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Related papers: CH$_3$OH as a User-Friendly Density Probe: Calibra…

200 papers

We use spectra and maps of the $J=1-0$ and $J=2-1$ DCO$^{+}$, DCN, DNC, $\rm N_2D^+$ lines and $1_{11}-1_{01}$ ortho- and para-NH$_{2}$D lines, obtained with the IRAM-30m telescope, as well as observations of their hydrogenated…

Astrophysics of Galaxies · Physics 2023-10-03 A. G. Pazukhin , I. I. Zinchenko , E. A. Trofimova , C. Henkel , D. A. Semenov

The low carbon content of Earth and primitive meteorites compared to the Sun and interstellar grains suggests that carbon-rich grains were destroyed in the inner few astronomical units of the young solar system. A promising mechanism to…

Astrophysics of Galaxies · Physics 2024-05-24 Merel L. R. van 't Hoff , Edwin A. Bergin , Penelope Riley , Sanil Mittal , Jes K. Jørgensen , John J. Tobin

Column density ratios of complex organic molecules are generally constant across protostellar systems with some low-level scatter. However, the scatter in formamide (NH$_2$CHO) to methanol (CH$_3$OH) column density ratio is one of the…

Astrophysics of Galaxies · Physics 2024-07-24 P. Nazari , B. Tabone , G. P. Rosotti , E. F. van Dishoeck

Multilevel observations of formaldehyde (H_2CO) and methanol (CH_3OH) toward the nearby spiral galaxies NGC 253, Maffei 2, IC 342, M 82 and NGC 6946 are presented. H_2CO was detected in all galaxies (tentatively in NGC 6946). CH_3OH was…

Astrophysics · Physics 2007-05-23 S. Huettemeister , R. Mauersberger , C. Henkel

Stars form in cold molecular clouds. However, molecular gas is difficult to observe because the most abundant molecule (H2) lacks a permanent dipole moment. Rotational transitions of CO are often used as a tracer of H2, but CO is much less…

We present a new method for estimating the H2 cooling rate in the optically thick regime in simulations of primordial star formation. Our new approach is based on the TreeCol algorithm, which projects matter distributions onto a spherical…

Solar and Stellar Astrophysics · Physics 2015-05-05 Tilman Hartwig , Paul C. Clark , Simon C. O. Glover , Ralf S. Klessen , Mei Sasaki

The optically thin critical densities and the effective excitation densities to produce a 1 K km/s (or 0.818 Jy km/s $(\frac{\nu_{jk}}{100 \rm{GHz}})^2 \, (\frac{\theta_{beam}}{10^{\prime\prime}})^2$) spectral line are tabulated for 12…

Instrumentation and Methods for Astrophysics · Physics 2015-06-23 Yancy L. Shirley

Iram 30-m Observations towards eight protostellar outflow sources were taken in the 96-\SI{176}{\giga\hertz} range. Transitions of CH$_3$OH and CH$_3$CHO were detected in seven of them. The integrated emission of the transitions of each…

In the Halo21 absorption modeling challenge we generated synthetic absorption spectra of the circumgalactic medium (CGM), and attempted to estimate the metallicity, temperature, and density (Z, T, and nH) of the underlying gas using…

For accurate modelling of observations of exoplanet atmospheres, quantification of the pressure broadening of infrared absorption lines for and by a variety of gases at elevated temperatures is needed. High-resolution high-temperature…

Earth and Planetary Astrophysics · Physics 2019-10-23 Ehsan Gharib-Nezhad , Alan N. Heays , Hans A. Bechtel , James R. Lyons

The observed molecular properties of a sample of FIR-luminous and OH megamaser (OH-MM) galaxies have been investigated. The ratio of high and low-density tracer lines is found to be determined by the progression of the star formation in the…

Astrophysics · Physics 2009-11-13 A. F. Loenen , W. A. Baan , M. Spaans

The 12C/13C isotope ratio has been derived towards numerous cold clouds (20-50 K) and a couple protoplanetary disks and exoplanet atmospheres. However, direct measurements of this ratio in the warm gas (>100 K) around young low-mass…

We develop a method of analyzing radio frequency spectral line observations to derive data on the temperature, density, velocity, and molecular abundance of the emitting gas. The method incorporates a radiative transfer code with a new…

Astrophysics · Physics 2009-11-10 Eric Keto , George B. Rybicki , Edwin A. Bergin , Rene Plume

The outer Galaxy is an environment with metallicity lower than the Solar one and, because of this, the formation and survival of molecules in star-forming regions located in the inner and outer Galaxy is expected to be different. To gain…

We use galaxies from the Herschel Reference Survey to evaluate commonly used indirect predictors of cold gas masses. We calibrate predictions for cold neutral atomic and molecular gas using infrared dust emission and gas depletion time…

Astrophysics of Galaxies · Physics 2018-05-02 Steven Janowiecki , Luca Cortese , Barbara Catinella , Adelle Goodwin

The results of spectral observations in the $\sim 84-92$ GHz frequency range of six objects in the southern sky containing dense cores and associated with regions of massive stars and star clusters formation are presented. The observations…

Astrophysics of Galaxies · Physics 2024-03-06 L. E. Pirogov , P. M. Zemlyanukha , E. M. Dombek , M. A. Voronkov

We present an overview of a high-mass star formation region through the major (sub-)mm, and far-infrared cooling lines to gain insight into the physical conditions and the energy budget of the molecular cloud. We used the KOSMA 3m telescope…

Astrophysics · Physics 2009-11-11 H. Jakob , C. Kramer , R. Simon , N. Schneider , V. Ossenkopf , S. Bontemps , U. U. Graf , J. Stutzki

We have observed the four hyperfine components of the 18 cm OH transition toward the translucent cloud eastward of Heiles Cloud 2 (HCL2E), the cold dark cloud L134N, and the photodissociation region of the $\rho$-Ophiuchi molecular cloud…

Astrophysics of Galaxies · Physics 2016-02-18 Yuji Ebisawa , Hiroshi Inokuma , Nami Sakai , Karl M. Menten , Hiroyuki Maezawa , Satoshi Yamamoto

We present wide area radio (12 mm) Mopra Telescope observations of the complex and rich massive star forming region G305. Our goals are to determine the reservoir for star formation within G305 using NH3 to trace the dense molecular…

Astrophysics of Galaxies · Physics 2015-05-19 L. Hindson , M. A. Thompson , J. S. Urquhart , J. S. Clark , B. Davies

The sample of nearby LIRGs and ULIRGs for which dense molecular gas tracers have been measured is building up, allowing for the study of the physical and chemical properties of the gas in the variety of objects in which the most intense…

Astrophysics · Physics 2008-11-26 J. Gracia-Carpio , S. Garcia-Burillo , P. Planesas
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