scholarly journals Star-forming Regions in the Small Magellanic Cloud: Multiwavelength Properties of Stellar Complexes

2007 ◽  
Vol 133 (5) ◽  
pp. 2179-2186 ◽  
Author(s):  
E. Livanou ◽  
I. Gonidakis ◽  
E. Kontizas ◽  
U. Klein ◽  
M. Kontizas ◽  
...  
2008 ◽  
Vol 4 (S256) ◽  
pp. 160-165
Author(s):  
Karin M. Sandstrom ◽  
Alberto D. Bolatto ◽  
Snežana Stanimirović ◽  
J. D. T. Smith ◽  
Jacco Th. van Loon ◽  
...  

AbstractBecause of its proximity, the Small Magellanic Cloud provides a unique opportunity to map the polycyclic aromatic hydrocarbon (PAH) emission from photo-dissociation regions (PDRs) in a low-metallicity (12 + log(O/H) ~ 8) galaxy at high spatial resolution in order to learn about their abundance and physical state. We present mid-IR spectral mapping observations of star-forming regions in the Small Magellanic Cloud obtained as part of the Spitzer Spectroscopic Survey of the SMC (S4MC) project. These observations allow us to map the distribution of PAH emission in these regions and the measure the variation of PAH band strengths with local physical conditions. In these proceedings we discuss preliminary results on the physical state of the PAHs, in particular their ionization fraction.


1999 ◽  
Vol 190 ◽  
pp. 452-453
Author(s):  
F. Maragoudaki ◽  
M. Kontizas ◽  
E. Kontizas ◽  
A. Dapergolas ◽  
D. H. Morgan

A method has been developed for the detection of stellar complexes and the derivation of their fundamental properties in the LMC. We have used digitized UKST plates in order to perform star counts and produce isodensity contour maps in various colours and luminosity slices. About 50 large stellar groupings have been revealed. Their properties favour a “top-down” mechanism acting in star forming regions.


2007 ◽  
Vol 664 (1) ◽  
pp. 322-331 ◽  
Author(s):  
Boyke Rochau ◽  
Dimitrios A. Gouliermis ◽  
Wolfgang Brandner ◽  
Andrew E. Dolphin ◽  
Thomas Henning

2018 ◽  
Vol 14 (S344) ◽  
pp. 118-121
Author(s):  
Rhorom Priyatikanto ◽  
Mochamad Ikbal Arifyanto ◽  
Rendy Darma ◽  
Aprilia ◽  
Muhamad Irfan Hakim

AbstractGlobal history of star or cluster formation in the Large Magellanic Cloud (LMC) has been the center of interest in several studies as it is thought to be influenced by tidal interaction with the Small Magellanic Cloud and even the Milky Way. This study focus on the formation history of the LMC in relation with the context of binary star clusters population, the apparent binary fraction (e.g., percentage of cluster pairs) in different epoch were calculated and analyzed. From the established distributions, it can be deduced that the binary clusters tend to be young (∽ 100 Myr) while their locations coincide with the locations of star forming complexes. There is an indication that the binary fraction increases as the rise of star formation rate in the last millions years. In the LMC, the increase of binary fraction at age ∽ 100 Myr can be associated to the last episode of close encounter with the Small Magellanic Cloud at ∽ 150 Myr ago. This observational evidence supports the theory of binary cluster formation through the fission of molecular cloud where the encounter between galaxies enhanced the clouds velocity dispersion which in turn increased the probability of cloud-cloud collisions that produce binary clusters.


2019 ◽  
Vol 631 ◽  
pp. L12 ◽  
Author(s):  
Yoko Okada ◽  
Ronan Higgins ◽  
Volker Ossenkopf-Okada ◽  
Cristian Guevara ◽  
Jürgen Stutzki ◽  
...  

Context. [13C II] observations in several Galactic sources show that the fine-structure [12C II] emission is often optically thick (the optical depths around 1 to a few). Aims. Our goal was to test whether this also affects the [12C II] emission from nearby galaxies like the Large Magellanic Cloud (LMC). Methods. We observed three star-forming regions in the LMC with upGREAT on board SOFIA at the frequency of the [C II] line. The 4 GHz bandwidth covers all three hyperfine lines of [13C II] simultaneously. For the analysis, we combined the [13C II] F = 1−0 and F = 1−1 hyperfine components as they do not overlap with the [12C II] line in velocity. Results. Three positions in N159 and N160 show an enhancement of [13C II] compared to the abundance-ratio-scaled [12C II] profile. This is likely due to the [12C II] line being optically thick, supported by the fact that the [13C II] line profile is narrower than [12C II], the enhancement varies with velocity, and the peak velocity of [13C II] matches the [O I] 63 μm self-absorption. The [12C II] line profile is broader than expected from a simple optical depth broadening of the [13C II] line, supporting the scenario of several PDR components in one beam having varying [12C II] optical depths. The derived [12C II] optical depth at three positions (beam size of 14″, corresponding to 3.4 pc) is 1−3, which is similar to values observed in several Galactic sources shown in previous studies. If this also applies to distant galaxies, the [C II] intensity will be underestimated by a factor of approximately 2.


2019 ◽  
Vol 621 ◽  
pp. A62 ◽  
Author(s):  
Yoko Okada ◽  
Rolf Güsten ◽  
Miguel Angel Requena-Torres ◽  
Markus Röllig ◽  
Jürgen Stutzki ◽  
...  

Aims. The aim of our study is to investigate the physical properties of the star-forming interstellar medium (ISM) in the Large Magellanic Cloud (LMC) by separating the origin of the emission lines spatially and spectrally. The LMC provides a unique local template to bridge studies in the Galaxy and high redshift galaxies because of its low metallicity and proximity, enabling us to study the detailed physics of the ISM in spatially resolved individual star-forming regions. Following Okada et al. (Okada, Y., Requena-Torres, M. A., Güsten, R., et al. 2015, A&A, 580, A54), we investigate different phases of the ISM traced by carbon-bearing species in four star-forming regions in the LMC, and model the physical properties using the KOSMA-τ PDR model. Methods. We mapped 3–13 arcmin2 areas in 30 Dor, N158, N160, and N159 along the molecular ridge of the LMC in [C II] 158 μm with GREAT on board SOFIA. We also observed the same area with CO(2-1) to (6-5), 13CO(2-1) and (3-2), [C I] 3P1–3P0 and 3P2–3P1 with APEX. For selected positions in N159 and 30 Dor, we observed [O I] 145 μm and [O I] 63 μm with upGREAT. All spectra are velocity resolved. Results. In all four star-forming regions, the line profiles of CO, 13CO, and [C I] emission are similar, being reproduced by a combination of Gaussian profiles defined by CO(3-2), whereas [C II] typically shows wider line profiles or an additional velocity component. At several positions in N159 and 30 Dor, we observed the velocity-resolved [O I] 145 and 63 μm lines for the first time. At some positions, the [O I] line profiles match those of CO, at other positions they are more similar to the [C II] profiles. We interpret the different line profiles of CO, [C II] and [O I] as contributions from spatially separated clouds and/or clouds in different physical phases, which give different line ratios depending on their physical properties. We modeled the emission from the CO, [C I], [C II], and [O I] lines and the far-infrared continuum emission using the latest KOSMA-τ PDR model, which treats the dust-related physics consistently and computes the dust continuum SED together with the line emission of the chemical species. We find that the line and continuum emissions are not well-reproduced by a single clump ensemble. Toward the CO peak at N159 W, we propose a scenario that the CO, [C II], and [O I] 63 μm emission are weaker than expected because of mutual shielding among clumps.


2012 ◽  
Vol 542 ◽  
pp. A66 ◽  
Author(s):  
L. R. Carlson ◽  
M. Sewiło ◽  
M. Meixner ◽  
K. A. Romita ◽  
B. Lawton

2015 ◽  
Vol 11 (S315) ◽  
pp. 13-16
Author(s):  
Katherine E. Jameson ◽  
Alberto D. Bolatto ◽  
Mark Wolfire ◽  
Monica Rubio ◽  
Rodrigo Herrera Camus ◽  
...  

AbstractAt a distance of 61 kpc, the Small Magellanic Cloud (SMC) affords an absolutely unique view of the low metallicity star-forming interstellar medium, providing the nearest laboratory to study processes relevant to star formation at high redshifts. We present new ALMA 7m-array maps of CO and 12CO (2-1) for one of the four observed regions in the Southwest Bar of the SMC. These maps are the first high-resolution (~6″ ~ 1.7 pc) images of CO in a molecular cloud at 1/5 Solar metallicity. We show the structure of photodissociation regions for the first time at 1/5 Solar metallicity by combining the new ALMA data with Herschel maps of [C ii] and [O i]. We present preliminary evidence that there is extended, faint 12CO (2-1) emission near where we expect the Hi-to-H2 transition. We also compare our data to the low metallicity 3D simulations by Glover & Mac Low (2011) and Shetty et al. (2011).


2007 ◽  
Vol 665 (1) ◽  
pp. 306-314 ◽  
Author(s):  
Dimitrios A. Gouliermis ◽  
Sascha P. Quanz ◽  
Thomas Henning

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