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相关论文: Exploring HNC and HCN line emission as probes of t…

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We present new observations of HCN and HCO+in the circumnuclear disk (CND) of the Galaxy, obtained with the APEX telescope. We have mapped emission in rotational lines of HCN J = 3-2, 4-3, and 8-7, as well as HCO+ J = 3-2, 4-3, and 9-8. We…

星系天体物理 · 物理学 2015-06-17 Elisabeth A. C. Mills , Rolf Güsten , Miguel A. Requena Torres , Mark R. Morris

Observations of molecular clouds, prestellar cores, and protoplanetary disks have established that the HNC/HCN ratio may be a potent diagnostic of molecular gas physical conditions. The processes that govern the relative abundances of these…

The detection of Keplerian rotation is rare among Class 0 protostellar systems. We have investigated the high-density tracer HCN as a probe of the inner disk in a Class 0 proto-brown dwarf candidate. Our ALMA high angular resolution…

太阳与恒星天体物理 · 物理学 2024-05-21 B. Riaz , W. -F. Thi , M. N. Machida

The UV radiation field is a critical regulator of gas-phase chemistry in surface layers of disks around young stars. In an effort to understand the relationship between photocatalyzing UV radiation fields and gas emission observed at…

Small organic molecules, such as C2H, HCN, and H2CO, are tracers of the C, N, and O budget in protoplanetary disks. We present high angular resolution (10-50 au) observations of C2H, HCN, and H2CO lines in five protoplanetary disks from the…

The distributions of deuterated molecules in protoplanetary disks are expected to depend on the molecular formation pathways. We use observations of spatially resolved DCN emission from the disk around TW Hya, acquired during ALMA Science…

星系天体物理 · 物理学 2015-06-04 Karin I. Oberg , Chunhua Qi , David J. Wilner , Michiel R. Hogerheijde

The gas-solid budget of carbon in protoplanetary disks is related to the composition of the cores and atmospheres of the planets forming in them. The key gas-phase carbon carriers CO, C$^{0}$ and C$^{+}$ can now be observed in disks. The…

Deuterium fractionation is dependent on various physical and chemical parameters. Thus, the formation location and thermal history of material in the solar system is often studied by measuring its D/H ratio. This requires knowledge about…

Cometary studies suggest that the organic composition of the early Solar Nebula was rich in complex nitrile species such a CH$_3$CN. Recent ALMA detections in protoplanetary disks suggest that these species may be common during planet and…

Snowlines of major volatiles regulate the gas and solid C/N/O ratios in the planet-forming midplanes of protoplanetary disks. Snow surfaces are the 2D extensions of snowlines in the outer disk regions, where radiative heating results in a…

We present results from a study of nitrogen chemistry in Class 0/I proto-brown dwarfs (proto-BDs). We have used the IRAM 30 m telescope to observe the CN (2-1), HCN (3-2), and HNC (3-2) lines in 7 proto-BDs. All proto-BDs show a large…

太阳与恒星天体物理 · 物理学 2018-10-03 B. Riaz , W. -F. Thi , P. Caselli

We have observed the clump G34.43+00.24 MM3 associated with an infrared dark cloud in DNC $J$=3--2, HN$^{13}$C $J$=3--2, and N$_2$H$^+$ $J$=3--2 with the Atacama Large Millimeter/submillimeter Array (ALMA). The N$_2$H$^+$ emission is found…

The thermal structure of protoplanetary disks is a fundamental characteristic of the system that has wide reaching effects on disk evolution and planet formation. In this study, we constrain the 2D thermal structure of the protoplanetary…

We predict how protoplanetary disks around low-mass young stars would appear in molecular lines observed with the ALMA interferometer. Our goal is to identify those molecules and transitions that can be used to probe and distinguish between…

天体物理学 · 物理学 2009-11-13 D. Semenov , Ya. Pavlyuchenkov , Th. Henning , S. Wolf , R. Launhardt

With two directly detected protoplanets, the PDS 70 system is a unique source in which to study the complex interplay between forming planets and their natal environment. The large dust cavity carved by the two giant planets can affect the…

地球与行星天体物理 · 物理学 2024-09-04 L. Rampinelli , S. Facchini , M. Leemker , J. Bae , M. Benisty , R. Teague , C. J. Law , K. I. Öberg , B. Portilla-Revelo , A. J. Cridland

We present high spatial resolution (5.1" x 2.7") OVRO millimeter array observations of HCN (J=1-0) and HCO+ (J=1-0) emission in the inner 3 pc of the galaxy. The HCN and HCO+ emission of the circumnuclear disk (CND) is distributed in a…

天体物理学 · 物理学 2009-11-10 M. H. Christopher , N. Z. Scoville , S. R. Stolovy , Min S. Yun

The high spatial and line sensitivity of ALMA opens the possibility of resolving emission from molecules in circumstellar disks. With an understanding of physical conditions under which molecules have high abundance, they can be used as…

We report the detection of an excess in dust continuum emission at 233~GHz (1.3~mm in wavelength) in the protoplanetary disk around TW~Hya revealed through high-sensitivity observations at $\sim$3~au resolution with the Atacama Large…

We examine changes in the molecular abundances resulting from increased heating due to a self-luminous planetary companion embedded within a narrow circumstellar disk gap. Using 3D models that include stellar and planetary irradiation, we…

太阳与恒星天体物理 · 物理学 2015-05-29 L. Ilsedore Cleeves , Edwin A. Bergin , Tim J. Harries