnetic field in star formation processes of L1521 F revealed by submillimeter dual-band polarimetry using the James Clerk Maxwell Telescope
Shinnaga, Hiroko; Tomisaka, Kohji; Harada, Naoto +3 more
Understanding the initial conditions of star formation requires both observational studies and theoretical works taking into account the magnetic field, which plays an important role in star formation processes. Herein, we study the young nearby dense cloud core L1521 F [n(H2) ~104-6 cm-3] in the Taurus Molecular C…
The statistical properties of 28 IR-bright dust-obscured galaxies and SED modelling using CIGALE
Burgarella, Denis; Frey, Sándor; Toba, Yoshiki +7 more
The aim of this study is to characterize the physical and statistical properties of a sample of infrared-bright dust-obscured galaxies (DOGs) by fitting their spectral energy distributions (SEDs). We examined 28 DOGs at redshifts 0.47 ≤ z ≤ 1.63 discovered by combining images of the Subaru Hyper Suprime-Cam (HSC) survey, the VISTA Kilo-degree Infr…
Nobeyama 45 m Local Spur CO survey. I. Giant molecular filaments and cluster formation in the Vulpecula OB association
Miyamoto, Yusuke; Tokuda, Kazuki; Tachihara, Kengo +13 more
We have performed new large-scale 12CO, 13CO, and C18O J = 1-0 observations toward the Vulpecula OB association (l ~ 60°) as part of the Nobeyama 45 m Local Spur CO survey project. Molecular clouds are distributed over ~100 pc, with local peaks at the Sh 2-86, Sh 2-87, and Sh 2-88 high-mass star-forming regions in …
Cloud-cloud collisions and triggered star formation
Inoue, Tsuyoshi; Tachihara, Kengo; Fukui, Yasuo +2 more
Star formation is a fundamental process for galactic evolution. One issue over the last several decades has been determining whether star formation is induced by external triggers or self-regulated in a closed system. The role of an external trigger, which can effectively collect mass in a small volume, has attracted particular attention in connec…
CO Multi-line Imaging of Nearby Galaxies (COMING). IX. 12CO(J = 2-1)/12CO(J = 1-0) line ratio on kiloparsec scales
Kobayashi, Masato I. N.; Kuno, Nario; Miyamoto, Yusuke +8 more
While molecular gas mass is usually derived from 12CO(J = 1-0)—the most fundamental line for exploring molecular gas—it is often derived from 12CO(J = 2-1) assuming a constant 12CO(J = 2-1) $/$ 12CO(J = 1-0) line ratio (R2/1). We present variations of R2/1 and effects of the assumpt…