scholarly journals A Multiwavelength Study of M17: The Spectral Energy Distribution and PAH Emission Morphology of a Massive Star Formation Region

2007 ◽  
Vol 660 (1) ◽  
pp. 346-362 ◽  
Author(s):  
Matthew S. Povich ◽  
Jennifer M. Stone ◽  
Ed Churchwell ◽  
Ellen G. Zweibel ◽  
Mark G. Wolfire ◽  
...  
2015 ◽  
Vol 12 (S316) ◽  
pp. 151-152
Author(s):  
Randolf Klein ◽  
Jennifer Cooper ◽  
Leslie Looney ◽  
Thomas Henning ◽  
Sukanya Chakrabarti ◽  
...  

AbstractWe have selected cold and massive (M > 100M⊙) cores as candidates for early phases of star formation from millimeter continuum surveys without associations at short wavelengths. We compared the millimeter continuum peak positions with IR and radio catalogs and excluded cores that had sources associated with the cores’ peaks. We compiled a list of 173 cores in over 117 regions that are candidates for very early phases of Massive Star Formation (MSF). Now with the Spitzer and Herschel archives, these cores can be characterized further. We are compiling this data set to construct the complete spectral energy distribution (SED) in the mid- and far-infrared with good spatial resolution and broad spectral coverage. This allow us to disentangle the complex regions and model the SED of the deeply embedded protostars/clusters. We present a status report of our efforts: a preview of the IR properties of all cores and their embedded source inferred from a grey body fit to the compiled SEDs.


2007 ◽  
Vol 3 (S242) ◽  
pp. 188-189
Author(s):  
James A. Green ◽  
A. M. S. Richards ◽  
H. Flood ◽  
W. H. T. Vlemmings ◽  
R. J. Cohen

AbstractMERLIN observations of 6.668-GHz Methanol and 6.035-GHz OH emission from the known massive star-formation region ON1 are presented. Maser components are found to lie at the southern edge of the UCHII with consistent polarization angles across the strongest features. Zeeman splitting of OH shows magnetic field strengths between +0.4 to −5.3 mG and from cross-correlation a tentative methanol magnetic field of −18mG is detected.


2009 ◽  
Vol 5 (S266) ◽  
pp. 516-516
Author(s):  
Ricardo Retes ◽  
Abraham Luna ◽  
Divakara Mayya ◽  
Luis Carrasco

AbstractWe test a membership method to select embedded young stellar objects (YSOs) from a Galactic molecular cloud with ongoing massive star formation using multiband analysis. We select and discuss the embedded stellar population in the molecular cloud associated with IRAS 18235−1205, a small, geometrically well-defined Galactic molecular cloud. The IRAS source has infrared fluxes characteristic of an UCHii region, CS(J = 2 − 1) emission, and methanol and water maser emission, suggesting that this region is a good candidate for studies of young, massive star formation. The selection method of embedded stellar populations is based on the spatial distribution of 13CO(J = 1 − 0) and Spitzer/MIPS 24 μm point sources. Photometric analysis using near/mid-infrared images are used to test our selection criteria. Three objects are associated with the IRAS source; two have a characteristic spectral-energy distribution (SED) of a Class I/0 object (protostar) and the third has an SED of Class II.


2007 ◽  
Vol 669 (1) ◽  
pp. 464-482 ◽  
Author(s):  
D. S. Shepherd ◽  
M. S. Povich ◽  
B. A. Whitney ◽  
T. P. Robitaille ◽  
D. E. A. Nurnberger ◽  
...  

2007 ◽  
Vol 59 (1) ◽  
pp. 221-225 ◽  
Author(s):  
Jun Hashimoto ◽  
Motohide Tamura ◽  
Hiroshi Suto ◽  
Lyu Abe ◽  
Miki Ishii ◽  
...  

2019 ◽  
Vol 15 (S352) ◽  
pp. 194-198
Author(s):  
Christina C. Williams

AbstractWe discuss the serendipitous discovery of a dusty high-redshift galaxy in a small (8 arcmin2) ALMA 3-mm survey Williams et al. (2019). The galaxy was previously unknown and is absent from existing multi-wavelength catalogs (“ALMA-only”). Using the ALMA position as prior, we perform forced deblended photometry to constrain its spectral energy distribution. The spectral energy distribution is well described by a massive (M* = 1010.8 M⊙) and highly obscured (AV ∼ 4) galaxy at redshift z = 5.5 ± 1.1 with star formation rate ∼ 300 M⊙yr−1. Our small survey area implies an uncertain but large contribution to the cosmic star formation rate density, similar to the contribution from all ultraviolet-selected galaxies combined at this redshift. This galaxy likely traces an abundant population of massive galaxies absent from current samples of infrared-selected or sub-millimeter galaxies, but with larger space densities, higher duty cycles, and significant contribution to the cosmic star-formation rate and stellar mass densities.


2020 ◽  
Vol 495 (1) ◽  
pp. 835-863 ◽  
Author(s):  
Jordan J Thirlwall ◽  
Cristina C Popescu ◽  
Richard J Tuffs ◽  
Giovanni Natale ◽  
Mark Norris ◽  
...  

ABSTRACT We present the first radiative transfer (RT) model of a non-edge-on disc galaxy in which the large-scale geometry of stars and dust is self-consistently derived through the fitting of multiwavelength imaging observations from the ultraviolet to the submm. To this end, we used the axisymmetric RT model of Popescu et al. and a new methodology for deriving geometrical parameters, and applied this to decode the spectral energy distribution (SED) of M33. We successfully account for both the spatial and spectral energy distribution, with residuals typically within $7{{\ \rm per\ cent}}$ in the profiles of surface brightness and within $8{{\ \rm per\ cent}}$ in the spatially integrated SED. We predict well the energy balance between absorption and re-emission by dust, with no need to invoke modified grain properties, and we find no submm emission that is in excess of our model predictions. We calculate that $80\pm 8{{\ \rm per\ cent}}$ of the dust heating is powered by the young stellar populations. We identify several morphological components in M33, a nuclear, an inner, a main and an outer disc, showing a monotonic trend in decreasing star formation surface density (ΣSFR) from the nuclear to the outer disc. In relation to surface density of stellar mass, the ΣSFR of these components defines a steeper relation than the ‘main sequence’ of star-forming galaxies, which we call a ‘structurally resolved main sequence’. Either environmental or stellar feedback mechanisms could explain the slope of the newly defined sequence. We find the star formation rate to be ${\rm SFR}=0.28^{+0.02}_{-0.01}{\rm M}_{\odot }{\rm yr}^{-1}$.


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