207 citations · 893 across the 40 of their papers we have counts for
42 papers
Metal-poor molecular clouds in dwarf galaxies at parsec-scale resolution
L. K. Hunt, M. Heyer, U. Lisenfeld +17
Understanding how stars form at low metallicity is challenging because carbon monoxide (CO) emission, which usually probes the molecular gas reservoir, is faint, and tends to be co…
AKARI near-infrared spectroscopy of circumstellar hydrocarbon dust associated with young stellar objects
Yuki Kuroda, Hidehiro Kaneda, Natsuko Izumi +2
We investigate the processing of the circumstellar polycyclic aromatic hydrocarbons (PAHs) associated with young stellar objects (YSOs) through their stellar activities. We analyze…
Molecular and Atomic Gas Associated with the Gamma Ray Supernova Remnant RCW 103
H. Inoue, Y. Asano, R. G. Bhuvana +15
We present a study of the interstellar molecular and atomic gas associated with the gamma-ray supernova remnant (SNR) RCW 103 using the Mopra CO( = 1-0), Atacama Large Mi…
Protoplanetary Disk Evolution in a Low-Metallicity Environment: JWST's First Mid-Infrared Census of Low-Mass Stars
Chikako Yasui, Natsuko Izumi, Masao Saito +3
This study presents the first high-resolution, high-sensitivity mid-infrared (MIR) investigation of protoplanetary disks in a low-metallicity environment, using JWST/NIRCam and MIR…
Digging into the chemical complexity in the outer Galaxy: A hot molecular core in Sharpless 2-283
Toki Ikeda, Takashi Shimonishi, Hiroyuki Kaneko +3
The outer Galaxy (galactocentric distance 13.5 kpc) serves as an excellent laboratory for investigating the chemical complexity in low-metallicity environments. Here, we p…
The detection of spatially resolved protosteller outflows and episodic jets in the outer Galaxy
Toki Ikeda, Takashi Shimonishi, Natsuko Izumi +5
We present the first detection of spatially resolved protostellar outflows and jets in the outer Galaxy. We observed five star-forming regions in the outer Galaxy (Sh 2--283, NOMF0…
Revealing Potential Initial Mass Function variations with metallicity: JWST observations of young open clusters in a low-metallicity environment
Chikako Yasui, Natsuko Izumi, Masao Saito +3
We present the substellar mass function of star-forming clusters (0.1 Myr old) in a low-metallicity environment (0.7 dex). We performed deep JWST/NIRCam and MIRI…
Overview Results of JWST Observations of Star-Forming Clusters in the Extreme Outer Galaxy
Natsuko Izumi, Michael E. Ressler, Ryan M. Lau +4
The extreme outer Galaxy (EOG), which we define as the region of the Milky Way with a galactocentric radius of more than 18 kpc, provides an excellent opportunity to study star for…
The ALMA Survey of 70 m Dark High-mass Clumps in Early Stages (ASHES). XI. Statistical Study of Early Fragmentation
Kaho Morii, Patricio Sanhueza, Qizhou Zhang +9
Fragmentation during the early stages of high-mass star formation is crucial for understanding the formation of high-mass clusters. We investigated fragmentation within thirty-nine…
The ALMA Survey of 70 μm Dark High-mass Clumps in Early Stages (ASHES). X: Hot Gas Reveals Deeply Embedded Star Formation
Natsuko Izumi, Patricio Sanhueza, Patrick M. Koch +10
Massive infrared dark clouds (IRDCs) are considered to host the earliest stages of high-mass star formation. In particular, 70 m dark IRDCs are the colder and more quiescent clo…
Cosmic-ray-driven enhancement of the C/CO abundance ratio in W51C
Mitsuyoshi Yamagishi, Kenji Furuya, Hidetoshi Sano +5
We examine spatial variations of the C/CO abundance ratio () in the vicinity of the -ray supernova remnant W51C, based on [CI] (-), C…
The ALMA Survey of 70 m Dark High-mass Clumps in Early Stages (ASHES). IX. Physical Properties and Spatial Distribution of Cores in IRDCs
Kaho Morii, Patricio Sanhueza, Fumitaka Nakamura +13
The initial conditions found in infrared dark clouds (IRDCs) provide insights on how high-mass stars and stellar clusters form. We have conducted high-angular resolution and high-s…
The ALMA Survey of 70 μm Dark High-mass Clumps in Early Stages (ASHES). VIII. Dynamics of Embedded Dense Cores
Shanghuo Li, Patricio Sanhueza, Qizhou Zhang +9
We present the dynamical properties of 294 cores embedded in twelve IRDCs observed as part of the ASHES Survey. Protostellar cores have higher gas masses, surface densities, column…
Mass function of a young cluster in a low-metallicity environment. Sh 2-209
Chikako Yasui, Naoto Kobayashi, Masao Saito +2
We present deep near-infrared (NIR) imaging of Sh 2-209 (S209), a low-metallicity ( dex) HII region in the Galaxy. From the NIR images, combined with astrometr…
The ALMA Survey of 70 Dark High-mass Clumps in Early Stages (ASHES). VII: Chemistry of Embedded Dense Cores
Shanghuo Li, Patricio Sanhueza, Xing Lu +15
We present a study of chemistry toward 294 dense cores in 12 molecular clumps using the data obtained from the ALMA Survey of 70 dark High-mass clumps in Early Stages (ASH…
The ALMA Survey of 70 μm Dark High-mass Clumps in Early Stages (ASHES). VI. The core-scale CO-depletion
Giovanni Sabatini, Stefano Bovino, Patricio Sanhueza +11
Studying the physical and chemical properties of cold and dense molecular clouds is crucial for the understanding of how stars form. Under the typical conditions of infrared dark c…
Star Formation Activity Beyond the Outer Arm II: Distribution and Properties of Star Formation
Natsuko Izumi, Naoto Kobayashi, Chikako Yasui +3
The outer Galaxy beyond the Outer Arm represents a promising opportunity to study star formation in an environment vastly different from the solar neighborhood. In our previous stu…
A Very Metal-poor RR Lyrae Star with a Disk Orbit Found in the Solar Neighborhood
Noriyuki Matsunaga, Akinori Itane, Kohei Hattori +28
Metal-deficient stars are important tracers for understanding the early formation of the Galaxy. Recent large-scale surveys with both photometric and spectroscopic data have report…
The ALMA Survey of 70 m Dark High-mass Clumps in Early Stages (ASHES). V. Deuterated Molecules in the 70 m dark IRDC G14.492-00.139
Takeshi Sakai, Patricio Sanhueza, Kenji Furuya +14
We have observed the 70 m dark infrared dark cloud (IRDC) G14.492-00.139 in the ND =3--2, DCO =3--2, DCN =3--2, and CO =2--1 lines, using the Atac…
The detection of a hot molecular core in the extreme outer Galaxy
Takashi Shimonishi, Natsuko Izumi, Kenji Furuya +1
Interstellar chemistry in low metallicity environments is crucial to understand chemical processes in the past metal-poor universe. Recent studies of interstellar molecules in near…
The ALMA Survey of 70 m Dark High-mass Clumps in Early Stages (ASHES). IV. Star formation signatures in G023.477
Kaho Morii, Patricio Sanhueza, Fumitaka Nakamura +15
With a mass of 1000 and a surface density of 0.5 g cm, G023.477+0.114 also known as IRDC 18310-4 is an infrared dark cloud (IRDC) that has the potentia…
The ALMA Survey of 70m Dark High-mass Clumps in Early Stages (ASHES) III. A Young Molecular Outflow Driven by a Decelerating Jet
Daniel Tafoya, Patricio Sanhueza, Qizhou Zhang +12
We present a spatio-kinematical analysis of the CO~(=21) line emission, observed with the Atacama Large Millimter/submillimter Array (ALMA), of the outflow associat…
Low-metallicity Young Clusters in the Outer Galaxy. III. Sh 2-127
Chikako Yasui, Naoto Kobayashi, Masao Saito +2
In deep near-infrared imaging of the low-metallicity ( dex) H II region Sh 2-127 (S127) with Subaru/MOIRCS, we detected two young clusters with 413 members (S127A…
Observations of the [CI] (-) emission toward the massive star-forming region RCW38: further evidence for highly-clumped density distribution of the molecular gas
Natsuko Izumi, Yasuo Fukui, Kengo Tachihara +14
We present observations of the - fine-structure line of atomic carbon using the ASTE 10 m sub-mm telescope towards RCW38, the youngest super star cluster in the Milky…