ABSTRACT
We present a survey of molecular line emission towards the molecular cloud surrounding Herbig Be star V645 Cyg. The survey was performed with the 20-m Onsala space telescope at 3 and 4 mm. ...We detected emission lines of 33 molecules and their isotopologues from diatomic molecules to four COMs up to seven atoms. Using detected lines, we estimated molecular column densities and abundances relative to molecular hydrogen in local thermodynamic equilibrium (LTE) approximation for all molecules except for methanol, for which we obtained physical parameters using a non-LTE model. Moreover, in the basement of the non-LTE model of methanol line emission, we consider that there is a weak maser effect in the additional spectral component of 51–40 E methanol line at 84.521 GHz. We compared the molecular abundances with values found in several astrochemical templates: molecular clouds, hot cores, and photodissociation regions, and found that signatures of these different types can be found towards V645 Cyg. We also obtained maps of the cloud in several molecular emission lines. The peaks of CO and CH3OH emission are shifted from the direction of the star, but the CS, HCO+, HNC, HCN, and N2H+ emission peaks are observed directly towards the star. Exploring the gas kinematics around V645 Cyg, we found that velocity structure in the ambient molecular cloud on the scale ≈1.6–2.0 pc is not the same as within ≈0.5 pc found previously by other authors.
ABSTRACT
We study molecular emission in a massive condensation at the border of the H ii region RCW 120, paying particular attention to the Core 1 and 2 objects, the most massive fragments of the ...condensation found previously by ALMA. The latter fragment was previously suggested to host a high-mass analogue of Class 0 young stellar object. We present spectra of molecular emission in the 1 mm range made with the APEX telescope. We detect CH3OH and C34S lines in Cores 1 and 2. The CH3CN series and the SO2 lines are only found in Core 2. We estimate gas physical parameters using methanol lines and obtain gas temperature less than 100 K in both regions. Molecular hydrogen number density in Core 2 is in the range of 105−107 cm−3 and is more uncertain in Core 1. However, the detection of the CH3CN lines corresponding to highly excited transitions (Eu > 400 K) in Core 2 indicates that the region contains hot gas, while the abundances of CH3OH, CS, SO2, and CH3CN are quite low for a hot core stage. We propose that Core 2 is in the warm-up phase prior to the establishing of the hot gas chemistry. We suggest that Core 2 is in the beginning of the hot core stage. There are no detected CH3CN lines in Core 1; therefore, it might be on an even less evolved evolutionary stage.
Molecular envelope around the HII region RCW 120 Kirsanova, M S; Pavlyuchenkov, Ya N; Wiebe, D S ...
Monthly notices of the Royal Astronomical Society,
10/2019, Letnik:
488, Številka:
4
Journal Article
Recenzirano
Odprti dostop
ABSTRACT
The H ii region RCW 120 is a well-known object, which is often considered as a target to verify theoretical models of gas and dust dynamics in the interstellar medium. However, the exact ...geometry of RCW 120 is still a matter of debate. In this work, we analyse observational data on molecular emission in RCW 120 and show that 13CO(2–1) and C18O(2–1) lines are fitted by a 2D model representing a ring-like face-on structure. The changing of the C18O(3–2) line profile from double-peaked to single-peaked from the dense molecular Condensation 1 might be a signature of stalled expansion in this direction. In order to explain a self-absorption dip of the 13CO(2–1) and 13CO(3–2) lines, we suggest that RCW 120 is surrounded by a diffuse molecular cloud, and find confirmation of this cloud on a map of interstellar extinction. Optically thick 13CO(2–1) emission and the infrared 8 $\mu$m PAH band form a neutral envelope of the H ii region resembling a ring, while the envelope breaks into separate clumps on images made with optically thin C18O(2–1) line and far-infrared dust emission.
ABSTRACT We report the results of our observations of the S255IR area with the Submillimeter Array (SMA) at 1.3 mm in the very extended configuration and at 0.8 mm in the compact configuration as ...well as with the IRAM 30 m at 0.8 mm. The best achieved angular resolution is about 0.4 arcsec. The dust continuum emission and several tens of molecular spectral lines are observed. The majority of the lines is detected only toward the S255IR-SMA1 clump, which represents a rotating structure (probably a disk) around the young massive star. The achieved angular resolution is still insufficient to make any conclusions about the Keplerian or non-Keplerian character of the rotation. The temperature of the molecular gas reaches 130-180 K. The size of the clump is about 500 AU. The clump is strongly fragmented as follows from the low beam-filling factor. The mass of the hot gas is significantly lower than the mass of the central star. A strong DCN emission near the center of the hot core most probably indicates a presence of a relatively cold ( 80 K) and rather massive clump there. High-velocity emission is observed in the CO line as well as in lines of high-density tracers HCN, HCO+, CS and other molecules. The outflow morphology obtained from a combination of the SMA and IRAM 30 m data is significantly different from that derived from the SMA data alone. The CO emission detected with the SMA traces only one boundary of the outflow. The outflow is most probably driven by jet bow shocks created by episodic ejections from the center. We detected a dense high velocity clump associated apparently with one of the bow shocks. The outflow strongly affects the chemical composition of the surrounding medium.
Results are reported of using subcontact layers with energy gap width
E
g
of 0.35 to 0.8 eV for obtaining low-resistivity electrical contacts to
p
-InP. An experimental dependence of the contact ...resistance on
E
g
of the subcontact material In
x
Ga
1 –
x
As was obtained.
The results of a detailed analysis of SMA, VLA, and IRAM observations of the region of massive star formation S255N in CO(2–1), N
2
H
+
(3–2), NH
3
(1, 1), C
18
O(2–1) and some other lines is ...presented. Combining interferometer and single-dish data has enabled a more detailed investigation of the gas kinematics in the moleclar core on various spatial scales. There are no signs of rotation or isotropic compression on the scale of the region as whole. The largest fragments of gas (≈0.3 pc) are located near the boundary of the regions of ionized hydrogen S255 and S257. Some smaller-scale fragments are associated with protostellar clumps. The kinetic temperatures of these fragments lie in the range 10–80 K. A circumstellar torus with inner radius
R
in
≈ 8000 AU and outer radius
R
out
≈ 12 000 AU has been detected around the clump SMA1. The rotation profile indicates the existence of a central object with mass ≈8.5/ sin
2
(
i
)
M
⊙
. SMA1 is resolved into two clumps, SMA1–NE and SMA1–SE, whose temperatures are≈150Kand≈25 K, respectively. To all appearances, the torus is involved in the accretion of surrounding gas onto the two protostellar clumps.
One of the main rapidly developing directions of tourism both in the world and in Ukraine in particular is urban tourism. As centuries ago, so nowadays, the cities are the goal of many travels, and ...the territorial recreational systems based on them are the most developed ones, which is explained by the high concentration of tourism resources in a conventionally limited space. Despite all this, in the sphere of urban tourism in terms of a territorial recreational system there is an uneven provision of recreational demand for communication with nature due to the insufficient number of natural recreational objects. As a solution to the common problem for recreation and urban tourism, it is proposed to implement a number of measures consistently both at the State level and at the level of local authorities or local self-government bodies, namely: to create conditions under which private and communal enterprises would be interested in the creation and development of natural recreational formations in the form of parks, gardens, squares, embankments. The program for the development of natural recreational spaces in cities – i.e., tourism centers – envisages that private and communal enterprises that will create these natural recreational spaces will carry out reconstructions of the already existing formations and will have the opportunity to engage in such natural recreational formations with commercial activities related to the organization of the provision of recreational services. In addition, it is important to strengthen the State supervision over compliance with the State sanitary rules for planning and development of settlements, because, in terms of landscaping, large cities of Ukraine have long failed to meet the requirements. At this, one considers appropriate to involve scientific and educational institutions related to tourism and recreation in the design of these natural recreational formations, which will allow to implement tourism in the city on not only practical, but also on scientific basis. It is believed that in case of materialization of the proposed program, the city will receive additional centers of attraction for tourists, which, in turn, will have positive consequences for the further development of cities as centers of tourism and recreation.
We have used the ATNF Mopra antenna and the SEST antenna to search in the directions of several class II methanol maser sources for emission from six methanol transitions in the frequency range ...85–115 GHz. The transitions were selected from excitation studies as potential maser candidates. Methanol emission at one or more frequencies was detected from five of the maser sources, as well as from Orion KL. Although the lines are weak, we find evidence of maser origin for three new lines in G345.01+1.79, and possibly one new line in G9.62+0.20. The observations, together with published maser observations at other frequencies, are compared with methanol maser modelling for G345.01+1.79 and NGC 6334F. We find that the majority of observations in both sources are consistent with a warm dust (175 K) pumping model at hydrogen density ∼106 cm−3 and methanol column density ∼5×1017 cm−2. The substantial differences between the maser spectra in the two sources can be attributed to the geometry of the maser region.
Піогенна гранульома (granuloma pyogenicum) – доброякісне судинне утворення, що виникає внаслідок порушення загоєння рани в поєднанні з проліферацією судин і може розцінюватися як реактивний процес. ...Гістологічно піогенна гранульома характеризується розростанням грануляційної тканини з великою кількістю розширених, із набряклим ендотелієм капілярів, набряклою стромою, іноді містить запальний інфільтрат, що складається з лімфоцитів, нейтрофілів, плазматичних клітин і фібробластів серед пухкої сполучної тканини. Екзофітна дольчаста проліферація капілярів добре виражена, епідерміс іноді ерозований з периферійними епідермальними нашаруваннями та ділянками акантозу по периферії. За останні 5 років (у період 2015–2020 рр.) у клініці дитячої хірургії Вінницького національного медичного університету імені М.І. Пирогова перебували на стаціонарному лікуванні 18 пацієнтів із діагнозом піогенної гранульоми. Середній вік пацієнтів становив 8,98±0,97 року. За отриманими даними, максимальна кількість пацієнтів припадала на вікову категорію 5–13 років, що співпало з результатами інших дослідників. Серед усіх пацієнтів групи дослідження піогенна гранульома локалізувалася на: голові‑шиї – у 14 пацієнтів, верхній частині тулуба – у 3 випадках, пальці – в 1 дитини. Всім дітям проведено хірургічне видалення піогенної гранульоми в межах здорових тканин. Ускладнень і рецидивів захворювання не виявлено в жодному клінічному випадку. Лікарі педіатричного профілю мають звертати увагу на пухлиноподібні утворення, особливо виниклі в місцях травм, навіть незначні, для виключення складнішої патології (меланоми). Дослідження виконано відповідно до принципів Гельсінської декларації. Протокол дослідження ухвалено Локальним етичним комітетом зазначеної в роботі установи. На проведення досліджень отримано інформовану згоду батьків дітей. Автори заявляють про відсутність конфлікту інтересів.
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