scholarly journals IONIZED GAS TOWARD MOLECULAR CLUMPS: PHYSICAL PROPERTIES OF MASSIVE STAR-FORMING REGIONS

2009 ◽  
Vol 707 (1) ◽  
pp. 283-309 ◽  
Author(s):  
Katharine G. Johnston ◽  
Debra S. Shepherd ◽  
James E. Aguirre ◽  
Miranda K. Dunham ◽  
Erik Rosolowsky ◽  
...  
2006 ◽  
Vol 651 (2) ◽  
pp. 914-932 ◽  
Author(s):  
Guido Garay ◽  
Kate J. Brooks ◽  
Diego Mardones ◽  
Ray P. Norris

2010 ◽  
Vol 717 (2) ◽  
pp. 1157-1180 ◽  
Author(s):  
Miranda K. Dunham ◽  
Erik Rosolowsky ◽  
Neal J. Evans ◽  
Claudia J. Cyganowski ◽  
James Aguirre ◽  
...  

2007 ◽  
Vol 3 (S242) ◽  
pp. 228-229
Author(s):  
Jarken Esimbek ◽  
Zhou Jianjun ◽  
Zheng Xingwu

AbstractWe are conducting a large survey with the Urumqi 25 m radio telescope to study the distribution and physical properties of massive star forming regions in the Milky Way. We will accomplish this by observing the H110α hydrogen recombination line at 4.874 GHz and the H2CO absorption line at 4830 GHz. These lines are associated with compact HII regions and dense molecular clouds. As a test of the 6 cm spectral line receiving system, we observed the two spectral lines toward massive star forming regions. We plan to study the large scale distribution and physical properties of massive star forming regions in the Milky way.


2020 ◽  
Vol 494 (2) ◽  
pp. 2823-2838 ◽  
Author(s):  
Ana Trčka ◽  
Maarten Baes ◽  
Peter Camps ◽  
Sharon E Meidt ◽  
James Trayford ◽  
...  

ABSTRACT We compare the spectral energy distributions (SEDs) and inferred physical properties for simulated and observed galaxies at low redshift. We exploit UV-submillimetre mock fluxes of ∼7000 z = 0 galaxies from the EAGLE suite of cosmological simulations, derived using the radiative transfer code skirt. We compare these to ∼800 observed galaxies in the UV-submillimetre range, from the DustPedia sample of nearby galaxies. To derive global properties, we apply the SED fitting code cigale consistently to both data sets, using the same set of ∼80 million models. The results of this comparison reveal overall agreement between the simulations and observations, both in the SEDs and in the derived physical properties, with a number of discrepancies. The optical and far-infrared regimes, and the scaling relations based upon the global emission, diffuse dust, and stellar mass, show high levels of agreement. However, the mid-infrared fluxes of the EAGLE galaxies are overestimated while the far-UV domain is not attenuated enough, compared to the observations. We attribute these discrepancies to a combination of galaxy population differences between the samples and limitations in the subgrid treatment of star-forming regions in the EAGLE-skirt post-processing recipe. Our findings show the importance of detailed radiative transfer calculations and consistent comparison, and provide suggestions for improved numerical models.


2002 ◽  
Vol 12 ◽  
pp. 143-145 ◽  
Author(s):  
Lee G. Mundy ◽  
Friedrich Wyrowski ◽  
Sarah Watt

Millimeter and submillimeter wavelength images of massive star-forming regions are uncovering the natal material distribution and revealing the complexities of their circumstellar environments on size scales from parsecs to 100’s of AU. Progress in these areas has been slower than for low-mass stars because massive stars are more distant, and because they are gregarious siblings with different evolutionary stages that can co-exist even within a core. Nevertheless, observational goals for the near future include the characterization of an early evolutionary sequence for massive stars, determination if the accretion process and formation sequence for massive stars is similar to that of low-mass stars, and understanding of the role of triggering events in massive star formation.


2007 ◽  
Vol 3 (S242) ◽  
pp. 234-235
Author(s):  
T. Umemoto ◽  
N. Mochizuki ◽  
K. M. Shibata ◽  
D.-G. Roh ◽  
H.-S. Chung

AbstractWe present the results of a mm wavelength methanol maser survey towards massive star forming regions. We have carried out Class II methanol maser observations at 86.6 GHz, 86.9 GHz and 107.0 GHz, simultaneously, using the Nobeyama 45 m telescope. We selected 108 6.7 GHz methanol maser sources with declinations above −25 degrees and fluxes above 20 Jy. The detection limit of maser observations was ~3 Jy. Of the 93 sources surveyed so far, we detected methanol emission in 25 sources (27%) and “maser” emission in nine sources (10%), of which thre “maser” sources are new detections. The detection rate for maser emission is about half that of a survey of the southern sky (Caswell et al. 2000). There is a correlation between the maser flux of 107 GHz and 6.7 GHz/12 GHz emission, but no correlation with the “thermal” (non maser) emission. From results of other molecular line observations, we found that the sources with methanol emission show higher gas temperatures and twice the detection rate of SiO emission. This may suggest that dust evaporation and destruction by shock are responsible for the high abundance of methanol molecules, one of the required physical conditions for maser emission.


2018 ◽  
Vol 477 (2) ◽  
pp. 2455-2469 ◽  
Author(s):  
N Cunningham ◽  
S L Lumsden ◽  
T J T Moore ◽  
L T Maud ◽  
I Mendigutía

2010 ◽  
Vol 521 ◽  
pp. L37 ◽  
Author(s):  
L. Chavarría ◽  
F. Herpin ◽  
T. Jacq ◽  
J. Braine ◽  
S. Bontemps ◽  
...  

2007 ◽  
Vol 666 (1) ◽  
pp. 309-320 ◽  
Author(s):  
Guido Garay ◽  
Diego Mardones ◽  
Kate J. Brooks ◽  
Liza Videla ◽  
Yanett Contreras

2009 ◽  
Vol 693 (1) ◽  
pp. 424-429 ◽  
Author(s):  
A. Brunthaler ◽  
M. J. Reid ◽  
K. M. Menten ◽  
X. W. Zheng ◽  
L. Moscadelli ◽  
...  

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