English
Related papers

Related papers: Dense core formation by fragmentation of velocity-…

200 papers

We present observations of the CO isotopologues ($^{12}$CO, $^{13}$CO, and C$^{18}$O) toward the Galactic region with $169\arcdeg.75 \leqslant l \leqslant 174\arcdeg.75$ and $-0\arcdeg.75 \leqslant b \leqslant 0\arcdeg.5$, using the Purple…

Astrophysics of Galaxies · Physics 2019-08-22 Fang Xiong , Xuepeng Chen , Qizhou Zhang , Ji Yang , Min Fang , Miaomiao Zhang , Weihua Guo , Li Sun

Five regions of massive star formation have been observed in various molecular lines in the frequency range $\sim 85-89$ GHz. The studied regions possess dense cores, which host young stellar objects. The physical parameters of the cores…

Astrophysics of Galaxies · Physics 2016-10-19 L. E. Pirogov , V. M. Shul'ga , I. I. Zinchenko , P. M. Zemlyanukha , O. N. Patoka , M. Thomasson

Improving our understanding of the initial conditions and earliest stages of star formation is crucial to gain insight into the origin of stellar masses, multiple systems, and protoplanetary disks. We review the properties of low-mass dense…

Astrophysics · Physics 2008-01-29 Philippe André , Shantanu Basu , Shu-ichiro Inutsuka

We present the results of a single-pointing survey of 207 dense cores embedded in Planck Galactic Cold Clumps distributed in five different environments ($\lambda$ Orionis, Orion A, B, Galactic plane, and high latitudes) to identify dense…

Low-velocity large-scale shocks impacting on the ISM may efficiently shape molecular clouds and trigger star formation within them. These shocks, both driven by galactic bubbles and/or cloud-cloud collisions, leave specific signatures in…

Astrophysics of Galaxies · Physics 2025-09-24 G. Cosentino , I. Jiménez-Serra , R. Liu , C. -Y. Law , J. C. Tan , J. D. Henshaw , A. T. Barnes , F. Fontani , P. Caselli , S. Viti

In this paper we present the results of a systematic investigation of an entire population of starless dust cores within a single molecular cloud. Analysis of extinction data shows the cores to be dense objects characterized by a narrow…

The physical structure of hot molecular cores, where forming massive stars have heated up dense dust and gas, but have not yet ionized the molecules, poses a prominent challenge in the research of high-mass star formation and…

Astrophysics of Galaxies · Physics 2018-07-04 Rainer Rolffs , Peter Schilke , Qizhou Zhang , Luis Zapata

Using recent dust continuum data, we generate the intrinsic ellipticity distribution of dense, starless molecular cloud cores. Under the hypothesis that the cores are all either oblate or prolate randomly-oriented spheroids, we show that a…

Astrophysics · Physics 2009-11-07 Charles L. Curry

Filamentary structures are often identified in column density maps of molecular clouds, and appear to be important for both low- and high-mass star formation. Theoretically, these structures are expected to form in regions where the…

Astrophysics of Galaxies · Physics 2023-05-03 F. D. Priestley , D. Arzoumanian , A. P. Whitworth

Dense cores in massive, parsec-scale molecular clumps are sites that harbor protocluster formation. We present results from observations towards a hub-filament structure of a massive Infrared Dark Cloud (IRDC) G14.225-0.506 using the…

Astrophysics of Galaxies · Physics 2025-03-14 Yanhanle Zhao , Qizhou Zhang , Junhao Liu , Xing Pan , Lingzhen Zeng

We investigate the thermal and dynamical evolution of primordial gas clouds in the universe after decoupling. Comparing the time-scale of dynamical evolution with that of fragmentation, we can estimate the typical fragmentation scale. We…

Astrophysics · Physics 2009-10-31 Ryoichi Nishi , Hajime Susa , Hideya Uehara , Masako Yamada , Kazuyuki Omukai

High-latitude ($|b|>30^{\circ}$) molecular clouds have virial parameters that exceed 1, but whether these clouds can form stars has not been studied systematically. Using JCMT SCUBA-2 archival data, we surveyed 70 fields that target…

We investigate the condition for the formation of micron-sized grains in dense cores of molecular clouds. This is motivated by the detection of the mid-infrared emission from deep inside a number of dense cores, the so-called `coreshine,'…

Astrophysics of Galaxies · Physics 2015-06-16 Hiroyuki Hirashita , Zhi-Yun Li

We present FCRAO maps as well as combined BIMA and FCRAO maps of the high density molecular emission towards the CS core in the L673 region. With the FCRAO telescope, we mapped the emission in the CS(2-1), C34S(2-1), HCO+(1-0), and…

Astrophysics · Physics 2009-11-10 Oscar Morata , Josep Miquel Girart , Robert Estalella

[abridged] We investigate the velocity structure of protostellar cores that result from non-magnetic numerical models of the gravoturbulent fragmentation of molecular cloud material. A large fraction of the cores analyzed are ``quiescent'',…

During hierarchical clustering, smaller masses generally collapse earlier than larger masses and so are denser on the average. The core of a small mass halo could be dense enough to resist disruption and survive undigested, when it is…

Astrophysics · Physics 2009-10-31 Kandaswamy Subramanian , Renyue Cen , Jeremiah P. Ostriker

Recent Herschel observations of nearby clouds have shown that filamentary structures are ubiquitous and that most prestellar cores form in filaments. Probing the density ($n$) and velocity ($V$) structure of filaments is crucial for the…

Astrophysics of Galaxies · Physics 2023-04-12 Y. Shimajiri , Ph. André , N. Peretto , D. Arzoumanian , E. Ntormousi , V. Könyves

Stars form in dense, dusty structures, which are embedded in larger clumps of molecular clouds often showing a clear filamentary structure on large scales (> 1pc). One of the best-studied regions in the Hi-GAL survey can be observed toward…

Astrophysics of Galaxies · Physics 2016-08-19 L. Olmi , M. Cunningham , D. Elia , P. Jones

Recent numerical works, including ours, lend credence to the thesis that ambient environment, i.e., external pressure, affects star-forming ability of clouds & filaments. In continuation with our series of papers on the subject we explore…

Astrophysics of Galaxies · Physics 2024-09-17 S. V. Anathpindika , J. Di Francesco

G10.21-0.31 is a 70 $\mu$m-dark high-mass starless core ($M>300$ $\mathrm{M_{\odot}}$ within $r<0.15$ pc) identified in $Spitzer$, $Herschel$, and APEX continuum surveys, and is believed to harbor the initial stages of high-mass star…

Astrophysics of Galaxies · Physics 2023-03-15 Wenyu Jiao , Ke Wang , Thushara G. S. Pillai , Tapas Baug , Siju Zhang , Fengwei Xu