<i>Herschel</i>-SPIRE spectroscopy of the DR21 molecular cloud core

White, G. J.; Abergel, A.; Spencer, L. D.; Schneider, N.; Naylor, David; Anderson, L. D.; Joblin, C.; Ade, Peter A. R.; André, Ph.; Arab, H.; Baluteau, Jean-Paul; Bernard, J.-P.; Blagrave, K.; Bontemps, Sylvain; Boulanger, F.; Cohen, Martin; Compiègne, M.; Cox, P.; Dartois, E.; Davis, G. R.; Emery, R. J.; Fulton, T.; Gom, Brad; Griffin, Matthew Joseph; Gry, C.; Habart, E.; Huang, M.; Jones, Scott C.; Kirk, J. M.; Lagache, G.; Leeks, S. J.; Lim, T.; Madden, S.; Makiwa, G.; Martín, P. G.; Miville-Deschênes, M.-A.; Molinari, S.; Moseley, H.; Motte, F.; Okumura, K.; Gonçalves, D. Pinheiro; Polehampton, E. T.; Rodet, Thomas; Rodón, J. A.; Russeil, D.; Saraceno, P.; Sidher, S.; Swinyard, B. M.; Ward-Thompson, Derek; Zavagno, A.

doi:10.1051/0004-6361/201014622

Cited by 17 publications

(13 citation statements)

References 15 publications

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“…Excitation temperatures around 8-30 K are found in extended diffuse emission and towards the brightest positions, respectively, in low-mass star forming regions (e.g., Davis et al 2010;Curtis et al 2010), while massive star-forming regions are usually warmer as confirmed by our findings (see also Wilson et al 2001;Jakob et al 2007;Kirk et al 2010;Wilson et al 2011;Peng et al 2012). The CO column densities (10 17 -10 18 cm −2 from the LTE analysis) found in G327 are also comparable with values obtained in other massive star-forming regions (Wilson et al 2001;Jakob et al 2007;White et al 2010;Wilson et al 2011).…”

Section: Comparisons With Other Star Forming Regionssupporting

confidence: 90%

The distribution of warm gas in the G327.3–0.6 massive star-forming region

Leurini

Wyrowski

Herpin

et al. 2013

A&A

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Aims. Most studies of high-mass star formation focus on massive and/or luminous clumps, but the physical properties of their larger scale environment are poorly known. In this work, we aim at characterising the effects of clustered star formation and feedback of massive stars on the surrounding medium by studying the distribution of warm gas through mid-J 12 CO and 13 CO observations. Methods. We present APEX 12 CO(6-5), (7-6), 13 CO(6-5), (8-7) and HIFI 13 CO(10-9) maps of the star forming region G327.36-0.6 with a linear size of ∼3 pc × 4 pc. We infer the physical properties of the emitting gas on large scales through a local thermodynamic equilibrium analysis, while we apply a more sophisticated large velocity gradient approach on selected positions. Results. Maps of all lines are dominated in intensity by the photon dominated region around the Hii region G327.3-0.5. Mid-J 12 CO emission is detected over the whole extent of the maps with excitation temperatures ranging from 20 K up to 80 K in the gas around the Hii region, and H 2 column densities from few 10 21 cm −2 in the inter-clump gas to 3 × 10 22 cm −2 towards the hot core G327.3-0.6. The warm gas (traced by 12 and 13 CO(6-5) emission) is only a small percentage (∼10%) of the total gas in the infrared dark cloud, while it reaches values up to ∼35% of the total gas in the ring surrounding the Hii region. The 12 CO ladders are qualitatively compatible with photon dominated region models for high density gas, but the much weaker than predicted 13 CO emission suggests that it comes from a large number of clumps along the line of sight. All lines are detected in the inter-clump gas when averaged over a large region with an equivalent radius of 50 (∼0.8 pc), implying that the mid-J 12 CO and 13 CO inter-clump emission is due to high density components with low filling factor. Finally, the detection of the 13 CO(10-9) line allows to disentangle the effects of gas temperature and gas density on the CO emission, which are degenerate in the APEX observations alone.

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Section: Comparisons With Other Star Forming Regionssupporting

confidence: 90%

The distribution of warm gas in the G327.3–0.6 massive star-forming region

Leurini

Wyrowski

Herpin

et al. 2013

A&A

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“…Nonetheless, small velocity gradients also appear locally on the CS velocity map in the environment of RCW 36, suggesting that A50, page 10 of 14 small-scale motions are also at play. Similar lateral gradients are observed in the DR21 filament dynamics (Schneider et al 2010;White et al 2010). …”

Section: Kinematics and The 3-dimensional Model Of Rcw 36supporting

confidence: 73%

Ionisation impact of high-mass stars on interstellar filaments

Minier

Tremblin

Hill

et al. 2013

A&A

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Context. Ionising stars reshape their original molecular cloud and impact star formation, leading to spectacular morphologies such as bipolar nebulae around H ii regions. Molecular clouds are structured in filaments where stars principally form, as revealed by the Herschel space observatory. The prominent southern hemisphere H ii region, RCW 36, is one of these bipolar nebulae.Aims. We study the physical connection between the filamentary structures of the Vela C molecular cloud and the bipolar morphology of RCW 36, providing an in-depth view of the interplay occurring between ionisation and interstellar structures (bright-rims and pillars) around an H ii region. Methods.We have compared Herschel observations in five far-infrared and submillimetre filters with the PACS and SPIRE imagers, to dedicated numerical simulations and molecular line mapping. Results. Our results suggest that the RCW 36 bipolar morphology is a natural evolution of its filamentary beginnings under the impact of ionisation.Conclusions. Such results demonstrate that, filamentary structures can be the location of very dynamical phenomena inducing the formation of dense clumps at the edge of H ii regions. Moreover, these results could apply to better understanding the bipolar nebulae as a consequence of the expansion of an H ii region within a molecular ridge or an interstellar filament.

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“…Unlike for these works, possible line-ofsight confusion needed to be addressed in our analysis because of the low-density foreground cloud Cygnus Rift and the closeby W75N cloud component (e.g., Schneider et al 2006). We also avoided the strong DR21 outflow (e.g., Richardson et al 1986;White et al 2010). Subsequent studies will analyse the combined column density, temperature, and kinematical data for a more extended region, but here we conservatively limited this study to filaments that (1) have main velocities in 13 CO coherent with the ridge and no strong secondary velocity components a , and (2) have crest column densities above 1.5 × 10 22 cm −2 ; the resulting selection is shown in Fig.…”

Section: The Dr21 Filamentsmentioning

confidence: 99%

The spine of the swan: aHerschelstudy of the DR21 ridge and filaments in Cygnus X

Hennemann¹,

Motte²,

Schneider³

et al. 2012

A&A

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118

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In order to characterise the cloud structures responsible for the formation of high-mass stars, we present Herschel observations of the DR21 environment. Maps of the column density and dust temperature unveil the structure of the DR21 ridge and several connected filaments. The ridge has column densities higher than 10 23 cm −2 over a region of 2.3 pc 2 . It shows substructured column density profiles and branches into two major filaments in the north. The masses in the filaments range between 130 and 1400 M , whereas the mass in the ridge is 15 000 M . The accretion of these filaments onto the DR21 ridge, suggested by a previous molecular line study, could provide a continuous mass inflow to the ridge. In contrast to the striations seen in, e.g., the Taurus region, these filaments are gravitationally unstable and form cores and protostars. These cores formed in the filaments potentially fall into the ridge. Both inflow and collisions of cores could be important to drive the observed high-mass star formation. The evolutionary gradient of star formation running from DR21 in the south to the northern branching is traced by decreasing dust temperature. This evolution and the ridge structure can be explained by two main filamentary components of the ridge that merged first in the south.

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Herschel-SPIRE spectroscopy of the DR21 molecular cloud core

Cited by 17 publications

References 15 publications

The distribution of warm gas in the G327.3–0.6 massive star-forming region

The distribution of warm gas in the G327.3–0.6 massive star-forming region

Ionisation impact of high-mass stars on interstellar filaments

The spine of the swan: aHerschelstudy of the DR21 ridge and filaments in Cygnus X

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