[12Cii]  and [13C ii]  158μm emission from NGC 2024: Large column densities of ionized carbon

Graf, U. U.; Simon, R.; Stützki, J.; Colgan, Sean W. J.; Guan, Xin; Güsten, R.; Hartogh, P.; Honingh, C. E.; Hübers, Heinz‐Wilhelm

doi:10.1051/0004-6361/201218930

Cited by 50 publications

(40 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Even though [C ii] emission is seen, it is faint and there is no enhancement in the emission at the position of the southern C91α peak. (Cooksy et al 1986;Graf et al 2012;Ossenkopf et al 2013). Although the short integration times did not allow a clear detection of the [ 13 C ii] F = 2−1 line in individual GREAT spectra, the F = 2−1 transition is definitely present even in the average of all spectra in the map cube.…”

Section: The Origin Of [Cii] and C91α Emissionmentioning

confidence: 91%

High spectral and spatial resolution observations of the PDR emission in the NGC 2023 reflection nebula with SOFIA and APEX

Sandell¹,

Mookerjea²,

Güsten³

et al. 2015

A&A

Self Cite

View full text Add to dashboard Cite

We have mapped the NGC 2023 reflection nebula in [C ii] and CO(11−10) with the heterodyne receiver GREAT on SOFIA and obtained slightly smaller maps in 13 CO(3−2), CO(3−2), CO(4−3), CO(6−5), and CO(7−6) with APEX in Chile. We use these data to probe the morphology, kinematics, and physical conditions of the C ii region, which is ionized by FUV radiation from the B2 star HD 37903. The [C ii] emission traces an ellipsoidal shell-like region at a position angle of ∼−50• , and is surrounded by a hot molecular shell. In the southeast, where the C ii region expands into a dense, clumpy molecular cloud ridge, we see narrow and strong line emission from high-J CO lines, which comes from a thin, hot molecular shell surrounding the [C ii] emission. The [C ii] lines are broader and show photo evaporating gas flowing into the C ii region. Based on the strength of the [ 13 C ii] F = 2−1 line, the [C ii] line appears to be somewhat optically thick over most of the nebula with an optical depth of a few. We model the physical conditions of the surrounding molecular cloud and the PDR emission using both RADEX and simple PDR models. The temperature of the CO emitting PDR shell is ∼90−120 K, with densities of 10 5 −10 6 cm −3 , as deduced from RADEX modeling. Our PDR modeling indicates that the PDR layer where [C ii] emission dominates has somewhat lower densities, 104 to a few times 10 5 cm −3 .

show abstract

Section: The Origin Of [Cii] and C91α Emissionmentioning

confidence: 91%

High spectral and spatial resolution observations of the PDR emission in the NGC 2023 reflection nebula with SOFIA and APEX

Sandell¹,

Mookerjea²,

Güsten³

et al. 2015

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…Ossenkopf et al 2013) and SOFIA (e.g. Graf et al 2012), were mostly limited to hot and dense photon-dominated regions (PDRs) associated with massive star-forming regions. Far-infrared dust continuum emission has been widely used as a mass tracer of the ISM, and several high-resolution, largescale, sensitive maps of the Galactic plane exist (Carey et al 2009;Molinari et al 2010).…”

Section: Introductionmentioning

confidence: 99%

AHerschel[C ii] Galactic plane survey

Pineda

Langer

Velusamy

et al. 2013

A&A

338

497

View full text Add to dashboard Cite

Context. The [C ii] 158 μm line is an important tool for understanding the life cycle of interstellar matter. Ionized carbon is present in a variety of phases of the interstellar medium (ISM), including the diffuse ionized medium, warm and cold atomic clouds, clouds in transition from atomic to molecular, and dense and warm photon dominated regions.Aims. Velocity-resolved observations of [C ii] are the most powerful technique available to disentangle the emission produced by these components. These observations can also be used to trace CO-dark H 2 gas and determine the total mass of the ISM.Methods. The Galactic Observations of Terahertz C+ (GOT C+) project surveys the [C ii] 158 μm line over the entire Galactic disk with velocity-resolved observations using the Herschel/HIFI instrument. We present the first longitude-velocity maps of the [C ii] emission for Galactic latitudes b = 0• , ±0.5• , and ±1.0• . We combine these maps with those of H i, 12 CO, and 13 CO to separate the different phases of the ISM and study their properties and distribution in the Galactic plane.Results. [C ii] emission is mostly associated with spiral arms, mainly emerging from Galactocentric distances between 4 and 10 kpc.It traces the envelopes of evolved clouds as well as clouds that are in the transition between atomic and molecular. We estimate that most of the observed [C ii] emission is produced by dense photon dominated regions (∼47%), with smaller contributions from COdark H 2 gas (∼28%), cold atomic gas (∼21%), and ionized gas (∼4%). Atomic gas inside the Solar radius is mostly in the form of cold neutral medium (CNM), while the warm neutral medium gas dominates the outer galaxy. The average fraction of CNM relative to total atomic gas is ∼43%. We find that the warm and diffuse CO-dark H 2 is distributed over a larger range of Galactocentric distances (4−11 kpc) than the cold and dense H 2 gas traced by 12 CO and 13 CO (4−8 kpc). The fraction of CO-dark H 2 to total H 2 increases with Galactocentric distance, ranging from ∼20% at 4 kpc to ∼80% at 10 kpc. On average, CO-dark H 2 accounts for ∼30% of the molecular mass of the Milky Way. When the CO-dark H 2 component is included, the radial distribution of the CO-to-H 2 conversion factor is steeper than that when only molecular gas traced by CO is considered. Most of the observed [C ii] emission emerging from dense photon dominated regions is associated with modest far-ultraviolet fields in the range χ 0 1−30.

show abstract

“…Such self-absorption is seen toward the galactic center and in the Galactic star formation region M17 (Boreiko & Betz 1997;Graf et al 2012). This hypothesis seems to be supported by the correlation between a spatially compact mid-IR dust distribution and a suppressed [C II]/FIR ratio, seen for luminous infrared galaxies by Díaz-Santos et al (2013).…”

Section: Discussionmentioning

confidence: 71%

HERSCHEL EXTREME LENSING LINE OBSERVATIONS: [C ii] VARIATIONS IN GALAXIES AT REDSHIFTS z = 1–3*

Malhotra

Rhoads

Finkelstein

et al. 2017

ApJ

View full text Add to dashboard Cite

We observed the [C II] line in 15 lensed galaxies at redshifts 1<z<3 using HIFI on the Herschel Space Observatory and detected 14/15 galaxies at 3σ or better. High magnifications enable even modestly luminous galaxies to be detected in [C II] with Herschel. The [C II] luminosity in this sample ranges from 8 × 107 L e to 3.7 × 10 9 L e (after correcting for magnification), confirming that [C II] is a strong tracer of the ISM at high redshifts. The ratio of the [C II] line to the total far-infrared (FIR) luminosity serves as a measure of the ratio of gas to dust cooling and thus the efficiency of the grain photoelectric heating process. It varies between 3.3% and 0.09%. We compare the [C II]/FIR ratio to that of galaxies at z=0 and at high redshifts and find that they follow similar trends. The [C II]/FIR ratio is lower for galaxies with higher dust temperatures. This is best explained if increased UV intensity leads to higher FIR luminosity and dust temperatures, but gas heating does not rise due to lower photoelectric heating efficiency. The [C II]/FIR ratio shows weaker correlation with FIR luminosity. At low redshifts highly luminous galaxies tend to have warm dust, so the effects of dust temperature and luminosity are degenerate. Luminous galaxies at high redshifts show a range of dust temperatures, showing that [C II]/FIR correlates most strongly with dust temperature. The [C II] to mid-IR ratio for the HELLO sample is similar to the values seen for low-redshift galaxies, indicating that small grains and PAHs dominate the heating in the neutral ISM, although some of the high [CII]/FIR ratios may be due to turbulent heating.

show abstract

[¹²Cii] and [¹³C ii] 158μm emission from NGC 2024: Large column densities of ionized carbon

Cited by 50 publications

References 20 publications

High spectral and spatial resolution observations of the PDR emission in the NGC 2023 reflection nebula with SOFIA and APEX

High spectral and spatial resolution observations of the PDR emission in the NGC 2023 reflection nebula with SOFIA and APEX

AHerschel[C ii] Galactic plane survey

HERSCHEL EXTREME LENSING LINE OBSERVATIONS: [C ii] VARIATIONS IN GALAXIES AT REDSHIFTS z = 1–3*

Contact Info

Product

Resources

About