Galactic fine-structure lines - Morphologies of the warm ionized interstellar medium

1993 ◽  
Vol 405 ◽  
pp. 591 ◽  
Author(s):  
S. J. Petuchowski ◽  
C. L. Bennett
Keyword(s):  
Fine Structure ◽  
Interstellar Medium ◽  
Fine Structure Lines

scholarly journals A dense, solar metallicity ISM in the z = 4.2 dusty star-forming galaxy SPT 0418−47

2019 ◽  
Vol 631 ◽  
pp. A167 ◽  
Author(s):  
Carlos De Breuck ◽  
Axel Weiß ◽  
Matthieu Béthermin ◽  
Daniel Cunningham ◽  
Yordanka Apostolovski ◽  
...  
Keyword(s):  
Fine Structure ◽  
Interstellar Medium ◽  
Far Infrared ◽  
Line Ratio ◽  
Star Forming ◽  
Physical Conditions ◽  
Solar Metallicity ◽  
Fine Structure Lines ◽  
Compact Array

We present a study of six far-infrared fine structure lines in the z = 4.225 lensed dusty star-forming galaxy SPT 0418−47 to probe the physical conditions of its interstellar medium (ISM). In particular, we report Atacama Pathfinder EXperiment (APEX) detections of the [OI] 145 μm and [OIII] 88 μm lines and Atacama Compact Array (ACA) detections of the [NII] 122 and 205 μm lines. The [OI] 145 μm/[CII] 158 μm line ratio is ∼5× higher compared to the average of local galaxies. We interpret this as evidence that the ISM is dominated by photo-dissociation regions with high gas densities. The line ratios, and in particular those of [OIII] 88 μm and [NII] 122 μm imply that the ISM in SPT 0418−47 is already chemically enriched to nearly solar metallicity. While the strong gravitational amplification was required to detect these lines with APEX, larger samples can be observed with the Atacama Large Millimeter/submillimeter Array (ALMA), and should allow observers to determine if the dense, solar metallicity ISM is common among these highly star-forming galaxies.

scholarly journals AGN Spectra as Seen by the Infrared Space Observatory: First Results

1997 ◽  
Vol 159 ◽  
pp. 333-336
Author(s):  
D. Lutz ◽  
R. Genzel ◽  
E. Sturm ◽  
A.F.M. Moorwood ◽  
E. Oliva ◽  
...  
Keyword(s):  
Fine Structure ◽  
Short Wavelength ◽  
Molecular Hydrogen ◽  
Molecular Gas ◽  
Space Observatory ◽  
Infrared Space Observatory ◽  
First Results ◽  
External Galaxies ◽  
First Time ◽  
Fine Structure Lines

AbstractWe discuss 2.5–45 µm spectra of the Circinus galaxy and of Cen A, obtained with the Short Wavelength Spectrometer (SWS) on board the Infrared Space Observatory. The large number of detected ionic fine structure lines, observable also in visually obscured sources, provides strong constraints on the shape of the ionizing spectrum, which is found to exhibit a UV bump peaking at ~ 70 eV in the case of Circinus. Pure rotational emission of molecular hydrogen, directly probing warm molecular gas, can for the first time be detected in external galaxies.

scholarly journals The prospects for observing [O iii] 52 micron emission from galaxies during the Epoch of Reionization

2021 ◽  
Vol 504 (1) ◽  
pp. 723-730
Author(s):  
Shengqi Yang ◽  
Adam Lidz ◽  
Gergö Popping
Keyword(s):  
Fine Structure ◽  
Interstellar Medium ◽  
Emission Line ◽  
Parameter Space ◽  
Gas Density ◽  
Star Forming ◽  
Upper Limits ◽  
Redshift Galaxies

ABSTRACT The [O iii] 88 $\mu$m fine-structure emission line has been detected into the Epoch of Reionization (EoR) from star-forming galaxies at redshifts 6 < z ≲ 9 with ALMA. These measurements provide valuable information regarding the properties of the interstellar medium (ISM) in the highest redshift galaxies discovered thus far. The [O iii] 88 $\mu$m line observations leave, however, a degeneracy between the gas density and metallicity in these systems. Here, we quantify the prospects for breaking this degeneracy using future ALMA observations of the [O iii] 52 $\mu$m line. Among the current set of 10 [O iii] 88 $\mu$m emitters at 6 < z ≲ 9, we forecast 52 $\mu$m detections (at 6σ) in SXDF-NB1006-2, B14-6566, J0217-0208, and J1211-0118 within on-source observing times of 2–10 h, provided their gas densities are larger than about nH ≳ 102–103 cm−3. Other targets generally require much longer integration times for a 6σ detection. Either successful detections of the 52 $\mu$m line or reliable upper limits will lead to significantly tighter constraints on ISM parameters. The forecasted improvements are as large as ∼3 dex in gas density and ∼1 dex in metallicity for some regions of parameter space. We suggest SXDF-NB1006-2 as a promising first target for 52 $\mu$m line measurements. We discuss how such measurements will help in understanding the mass–metallicity relationship during the EoR.

Internal rotation of a light symmetric top relative to a heavy planar framework: theoretical calculations of vibration/internal-rotation spectra including effects of rotational barriers and non-degeneracy of perpendicular symmetric top vibrations

1969 ◽  
Vol 313 (1513) ◽  
pp. 149-167 ◽  
Keyword(s):  
Fine Structure ◽  
Internal Rotation ◽  
Theoretical Calculations ◽  
Site Symmetry ◽  
Frequency Range ◽  
Electronic Effects ◽  
Angular Variation ◽  
Band Contour ◽  
Lower Site ◽  
Fine Structure Lines

Model theoretical calculations have been made of the fine structure associated with the perpendicular vibrations of a ‘light’ symmetric top group (such as CH 3 , SiH 3 , etc.) resulting from its internal rotation with respect to an infinitely heavy planar framework. Investigations have been made of the effects on the internal rotational fine structure of the removal of the degeneracy of the perpendicular vibrations as required by the lower site symmetry. Separate calculations have been made for the cases where the removal of degeneracy is caused ( a ) by electronic effects which result in an angular variation of the appropriate force constant, or ( b ) by interaction with another vibration in the framework part of the molecule. It is found that no fine structure lines occur between the non-degenerate frequencies, but that the effect of internal rotation is to generate rotational wings outside this frequency range. The effects of a finite sixfold barrier to internal rotation on the vibrational/internal-rotational absorption band have been calculated for the degenerate and non-degenerate cases. It is shown that certain lines are split by amounts comparable to the barrier height, V 6 , which should therefore be experimentally obtainable from this type of spectrum in favourable cases. The effect of an increasing barrier is to cause more of the intensity within the overall band contour to occur in the vicinity of the vibrational frequency or frequencies, and less in the internal rotational wings, as expected on physical grounds.

Fine Structure Lines in HII Regions Interacting with Molecular Clouds

1982 ◽  
pp. 73-80 ◽  
Author(s):  
D. A. Naylor ◽  
R. Emery ◽  
B. Fitton ◽  
I. Furniss ◽  
R. E. Jennings ◽  
...  
Keyword(s):  
Fine Structure ◽  
Molecular Clouds ◽  
Hii Regions ◽  
Fine Structure Lines

scholarly journals Rotational Fine Structure Lines of Interstellar C2 Toward ζ Persei

1980 ◽  
Vol 87 ◽  
pp. 263-267
Author(s):  
Frederic H. Chaffee ◽  
Barry L. Lutz ◽  
John H. Black ◽  
Paul A. Vanden Bout ◽  
Ronald L. Snell
Keyword(s):  
Fine Structure ◽  
Thermal Equilibrium ◽  
Column Density ◽  
Rotational Temperature ◽  
Detailed Model ◽  
Data Yield ◽  
Fine Structure Lines

We have detected 9 of the rotational fine structure lines of the 2-0 Phillips band of interstellar C2 toward ζ Persei using the Tull spectrograph and Reticon detector on the 2.7 m telescope at the McDonald Observatory. These data yield a total C2 column density of 1.2 × 1013 cm-2 and a rotational temperature of 97 K compared to 1.4 × 1013 cm-2 and 45 K predicted by the detailed model of the cloud by Black, Hartquist and Dalgarno. We suggest that radiative pumping through the Mulliken and Phillips systems has modified the C2 level populations in such a way as to produce an observed rotational temperature which exceeds that arising in pure thermal equilibrium.

Sign in / Sign up

Export Citation Format

Share Document