J/other/AstBu/78.372 Near infrared view on PDRs (Kirsanova+, 2023)
Near infrared view on the photodissociation regions S255, S257, NGC7538
and S140.
Kirsanova M.S., Tatarnikov A.M., Boley P.A., Vibe D.A., Maclennikova N.A.,
Tatarnikov A.A.
<Astrophys. Bull., 78, 372-383 (2023)>
=2023AstBu..78..372K 2023AstBu..78..372K (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, IR ; H II regions ; Interstellar medium ; Abundances
Keywords: galaxies: abundances, galaxies: individual: ISM
Abstract:
We performed photometric observations of the S255, S257,
S140, NGC7358 and the Orion Bar photo-dissociation regions (PDRs) at
2 micron using narrow-band filters centered on the Br-gamma, H2 and
[FeII] lines, as well as the narrow-band Kcont and the broad-band H
filters for continuum subtraction. The observations were done with the
2.5-m telescope of the SAI Caucasian Mountain Observatory and the
near-infrared camera and spectrograph ASTRONIRCAM. We find several
high-density arc-like structures in the Br-gamma and [FeII] images of
the ionized gas in NGC 7538 and extended shells and arcs visible
through the H2 emission. The H ionization front and H2 dissociation
front are merged in NGC 7538. In S 255 and S 257 we detected only
Br-gamma emission from the H II regions and bright H2 emission from
the PDRs. The projected distance between the H ionization and H2
dissociation fronts are approx. 0.3-0.4pc, which cannot be
explained using models of a uniform medium. Most probably, the ionized
and neutral gas in these PDRs is clumpy. The H I-to-H2 transitions in
the NGC 7538, S 255, S 257 and S 140 PDRs are gradual with no sharp
borders. This conclusion also agrees with the suggestion of a clumpy
medium.
Description:
We present fits-files with the images of the PDRs at 2 micron using
narrow-band filters centered on the Br-gamma, H2 and [FeII] lines, as
well as the narrow-band Kcont and the broad-band H continuum filters.
Objects:
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RA (2000) DE Designation(s)
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23 13 37.20 +61 30 00.0 NGC 7538 = SH 2-158
05 35 22.30 -05 24 33.0 Orion Bar = NAME Ori Bar
22 19 07.79 +63 17 06.9 Sh2-140 = LBN 505
06 13 04.10 +17 58 43.9 Sh2-255 = IC 2162
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 113 33 List of fits images
fits/* . 33 Individual fits images
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 28 A9 --- Filter Narrow-band filter
30- 38 A9 ---- Name Target name
40- 44 F5.3 arcsec/pix scale Scale of the image
46- 48 I3 --- Nx Number of pixels along X-axis
50- 52 I3 --- Ny Number of pixels along Y-axis
54- 72 A19 "datime" Obs.date Observation date
74- 77 I4 Kibyte size Size of FITS file
79-113 A35 --- FileName Name of FITS file, in subdirectory fits
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Acknowledgements:
Maria Kirsanova, maria.kirsanova(at)gmail.com
(End) Patricia Vannier [CDS] 22-Aug-2023