J/ApJ/739/100 [NII] observations of the Carina Nebula (NGC 3372) (Oberst+, 2011)
A 205 µm [N II] map of the Carina Nebula.
Oberst T.E., Parshley S.C., Nikola T., Stacey G.J., Lohr A., Lane A.P.,
Stark A.A., Kamenetzky J.
<Astrophys. J., 739, 100 (2011)>
=2011ApJ...739..100O 2011ApJ...739..100O
ADC_Keywords: Interstellar medium ; Spectra, infrared ; Molecular clouds ;
Spectra, millimetric/submm
Keywords: H II regions - infrared: ISM - photon-dominated region (PDR) -
ISM: individual objects (Carina Nebula) - ISM: lines and bands -
submillimeter: ISM
Abstract:
We present the results of a ∼250arcmin2 mapping of the 205um [NII]
fine-structure emission over the northern Carina Nebula, including the
Car I and Car II HII regions. Spectra were obtained using the South
Pole Imaging Fabry-Perot Interferometer (SPIFI) at the Antarctic
Submillimeter Telescope and Remote Observatory (AST/RO) at the South
Pole. We supplement the 205um data with new reductions of far-IR
fine-structure spectra from the Infrared Space Observatory (ISO) Long
Wavelength Spectrometer (LWS) in 63um [OI], 122um [NII], 146um [OI],
and 158um [CII]; the 146um [OI] data include 90 raster positions which
have not been previously published. Morphological comparisons are made
with optical, radio continuum, and CO maps. The 122/205 line ratio is
used to probe the density of the low-ionization gas, and the 158/205
line ratio is used to probe the fraction of C+ arising from
photodissociation regions (PDRs). The [OI] and [CII] lines are used to
construct a PDR model of Carina. When the PDR properties are compared
with other sources, Carina is found to be more akin to 30 Doradus than
galactic star-forming regions such as Orion, M17, or W49; this is
consistent with the view of Carina as a more evolved region, where
much of the parent molecular cloud has been ionized or swept away.
These data constitute the first ground-based detection of the 205um
[NII] line, and the third detection overall since those of COBE FIRAS
and the Kuiper Airborne Observatory in the early 1990s.
Description:
The South Pole Imaging Fabry-Perot Interferometer (SPIFI) observed
spectra containing the [NII] 205um line in the Carina Nebula during 15
days (August 15-30) of the 2005 Polar winter, as previously reported
in Oberst et al. (2006ApJ...652L.125O 2006ApJ...652L.125O).
The Long Wavelength Spectrometer (LWS) aboard the Infrared Satellite
Observatory (ISO) was used to obtain full bandwidth (43-197um) spectra
of the Carina Nebula over four days - 1996 July 23 and 24 and August 1
and 4 - as part of a guaranteed time observation (GTO) by T. Onaka.
Objects:
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RA (2000) DE Designation(s)
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10 44 19.0 -59 53 21 Carina Nebula = NGC 3372
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 31 236 SPIFI 205um [NII] line intensities
table4.dat 60 104 ISO observations of the Carina Nebula
table5.dat 34 27 *Density of the ionized medium
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Note on table5.dat: This table lists density values derived from the 122/205
line intensity ratio (Section 4.2) and which are plotted in Figure 13.
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See also:
J/MNRAS/406/952 : Spitzer Catalogue of the Carina Nebula (Smith+, 2010)
J/ApJ/667/963 : Near-infrared photometry of Carina nebula (Sanchawala+, 2007)
J/MNRAS/367/513 : JHKs[3.5][4.5] photometry of NGC 3372 (Tapia+, 2006)
J/A+A/423/579 : Diffuse emissions in Carina nebula (Mizutani+, 2004)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Raster beam (1)
5- 12 F8.4 deg GLON Galactic longitude (1)
14- 20 F7.4 deg GLAT Galactic latitude (1)
22 A1 --- l_Int Limit flag on int (2)
23- 26 F4.1 10-8W/m2/sr Int ? Line intensity (2)
28- 31 F4.1 10-8W/m2/sr e_Int ? Int uncertainty (2)
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Note (1): Raster points and coordinates correspond to the SPIFI (South Pole
Pole Imaging Fabry-Perot Interferometer) 54" beam positions shown in Figure 2.
Note (2): For spectra with χ2 fits of S/N≲3, theoretical upper limits
to intensity are given (see the text for more details). Intensity errors
do not include the SPIFI absolute calibration error of 26%. In a few
rare cases, no intensity (or upper limit) is reported, indicating that
only the nonfunctional SPIFI array pixels observed that position.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Beam Raster beam
10- 16 F7.3 deg GLON Galactic longitude (1)
18- 23 F6.3 deg GLAT Galactic latitude (1)
25- 29 F5.1 10-8W/m2/sr OI63 OI (63um) line intensity
31- 33 F3.1 10-8W/m2/sr e_OI63 OI63 uncertainty (2)
35- 38 F4.1 10-8W/m2/sr NII122 NII (122um) line intensity
40- 42 F3.1 10-8W/m2/sr e_NII122 NII122 uncertainty (2)
44- 46 F3.1 10-8W/m2/sr OI146 OI (146um) line intensity
48- 50 F3.1 10-8W/m2/sr e_OI146 OI146 uncertainty (2)
52- 56 F5.1 10-8W/m2/sr CII158 CII (158um) line intensity
58- 60 F3.1 10-8W/m2/sr e_CII158 CII158 uncertainty (2)
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Note (1): Coordinates refer to the center positions of the ISO beam, as
shown in the raster map in Figure 2.
Note (2): Intensity errors do not include the ISO absolute calibration
error of ∼20%.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Beam Raster beam (1)
10- 16 F7.3 deg GLON Galactic longitude
18- 23 F6.3 deg GLAT Galactic latitude
25- 27 I3 cm-3 ne Electron density ne
29- 30 I2 cm-3 e_ne ? Lower 1σ error on ne (2)
32- 34 I3 cm-3 E_ne ? Upper 1σ error on ne (2)
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Note (1): The raster beam numbering notation matches that of Table 4, but
includes only the 27 ISO raster positions overlapped by one or more
SPIFI raster positions (i.e., only positions at which the 122/205
ratio could be computed).
Note (2): Upper and lower (1σ) errors are provided when they are
constrained. For example, in the first row of the present table,
ne=39cm-3 is the best-fit value plotted in Figure 13, while the
lower error bar would be (unconstrained) at 0cm-3 and the upper
error bar would be at 127cm-3 (error bars are omitted in the
figure for clarity).
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 28-Feb-2013