The RMS survey: Ammonia mapping of the environment of young massive stellar objects – II★

Billington, S. J.; Urquhart, J. S.; Figura, C.; Eden, David; Moore, T. J. T.

doi:10.1093/mnras/sty3053

Cited by 9 publications

(9 citation statements)

References 79 publications

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“…This suggests that embedded compact HII regions are having an impact on the physical conditions of the surrounding molecular gas. This feature of temperature distribution is also seen in some IRDCs, MYSOs and HII regions (Urquhart et al 2015;Billington et al 2019). Previous studies measuring molecular gas temperature have reported that quiescent regions exhibit temperatures of 10 -15 K, while active starforming regions associated with massive young stellar objects and HII regions show temperatures higher than 20 K (e.g.…”

Section: Star Formation Feedback Traced By Gas Temperaturementioning

confidence: 58%

“…Previous studies measuring molecular gas temperature have reported that quiescent regions exhibit temperatures of 10 -15 K, while active starforming regions associated with massive young stellar objects and HII regions show temperatures higher than 20 K (e.g. Urquhart et al 2015;Friesen et al 2017;Hogge et al 2018;Billington et al 2019;Keown et al 2019). In this study, the observation points that measured temperatures higher than 20 K are defined as the region under the influence of star-formation feedback.…”

Section: Star Formation Feedback Traced By Gas Temperaturementioning

confidence: 61%

“…Large surveys of nearby star-forming regions in NH 3 revealed that the average gas temper-ature in molecular clouds with inactive star formation is around 15 K, while active star-forming cores have temperatures above 20 K (e.g. Urquhart et al 2015;Friesen et al 2017;Hogge et al 2018;Billington et al 2019;Keown et al 2019;Tursun et al 2020). In the range of hydrogen number densities (H 2 ) > ∼ 10 4 cm −3 , the dust and gas temperatures are expected to be well coupled due to frequent collision of dust grains and gas (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…Wilson et al 1982;Rosolowsky et al 2008;Dunham et al 2010;Urquhart et al 2011;Wienen et al 2018), and mappings at scales of few parsec (e.g. Keto et al 1987;Mangum et al 1992;Toujima et al 2011;Chibueze et al 2013;Urquhart et al 2015;Nakano et al 2017;Billington et al 2019;Burns et al 2019). These studies have related the physical conditions of active star-forming cores to the surrounding environment.…”

Section: Introductionmentioning

confidence: 99%

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KAgoshima Galactic Object survey with Nobeyama 45-metre telescope by Mapping in Ammonia lines (KAGONMA): Star formation feedback on dense molecular gas in the W33 complex

Murase,

Handa,

Hirata

et al. 2021

Preprint

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We present the results of NH 3 (1,1), (2,2) and (3,3) and H 2 O maser simultaneous mapping observations toward the high-mass star-forming region W33 with the Nobeyama 45-m radio telescope. W33 has six dust clumps and one of which, W33 Main, is associated with a compact HII region. To investigate star-forming feedback activity on its surroundings, the spatial distribution of the physical parameters was established. The distribution of the rotational temperature shows a systematic change from west to east in our observed region. The hightemperature region obtained in the region near W33 Main is consistent with interaction between the compact HII region and the periphery molecular gas. The size of the interaction area is estimated to be approximately 1.25 pc. NH 3 absorption features are detected toward the centre of the HII region. Interestingly, the absorption feature was detected only in the NH 3 (1,1) and (2,2) transitions, with no absorption feature seen in the (3,3) transition. These complex profiles in NH 3 are difficult to explain by a simple model and may suggest that the gas distribution around the HII region is highly complicated.

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Section: Star Formation Feedback Traced By Gas Temperaturementioning

confidence: 58%

Section: Star Formation Feedback Traced By Gas Temperaturementioning

confidence: 61%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

KAgoshima Galactic Object survey with Nobeyama 45-metre telescope by Mapping in Ammonia lines (KAGONMA): Star formation feedback on dense molecular gas in the W33 complex

Murase,

Handa,

Hirata

et al. 2021

Preprint

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“…Recently, high-resolution (∼ 0.1 pc scale) observations of dense cores in giant molecular clouds were carried out using radio interferometers (e.g., Billington et al 2019), whereas large-scale NH 3 mapping observations (∼ 10 pc scale) aiming to investigate the impact of stellar feedback and interactions in high-mass star formation remain limited. Sh 2-255 and Sh 2-257 are ideal for studying the interaction between H II regions and molecular clouds.…”

Section: Introductionmentioning

confidence: 99%

Ammonia mapping observations toward the Galactic massive star-forming region Sh 2-255 and Sh 2-257

Kohno,

Omodaka,

Handa

et al. 2022

Preprint

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We performed NH 3 (J, K) = (1, 1), (2, 2), and (3, 3) mapping observations toward the Galactic massive star-forming region Sh 2-255 and Sh 2-257 using the Nobeyama 45-m telescope as a part of the KAGONMA (KAgoshima Galactic Object survey with the Nobeyama 45-metre telescope by Mapping in Ammonia lines) project. NH 3 (1,1) has an intensity peak at the cluster S255 N, is distributed over 3 pc × 2 pc and is located between two H II regions. The kinetic temperature derived from the NH 3 (2, 2)/(1, 1) ratio was ∼ 35 K near the massive cluster S255 IR. These clusters also show emission with a large line width of ∼ 3-4 km s −1 . Based on the reported data we suggest that NH 3 gas in these regions is affected by stellar feedback from embedded YSO clusters in S255 IR and S255 N. We also detected NH 3 (1,1) emission in a region west of the main gas clump at the location of a concentration of Class II YSOs adjacent to the H II regions Sh 2-254. The presence of Class II YSOs implies ∼ 2 Myr of star formation, younger than Sh 2-254 (∼ 5 Myr), thus we suggest that star formation in the western region could be influenced by the older H II region Sh 2-254.

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The Curated ATCA Census of High-Mass Clumps (CACHMC) Legacy Survey

Allingham,

Jackson,

Hogge

et al. 2024

Publ. Astron. Soc. Aust.

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In order to study the structure and temperature distribution within high-mass star-forming clumps, we employed the Australia Telescope Compact Array to image the $\mathrm{NH}_3$ (J,K) = (1,1) through (6,6) and the (2,1) inversion transitions, the $\mathrm{H}_2\mathrm{O}$ $6_{16}$ - $5_{23}$ maser line at 22.23508 GHz, several $\mathrm{CH}_3\mathrm{OH}$ lines and hydrogen and helium recombination lines. In addition, 22- and 24-GHz radio continuum emission was also imaged. The $\mathrm{NH}_3$ lines probe the optical depth and gas temperature of compact structures within the clumps. The $\mathrm{H}_2\mathrm{O}$ maser pinpoints the location of shocked gas associated with star formation. The recombination lines and the continuum emission trace the ionised gas associated with hot OB stars. The paper describes the data and presents sample images and spectra towards select clumps. The technique for estimating gas temperature from $\mathrm{NH}_3$ line ratios is described. The data show widespread hyperfine intensity anomalies in the $\mathrm{NH}_3$ (1,1) images, an indicator of non-LTE $\mathrm{NH}_3$ excitation. We also identify several new $\mathrm{NH}_3$ (3,3) masers associated with shocked gas. Towards AGAL328.809+00.632, the $\mathrm{H}_2\mathrm{O}$ $6_{16}$ - $5_{23}$ line, normally seen as a maser, is instead seen as a thermally excited absorption feature against a strong background continuum. The data products are described in detail.

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The RMS survey: Ammonia mapping of the environment of young massive stellar objects – II★

Cited by 9 publications

References 79 publications

KAgoshima Galactic Object survey with Nobeyama 45-metre telescope by Mapping in Ammonia lines (KAGONMA): Star formation feedback on dense molecular gas in the W33 complex

KAgoshima Galactic Object survey with Nobeyama 45-metre telescope by Mapping in Ammonia lines (KAGONMA): Star formation feedback on dense molecular gas in the W33 complex

Ammonia mapping observations toward the Galactic massive star-forming region Sh 2-255 and Sh 2-257

The Curated ATCA Census of High-Mass Clumps (CACHMC) Legacy Survey

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