J/other/PASA/33.20 MWA Survey of Galactic HII regions (Hindson+, 2016)
A large scale, low frequency Murchison Widefield Array Survey of Galactic HII
regions between 260 < l < 340.
Hindson L., Johnston-Hollitt M., Hurley-Walker N., Callingham J.R., Su H.,
Morgan J., Bell M., Bernardi G., Bowman J.D., Briggs F., Cappallo R.J.,
Deshpande A.A., Dwarakanath K.S., For B.-Q, Gaensler B.M., Greenhill L.J.,
Hancock P., Hazelton B.J., Kapin A.D., Kaplan D.L., Lenc E., Lonsdale C.J.,
Mckinley B., McWhirter S.R., Mitchell D.A., Morales M.F., Morgan E.,
Oberoi D., Offringa A., Ord S.M., Procopio P., Prabu T., Udaya Shankar N.,
Srivani K.S., Staveley-Smith L., Subrahmanyan R., Tingay S.J., Wayth R.B.,
Webster R.L., Williams A., Williams C.L., Wu C., Zheng Q.
<Publ. Astron. Soc. Australia, 33, 20 (2016)>
=2016PASA...33...20H 2016PASA...33...20H (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; H II regions ; Radio continuum
Keywords: catalogs - (ISM:) HII regions - radio continuum: ISM
Abstract:
We have compiled a catalogue of HII regions detected with the
Murchison Widefield Array between 72 and 231MHz. The multiple
frequency bands provided by the Murchison Widefield Array allow us
identify the characteristic spectrum generated by the thermal
Bremsstrahlung process in HII regions. We detect 306 HII regions
between 260°<l<340° and report on the positions, sizes,
peak, integrated flux density, and spectral indices of these HII
regions. By identifying the point at which HII regions transition from
the optically thin to thick regime, we derive the physical properties
including the electron density, ionised gas mass, and ionising photon
flux, towards 61 HII regions. This catalogue of HII regions represents
the most extensive and uniform low frequency survey of HII regions in
the Galaxy to date.
Description:
We use observations that utilise the MWA interferometer, which is the
low frequency precursor for the Square Kilometre Array (SKA), located
at the Murchison Radio-astronomy Observatory in Western Australia.
The observations presented in this study were obtained as part of the
GLEAM survey (Wayth et al., 2015PASA...32...25W 2015PASA...32...25W).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
mwahii.dat 177 302 MWA HII regions (table 2)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: mwahii.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Name Source Name, GLLL.II+BB.bb, peak location
14- 19 F6.2 deg GLON Right ascension (Galactic), ellipse centre
21- 25 F5.2 deg GLAT Declination (Galactic), ellipse centre
27- 32 F6.2 deg PA Position angle
34- 37 F4.2 deg Lx Ellipse major axis
39- 42 F4.2 deg Ly Ellipse minor axis
44- 47 F4.1 Jy Sp88 Peak flux at 88MHz in Jy/Beam
49- 51 F3.1 Jy e_Sp88 Error on peak flux at 88MHz in Jy/Beam
53- 56 F4.1 Jy Sp118 Peak flux at 118MHz in Jy/Beam
58- 60 F3.1 Jy e_Sp118 Error on peak flux at 118MHz in Jy/Beam
62- 65 F4.1 Jy Sp154 Peak flux at 154MHz in Jy/Beam
67- 69 F3.1 Jy e_Sp154 Error on peak flux at 154MHz in Jy/Beam
71- 74 F4.1 Jy Sp185 Peak flux at 185MHz in Jy/Beam
76- 78 F3.1 Jy e_Sp185 Error on peak flux at 185MHz in Jy/Beam
80- 83 F4.1 Jy Sp216 Peak flux at 216MHz in Jy/Beam
85- 87 F3.1 Jy e_Sp216 Error on peak flux at 216MHz in Jy/Beam
89- 93 F5.1 Jy Si88 Integrated flux at 88MHz
95- 98 F4.1 Jy e_Si88 Error on Integrated flux at 88MHz
100-104 F5.1 Jy Si118 Integrated flux at 118MHz
106-110 F5.1 Jy e_Si118 Error on Integrated flux at 118MHz
112-116 F5.1 Jy Si154 Integrated flux at 154MHz
118-122 F5.1 Jy e_Si154 Error on Integrated flux at 154MHz
124-128 F5.1 Jy Si185 Integrated flux at 185MHz
130-134 F5.1 Jy e_Si185 Error on Integrated flux at 185MHz
136-141 F6.1 Jy Si216 Integrated flux at 216MHz
143-147 F5.1 Jy e_Si216 Error on Integrated flux at 216MHz
149-153 F5.1 Jy Si843 ?=- Integrated flux at 843MHz
155-158 F4.1 Jy e_Si843 ?=- Error on Integrated flux at 843MHz
160-164 F5.1 Jy Si1400 ?=- Integrated flux at 1400MHz
166-169 F4.1 Jy e_Si1400 ?=- Error on Integrated flux at 1400MHz
171-173 F3.1 --- Sp+Index ?=- Spectral index alpha,
Sν=a*να
175-177 F3.1 --- e_Sp+Index ?=- Error on spectral index
--------------------------------------------------------------------------------
Acknowledgements:
Luke Hindson, l.hindson3(at)herts.ac.uk
(End) Luke Hindson [Univ. of Hertfordshire], Patricia Vannier [CDS] 03-Jun-2016