J/MNRAS/461/2502 Multiwavelength study of HII region S311 (Yadav+, 2016)
A multiwavelength investigation of the H II region S311:
young stellar population and star formation.
Yadav R.K., Pandey A.K., Sharma S., Ojha D.K., Samal M.R., Mallick K.K.,
Jose J., Ogura K., Richichi A., Irawati P., Kobayashi N., Eswaraiah C.
<Mon. Not. R. Astron. Soc., 461, 2502-2518 (2016)>
=2016MNRAS.461.2502Y 2016MNRAS.461.2502Y (SIMBAD/NED BibCode)
ADC_Keywords: H II regions ; Photometry, UBVRI ; Photometry, infrared ;
Stars, masses
Keywords: stars: clusters - star clusters: individual: Haffner 18 -
stars: formation - stars: pre-main sequence - ISM: H II regions -
ISM: individual objects: S311
Abstract:
We present a multiwavelength investigation of the young stellar
population and star formation activities around the HII region
Sharpless 311. Using our deep near-infrared observations and archival
Spitzer-IRAC observations, we have detected a total of 125 young
stellar objects (YSOs) in an area of ∼86 arcmin2. The YSO sample
includes eight Class I and 117 Class II candidate YSOs. The mass
completeness of the identified YSO sample is estimated to be
1.0M☉. The ages and masses of the majority of the candidate YSOs
are estimated to be in the range ∼0.1-5Myr and ∼0.3-6M☉,
respectively. The 8um image of S311 displays an approximately
spherical cavity around the ionizing source, which was possibly
created by the expansion of the H ii region. The spatial distribution
of the candidate YSOs reveals that a significant number of them are
distributed systematically along the 8-µm emission with a majority
clustered around the eastern border of the HII region. Four
clumps/compact HII regions are detected in the radio continuum
observations at 1280MHz, which may have been formed during the
expansion of the HII region. The estimated dynamical age of the
region, main-sequence lifetime of the ionizing source, the spatial
distribution and ages of the candidate YSOs indicate triggered star
formation in the complex.
Description:
We observed the HII region S311 (centred on RA(2000)=07:52:24,
DE(2000)=-26:24:58.40) in NIR broad-bands J (1.25um), H (1.63um) and
Ks (2.14um) on 2010 March 3 using the Infrared Side Port Imager (ISPI)
camera mounted on the CTIO Blanco 4-m telescope.
We consider only those sources having error <0.1mag in all three
bands, resulting in a final catalogue of 2671 point sources.
The Spitzer-IRAC observations for the S311 region (PID 20726) were
made on 2006 May 3 using the 3.6, 4.5, 5.8 and 8.0um bands and were
downloaded from the Spitzer heritage archive (SHA).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 73 2671 JHKs photometric data of stars in the S311 region
table2.dat 171 125 Photometric data of candidate YSOs identified by
using different schemes discussed in Section 4.1
table4.dat 90 16 Inferred physical parameters from SED fits to 16
of 125 candidate YSOs
table5.dat 74 55 Ages and masses of the candidate YSOs
from V/(V-I) CMDs
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See also:
J/MNRAS/362/301 : Spectrophotometry of HII region S311 (Garcia-Rojas+, 2005)
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 J-H J-H colour index
30- 34 F5.3 mag e_J-H rms uncertainty on J-H
36- 41 F6.3 mag H-Ks H-Ks colour index
43- 47 F5.3 mag e_H-Ks rms uncertainty on H-Ks
49- 54 F6.3 mag J-Ks J-Ks colour index
56- 60 F5.3 mag e_J-Ks rms uncertainty on J-Ks
62- 67 F6.3 mag Ksmag Ks magnitude
69- 73 F5.3 mag e_Ksmag rms uncertainty on Ksmag
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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- 3 I3 --- ID [1/125] Sequential number
5- 14 F10.6 deg RAdeg Right ascension (J2000)
16- 25 F10.6 deg DEdeg Declination (J2000)
27- 32 F6.3 mag Umag ?=99.999 U magnitude
34- 38 F5.3 mag e_Umag ?=9.999 rms uncertainty on Umag
40- 45 F6.3 mag Bmag ?=99.999 B magnitude
47- 51 F5.3 mag e_Bmag ?=9.999 rms uncertainty on Bmag
53- 58 F6.3 mag Vmag ?=99.999 V magnitude
60- 64 F5.3 mag e_Vmag ?=9.999 rms uncertainty on Vmag
66- 71 F6.3 mag Imag ?=99.999 I magnitude
73- 77 F5.3 mag e_Imag ?=9.999 rms uncertainty on Imag
79- 84 F6.3 mag Jmag ?=99.999 J magnitude
86- 90 F5.3 mag e_Jmag ?=9.999 rms uncertainty on Jmag
92- 97 F6.3 mag Hmag ?=99.999 H magnitude
99-103 F5.3 mag e_Hmag ?=9.999 rms uncertainty on Hmag
105-110 F6.3 mag Ksmag ?=99.999 Ks magnitude
112-116 F5.3 mag e_Ksmag ?=9.999 rms uncertainty on Ksmag
118-123 F6.3 mag [3.6] ?=99.999 IRAC [3.6] magnitude
125-129 F5.3 mag e_[3.6] ?=9.999 rms uncertainty on [3.6]
131-136 F6.3 mag [4.5] ?=99.999 IRAC [4.5] magnitude
138-142 F5.3 mag e_[4.5] ?=9.999 rms uncertainty on [4.5]
144-149 F6.3 mag [5.8] ?=99.999 IRAC [5.8] magnitude
151-155 F5.3 mag e_[5.8] ?=9.999 rms uncertainty on [5.8]
157-162 F6.3 mag [8.0] ?=99.999 IRAC [8.0] magnitude
164-168 F5.3 mag e_[8.0] ?=9.999 rms uncertainty on [8.0]
170-171 A2 --- Class [I II] Classfication
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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- 3 I3 --- ID [1/125] Sequential number
5- 14 F10.6 deg RAdeg Right ascension (J2000)
16- 25 F10.6 deg DEdeg Declination (J2000)
27- 30 F4.2 Msun M* Stellar mass
32- 35 F4.2 Msun e_M* rms uncertainty on M*
37- 40 F4.2 Myr t* Stellar age
42- 45 F4.2 Myr e_t* rms uncertainty on t*
47- 51 F5.3 Msun Mdisc Disc mass
53- 57 F5.3 Msun e_Mdisc rms uncertainty on Mdisc
59- 64 F6.3 10-8Msun/yr dMdisc/dt Disc mass loss rate
66- 71 F6.3 10-8Msun/yr e_dMdisc/dt rms uncertainty on dMdisc/dt
73- 76 F4.2 mag AV Extinction in V band
78- 81 F4.2 mag e_AV rms uncertainty on AV
83- 87 F5.2 --- chi2 chi2 value
89- 90 A2 --- Class [I II] Classificaiton
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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- 3 I3 --- ID [1/125] Sequential number
5- 14 F10.6 deg RAdeg Right ascension (J2000)
16- 25 F10.6 deg DEdeg Declination (J2000)
27- 32 F6.3 mag Vmag V magnitude
34- 38 F5.3 mag e_Vmag rms uncertainty on Vmag
40- 44 F5.3 mag V-I V-I colour index
46- 50 F5.3 mag e_V-I rms uncertainty on V-I
52- 56 F5.2 Myr t* Stellar age
58- 61 F4.2 Myr e_t* ?=0 rms uncertainty on t*
63- 66 F4.2 Msun M* Stellar mass
68- 71 F4.2 Msun e_M* rms uncertainty on M*
73- 74 A2 --- Class [I II] Classificaiton
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 07-Dec-2017