2011A&A...526A..52M


C.D.S. - SIMBAD4 rel 1.7 - 2020.07.10CEST03:03:43

2011A&A...526A..52M - Astronomy and Astrophysics, volume 526A, 52-52 (2011/2-1)

Polycyclic aromatic hydrocarbon processing by cosmic rays.

MICELOTTA E.R., JONES A.P. and TIELENS A.G.G.M.

Abstract (from CDS):

Cosmic rays are present in almost all phases of the ISM. Polycyclic aromatic hydrocarbons (PAHs) and cosmic rays represent an abundant and ubiquitous component of the interstellar medium. However, the interaction between them has never before been fully investigated. To study the effects of cosmic ray ion (H, He, CNO and Fe-Co-Ni) and electron bombardment of PAHs in galactic and extragalactic environments. We calculate the nuclear and electronic interactions for collisions between PAHs and cosmic ray ions and electrons with energies between 5 MeV/nucleon and 10 GeV, above the threshold for carbon atom loss, in normal galaxies, starburst galaxies and cooling flow galaxy clusters. The timescale for PAH destruction by cosmic ray ions depends on the electronic excitation energy E0 and on the amount of energy available for dissociation. Small PAHs are destroyed faster, with He and the CNO group being the more effective projectiles. For electron collisions, the lifetime is independent of the PAH size and varies with the threshold energy T0. Cosmic rays process the PAHs in diffuse clouds, where the destruction due to interstellar shocks is less efficient. In the hot gas filling galactic halos, outflows of starburst galaxies and intra-cluster medium, PAH destruction is dominated by collisions with thermal ions and electrons, but this mechanism is ineffective if the molecules are in denser cloudlets and isolated from the hot gas. Cosmic rays can access the denser clouds and together with X-rays will set the lifetime of those protected PAHs. This limits the use of PAHs as a ``dye'' for tracing the presence of cold entrained material.

Abstract Copyright:

Journal keyword(s): dust, extinction - cosmic rays - galaxies: halos - galaxies: starburst - ISM: jets and outflows - intergalactic medium

Simbad objects: 12

goto Full paper

goto View the reference in ADS

Number of rows : 12

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 ACO 85 ClG 00 41 37.8 -09 20 33           ~ 789 0
2 NGC 253 SyG 00 47 33.134 -25 17 19.68   8.03   6.94 8.1 ~ 2931 2
3 NGC 891 H2G 02 22 32.907 +42 20 53.95 11.08 10.81 9.93 7.86   ~ 1521 2
4 RAFGL 618 pA* 04 42 53.6245215366 +36 06 53.397219192   16.32   12.59   C-rich 954 0
5 NAME LMC G 05 23 34.6 -69 45 22     0.4     ~ 14832 1
6 SNR J052501-693842 SNR 05 25 02.20 -69 38 39.0           ~ 350 1
7 M 82 IG 09 55 52.430 +69 40 46.93 9.61 9.30 8.41     ~ 5336 6
8 NAME Vir I ClG 12 26 32.1 +12 43 24   10.00 8.49     ~ 5825 0
9 NGC 5529 GiP 14 15 34.226 +36 13 37.12   12.9       ~ 140 2
10 NGC 5906 GiG 15 15 53.687 +56 19 43.86   11.4       ~ 677 1
11 NAME Gal Center reg 17 45 40.04 -29 00 28.1           ~ 11540 0
12 NAME SDG G 18 55 03.1 -30 28 42   4.5 3.6     ~ 1738 2

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2011A&A...526A..52M and select 'bookmark this link' or equivalent in the popup menu


2020.07.10-03:03:43

© Université de Strasbourg/CNRS

    • Contact