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Related papers: CH3CCH as a thermometer in warm molecular gas

200 papers

We present combined interferometer and single dish telescope data of NH3 (J,K) = (1,1) and (2,2) emission towards the clustered star forming Ophiuchus B, C and F Cores at high spatial resolution (~1200 AU) using the Australia Telescope…

Solar and Stellar Astrophysics · Physics 2010-01-15 R. K. Friesen , J. Di Francesco , Y. L. Shirley , P. C. Myers

We present APEX 218 GHz observations of molecular emission in a complete sample of embedded protostars in the Ophiuchus star-forming region. To study the physical properties of the cores, we calculate H$_2$CO and c-C$_3$H$_2$ rotational…

Solar and Stellar Astrophysics · Physics 2017-01-25 Johan E. Lindberg , Steven B. Charnley , Jes K. Jørgensen , Martin A. Cordiner , Per Bjerkeli

We present a survey of molecules in a sample of Galactic center molecular clouds using the Karl G. Jansky Very large Array, which includes M0.25+0.01, the clouds near Sgr A, and Sgr B2. The molecules detected are primarily NH3 and HC3N; in…

Astrophysics of Galaxies · Physics 2015-06-18 E. A. C. Mills , C. C. Lang , M. R. Morris , J. Ott , N. Butterfield , D. Ludovici , S. Schmitz , A. Schmiedeke

Among the numerous molecular systems found in the interstellar medium (ISM), vinyl cyanide is the first identified olephinic nitrile. While it has been observed in various sources, its detection in Sgr B2 is notable as the 2$_{11}$-2$_{12}$…

Astrophysics of Galaxies · Physics 2025-06-23 Karina Sogomonyan , Malek Ben Khalifa , Jérôme Loreau

The amide-related molecules are essential for the formation of the other complex bio-molecules and an understanding of the prebiotic chemistry in the interstellar medium (ISM). We presented the first detection of the rotational emission…

Astrophysics of Galaxies · Physics 2023-05-10 Arijit Mannna , Sabyasachi Pal

We report the detection of methyl ketene towards TMC-1 with the QUIJOTE line survey. Nineteen rotational transitions with rotational quantum numbers ranging from J = 3 up to J = 5 and Ka =< 2 were identified in the frequency range 32.0-50.4…

Massive young stellar objects (MYSOs) with hot cores are classic sources of complex organic molecules. The origins of these molecules in such sources, as well as the small- and large-scale differentiation between nitrogen- and…

Solar and Stellar Astrophysics · Physics 2015-03-25 Edith C. Fayolle , Karin I. Öberg , Robin T. Garrod , Ewine F. van Dishoeck , Suzanne E. Bisschop

N-bearing molecules (like N2H+ or NH3) are excellent tracers of high-density, low-temperature regions like dense cloud cores and could shed light into snowlines in protoplanetary disks and the chemical evolution of comets. However,…

Astrophysics of Galaxies · Physics 2023-12-01 S. Kakkenpara Suresh , F. Dulieu , J. Vitorino , P. Caselli

The results of a submillimetre wavelength spectral line survey between 455.1 -- 507.4 GHz of the Orion-KL hot cloud core are reported. A total of 254 lines were detected to a main beam brightness temperature sensitivity ~ 1 - 3 K. The…

Astrophysics · Physics 2009-11-07 Glenn J. White , M. Araki , J. S. Greaves , M. Ohishi , N. S. Higginbottom

Several nitrogen-bearing molecules, such as methyl cyanide (or acetonitrile, CH$_3$CN) and methyl isocyanide (CH$_3$NC) of interest here, have been observed in various astrophysical environments. The accurate modeling of their abundance…

Chemical Physics · Physics 2023-09-14 Malek Ben Khalifa , Paul J. Dagdigian , Jérôme Loreau

We investigate ionization and heating of gas in the dense, shielded clumps/cores of molecular clouds bathed by an influx of energetic, charged cosmic rays (CRs). These molecular clouds have complex structures, with substantial variation in…

Astrophysics of Galaxies · Physics 2021-06-02 Ellis R. Owen , Alvina Y. L. On , Shih-Ping Lai , Kinwah Wu

Context. In dffuse interstellar clouds the excitation temperature derived from the lowest levels of H$^+_3$ is systematically lower than that derived from H2. The differences may be attributed to the lack of state-specific formation and…

We present the results of a spectral line survey from 138.3 to 150.7 GHz toward Orion-KL. The observations were made using the 14 m radio telescope of Taeduk Radio Astronomy Observatory. Typical system temperatures were between 500 and 700…

Astrophysics · Physics 2009-10-31 Chang Won Lee , Se-Hyung Cho , Sung-Min Lee

The HNC/HCN ratio is observationally known as a thermometer in Galactic interstellar molecular clouds. A recent study has alternatively suggested that the HNC/HCN ratio is affected by the ultraviolet (UV) field, not by the temperature. We…

Astrophysics of Galaxies · Physics 2024-05-16 Nanase Harada , Toshiki Saito , Yuri Nishimura , Yoshimasa Watanabe , Kazushi Sakamoto

The outer Galaxy (galactocentric distance $\gtrsim$13.5 kpc) serves as an excellent laboratory for investigating the chemical complexity in low-metallicity environments. Here, we present the chemical analyses for the outer Galactic hot core…

Astrophysics of Galaxies · Physics 2026-02-04 Toki Ikeda , Takashi Shimonishi , Hiroyuki Kaneko , Kenji Furuya , Kei Tanaka , Natsuko Izumi

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…

Earth and Planetary Astrophysics · Physics 2018-06-13 Ryan A. Loomis , L. Ilsedore Cleeves , Karin I. Öberg , Yuri Aikawa , Jennifer Bergner , Kenji Furuya , V. V. Guzman , Catherine Walsh

We investigate the thermal evolution of 3I/ATLAS, the third macroscopic interstellar object discovered on 2025 July 1. By comparing modeled thermal profiles with observations of volatile activity, it is possible to constrain bulk physical…

Earth and Planetary Astrophysics · Physics 2026-01-22 Atsuhiro Yaginuma , Aster G. Taylor , Darryl Z. Seligman

Here we report on new, multi-wavelength radio observations of the unusual point source "N3" that appears to be located in the vicinity of the Galactic Center. VLA observations between 2 and 50 GHz reveal that N3 is a compact and bright…

With MgH^+ ions as a test case, we investigate to what extent the rotational motion of smaller polar molecular ions sympathetically cooled into Coulomb crystals in linear Paul traps couples to the translational motions of the ion ensemble.…

Chemical Physics · Physics 2015-06-26 Anders Bertelsen , Solvejg Jørgensen , Michael Drewsen

A detailed interpretation of the detected emission lines of environments in which propyne (or methyl acetylene, CH$_3$CCH) is observed requires a knowledge of its collisional rate coefficients with the most abundant species in the…

Astrophysics of Galaxies · Physics 2024-02-28 M. Ben Khalifa , B. Darna , J. Loreau