High-velocity gas associated ultracompact HII regions

We present the results of a survey for high-velocity¹²CO (1-0) emission associated H₂O masers and ultracompact (UC) HII regions. The aim is to investigate the relationship between H₂O masers, CO high-velocity gas (HVG) and their associated infrared sources. Our sample satisfies Wood & Churchwell criterion. Almost 70 % of the sources have full widths (FWs) greater than 15 km · s^-1 atT* _a = 100 mK and 15 % have FWs greater than 30 km · s^-1 In most of our objects there is excess high velocity emission in the beam. There is a clear correlation between CO line FWs and far-infrared luminosities: the FW increases with the FIR luminosity. The relation suggests that more luminous sources are likely to be more energetic and able to inject more energy into their surroundings. As a result, larger FW of the CO line could be produced. In most of our sources, the velocities of peak of the H₂O emission are in agreement with those of the CO cloud, but a number of them have a large blueshift with respect to the CO peak. These masers might stem from the amplifications of a background source, which may amplify some unobservable weak masers to an observable level.     

Molecular lines and continuum from W51A (I) —CO and NH3 spectra and 3 mm continuum

As for the 5′ × 4′(～llpc × 9pc) region centered at W51 lRSl the observations of the 3.4 mm continuum, CO (J = 1-0) line and simultaneous NH₃(1,1), (2,2), (3,3), (4,4) inverse lines were made for studying the massive star formation region located in the main spiral arms of the Galaxy. In the directions of W51 IRS1, IRS2 and el/e2 in 3.4 mm continuum, analyses of the line profiles show that the absorption lines of ammonia, which arise from the gas in front of the HII region, are red-shifted with respect to the emission lines, which arise from the surrounding cloud. Furthermore, a radiation transfer and statistical equilibrium calculation of ammonia molecules show that the densities increase by 3–10 times from the eastern border to the center. These points hint that the collapse is happening in the molecular cloud core obscured in optical wavelengths. The effects of the radiation fields from radio, infrared and UCHII sources is non-negligible on the excitation of various molecules (e.g. NH₃) within the circle of radius 40″ centered at IRS1. The profiles of the COJ = 1–0 line in the circle change from double peaks ( ～ 60, ～ 68 km. s^-1) to triple peaks, i.e. the component ～53 km·s^?1, which associates with UCHII, also appears in the spectra. There are indications that the circle of radius 40″ centered at IRSI is a region of massive star forming activity     

Molecular lines and continuum from W51A (I) —CO and NH3 spectra and 3 mm continuum

As for the 5′ × 4′(∼llpc × 9pc) region centered at W51 lRSl the observations of the 3.4 mm continuum, CO (J = 1-0) line and simultaneous NH₃(1,1), (2,2), (3,3), (4,4) inverse lines were made for studying the massive star formation region located in the main spiral arms of the Galaxy. In the directions of W51 IRS1, IRS2 and el/e2 in 3.4 mm continuum, analyses of the line profiles show that the absorption lines of ammonia, which arise from the gas in front of the HII region, are red-shifted with respect to the emission lines, which arise from the surrounding cloud. Furthermore, a radiation transfer and statistical equilibrium calculation of ammonia molecules show that the densities increase by 3–10 times from the eastern border to the center. These points hint that the collapse is happening in the molecular cloud core obscured in optical wavelengths. The effects of the radiation fields from radio, infrared and UCHII sources is non-negligible on the excitation of various molecules (e.g. NH₃) within the circle of radius 40″ centered at IRS1. The profiles of the COJ = 1–0 line in the circle change from double peaks ( ∼ 60, ∼ 68 km. s^-1) to triple peaks, i.e. the component ∼53 km·s⁻¹, which associates with UCHII, also appears in the spectra. There are indications that the circle of radius 40″ centered at IRSI is a region of massive star forming activity     

New high-velocity bipolar outflows in S39 and IRAS 06306 + 0232

Mapping observations in¹²CO J = 1 - 0 lines were made towards S39 and IRAS 06306 + 0232 with the 13.7 m radio telescope at Qinghai Station of Purple Mountain Observatory. The results showed that both of them have bipolar outflows. We have calculated the outflow parameters. The outflows have significantly more mass and higher mass loss rate than those from low mass YSOs. We also find that although the bolometric luminosities of the associated sources are large, the radiation pressure of wind is not sufficient to drive the observed outflows. There exist several stars of different evolve states in S39. It suggests that the star formation in S39 is in sequence, not in eruption.     

High-velocity molecular outflows hear massive young stellar objects

By mapping the¹²COJ = 1—0 lines in IRAS 05391-0217, 06114 + 1745 and 06291 + 0421, three new high-velocity bipolar molecular outflows are found. Parameters of these outflows are derived, which suggest that they are massive and energetic outflows with total kinetic energies of about 10³⁸ J and mass loss rates about 10^-5 M/a. The driving sources are identified by analyzing the positions, intensities and color temperatures of the associated infrared sources. These outflows are most likely driven by single sources which correspond to massive young stellar objects. In these regions H₂O masers have been detected located near the embedded infrared sources, which indicates that their exciting mechanism may be correlated with that of the CO outflows. The relationship between the parameters of outflows and central sources shows that high-velocity outflow and thermal radiation of a star are two basic correlated but different features in the evolution of young stars. Project supported by the National Natural Science Foundation of China (Grant No. 19773002) and the United Radio Astronomy Lab. of Chinese Academy of Sciences.     

Gravitational Effects on the Motion of Interstellar Gas in the Neighbourhood of a Hot Radiating Star: Part I

The paper investigates the way gravity influences the expansionof interstellar gas about a hot radiating star. The problemis of the singular perturbation variety in which gravity playsa dominating role in the near vicinity of the star but is smallelsewhere and the mathematical technique used is that of matching.The governing parameter is the ratio of the distance over whichgravity effects are important to the radius of the ionized interstellargas (HII) region and only small values of this ratio are consideredhere (Part I). The case when this is not so will be discussedin a later paper (Part II).     

Toeplitz Quantization and Asymptotic Expansions: Peter–Weyl Decomposition

We obtain the Peter–Weyl decomposition of the star product and star restriction associated to the Toeplitz calculus on complex and real symmetric domains, respectively, under the action of the maximal compact subgroup. Both the Berezin and the Berezin–Toeplitz cases are covered.     

The Bisognano-Wichmann Theorem for Massive Theories

The geometric action of modular groups for wedge regions (Bisognano-Wichmann property) is derived from the principles of local quantum physics for a large class of Poincaré covariant models in d = 4. As a consequence,the CPT theorem holds for this class. The models must have a complete interpretation in terms of massive particles.The corresponding charges need not be localizable in compact regions: The most general case is admitted, namely localization in spacelike cones.     

The formation of compact groups of galaxies

In the compact group of galaxies the galaxies can merge into a few massive ones in a very short time, so they must be formed very recently. On the other hand, according to the theory of structure formation, the denser system should form earlier. By analyzing the apparent paradox, we suggest that the merging process of CDM halo plays an important role in the formation of the compact groups of galaxies: it delays the formation of compact groups of galaxies, and makes the pups of galaxies much denser. Project partially supporter1 hy the Ministry of Science and Technology (of China).     

Inverse problems for Sturm–Liouville operators on a compact equilateral graph by partial nodal data

Partial inverse nodal problems for Sturm–Liouville operators on a compact equilateral star graph are investigated in this paper. Uniqueness theorems from partial twin‐dense nodal subsets in interior subintervals or arbitrary interior subintervals having the central vertex are proved. In particular, we posed and solved a new type partial inverse nodal problems for the Sturm–Liouville operator on the compact equilateral star graph.     

New dected CO(1-0) emission from planetary nebulae

We report the results of CO(1-0) (J=1-0) observations for 20 selected planetary nebulae (PNe), using the 13.7 m radio telescope of Purple Mountain Observatory at the Qinghai Station. Due to weak CO(1-0) emission, long integrated time observations have been carried out for most of sampled PNe. Among these PNe, nine are first detections in CO(1-0) named NGC6445, M1-59, M4-9, M2-51, M4-18, He2-459, Sh2-71, K3-31, M2-52, and one is the first possible detection named V-V1-8, a probably misclassified PN. NGC 6445, M1-59, M4-9 and M2-51 have been detected in CO(2-1) (J=2-1). Although having been observed in previous CO surveys, Sh2-71 and M4-18 were not detected in CO; M2-52, K3-31, He2-459 are the first detected PNe in CO emission and V-V1-8 is given with a first completed spectrum detected in CO(1-0). Comparing these data with other previous observational ones, we discuss the relationships between CO(1-0) emission and evolution of PNe: While the nebular radii increase, the CO(1-0) line integrated intensities multiplied by distances have a decreasing trend. Also the masses of molecular envelopes (from 0.001 to 1 M⊙) for PNe are decreased with increasing nebular radii. All the results mean the CO(1-0) emission decreases dramatically with the nebular evolution. The detectability of CO restricted by different PNe which have different dust properties and different evolutionary stages is also analyzed.     

New detected CO(1-0) emission from planetary nebulae

We report the results of CO(1-0) (J=l-0) observations for 20 selected planetary nebulae (PNe), using the 13.7 m radio telescope of Purple Mountain Observatory at the Qinghai Station. Due to weak CO(1-0) emission, long integrated time observations have been carried out for most of sampled PNe. Among these PNe, nine are first detections in CO(1-0) named NGC 6445, Ml-59, M4-9, M2-51, M4-18, He2-459, Sh2-71, K3-31, M2-52, and one is the first possible detection named V-Vl-8, a probably misclassified PN. NGC 6445, Ml-59, M4-9 and M2-51 have been detected in CO(2-1)(J=2-1). Although having been observed in previous CO surveys, Sh2-71 and M4-18 were not detected in CO; M2-52, K3-31, He2-459 are the first detected PNe in CO emission and V-Vl-8 is given with a first completed spectrum detected in CO(1-0). Comparing these data with other previous observational ones, we discuss the relationships between CO(1-0) emission and evolution of PNe: While the nebular radii increase, the CO(l-0) line integrated intensities multiplied by distances have a decreasing trend. Also the masses of molecular envelopes (from 0.001 to 1 M⊙) for PNe are decreased with increasing nebular radii. All the results mean the CO(1-0) emission decreases dramatically with the nebular evolution. The detectability of CO restricted by different PNe which have different dust properties and different evolutionary stages is also analyzed.     

A Gelfand duality for compact pospaces

It is well known that the category of compact Hausdorff spaces is dually equivalent to the category of commutative \(C^\star \)-algebras. More generally, this duality can be seen as a part of a square of dualities and equivalences between compact Hausdorff spaces, \(C^\star \)-algebras, compact regular frames and de Vries algebras. Three of these equivalences have been extended to equivalences between compact pospaces, stably compact frames and proximity frames, the fourth part of what will be a second square being lacking. We propose the category of bounded Archimedean \(\ell \)-semi-algebras to complete the second square of equivalences and to extend the category of \(C^\star \)-algebras.     

Method of conformal mappings for calculation of electric currents in magnetospheres of compact stars

In the two-dimensional approximation with the method of conformal mappings, we analyze the magnetic-field structure in the magnetosphere of a compact star. The dependence of the solution on the input parameters of the model is investigated. The direct and reverse electric currents are calculated in the magnetosphere.     

CLASSES OF MEROMORPHIC FUNCTIONS ASSOCIATED WITH CONIC REGIONS

The object of this article is to introduce new classes of meromorphic functions associated with conic regions.Several properties like the coefficient bounds,growth and distortion theorems,radii of star...     

Polymer stars in three dimensions. Three-loop results

We study the scaling properties of self-avoiding polymer stars and networks of arbitrarily given but fixed topologies. We use the massive field theory renormalization group framework to calculate the critical exponents governing the universal properties (star exponents). Calculations are performed directly in three dimensions; renormalization group functions are obtained in the three-loop approximation. Resulting asymptotic series for the star exponents are resummed with the help of the Padé-Borel and conformal mapping transformations.Republished from Teoreticheskaya i Matematicheskaya Fizika, Vol. 108, No. 1, pp. 34–50, October, 1996.     

The predicted impact of revised Australian car design rules on Melbourne air quality trends

The emission of atmospheric pollutants such as carbon monoxide (CO), oxides of nitrogen (NO_x) and hydrocarbons (HC) from Australian motor vehicles depends on the performance of the emission control devices fitted to them. The total emission of these atmospheric pollutants was calculated for Melbourne, assuming deterioration rates for the control equipment such that vehicles comply with Australian Design Rules for five years. There is an initial decline in total emissions of CO and HC, but by the year 2011 the expected increase in total vehicle kilometres (VKT) means that the output of all pollutants to the airshed will increase with time. Significant decreases in atmospheric emissions are only possible by stricter emission controls.     

13CO mapping study for massive molecular cloud cores

Using the newly installed SIS receiving system on the 13.7 m telescope at Qinghai Station of PMO, United Radio Astronomy of CAS, CO isotope¹³CO J= 1-0 and C¹⁸O J= 1-0 lines were observed for three sources S241, S39 and ON3. Results show that the three sources have massive cores, of which the size is ～ 2-5 pc, masses are ～ 10³- 10⁴M⊙. The widths of lines are also larger than those in low mass cores. And high velocity characteristics were observed for all the sources. The V_LSR distribution presents rotation of the core in ON3. And all the three cores contain deeply embedded forming massive stars. The young stellar objects in S241 and ON3 seem to be moving away from their birth sites.     

数值模拟计算在1000MW塔式锅炉NO_x生成特性中的应用研究

在新建的大型燃煤电站锅炉设计时,通过对炉内燃烧过程的合理组织,以取得锅炉低NO_X排放的效果.采用计算流体力学(CFD)模拟的方法,进行了某电厂1000MW超超临界塔式锅炉的数值模拟计算分析,获得了该1000MW塔式锅炉炉内速度场、温度场、CO浓度场、O-2浓度场和NO_X浓度场分布.计算结果表明:该1000MW塔式锅炉炉膛主燃烧区域的中心形成了巨大还原区,并且在炉膛上部具有明显的还原区域,能实现低NO_X排放的预期目标.数值模拟计算研究结论可用于指导锅炉燃烧系统的优化运行和NO_X排放的控制.