A NIKA view of two star-forming infrared dark clouds: Dust emissivity variations and mass concentration
A NIKA view of two star-forming infrared dark clouds: Dust emissivity variations and mass concentration
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两颗恒星形成红外暗云的 NIKA 视图：尘埃发射率变化和质量浓度
DOI：
10.1051/0004-6361/201732258
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发表时间：
2018
影响因子：
6.5
通讯作者：
Rigby A
中科院分区：
文献类型：
--
作者：
Rigby A
尘埃颗粒的热发射是探测星际介质中分子气体的冷而密集区域的有力工具，因此限制尘埃特性是获得尘埃质量和温度精确测量的关键。对两个恒星形成的红外暗云- SDC18.888-0.476和SDC24.489-0.689 -我们的目标是评估质量浓度在相关星星中的作用，方法我们利用IRAM 30米望远镜上的NIKA照相机的同时1.2和2.0毫米成像能力来构建两种云的β图，并通过计算Herschel观测值，我们制作了13′′角分辨率的H2柱密度图。结果虽然我们在0.1pc尺度上没有发现两个云中最大质量团块周围有显著的系统性径向变化，但它们的平均β值有显著差异，SDC18.888-0.476（随机）± 0.25（系统），SDC24.489-0.689（随机）± 0.25（系统）。这些差异可能是两个云所处的环境非常不同的结果，我们认为，SDC18.888-0.476与W39 H II区域的接近可能会在约1 pc的尺度上提高β。我们还发现，SDC24.489-0.689中的质量比SDC18.888-0.476中的质量更集中和圆对称，并且与球形全球坍缩云将其质量的更高部分集中到单个核心中的情况相一致，而细长的云更容易破碎，结论我们证明，对星际云的β变化可以鲁棒地约束与高信噪比（S/N）NIKA观测，提供更准确的估计他们的质量。这里提出的方法将适用于银河系星星形成与NIKA 2（GASTON）保证时间大的程序，扩展我们的分析，以统计上显着的样本恒星形成云。
ContextThe thermal emission of dust grains is a powerful tool for probing cold, dense regions of molecular gas in the interstellar medium, and so constraining dust properties is key to obtaining accurate measurements of dust mass and temperature.AimsBy placing constraints on the dust emissivity spectral index,β, towards two star-forming infrared dark clouds – SDC18.888–0.476 and SDC24.489–0.689 – we aim to evaluate the role of mass concentration in the associated star-formation activity.MethodsWe exploited the simultaneous 1.2 and 2.0 mm imaging capability of the NIKA camera on the IRAM 30 m telescope to construct maps ofβfor both clouds, and by incorporatingHerschelobservations, we created H2column density maps with 13′′ angular resolution.ResultsWhile we find no significant systematic radial variations around the most massive clumps in either cloud on ≳0.1 pc scales, their meanβvalues are significantly different, with (random) ± 0.25 (systematic) for SDC18.888–0.476 and (random) ± 0.25 (systematic) for SDC24.489–0.689. These differences could be a consequence of the very different environments in which both clouds lie, and we suggest that the proximity of SDC18.888–0.476 to the W39 H II region may raiseβon scales of ~1 pc. We also find that the mass in SDC24.489–0.689 is more centrally concentrated and circularly symmetric than in SDC18.888–0.476, and is consistent with a scenario in which spherical globally-collapsing clouds concentrate a higher fraction of their mass into a single core than elongated clouds that will more easily fragment, distributing their mass into many cores.ConclusionsWe demonstrate thatβvariations towards interstellar clouds can be robustly constrained with high signal-to-noise ratio (S/N) NIKA observations, providing more accurate estimates of their masses. The methods presented here will be applied to the Galactic Star Formation with NIKA2 (GASTON) guaranteed time large programme, extending our analysis to a statistically significant sample of star-forming clouds.
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DOI：
10.1051/0004-6361/201630265
发表时间：
2017-06
期刊：
arXiv: Astrophysics of Galaxies
影响因子：
--
作者：
A. Chac'on-Tanarro;P. Caselli;L. Bizzocchi;J. Pineda;J. Harju;M. Spaans;F. I. F. Physik-F.-I.-F.-Physik-103024816;H Germany;D. Physics;U. Helsinki;Finland.;K. Institute;U. Groningen;The Netherlands.;U. G. Alpes;Cnrs;Ipag;France.
通讯作者：
A. Chac'on-Tanarro;P. Caselli;L. Bizzocchi;J. Pineda;J. Harju;M. Spaans;F. I. F. Physik-F.-I.-F.-Physik-103024816;H Germany;D. Physics;U. Helsinki;Finland.;K. Institute;U. Groningen;The Netherlands.;U. G. Alpes;Cnrs;Ipag;France.
IRAM 30 m 望远镜上 NIKA 相机的性能和校准
影响因子：
6.5
作者：
A. Catalano;M. Calvo;N. Ponthieu;R. Adam;A. Adane;P. Ade;P. André;A. Beelen;B. Belier;A. Benoȋt;A. Bideaud;N. Billot;N. Boudou;O. Bourrion;G. Coiffard;B. Comis;A. D’Addabbo;F. Désert;S. Doyle;J. Goupy;C. Kramer;S. Leclercq;J. Macías;J. Martino;P. Mauskopf;P. Mauskopf;F. Mayet;A. Monfardini;F. Pajot;E. Pascale;L. Perotto;V. Révéret;L. Rodriguez;G. Savini;K. Schuster;A. Sievers;C. Tucker;R. Zylka
通讯作者：
R. Zylka
DOI：
10.1088/0004-637x/696/1/676
发表时间：
2009-02
期刊：
The Astrophysical Journal
影响因子：
--
作者：
R. Shetty;J. Kauffmann;S. Schnee;A. Goodman
通讯作者：
R. Shetty;J. Kauffmann;S. Schnee;A. Goodman
影响因子：
6.5
作者：
T. Csengeri;A. Weiss;F. Wyrowski;K. Menten;J. Urquhart;S. Leurini;F. Schuller;H. Beuther;S. Bontemps;L. Bronfman;T. Henning;N. Schneider;N. Schneider
通讯作者：
T. Csengeri;A. Weiss;F. Wyrowski;K. Menten;J. Urquhart;S. Leurini;F. Schuller;H. Beuther;S. Bontemps;L. Bronfman;T. Henning;N. Schneider;N. Schneider
DOI：
10.1088/0004-637x/767/2/126
发表时间：
2013-03
期刊：
The Astrophysical Journal
影响因子：
--
作者：
S. Sadavoy;S. Sadavoy;J. D. Francesco;J. D. Francesco;D. Johnstone;D. Johnstone;M. Currie;E. D
通讯作者：
S. Sadavoy;S. Sadavoy;J. D. Francesco;J. D. Francesco;D. Johnstone;D. Johnstone;M. Currie;E. D