J/MNRAS/447/2307 Galactic HII region IRAS 16148-5011 content (Mallick+, 2015)
Study of morphology and stellar content of the Galactic HII region
IRAS 16148-5011.
Mallick K.K., Ojha D.K., Tamura M., Linz H., Samal M.R., Ghosh S.K.
<Mon. Not. R. Astron. Soc., 447, 2307-2321 (2015)>
=2015MNRAS.447.2307M 2015MNRAS.447.2307M (SIMBAD/NED BibCode)
ADC_Keywords: H II regions ; Photometry, infrared ; Stars, masses
Keywords: stars: formation - dust, extinction - HII regions -
ISM: individual objects: IRAS 16148-5011 - infrared: ISM -
radio continuum: ISM
Abstract:
An investigation of the IRAS 16148-5011 region - a cluster at a
distance of 3.6kpc - is presented here, carried out using
multiwavelength data in near-infrared (NIR) from the 1.4m Infrared
Survey Facility telescope, mid-infrared (MIR) from the archival
Spitzer GLIMPSE (Galactic Legacy Infrared Midplane Survey
Extraordinaire) survey, far-infrared (FIR) from the Herschel archive,
and low-frequency radio continuum observations at 1280 and 843MHz from
the Giant Metrewave Radio Telescope and Molonglo Survey archive,
respectively. A combination of NIR and MIR data is used to identify 7
Class I and 133 Class II sources in the region. Spectral energy
distribution (SED) analysis of selected sources reveals a 9.6M☉
high-mass source embedded in nebulosity. However, Lyman continuum
luminosity calculation using radio emission - which shows a compact
HII region - indicates the spectral type of the ionizing source to be
earlier than B0-O9.5. Free-free emission SED modelling yields the
electron density as 138cm-3, and thus the mass of the ionized
hydrogen as ∼16.4M☉. Thermal dust emission modelling, using the
FIR data from Herschel and performing modified blackbody fits, helped
us construct the temperature and column density maps of the region,
which show peak values of 30K and 3.3x1022cm-2, respectively. The
column density maps reveal an AV>20mag extinction associated with
the nebular emission, and weak filamentary structures connecting dense
clumps. The clump associated with this IRAS object is found to have
dimensions of ∼1.1pcx0.8pc, and a mass of 1023M☉.
Description:
NIR photometric observations in J (1.25um), H (1.63um), and Ks
(2.14um) bands (centred on RA=16:18:31, DE=-50:17:32 (2000)) were
carried out on 2004 July 29 using the 1.4m Infrared Survey Facility
(IRSF) telescope, South Africa. The observations were taken with the
help of the Simultaneous InfraRed Imager for Unbiased Survey (SIRIUS)
instrument, a three colour simultaneous camera mounted at the f/10
Cassegrain focus of the telescope.
Radio continuum observations at 1280MHz were obtained on 2012
November 09 using the Giant Metrewave Radio Telescope (GMRT) array.
The GMRT array consists of 30 antennas arranged in an approximate
Y-shaped configuration, with each antenna having a diameter of 45m.
This translates to a primary beam-size of 26.2-arcmin at 1280MHz.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 122 140 YSOs identified using NIR and MIR data
table2.dat 120 28 Main parameters from SED analysis
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 F10.6 deg RAdeg Right ascension (J2000)
12- 21 F10.6 deg DEdeg Declination (J2000)
23- 28 F6.3 mag Jmag ?=- IRSF J magnitude
30- 34 F5.3 mag e_Jmag ?=- rms uncertainty on Jmag
36- 41 F6.3 mag Hmag ?=- IRSF H magnitude
43- 47 F5.3 mag e_Hmag ?=- rms uncertainty on Hmag
49- 54 F6.3 mag Ksmag ?=- IRSF Ks magnitude
56- 60 F5.3 mag e_Ksmag ?=- rms uncertainty on Ksmag
62- 67 F6.3 mag [3.6] ?=- IRAC 3.6um magnitude
69- 73 F5.3 mag e_[3.6] ?=- rms uncertainty on [3.6]
75- 80 F6.3 mag [4.5] ?=- IRAC 4.5um magnitude
82- 86 F5.3 mag e_[4.5] ?=- rms uncertainty on [4.5]
88- 93 F6.3 mag [5.8] ?=- IRAC 5.8um magnitude
95- 99 F5.3 mag e_[5.8] ?=- rms uncertainty on [5.8]
101-106 F6.3 mag [8.0] ?=- IRAC 8.0um magnitude
108-112 F5.3 mag e_[8.0] ?=- rms uncertainty on [8.0]
114-119 A6 --- YSO YSO Type (Class1 or Class2)
121-122 I2 --- Source [1/27]? Source sequential number in table2
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- Type [I E] Source type (1)
4- 5 I2 --- Source [1/28] Source sequential number
6- 8 A3 --- n_Source [abc, ] Note on Source (2)
10- 19 F10.6 deg RAdeg Right ascension (J2000)
21- 30 F10.6 deg DEdeg Declination (J2000)
32- 35 F4.2 [yr] logtau* Age of the central source
37- 40 F4.2 [yr] e_logtau* rms uncertainty on logtau*
42- 45 F4.2 [Msun] Mass Mass of the central source
47- 50 F4.2 [Msun] e_Mass rms uncertainty on Mass
52- 56 F5.2 [Msun] logMd ?=- Disc mass
58- 61 F4.2 [Msun] e_logMd ? rms uncertainty on logMd
63- 67 F5.2 [Msun/yr] logdMd/dt ?=- Disc accretion rate
69- 72 F4.2 [Msun/yr] e_logdMd/dt ? rms uncertainty on logdMd/dt
74- 78 F5.2 [Msun] logMenv ?=- Envelope mass
80- 83 F4.2 [Msun] e_logMenv ? rms uncertainty on logMenv
85- 88 F4.2 [K] logT* Temperature of the central source
90- 93 F4.2 [K] e_logT* ? rms uncertainty on logT*
95- 98 F4.2 [Lsun] logLtot Total system luminosity
100-103 F4.2 [Lsun] e_logLtot ? rms uncertainty on logLtot
105-109 F5.2 mag AV Interstellar visual extinction
111-114 F4.2 mag e_AV ? rms uncertainty on AV
116-120 F5.2 --- chi2min Minimum chi2 per data point
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Note (1): Source type as follows:
I = Class I sources
II = Class II sources
E = Extra central source
Note (2): Notes as follows:
a = Prominent sources associated with the central nebula
b = Did not have 8.0um photometry
c = Identified as 'G333.0494+00.0324B' (and also classified as a YSO) in
Lumsden et al. (2013, Cat. J/ApJS/208/11).
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 10-Nov-2015