J/A+A/612/A36 G346.056-0.021 and G346.077-0.056 radio images (Das+, 2018)
Radio and infrared study of southern H II regions G346.056-0.021 and
G346.077-0.056.
Das S.R., Tej A., Vig S., Liu T., Ghosh S.K., Chandra C.H.I.
<Astron. Astrophys. 612, A36 (2018)>
=2018A&A...612A..36D 2018A&A...612A..36D (SIMBAD/NED BibCode)
ADC_Keywords: H II regions ; Radio sources ; Radio continuum
Keywords: infrared: ISM - radio continuum: ISM - ISM: H II regions -
ISM: individual objects: G346.056-0.021 -
ISM: individual objects: G346.077-0.056
Abstract:
We present a multiwavelength study of two southern Galactic H II
regions G346.056-0.021 and G346.077-0.056 which are located at a
distance of 10.9kpc. The distribution of ionized gas, cold and warm
dust, and the stellar population associated with the two H II regions
are studied in detail using measurements at near-infrared,
mid-infrared, far-infrared, submillimeter and radio wavelengths.
The radio continuum maps at 1280 and 610MHz were obtained using the
Giant Metrewave Radio Telescope to probe the ionized gas. The dust
temperature, column density, and dust emissivity maps were generated
using modified blackbody fits in the far-infrared wavelength range
160-500um. Various near- and mid-infrared color and magnitude criteria
were adopted to identify candidate ionizing star(s) and the population
of young stellar objects in the associated field.
The radio maps reveal the presence of diffuse ionized emission
displaying distinct cometary morphologies. The 1280MHz flux densities
translate to ZAMS spectral types in the range O7.5V-O7V and O8.5V-O8V
for the ionizing stars of G346.056-0.021 and G346.077-0.056,
respectively. A few promising candidate ionizing star(s) are
identified using near-infrared photometric data. The column density
map shows the presence of a large, dense dust clump enveloping
G346.077-0.056. The dust temperature map shows peaks towards the two
HII regions. The submillimeter image shows the presence of two
additional clumps, one being associated with G346.056-0.021. The
masses of the clumps are estimated to range between ∼1400 and
15250M☉. Based on simple analytic calculations and the
correlation seen between the ionized gas distribution and the local
density structure, the observed cometary morphology in the radio maps
is better explained invoking the champagne-flow model.
Description:
To probe the ionized emission associated with the HII regions, radio
continuum mapping was carried out at 610 and 1280MHz using the Giant
Metrewave Radio Telescope (GMRT), Pune India.
The continuum observations were carried out at 610 and 1280MHz with a
bandwidth of 32MHz.
For any clarification kindly contact :
swagat.12(at)iist.ac.in / dasswagat77(at)gmail.com
Objects:
----------------------------------------------------------------
RA (2000) DE Designation(s)
----------------------------------------------------------------
17 07 54.1 -40 31 36 G346.077-0.056 = HRDS G346.077-0.056
17 07 40.5 -40 31 38 G346.056-0.021 = HRDS G346.056-0.021
----------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 169 4 List of fits images
fits/* . 4 Individual fits images
--------------------------------------------------------------------------------
Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 23 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 39 A10 "date" Obs.date Observation date
41- 47 F7.2 MHz Freq Observed frequency
49- 53 I5 Kibyte size Size of FITS file
55- 75 A21 --- FileName Name of FITS file, in subdirectory fits
77-169 A93 --- Title Title of the FITS file
--------------------------------------------------------------------------------
Acknowledgements:
Swagat Ranjan Das, swagat.12(at)iist.ac.in
(End) Patricia Vannier [CDS] 19-Feb-2018