Results 21 to 30 of about 238,168 (251)

Photometry and kinematics of extragalactic star-forming complexes

Open Astronomy, 2022
We investigate spectral and photometric properties of extragalactic star-forming complexes (SFCs). The SFCs were selected in 17 nearby galaxies of a spiral or irregular type, having inclinations less than 45° and distances less than 15 Mpc.
Kuzin Aleksey, Lisitsin Danil
doaj   +1 more source

On the structure of molecular clouds [PDF]

Monthly Notices of the Royal Astronomical Society, 2012
We show that the inter-cloud Larson scaling relation between mean volume density and size $ \propto R^{-1}$, which in turn implies that mass $M\propto R^2$, or that the column density $N$ is constant, is an artifact of the observational methods used.
Ballesteros-Paredes, J., D'Alessio, P., Hartmann, W., L.   +5 more
openaire   +5 more sources

Molecular line signatures of cloud–cloud collisions [PDF]

Monthly Notices of the Royal Astronomical Society, 2021
ABSTRACT Collisions between interstellar gas clouds are potentially an important mechanism for triggering star formation. This is because they are able to rapidly generate large masses of dense gas. Observationally, cloud collisions are often identified in position–velocity (PV) space through bridging features between intensity peaks ...
Anthony Peter Whitworth, F. D. Priestley
openaire   +4 more sources

Molecular Precursors of the RNA-World in Space: New Nitriles in the G+0.693−0.027 Molecular Cloud

Frontiers in Astronomy and Space Sciences, 2022
Nitriles play a key role as molecular precursors in prebiotic experiments based on the RNA-world scenario for the origin of life. These chemical compounds could have been partially delivered to the young Earth from extraterrestrial objects, stressing the
Víctor M. Rivilla, Izaskun Jiménez-Serra, Jesús Martín-Pintado, Laura Colzi, Belén Tercero, Pablo de Vicente, Shaoshan Zeng, Sergio Martín, Sergio Martín, Juan García de la Concepción, Luca Bizzocchi, Mattia Melosso, Mattia Melosso, Fernando Rico-Villas, Miguel A. Requena-Torres, Miguel A. Requena-Torres   +15 more
doaj   +1 more source

Study the Effect of Perturbation in the Evolution of the Filamentary Molecular Clouds [PDF]

Iranian Journal of Astronomy and Astrophysics, 2020
Observatory studies indicate that stars are caused by the collapse of dense molecular clouds, and thermal instability can be a factor in creating this collapse.
Maryam Mesgaran, Khodadad Kokabi
doaj   +1 more source

Fragmentation in molecular clouds [PDF]

Symposium - International Astronomical Union, 1991
B209. Fragments are detected in the outer parts of the B209 molecular cloud in a region of density 1000 cm−3 using 12CO, 13CO, H2CO, IRAS 60 and 100 μm images, discernable as velocity components, and have characteristics: <Rfragment>∼ 0.4 pc; <Mfragment>∼ 2 M⊙; <MVRfragment>∼ 1.6 M⊙ km/s pc; Tgas ∼ 11 K; Tdust> ∼ 16 K??. The system
Frank O. Clark, Timo Prusti, Rene J. Laureijs   +2 more
openaire   +3 more sources

Molecular-Clump Detection Based on an Improved YOLOv5 Joint Density Peak Clustering

Universe, 2023
The detection and analysis of molecular clumps can lead to a better understanding of star formation in the Milky Way. Herein, we present a molecular-clump-detection method based on improved YOLOv5 joint Density Peak Clustering (DPC). The method employs a
Jin-Bo Hu, Yao Huang, Sheng Zheng, Zhi-Wei Chen, Xiang-Yun Zeng, Xiao-Yu Luo, Chen Long   +6 more
doaj   +1 more source

Dependence of Molecular Cloud Samples on Angular Resolution, Sensitivity, and Algorithms [PDF]

, 2022
In this work, we investigate the observational and algorithmic effects on molecular cloud samples identified from position-position-velocity (PPV) space. By smoothing and cutting off the high quality data of the Milky Way Imaging Scroll Painting (MWISP) survey, we extract various molecular cloud samples from those altered data with the DBSCAN (density ...
arxiv   +1 more source

The Global Evolution of Giant Molecular Clouds II: The Role of Accretion [PDF]

, 2011
We present virial models for the global evolution of giant molecular clouds. Focusing on the presence of an accretion flow, and accounting for the amount of mass, momentum, and energy supplied by accretion and star formation feedback, we are able to ...
Abdo, Ballesteros-Paredes, Ballesteros-Paredes, Bigiel, Blitz, Bolatto, Christopher D. Matzner, Christopher F. McKee, Dickel, Engargiola, Evans, Fall, Fukui, Glover, Heiles, Heyer, Heyer, Heyer, Hughes, Imara, Kawamura, Kegel, Kennicutt, Kim, Kim, Kim, Krumholz, Krumholz, Krumholz, Krumholz, Krumholz, Krumholz, Lada, Larson, Leroy, Leroy, Li, Li, Li, Li, Lopez, Mark R. Krumholz, Matzner, Matzner, Matzner, McKee, McKee, McKee, Meynet, Mizuno, Murray, Nathan J. Goldbaum, Onodera, Parravano, Roman-Duval, Rosolowsky, Schaerer, Schlegel, Schruba, Schruba, Stark, Stone, Strong, Tamburro, Tan, Tan, Tasker, Tasker, Thilker, Troland, Vazquez-Semadeni, Vázquez-Semadeni, Wang, Wang, Williams, Wise, Wolfire, Wong, Wong, Yang   +79 more
core   +2 more sources

Filaments in the Lupus molecular clouds [PDF]

Monthly Notices of the Royal Astronomical Society, 2015
We have studied the filaments extracted from the column density maps of the nearby Lupus 1, 3, and 4 molecular clouds, derived from photometric maps observed with the Herschel satellite. Filaments in the Lupus clouds have quite low column densities, with a median value of $\sim$1.5$\times$10$^{21}$ cm$^{-2}$ and most have masses per unit length lower ...
Davide Elia, Kazi L.J. Rygl, Pascal Tremblin, Tracey Hill, Quang Nguyen-Luong, Vera Könyves, P. Palmeirim, Stefano Pezzuto, Eugenio Schisano, Luigi Spinoglio, A. Rivera-Ingraham, A. Rivera-Ingraham, Doris Arzoumanian, Ph. André, Sergio Molinari, Derek Ward-Thompson, Frédérique Motte, A. M. di Giorgio, A. Roy, J. Di Francesco, J. Di Francesco, Nicola Schneider, Glenn J. White, M. Benedettini   +23 more
openaire   +9 more sources