共查询到19条相似文献，搜索用时 109 毫秒
1.
根据（１）和中图１（ａ）和图１（ｂ）分别对ＣｅｐＢ和ＣｅｐＦ进行成图处理，得到了它们的强度分布图和速度分段积分等高图，通过对这些强度分布图和速度分段积分等高图的分析和研究，也得到了ＣｅｐｈｅｕｓＯＢ３巨分子云复合体是成块的。并且这些块是没有被自引力束缚的，同时还得到了ＣｅｐＢ和ＣｅｐＦ的外流的动力学时标。 相似文献
2.
俞志尧 《中国天文和天体物理学报》1996,(4)
根据文[1]中图1（a）和图1（b），分别对CepB和CepF进行成图处理，得到了它们的强度分布图和速度分段积分等高图，通过对这些强度分布图和速度分段积分等高图的分析和研究，也得到了CegheusOB3巨分子云复合体是成块的，并且这些块是没有被自引力束缚的，同时还得到了CepB和CepF的外流的动力学时标。 相似文献
3.
利用Ｍａｓａｃｈｕｓｅｔｓ－ＳｔｏｎｙＢｒｏｏｋ的１２ＣＯ的分辨率为４７″的银道面巡天和ＩＲＡＳ的分辨率为１５′的红外巡天图像资料,系统地进行了ｌ＝８°～３８°,ｂ＝－１°～＋１°天区内不同分子云演化阶段与恒星形成过程的对比研究．将上述天区划分成３０个小区,通过图像处理,得到了每个小区的ＣＯ（１－０）和波长６０μｍ上远红外发射的空间分布,计算出相应天区的分子云复合体的红外色温度和光深分布,结合ＩＲＡＳ红外点源和ＨＩＩ区星表,把分子云从年轻到年老的演化阶段分成四大类,分析了它们的主要特征以及与恒星形成过程的关系．文章最后对超致密ＨＩＩ区和原恒星候选体沿银经的分布,以及ＨＩＩ区和原恒星候选体与分子云成协的比例进行了统计研究,再次说明在银河系中恒星形成活动仍在不断地发生和进行． 相似文献
4.
利用紫金山天文台青海站的 １３．７ ｍ毫米波望远镜,对 Ｏｒｉｏｎ Ａ分子云中的 ＯＭＣ－３区域,进行了较高分辨率的１３ＣＯ（Ｊ＝１－０）和Ｃ１８Ｏ（Ｊ＝１－０）分子辐射的成图观测．给出了该分子云中１３ＣＯ和 Ｃ１８Ｏ云核分布的整体结构和平均物理参数．观测发现,该分子云的１３ＣＯ和 Ｃ１８Ｏ的云核中心分别与最年轻的天体－Ｃｌａｓｓ ０类源 ＭＭＳＩ, ＭＭＳ４,ＭＭＳ６和ＭＭＳ７,ＭＭＳ８;ＭＭＳ９成协．此外,通过分析ＯＭＣ－３整个区域的速度场结构,发现沿 Ｃ１８Ｏ和１３ＣＯ云核方向从南到北有一个～ １．７ｋｍ／ｓ的速度场梯度,而分子云的红、蓝移团块则分别趋于云的北部和南部．并对ＯＭＣ－３区的恒星形成特征进行了讨论． 相似文献
5.
罗绍光 《中国天文和天体物理学报》1995,(2)
对恒星形成区ＣｅｐＯＢ４的ＩＲＡＳ观测结果的详细分析和研究表明，与年轻星团Ｂｅ５９相联系的分子云物质的原始分布是高度成块的。Ｂｅ５９诞生于一个平均密度为１００─２００ｃｍ（－３）云的背向太阳一侧。强烈的电离辐射以及星风已经在其诞生地产生了一个半径大约为５ｐｃ的＂水泡型（Ｂｌｉｓｔｅｒ）＂电离氢区及与之相关的红外源。电离辐射也穿过云际介质到达与母云分离的另两个云的表面，形成了从侧面看到的电离波前及被压缩和加热的中性物质壳。在这个恒星形成区中，虽然有大量年轻恒星存在，但大质量恒星的形成已经停止。红外发射主要起源于标准尘埃粒子的热平衡发射。但在主激发星团Ｂｅ５９附近的ＨＩＩ区中２５μｍ发射的显著增强可能与某种与电离气体相混合的新型尘埃粒子有关。 相似文献
6.
本论文用ＩＲＡＳ巡天数据的最新版本ＩＳＳＡ，经过进一步处理，得到了Ｓ１４０、Ｓ１４１、Ｓ１４２ＳｈａｒｐｌｅｓｓＨⅡ区－分子云复合体的红外发射强度、温度及其光深的分布图。在此基础上对各ＨⅡ区的特性参量进行了统计分析，得到了分子云复合体的红外发射总光度以及复合体中尘埃的分布情况，对尘埃中ＶＳＧ的丰度作出了分析。 相似文献
7.
利用日本名古层大学天体物理系的毫米波电远镜对ＣｅｐｈｅｕｓＡ的Ｃ１８Ｏ（Ｊ＝１－０）分子辐射进行了观测。得到了它的谱线频谱图，强度分布图，速度分段积分等高图和位置速度图，并且得最核区的有关参数。 相似文献
8.
本分析了在巨分子云聚合形成机制下旋臂扰动的影响，结果表明，在巨分子云聚合形成过程中，当不考虑恒星形成引起的巨分子云的破裂时，旋臂的存在使分子云在绕星系中心作自转运动时，在旋臂区域分子云的密度大大增加而使大质量分子云由于碰撞而形成，特别能促使一些质量更大的巨分子云形成。但当这些聚合形成的大质量分子云走出旋臂区域进入臂间区域时，它们又会自动瓦解。因此在整个星系盘上，与没有旋臂扰动情况相比，Ｆ（Ｍ）〈 相似文献
9.
利用日本名古屋大学天体物理系的毫米波射电望远镜对ＣｅｐｈｅｕｓＡ的Ｃ１８Ｏ（Ｊ＝１—０）分子辐射进行了观测．得到了它的谱线频谱图、强度分布图、速度分段积分等高图和位置速度图，并且得到了核区的有关参数． 相似文献
10.
分析在聚合形成机制下,巨分子云在刚体自转盘中的形成过程。研究结果表明,形成的巨分子云主要由其附近的分子云组成,由于速度弥散的作用,非弹性碰撞才自引力使分子云聚合在一起,以这种方式形成的巨分子云是小质量的,如果较差自转存在这些小质量的巨分子云便有更多的机会聚合在一起形成更大质量的巨分子云,这进一步说明,较差自转在巨分子云的形成中起了很大的积极作用。 相似文献
11.
C. A. Olano † P. I. Meschin V. S. Niemela ‡ 《Monthly notices of the Royal Astronomical Society》2006,369(2):867-874
We have studied the kinematics and spatial distribution of the interstellar gas in the sky region 110°≤ l ≤ 135°, 10°≤ b ≤ 20° , using the extensive Leiden–Dwingeloo Survey of H i emission and the Columbia Survey of CO emission. The spectra show two main velocity components, namely feature A that has a mean local standard of rest (LSR) velocity of ∼0 km s−1 and is due to the Lindblad ring of the Gould belt, and feature C that has a mean LSR velocity of ∼−11 km s−1 and is associated to the local arm or Orion arm. The H i and CO distributions of feature A in the region trace a large complex of gas and dust known as the Cepheus Flare, which lies at a distance of 300 pc. The spectral line profiles of feature A, which are rather broad and often double-peaked, reveal that the Cepheus Flare forms part of a big expanding shell of interstellar matter that encloses an old supernova remnant associated with a void inside the Cepheus Flare. On the other hand, by analysing the distribution and velocity structure of feature C, we have detected a second large expanding shell in the region, located at a distance of 800 pc in the local arm. This shell surrounds the stellar association Cepheus OB4 and was probably generated by stellar winds and supernovae of Cepheus OB4. The radii, expansion velocities and H i masses of the two shells are approximately 50 pc, 4 km s−1 and 1.3 × 104 M⊙ for the Cepheus Flare shell and 100 pc, 4 km s−1 and 9.9 × 104 M⊙ for the Cepheus OB4 shell. Both shells have similar ages of the order of a few 106 yr. 相似文献
12.
The properties of IRAS point sources in the region of the “Cepheus bubble” were studied. This bubble is a possible very old supernova remnant which includes the association Cepheus OB2. A large number of sources which are probably low- and medium-mass embedded stars are situated around the bubble. It is concluded that whereas high-mass stars which have formed in the bubble are already on the main sequence, lower-mass stars are still embedded in their parent clouds. 相似文献
13.
A survey for emission line stars was carried out in 1980 with the Schmidt telescope of Konkoly Observatory in the region of IC 1396 (Kun, 1986a, hereafter referred to as Paper I). This work was aimed at a preliminary mapping of the probable medium mass members of the association Cepheus OB 2. The stars of the region have been followed since then with the same telescope in order to obtain a more complete view on the stellar content of this giant star-forming region. The common variability of the H emission strength makes the sense of repeating such surveys. The new survey resulted in the discovery of 65 further emission stars. Equatorial coordinates and finding charts are given for them.PhotographicBVRI photometry was carried out for all known emission stars of the field. The colourmagnitude and two-colour diagrams derived from theB, V, R, andI magnitudes show that these stars are probably F-G-type (1.5M
<M<3M
), partly pre-Main-Sequence members of Cep OB 2, whereas a few of them may be distant red giants.The youngest objects of the region can be found among the IRAS point sources. Their properties are discussed on the basis of IRAS data alone. 相似文献
14.
Michael D. Smith 《Astrophysics and Space Science》1998,261(1-4):183-184
The youngest protostars are obscured from direct view by a high column of molecular gas. Nevertheless, their presence is betrayed
through spectacular infrared outflows. I demonstrate here that infrared spectroscopy has the potential to reveal a remarkable
variety of details concerning the underlying physics.
Near-infrared spectroscopic analyses of the OMC-1, DR 21 & Cepheus A outflows are discussed here. Molecular hydrogen is vibrationally
excited by collisions in shock waves. In OMC-1, the ortho-para ratio has been mapped. The ratio is close to 3, suggesting
efficient shock thermalisation. In DR 21, shocked (up to the first vibrational level) and fluorescent (higher v-levels) components
have been successfully separated. In Cepheus A, non-LTE effects imply low densities.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
15.
This paper presents the results of monochromatic [Oiii], [Nii], and [Sii] observations of ring nebula Sh157 around the star (WR + B0III) HD 219460 belonging to the Ba 3 cluster. A stratification of radiation typical for photoionization excitation has been revealed. The observations suggest that the Sh157 ring structure may arise as a result of the HD 219460 stellar wind blowing the surroundingHii region, and the bubble age is found to bet(2–5)×105 yr. Three outer envelopes have been distinguished: a weaker extended emission shell apparently blown out by the wind from B-stars of the Ba 3 cluster, and two dust shells which are likely to be associated with NGC 7510 and Cas OB2. The paper is also concerned with the discussion of young star aggregates Ba 3, NGC 7510, Cas OB1, OB2, OB4, OB5, OB7, and Cep OBI and the associatedHii regions, shells and supershells of gas and dust, molecular clouds, and supernova remnants which may be probable members of a single giant stellar complex where the star formation process is in progress. 相似文献
16.
《天文和天体物理学研究(英文版)》2021,(8)
Results from optical CCD photometric observations of 13 pre-main-sequence stars collected during the period from February 2007 to November 2020 are presented. These stars are located in the association Cepheus OB3, in the field of the young star V733 Cephei. Photometric observations, especially concerning the long-term variability of the stars, are missing in the literature. We present the first longterm V(RI)_c monitoring for them, that cover 13 years. Results from our study indicate that all of the investigated stars manifest strong photometric variability. The presented paper is a part of our program for the photometric study of pre-main-sequence stars located in active star-forming regions. 相似文献
17.
A ring-shaped infrared emission region is recognizable on the IRAS Sky Flux images of a Cepheus region which happens to include the association Cepheus OB 2. The ring is easily visible both at 60 and 100 microns. The approximate galactic coordinates of its centre arel=102°.8 andb=+6°.7, with an outer diameter of 7 deg. IC 1396 and several otherHii regions, such as S 129, S 133, S 134, and S 140 are apparently parts of the ring. If it is assumed that these Hii regions are physically connected to the ring its distance must be about 900 pc and its diameter 120 pc. The existence of several arc-shaped H filaments along the ring, the proper motion of the nearby runaway star Cephei, and the possible presence of the [Fex] 6375 interstellar line in the spectra of two stars of Cep OB 2 combine to suggest that the infrared ring might well be a result of a supernova explosion which occurred in this region about 2–3 million years ago. 相似文献
18.
M. Kun 《Astrophysics and Space Science》1986,125(1):13-31
155 H emission stars not catalogued earlier have been detected with the 60/90/180 cm Schmidt telescope of Konkoly Observatory in a field of 19.5 square degrees centred on theHii region IC 1396.UBVR photohraphic magnitudes were obtained for most of them. Equatorial coordinates for the epoch 1950.0 as well as identification charts are given. Space distribution of the emission stars and their connection with the association Cepheus OB 2 are briefly discussed. 相似文献
19.
Massive stars have significant influence on the evolution of the interstellar medium. Bright rims, cometary morphology of clouds, as well as their motion are some examples of the influence of massive stars on nearby molecular clouds. The cometary clouds in the Gum-Vela region are very good examples. In an attempt to understand the kinematics of the clouds in such regions we have carried out CO line observations towards bright-rimmed clouds near the OB Association Cep OB2. The radial velocities of the clouds are consistent with an expansion of the system at ≈ 4kms?1 away from the dominant O6.5V star in the association, HD206267. We find the rocket mechanism to be the most likely cause for expansion as found for both the Gum-Vela and the Rosette globules. We conclude that such expanding motions are quite common in regions near massive stars and make a brief comparison of the Cepheus system with the Gum-Vela system. 相似文献