2012A&A...542L..16G


C.D.S. - SIMBAD4 rel 1.7 - 2019.11.19CET10:24:30

2012A&A...542L..16G - Astronomy and Astrophysics, volume 542, L16-16 (2012/6-1)

[12CII] and [13CII] 158 µm emission from NGC 2024: large column densities of ionized carbon.

GRAF U.U., SIMON R., STUTZKI J., COLGAN S.W.J., GUAN X., GUESTEN R., HARTOGH P., HONINGH C.E. and HUEBERS H.-W.

Abstract (from CDS):

We analyze the NGC 2024 HII region and molecular cloud interface using [12CII] and [13CII] observations. We attempt to gain insight into the physical structure of the interface layer between the molecular cloud and the HII region. Observations of [12CII] and [13CII] emission at 158µm with high spatial and spectral resolution allow us to study the detailed structure of the ionization front and estimate the column densities and temperatures of the ionized carbon layer in the photon-dominated region. The [12CII] emission closely follows the distribution of the 8 µm continuum. Across most of the source, the spectral lines have two velocity peaks similar to lines of rare CO isotopes. The [13CII] emission is detected near the edge-on ionization front. It has only a single velocity component, which implies that the [12CII] line shape is caused by self-absorption. An anomalous hyperfine line-intensity ratio observed in [13CII] cannot yet be explained. Our analysis of the two isotopes results in a total column density of N(H)≃1.6x1023cm–2 in the gas emitting the [CII] line. A large fraction of this gas has to be at a temperature of several hundred K. The self-absorption is caused by a cooler (T≤100K) foreground component containing a column density of N(H)≃1022cm–2.

Abstract Copyright:

Journal keyword(s): ISM: atoms - ISM: clouds - ISM: individual objects: NGC 2024 - photon-dominated region (PDR)

Simbad objects: 9

goto Full paper

goto View the reference in ADS

Number of rows : 9

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 NAME Orion Bright Bar reg 05 35 22.30 -05 24 33.0           ~ 691 0
2 [MCK88] NGC 2024 FIR 2 Y*? 05 41 42.50 -01 54 06.0           ~ 38 0
3 NAME Ori B MoC 05 41 43.0 -01 54 44           ~ 1131 0
4 NGC 2024 Cl* 05 41 43 -01 50.5           ~ 1058 1
5 [MCK88] NGC 2024 FIR 4 Y*O 05 41 44.00 -01 54 42.0           ~ 54 0
6 [BCB89] IRS 3 pr* 05 41 44.429 -01 55 23.59           ~ 15 0
7 [MCK88] NGC 2024 FIR 5 cor 05 41 44.6 -01 55 38           ~ 91 0
8 [MCK88] NGC 2024 FIR 6 IR 05 41 45.00 -01 56 01.0           ~ 53 0
9 [BCB89] IRS 2 * 05 41 45.81 -01 54 29.8           B 90 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2012A&A...542L..16G and select 'bookmark this link' or equivalent in the popup menu


2019.11.19-10:24:30

© Université de Strasbourg/CNRS

    • Contact