The magnetic evolution of the Taurus molecular clouds. I - Large-scale properties

1987 ◽  
Vol 321 ◽  
pp. 855 ◽  
Author(s):  
Mark H. Heyer ◽  
Frederick J. Vrba ◽  
Ronald L. Snell ◽  
F. P. Schloerb ◽  
Stephen E. Strom ◽  
...  
1987 ◽  
Vol 315 ◽  
pp. 122 ◽  
Author(s):  
D. A. Grabelsky ◽  
R. S. Cohen ◽  
L. Bronfman ◽  
P. Thaddeus ◽  
J. May

2008 ◽  
Vol 4 (S259) ◽  
pp. 603-612 ◽  
Author(s):  
Wolfgang Reich ◽  
Patricia Reich

AbstractOur position inside the Galaxy requires all-sky surveys to reveal its large-scale properties. The zero-level calibration of all-sky surveys differs from standard ‘relative’ measurements, where a source is measured in respect to its surroundings. All-sky surveys aim to include emission structures of all angular scales exceeding their angular resolution including isotropic emission components. Synchrotron radiation is the dominating emission process in the Galaxy up to frequencies of a few GHz, where numerous ground based surveys of the total intensity up to 1.4 GHz exist. Its polarization properties were just recently mapped for the entire sky at 1.4 GHz. All-sky total intensity and linear polarization maps from WMAP for frequencies of 23 GHz and higher became available and complement existing sky maps. Galactic plane surveys have higher angular resolution using large single-dish or synthesis telescopes. Polarized diffuse emission shows structures with no relation to total intensity emission resulting from Faraday rotation effects in the interstellar medium. The interpretation of these polarization structures critically depends on a correct setting of the absolute zero-level in Stokes U and Q.


1991 ◽  
Vol 147 ◽  
pp. 37-40
Author(s):  
G. Joncas

The presence of HI in the interstellar medium is ubiquitous. HI is the principal actor in the majority of the physical processes at work in our Galaxy. Restricting ourselves to the topics of this symposium, atomic hydrogen is involved with the formation of molecular clouds and is one of the byproducts of their destruction by young stars. HI has different roles during a molecular cloud's life. I will discuss here a case of coexisting HI and H2 at large scale and the origin of HI in star forming regions. For completeness' sake, it should be mentionned that there are at least three other aspects of HI involvement: HI envelopes around molecular clouds, the impact of SNRs (see work on IC 443), and the role of HI in quiescent dark clouds (see van der Werf's work).


Astrophysics ◽  
2019 ◽  
Vol 62 (2) ◽  
pp. 261-275 ◽  
Author(s):  
K. M. Kuzanyan ◽  
N. Safiullin ◽  
N. Kleeorin ◽  
I. Rogachevskii ◽  
S. Porshnev

2015 ◽  
Vol 11 (A29B) ◽  
pp. 709-710
Author(s):  
Enrique Vázquez-Semadeni ◽  
Gilberto Gómez

AbstractWe discuss the formation of filaments in molecular clouds (MCs) as the result of large-scale collapse in the clouds. We first give arguments suggesting that self-gravity dominates the nonthermal motions, and then briefly describe the resulting structure, similar to that found in molecular-line and dust observations of the filaments in the clouds. The filaments exhibit a hierarchical structure in both density and velocity, suggesting a scale-free nature, similar to that of the cosmic web, resulting from the domination of self-gravity from the MC down to the core scale.


1994 ◽  
Vol 140 ◽  
pp. 245-246
Author(s):  
T. Umemoto ◽  
N. Ohashi ◽  
Y. Murata ◽  
K. Tatematsu ◽  
M. Suzuki

It is known that stars in GMCs are often born as clusters. Recently, near infrared imaging has enabled us to study the young stars within molecular clouds (e.g., Lada & Lada 1991). Orion Molecular Cloud 2 (OMC2) is located 12' north of the Trapezium cluster in the Orion A cloud, and contains a cluster of about 20 near-IR sources and several FIR sources distributed within a diameter of 0.2 pc (Rayner et al... 1989; Johnson et al. 1990; Mezger, Wink, & Zylka 1990). By large scale mapping observations using the NRO 45 m telescope, this infrared cluster is found to be associated with a dense molecular core (Tatematsu et al. 1993, Umemoto et al. 1993). The region was observed using the Nobeyama Millimeter Array (NMA) to elucidate the structure and cluster formation process within a core.


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