Results 1 to 10 of about 42,575 (298)

OH+ in Diffuse Molecular Clouds [PDF]

open access: yesThe Astrophysical Journal, 2013
Near ultraviolet observations of OH+ and OH in diffuse molecular clouds reveal a preference for different environments. The dominant absorption feature in OH+ arises from a main component seen in CH+ (that with the highest CH+/CH column density ratio ...
Federman, S. R.   +3 more
core   +5 more sources

The contribution of unresolved sources on the gamma-ray spectrum of molecular clouds [PDF]

open access: yesEPJ Web of Conferences, 2023
Fermi-LAT observations of the large-scale diffuse gamma-ray emission unveiled that in some locations, towards the inner Galaxy, the spectrum of this component is harder than the local one, measured at the Earth position. If this signal is associated with
Vecchiotti Vittoria   +3 more
doaj   +1 more source

Dissociative Recombination of Rotationally Cold OH+ and Its Implications for the Cosmic Ray Ionization Rate in Diffuse Clouds

open access: yesThe Astrophysical Journal Letters, 2023
Observations of OH ^+ are used to infer the interstellar cosmic ray ionization rate in diffuse atomic clouds, thereby constraining the propagation of cosmic rays through and the shielding by interstellar clouds, as well as the low energy cosmic ray ...
Ábel Kálosi   +14 more
doaj   +1 more source

Shaken or Stirred: The Diffuse Interstellar Medium with Exceptionally High SiO Abundance

open access: yesThe Astrophysical Journal, 2023
Interstellar shocks, a key element of stellar feedback processes, shape the structure of the interstellar medium (ISM) and are essential for the chemistry, thermodynamics, and kinematics of interstellar gas.
Daniel R. Rybarczyk   +2 more
doaj   +1 more source

ACA CO(J = 2–1) Mapping of the Nearest Spiral Galaxy M33. I. Initial Results and Identification of Molecular Clouds

open access: yesThe Astrophysical Journal, 2023
We present the results of ALMA-ACA 7 m array observations in ^12 CO( J = 2–1), ^13 CO( J = 2–1), and C ^18 O( J = 2–1) line emission toward the molecular-gas disk in the Local Group spiral galaxy M33 at an angular resolution of 7.″31 × 6.″50 (30 × 26 pc).
Kazuyuki Muraoka   +21 more
doaj   +1 more source

Absorption-line Observations of and CO in Sight Lines Toward the Vela and W28 Supernova Remnants

open access: yesThe Astrophysical Journal, 2023
Supernova remnants act as particle accelerators, providing the cosmic-ray protons that permeate the interstellar medium and initiate the ion–molecule reactions that drive interstellar chemistry. Enhanced fluxes of cosmic-ray protons in close proximity to
Nick Indriolo
doaj   +1 more source

A Search for OH 18 cm Emission from Intermediate-velocity Gas at High Galactic Latitudes

open access: yesThe Astrophysical Journal, 2023
We present search results of 22 high-latitude (∣ b ∣ > 25°) sightlines for OH 18 cm emission using the 305 m radio telescope at the Arecibo Observatory. These sightlines appear in neutral hydrogen emission at intermediate velocities −90 ≤ V _LSR ≤ −20 km
Allison J. Smith, D. Anish Roshi
doaj   +1 more source

Results of the ESO-SEST Key Programme on CO in the Magellanic Clouds. IX. The giant LMC HII region complex N11 [PDF]

open access: yes, 2002
We present maps and a catalogue containing the J=1-0 12CO parameters of 29 individual molecular clouds in the second-brightest LMC star formation complex, N11.
Caldwell   +33 more
core   +22 more sources

A Herschel [C II] Galactic plane survey II: CO-dark H2 in clouds [PDF]

open access: yes, 2014
ABRIDGED: Context: HI and CO large scale surveys of the Milky Way trace the diffuse atomic clouds and the dense shielded regions of molecular hydrogen clouds.
Goldsmith, P. F.   +4 more
core   +1 more source

Abundance Ratios of OH/CO and HCO+/CO as Probes of the Cosmic-Ray Ionization Rate in Diffuse Clouds

open access: yesThe Astrophysical Journal, 2023
The cosmic-ray ionization rate (CRIR, ζ _2 ) is one of the key parameters controlling the formation and destruction of various molecules in molecular clouds. However, the current most commonly used CRIR tracers, such as ${{\rm{H}}}_{3}^{+}$ , OH ^+ , and
Gan Luo   +8 more
doaj   +1 more source

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