J/MNRAS/467/2943 NGC 7538 region YSOs (Sharma+, 2017)
Stellar contents and star formation in the NGC 7538 region.
Sharma S., Pandey A.K., Ojha D.K., Bhatt H., Ogura K., Kobayashi N.,
Yadav R., Pandey J.C.
<Mon. Not. R. Astron. Soc., 467, 2943-2965 (2017)>
=2017MNRAS.467.2943S 2017MNRAS.467.2943S (SIMBAD/NED BibCode)
ADC_Keywords: H II regions ; YSOs ; Photometry, infrared ; Photometry, UBVRI ;
Stars, ages ; Stars, masses ; Stars, distances
Keywords: stars: formation - stars: pre-main-sequence - H II regions
Abstract:
Deep optical photometric data on the NGC 7538 region were collected
and combined with archival data sets from the Chandra, 2MASS and
Spitzer surveys to generate a new catalogue of young stellar objects
(YSOs) including those not showing infrared excess emission. This new
catalogue is complete down to 0.8M☉. The nature of the YSOs
associated with the NGC 7538 region and their spatial distribution are
used to study the star-formation process and the resultant mass
function (MF) in the region. Out of the 419 YSOs, ∼91 per cent
have ages between 0.1 and 2.5Myr and ∼86 per cent have masses
between 0.5 and 3.5M☉, as derived by the spectral energy
distribution fitting analysis. Around 24, 62 and 2 per cent of these
YSOs are classified to be class I, class II and class III sources,
respectively. The X-ray activities for the class I, class II and class
III objects are not significantly different from each other. This
result implies that the enhanced X-ray surface flux due to the
increase in the rotation rate may be compensated for by the decrease
in the stellar surface area during the pre-main-sequence evolution.
Our analysis shows that the O3V type high-mass star IRS 6 may have
triggered the formation of young low-mass stars up to a radial
distance of 3pc. The MF shows a turn-off at around 1.5M☉ and
the value of its slope Γ in the mass range 1.5<M/M☉<6
is -1.76±0.24, which is steeper than the Salpeter value.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 54 890 Information for 890 cataloged YSOs in the
NGC 7538 region
table4.dat 74 53 Information for 53 newly identified YSOs
table5.dat 85 74 Information for 74 optically identified YSOs
along with their magnitudes and colours
table6.dat 62 419 Stellar parameters of selected 419 YSOs derived
by using the SED fitting analysis
table7.dat 61 91 Spectral parameters of the X-ray sources having
NIR counterparts and identified as YSOs
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See also:
J/MNRAS/439/3719 : Embedded clusters infrared photometry (Chavarria+, 2014)
J/MNRAS/443/3218 : NGC 7538 IRS 1-3 and IRS 9 sources (Mallick+, 2014)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- ID Name (G1)
9- 10 I2 h RAh Right ascension (J2000)
12- 13 I2 min RAm Right ascension (J2000)
15- 19 F5.2 s RAs Right ascension (J2000)
22 A1 --- DE- Declination sign (J2000)
23- 24 I2 deg DEd Declination (J2000)
26- 27 I2 arcmin DEm Declination (J2000)
29- 32 F4.1 arcsec DEs Declination (J2000)
34- 35 A2 --- Classa Classification by Chavarria et al.,
2014MNRAS.439.3719C 2014MNRAS.439.3719C, Cat. J/MNRAS/439/3719
based on IRAC slope
37- 38 A2 --- Classb Classification by IRAC TCD
(C=contamination, nC=not classified.)
40- 41 A2 --- Classc Classification by Ojha et al.
(2004ApJ...616.1042O 2004ApJ...616.1042O) and Mallick et al.
(2014MNRAS.443.3218M 2014MNRAS.443.3218M, Cat. J/MNRAS/443/3218)
through NIR TCDs
43- 54 A12 --- Classd Classification by Hα and X-ray
emission (G2)
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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- 4 A4 --- ID Star identifier, S_NN
6- 7 I2 h RAh Right ascension (J2000)
9- 10 I2 min RAm Right ascension (J2000)
12- 16 F5.2 s RAs Right ascension (J2000)
18 A1 --- DE- Declination sign (J2000)
19- 20 I2 deg DEd Declination (J2000)
22- 23 I2 arcmin DEm Declination (J2000)
25- 28 F4.1 arcsec DEs Declination (J2000)
30- 35 F6.3 mag Jmag 2MASS J magnitude
37- 41 F5.3 mag e_Jmag ?=- rms uncertainty on Jmag
43- 48 F6.3 mag Hmag 2MASS H magnitude
50- 54 F5.3 mag e_Hmag ?=- rms uncertainty on Hmag
56- 61 F6.3 mag Kmag 2MASS K magnitude
63- 67 F5.3 mag e_Kmag ?=- rms uncertainty on Kmag
69- 74 A6 --- Classd Classification by Hα and X-ray
emission (G2)
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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- 6 A6 --- ID Name (G1)
8- 13 F6.3 mag Vmag V magnitude
15- 19 F5.3 mag e_Vmag rms uncertainty on Vmag
21- 26 F6.3 mag U-B ?=- U-B colour index
28- 32 F5.3 mag e_U-B ?=- rms uncertainty on U-B
34- 38 F5.3 mag B-V ?=- B-V colour index
40- 44 F5.3 mag e_B-V ?=- rms uncertainty on B-V
46- 50 F5.3 mag V-R ?=- V-R colour index
52- 56 F5.3 mag e_V-R ?=- rms uncertainty on V-R
58- 62 F5.3 mag V-I V-I colour index
64- 68 F5.3 mag e_V-I rms uncertainty on V-I
70- 73 F4.1 Myr Age Age, derived from the optical CMD
75- 77 F3.1 Myr e_Age rms uncertainty on Age
79- 81 F3.1 Msun Mass Mass, derived from the optical CMD
83- 85 F3.1 Msun e_Mass rms uncertainty on Mass
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- ID Name (G1)
9- 10 I2 --- N Number of data used
12- 14 A3 --- Class Evolutionnary class
16- 19 F4.1 --- chi2 Minimum chi2
21- 24 F4.2 kpc Dist Distance
26- 29 F4.2 kpc e_Dist rms uncertainty on Dist
31- 35 F5.2 mag AV Extinction in V band
37- 41 F5.2 mag e_AV rms uncertainty on AV
43- 47 F5.2 Myr Age Stellar age
49- 52 F4.2 Myr e_Age rms uncertainty on Age
54- 57 F4.2 Msun Mass Stellar mass
59- 62 F4.2 Msun e_Mass rms uncertainty on Mass
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- ID Name (G1)
8 A1 --- l_NH Limit flag on NH
9- 12 F4.2 10+22cm-2 NH ?=- Hydrogen column density
15- 18 F4.2 10+22cm-2 E_NH ?=- Error on NH (upper value)
21- 24 F4.2 10+22cm-2 e_NH ?=- Error on NH (lower value)
26 A1 --- l_kT Limit flag on kT
27- 31 F5.2 keV kT ?=- Plasma temperature
33- 37 F5.2 keV E_kT ?=- Error on kT (upper value)
40- 43 F4.2 keV e_kT ?=- Error on kT (lower value)
45- 49 F5.2 [10-7W] logLX X-ray luminosity (in erg/s)
52- 55 F4.2 [10-7W] e_logLX Error on logLX (lower value)
58- 61 F4.2 [10-7W] E_logLX Error on logLX (upper value)
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Global notes:
Note (G1): Origin of YSOs names:
C_NNNN = Chavarria et al., 2014MNRAS.439.3719C 2014MNRAS.439.3719C, Cat. J/MNRAS/439/3719,
[CAB2014] NGC7539 NNNN in Simbad
O_NNN = Ojha et al., 2004ApJ...616.1042O 2004ApJ...616.1042O
M_NNN = Mallick et al., 2014MNRAS.443.3218M 2014MNRAS.443.3218M, Cat. J/MNRAS/443/3218,
Note (G2): i.e., I/II/III(Comment),
if Comment = 7: Hα emission star (spectroscopy),
Comment = 8: Hα emission star (photometry),
Comment = 9: X-ray emitting star.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 18-Nov-2019