<i>SPITZER</i>VIEW OF YOUNG MASSIVE STARS IN THE LARGE MAGELLANIC CLOUD H II COMPLEXES. II. N 159

Chen, C.-H. Rosie; Indebetouw, R.; Chu, You‐Hua; Gruendl, R. A.; Testor, G.; Heitsch, Fabian; Seale, Jonathan; Meixner, Margaret; Sewiło, M.

doi:10.1088/0004-637x/721/2/1206

Cited by 67 publications

(171 citation statements)

References 82 publications

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“…This was the first discovery of extragalactic protostellar outflows. The outflows were found to have a velocity span of 10-20 km s −1 and to be associated with two massive YSOs previously studied by Chen et al (2010). Redshifted and blueshifted lobes were clearly found for N159W-S, while N159W-N shows a blueshifted lobe only.…”

Section: Origin Of Shocksmentioning

confidence: 66%

“…Figure 13 shows the locations of such UV sources (massive YSOs from Chen et al 2010 and OB stars from Fariña et al 2009) on the integrated intensity image of CO(6-5), the transition where most of the observed CO SLEDs peak (Section 4.1). Other than UV photons, X-rays from the nearby LMC X-1, the most powerful X-ray source in the LMC (Section 1; black cross on Figure 13), could be another important source of heating.…”

Section: Uv Photons and X-raysmentioning

confidence: 99%

“…UV and X-ray heating sources on the CO(6-5) integrated intensity image. Massive YSOs from Chen et al (2010) are shown as the red triangles, while spectroscopically identified early-type stars from Fariña et al (2009) are overlaid as the blue circles. The black cross and arrow indicate LMC X-1 and the orientation of its jet (Cooke et al 2007).…”

Section: Meudon Pdr Modellingmentioning

confidence: 99%

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Radiative and mechanical feedback into the molecular gas in the Large Magellanic Cloud

Lee

Madden

Lebouteiller

et al. 2016

A&A

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We present Herschel SPIRE Fourier Transform Spectrometer (FTS) observations of N159W, an active star-forming region in the Large Magellanic Cloud (LMC). In our observations, a number of far-infrared cooling lines including CO J = 4 → 3 to J = 12 → 11, [CI] 609 µm and 370 µm, and [NII] 205 µm are clearly detected. With an aim of investigating the physical conditions and excitation processes of molecular gas, we first construct CO spectral line energy distributions (SLEDs) on ∼10 pc scales by combining the FTS CO transitions with ground-based low-J CO data and analyze the observed CO SLEDs using non-LTE radiative transfer models. We find that the CO-traced molecular gas in N159W is warm (kinetic temperature of 153-754 K) and moderately dense (H 2 number density of (1.1-4.5) × 10 3 cm −3 ). To assess the impact of the energetic processes in the interstellar medium on the physical conditions of the CO-emitting gas, we then compare the observed CO line intensities with the models of photodissociation regions (PDRs) and shocks. We first constrain the properties of PDRs by modelling Herschel observations of [OI] 145 µm, [CII] 158 µm, and [CI] 370 µm fine-structure lines and find that the constrained PDR components emit very weak CO emission. X-rays and cosmic-rays are also found to provide a negligible contribution to the CO emission, essentially ruling out ionizing sources (ultraviolet photons, X-rays, and cosmic-rays) as the dominant heating source for CO in N159W. On the other hand, mechanical heating by low-velocity C-type shocks with ∼10 km s −1 appears sufficient enough to reproduce the observed warm CO.

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Section: Origin Of Shocksmentioning

confidence: 66%

Section: Uv Photons and X-raysmentioning

confidence: 99%

Section: Meudon Pdr Modellingmentioning

confidence: 99%

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Radiative and mechanical feedback into the molecular gas in the Large Magellanic Cloud

Lee

Madden

Lebouteiller

et al. 2016

A&A

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“…An exception is p13, where the [C ii] emission indicates a clump but there is no corresponding IRAC 8 µm emission. All CO and [C i] emission lines are also very weak, and the Hα map by Chen et al (2010) and the 843 MHz radio continuum map by Mills & Turtle (1984) show the presence of ionized gas position, so that it is likely that the [C ii] emission at p13 also originates in the ionized gas component. Unfortunately, our [N ii] map, which would allow the [C ii] contribution from ionized gas to be estimated, does not cover this position.…”

Section: Resultsmentioning

confidence: 99%

“…Three CO cores are identified (N159 W, E, and S; Johansson et al 1998). N159 S shows no evidence of starforming activity, while W and E possess O-type stars and H ii regions, where massive stars formed a few Myr ago (Chen et al 2010). The results of 30 Dor and N66 in the SMC are presented in a separate paper (Requena et al in prep.).…”

Section: Introductionmentioning

confidence: 92%

Velocity resolved [C ii], [C i], and CO observations of the N159 star-forming region in the Large Magellanic Cloud: a complex velocity structure and variation of the column densities

Okada

Requeña-Torres

Güsten

et al. 2015

A&A

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Context. The [C ii] 158 µm fine structure line is one of the dominant cooling lines in star-forming active regions. Together with models of photon-dominated regions, the data is used to constrain the physical properties of the emitting regions, such as the density and the radiation field strength. According to the modeling, the [C ii] 158 µm line integrated intensity compared to the CO emission is expected to be stronger in lower metallicity environments owing to lower dust shielding of the UV radiation, a trend that is also shown by spectral-unresolved observations. In the commonly assumed clumpy UV-penetrated cloud scenario, the models predict a [C ii] line profile similar to that of CO. However, recent spectral-resolved observations by Herschel/HIFI and SOFIA/GREAT (as well as the observations presented here) show that the velocity resolved line profile of the [C ii] emission is often very different from that of CO lines, indicating a more complex origin of the line emission including the dynamics of the source region. Aims. The Large Magellanic Cloud (LMC) provides an excellent opportunity to study in great detail the physics of the interstellar medium (ISM) in a low-metallicity environment by spatially resolving individual star-forming regions. The aim of our study is to investigate the physical properties of the star-forming ISM in the LMC by separating the origin of the emission lines spatially and spectrally. In this paper, we focus on the spectral characteristics and the origin of the emission lines, and the phases of carbon-bearing species in the N159 star-forming region in the LMC. Methods. We mapped a 4 ′ ×(3 ′ -4 ′ ) region in N159 in [C ii] 158 µm and [N ii] 205 µm with the GREAT instrument on board SOFIA. We also observed CO(3-2), (4-3), (6-5), 13 CO(3-2), and [C i] 3 P 1 -3 P 0 and 3 P 2 -3 P 1 with APEX. All spectra are velocity resolved. Results. The emission of all transitions observed shows a large variation in the line profiles across the map and in particular between the different species. At most positions the [C ii] emission line profile is substantially wider than that of CO and [C i]. We estimated the fraction of the [C ii] integrated line emission that cannot be fitted by the CO line profile to be 20% around the CO cores, and up to 50% at the area between the cores, indicating a gas component that has a much larger velocity dispersion than the ones probed by the CO and [C i] emission. We derived the relative contribution from C + , C, and CO to the column density in each velocity bin. The result clearly shows that the contribution from C + dominates the velocity range far from the the velocities traced by the dense molecular gas. Spatially, the region located between the CO cores of N159 W and E has a higher fraction of C + over the whole velocity range. We estimate the contribution of the ionized gas to the [C ii] emission using the ratio to the [N ii] emission, and find that the ionized gas contributes ≤ 19% to the [C ii] emission at its peak position, and ≤ 15% over the whol...

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Resolved Schmidt-Kennicutt Relation for Star Forming Regions in the Galaxy and Magellanic Clouds

et al. 2012

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The relationship between star formation rate (SFR) and the gas surface density (Σgas) is one of the most critical links between star formation and galaxy evolution. The observed SFR- Σgas relation, the “Schmidt-Kennicutt (S-K) law”, is tight when properties are averaged over kpc, but breaks down at the scale of giant molecular clouds (GMCs). To understand the physics governing the variations at GMC scales and the tight correlation at kpc scales, spatially and temporally resolved data covering a wide range of linear scale are needed. We have used the Spitzer surveys of the Large Magellanic Cloud and Magellanic Bridge to identify massive young stellar objects (YSOs), estimate “instantaneous” SFRs, and compare them to the S-K relation. These instantaneous SFRs are further compared to that estimated from integrated Hα and 24 μm luminosities to examine how SFRs vary on 10 Myr timescales. We have also used SINFONI near-IR integral field spectra of two Galactic mini-starbursts W31 and W43 to determine their underlying massive stellar content, estimate the SFRs, and compare to the S-K relation. To investigate evironmental effects on star formation, we have used complete YSO samples in the LMC and the Bridge to estimate global star formation efficiencies (SFE) in these two systems.

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SPITZERVIEW OF YOUNG MASSIVE STARS IN THE LARGE MAGELLANIC CLOUD H II COMPLEXES. II. N 159

Cited by 67 publications

References 82 publications

Radiative and mechanical feedback into the molecular gas in the Large Magellanic Cloud

Radiative and mechanical feedback into the molecular gas in the Large Magellanic Cloud

Velocity resolved [C ii], [C i], and CO observations of the N159 star-forming region in the Large Magellanic Cloud: a complex velocity structure and variation of the column densities

Resolved Schmidt-Kennicutt Relation for Star Forming Regions in the Galaxy and Magellanic Clouds

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