Results 41 to 50 of about 16,662 (218)

Herschel spectral-mapping of the Helix Nebula (NGC 7293): Extended CO photodissociation and OH+ emission [PDF]

, 2014
The Helix Nebula (NGC 7293) is the closest planetary nebulae. Therefore, it is an ideal template for photochemical studies at small spatial scales in planetary nebulae. We aim to study the spatial distribution of the atomic and the molecular gas, and the
Barlow, M. J., Cernicharo, J., Etxaluze, M., Goicoechea, J. R., Groenewegen, M. A. T., Kerschbaum, F., Lim, T. L., Lique, F., Matsuura, M., Pearson, C., Polehampton, E. T., Royer, P., Swinyard, B. M., Ueta, T., van de Steene, G. C., van Hoof, P. A. M.   +15 more
core   +3 more sources

A multifrequency study of the active star forming complex NGC6357. I. Interstellar structures linked to the open cluster Pis24 [PDF]

, 2011
We investigate the distribution of the gas (ionized, neutral atomic and molecular), and interstellar dust in the complex star forming region NGC6357 with the goal of studying the interplay between the massive stars in the open cluster Pis24 and the ...
Benjamin, Bohigas, C. E. Cappa, Cesarsky, Churchwell, Cichowolski, Damke, E. Fernández Lajús, E. M. Arnal, Fazio, Felli, Haynes, Hester, Hester, Hildebrand, Inoue, J. Vasquez, Kutner, Lortet, Marston, Martins, Massey, Massi, Maíz, McBreen, Mezger, Murphy, N. U. Duronea, Neckel, Penzias, Persi, Prinja, Quireza, R. Barbá, Russeil, Shaver, Ulich, Vacca, van der Hucht, W. M. Goss, Walborn, Wang, Watson, Watson, Westmoquette, Wilson   +45 more
core   +2 more sources

Surface chemistry in photodissociation regions [PDF]

Astronomy & Astrophysics, 2016
The presence of dust can strongly affect the chemical composition of the interstellar medium. We model the chemistry in photodissociation regions (PDRs) using both gas-phase and dust-phase chemical reactions. Our aim is to determine the chemical compositions of the interstellar medium (gas/dust/ice) in regions with distinct (molecular) gas densities ...
Esplugues, G., Cazaux, .S., Meijerink, R., Spaans, M., Caselli, P.   +4 more
openaire   +5 more sources

Dust temperature and time-dependent effects in the chemistry of photodissociation regions [PDF]

, 2019
When studying the chemistry of PDRs, time dependence becomes important as visual extinction increases, since certain chemical timescales are comparable to the cloud lifetime.
Caselli, Paola, Cazaux, Stephanie, Esplugues, Gisela, Hocuk, Seyit, Spaans, Marco   +4 more
core   +2 more sources

SATELLITE: Application to Planetary Nebulae IFU Data

Galaxies, 2022
The integral field unit (IFU) spectroscopic view of extended ionized nebulae, such as planetary nebulae (PNe), H II regions, and galaxies, has changed the approach of studying these objects, providing a simultaneous characterization in both spatial ...
Stavros Akras, Hektor Monteiro, Jeremy R. Walsh, Isabel Aleman, Denise R. Gonçalves, Panayotis Boumis   +5 more
doaj   +1 more source

Structure of Stationary Photodissociation Fronts [PDF]

, 1996
The structure of stationary photodissociation fronts is revisited. H_2 self- shielding is discussed, including the effects of line overlap. We find that line overlap is important for N(H_2) > 10^{20} cm^{-2}.
Bertoldi, Frank, Draine, B. T.
core   +3 more sources

Photodissociation Regions in Planetary Nebulae [PDF]

Symposium - International Astronomical Union, 1993
The photodissociation rate of H2 molecules by UV photons from PN central stars is generally several orders of magnitude larger than the rate produced by the average interstellar field (Sternberg 1988, Escalante et al. 1991). Thus, in neutral envelopes of PN's, H2 molecules are destroyed quickly, and a photodissociation region forms around ionization ...
V. Escalante, A. Góngora-T
openaire   +1 more source

Rovibrationally resolved photodissociation of HeH+

, 2011
Accurate photodissociation cross sections have been obtained for the A-X electronic transition of HeH+ using ab initio potential curves and dipole transition moments.
Argyros, Basu, C. D. Gay, Cooley, Dabrowski, Dinerstein, Dumitriu, Flower, France, Galli, Gorti, Lepp, Liu, Miyake, P. C. Stancil, Rau, S. Miyake, Saha, Stancil, Zygelman   +19 more
core   +1 more source

Destruction of Refractory Carbon in Protoplanetary Disks [PDF]

, 2017
The Earth and other rocky bodies in the inner solar system contain significantly less carbon than the primordial materials that seeded their formation. These carbon-poor objects include the parent bodies of primitive meteorites, suggesting that at least ...
Anderson, Dana E., Bergin, Edwin A., Blake, Geoffrey A., Ciesla, Fred J., Lee, Jeong-Eun, Visser, Ruud   +5 more
core   +3 more sources

The Chemical Effects of Mutual Shielding in Photon Dominated Regions

, 2012
We investigate the importance of the shielding of chemical photorates by molecular hydrogen photodissociation lines and the carbon photoionization continuum deep within models of photon dominated regions. In particular, the photodissociation of N2 and CN
Rawlings, Jonathan M. C., Rollins, Richard P.   +1 more
core   +1 more source