English
Related papers

Related papers: SO2 and OCS toward high-mass protostars: A compara…

200 papers

(Abridged) Far-infrared Herschel-PACS spectra of 18 low-mass protostars of various luminosities and evolutionary stages are studied. We quantify their far-infrared line emission and the contribution of different atomic and molecular species…

We study the evolution of atomic and molecular gas in galaxies in semi-analytic models of galaxy formation that include new modeling of the partitioning of cold gas in galactic discs into atomic, molecular, and ionised phases. We adopt two…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Gergo Popping , Rachel S. Somerville , Scott C. Trager

The carbon monoxide (CO) spectral line energy distributions (SLEDs) of galaxies contain a wealth of information about conditions in their cold interstellar gas. Here we use galaxy-scale observations of the three lowest energy CO lines to…

Astrophysics of Galaxies · Physics 2025-07-28 Ryan P. Keenan , Daniel P. Marrone , Garrett K. Keating

The presence of asymmetries and substructures in protoplanetary disks, revealed by both dust and gas emission, highlights the potential interplay and the broader connection between chemistry and dynamics in disk evolution. We explore…

We investigate molecular evolution in a star-forming core that is initially a hydrostatic starless core and collapses to form a low-mass protostar. The results of a one-dimensional radiation-hydrodynamics calculation are adopted as a…

Astrophysics · Physics 2009-11-13 Yuri Aikawa , Valentine Wakelam , Robin T. Garrod , Eric Herbst

During the million years of evolution, gas dust and ice in protoplanetary disks can be chemically reprocessed. There are evidences that the gas-phase carbon and oxygen abundances are sub-solar in disks belonging to nearby star forming…

Solar and Stellar Astrophysics · Physics 2020-07-01 D. Fedele , C. Favre

We report the first detection of hot molecular cores in the Small Magellanic Cloud, a nearby dwarf galaxy with 0.2 solar metallicity. We observed two high-mass young stellar objects in the SMC with ALMA, and detected emission lines of CO,…

Astrophysics of Galaxies · Physics 2023-04-12 Takashi Shimonishi , Kei E. I. Tanaka , Yichen Zhang , Kenji Furuya

We present observations of Taurus-Auriga Class I/II protostars obtained with the Spitzer InfraRed Spectrograph. Detailed spectral fits to the 6 and 15 micron features are made, using publicly-available laboratory data, to constrain the…

Astrophysics · Physics 2015-05-13 G. Zasowski , F. Kemper , Dan M. Watson , E. Furlan , C. J. Bohac , C. Hull , J. D. Green

The Small Magellanic Cloud (SMC) provides the only laboratory to study the structure of molecular gas at high resolution and low metallicity. We present results from the Herschel Spectroscopic Survey of the SMC (HS$^{3}$), which mapped the…

We present far-IR (57-196 mu) spectra of 21 protostars in the Orion molecular clouds, obtained with the Photodetector Array Camera and Spectrometer (PACS) onboard the Herschel Space observatory, as part of the Herschel Orion Protostar…

We explore the relationship between stellar surface density and gas surface density (the star-gas or S-G correlation) in a 20,000 M$_{\odot}$ simulation from the STAR FORmation in Gaseous Environments (STARFORGE) Project. We create…

Astrophysics of Galaxies · Physics 2023-10-19 Samuel Millstone , Robert Gutermuth , Stella S. R. Offner , Riwaj Pokhrel , Michael Y. Grudić

Abundances of C, O, and Fe are determined for F and G main-sequence stars in the solar neighborhood in order to study trends and systematic differences in the C/Fe, O/Fe, and C/O ratios for stellar populations. Carbon abundances are…

Solar and Stellar Astrophysics · Physics 2014-09-05 P. E. Nissen , Y. Q. Chen , L. Carigi , W. J. Schuster , G. Zhao

CO is the most widely used gas tracer of protoplanetary disks. Its abundance is usually assumed to be an interstellar ratio throughout the warm molecular layer of the disk. But recent observations of low CO gas abundance in many…

Earth and Planetary Astrophysics · Physics 2019-10-02 Ke Zhang , Edwin A. Bergin , Kamber R. Schwarz , Sebastiaan Krijt , Fred Ciesla

To date, at least three comets -- 2I/Borisov, C/2016 R2 (PanSTARRS), and C/2009 P1 (Garradd) -- have been observed to have unusually high CO concentrations compared to water. We attempt to explain these observations by modeling the effect…

Earth and Planetary Astrophysics · Physics 2021-05-26 Ellen M. Price , L. Ilsedore Cleeves , Dennis Bodewits , Karin I. Öberg

Context. Low-mass protostars drive powerful molecular outflows that can be observed with mm and sub-mm telescopes. Various sulfuretted species are known to be bright in shocks and could be used to infer the physical and chemical conditions…

Methanol and its precursor formaldehyde are among the most studied organic molecules in the interstellar medium and are abundant in the gaseous and solid phases. We recently developed a model to simulate CO hydrogenation via H atoms on…

Astrophysics of Galaxies · Physics 2015-05-14 H. M. Cuppen , E. F. van Dishoeck , E. Herbst , A. G. G. M. Tielens

The chemical inventory of planets is determined by the physical and chemical processes that govern the early phases of star formation. The aim is to investigate N-bearing complex organic molecules towards two Class 0 protostars (B1-c and…

Processing by interstellar photons affects the composition of the icy mantles on interstellar grains. The rate of photodissociation in solids differs from that of molecules in the gas phase. The aim of this work was to determine an average,…

Astrophysics of Galaxies · Physics 2018-05-16 Juris Kalvans