J/A+A/619/A41 Photometric variability of massive YSOs (Teixeira+, 2018)
On the photometric variability of massive young stellar objects.
Teixeira G.D.C., Kumar M.S.N., Smith L., Lucas P.W., Morris C.,
Borissova J., Monteiro M.J.P.F.G., Caratti o Garatti A., Contreras Pena C.,
Froebrich D., Gameiro J.F.
<Astron. Astrophys. 619, A41 (2018)>
=2018A&A...619A..41T 2018A&A...619A..41T (SIMBAD/NED BibCode)
ADC_Keywords: YSOs ; Stars, pre-main sequence
Keywords: techniques: photometric - stars: formation - stars: massive -
stars: pre-main sequence - stars: protostars -
stars: variables: general
Abstract:
The Vista Variables in the Via Lactea (VVV) survey has allowed for an
unprecedented number of multi-epoch observations of the southern
Galactic plane. In a recent paper, 13 massive young stellar objects
(MYSOs) have already been identified within the highly variable
(ΔKs>1mag) YSO sample of another published work. This study aims
to understand the general nature of variability in MYSOs. Here we
present the first systematic study of variability in a large sample of
candidate MYSOs. We examined the data for variability of the putative
driving sources of all known Spitzer extended green objects (EGOs;
270) and bright 24um sources coinciding with the peak of 870um
detected ATLASGAL clumps (448), a total of 718 targets. Of these, 190
point sources (139 EGOs and 51 non-EGOs) displayed variability
(IQR>0.05, ΔKs>0.15mag). 111 and 79 light-curves were
classified as periodic and aperiodic respectively. Light-curves have
been sub-classified into eruptive, dipper, fader, short-term-variable
and long-period-variable-YSO categories. Lomb-Scargle periodogram
analysis of periodic light-curves was carried out. 1-870um spectral
energy distributions of all the variable sources were fitted with YSO
models to obtain the representative properties of the variable
sources. 41% of the variable sources are represented by >4M☉
objects, and only 6% were modelled as >8M☉ objects. The
highest-mass objects are mostly non-EGOs, and deeply embedded, as
indicated by nearly twice the extinction when compared with EGO
sources. By placing them on the HR diagram we show that most of the
lower mass, EGO type objects are concentrated on the putative
birth-line position, while the luminous non-EGO type objects group
around the zero-age-main-sequence track. Some of the most luminous far
infrared (FIR) sources in the massive clumps and infrared quiet
driving sources of EGOs have been missed out by this study owing to an
uniform sample selection method. A high rate of detectable variability
in EGO targets (139 out of 153 searched) implies that near-infrared
variability in MYSOs is closely linked to the accretion phenomenon and
outflow activity.
Description:
Photometric variability of MYSO candidates in the VVV survey and
parameters of the fitted YSO parameters.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 76 190 Source coordinates, photometric data and
variability
tablea1.dat 131 188 Input data to build the SEDs
tablea2.dat 111 183 Results of the weighted averaging of the fit SEDs
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See also:
II/337 : VISTA Variables in the Via Lactea Survey DR1 (Saito+, 2012)
II/348 : VISTA Variable in the Via Lactea Survey DR2 (Minniti+, 2017)
J/AJ/136/2391 : GLIMPSE Extended Green Objects catalog (Cyganowski+, 2008)
J/ApJS/206/9 : New EGOs from Spitzer GLIMPSE II survey. I. (Chen+, 2013)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- Source Source name
22- 29 F8.4 deg RAdeg Right ascension (J2000)
31- 38 F8.4 deg DEdeg Declination (J2000)
40- 44 F5.2 mag Kmag Kmag (median)
46- 49 F4.2 mag MAD Median Absolute Deviation of Light Curve
51- 55 F5.2 mag IQR Interquartile Range of Light Curve
57- 60 F4.2 mag DeltaK Amplitude of Light Curve
62- 69 A8 --- Class Classification (1)
71- 76 F6.1 d Period ?=- Best fit period (2)
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Note (1): Classification as follows:
LPV = Long Period Variable
STV = Short-Term Variable
Dip = Dipper
Fad = Fader
Erup = Eruptive
low-Erup = Low-amplitude Eruptive
Note (2): Only available for periodic LCs.
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 A18 --- Source Source name
21- 25 F5.2 mJy FJ ? J flux (2MASS)
27- 32 F6.2 mJy FH ? H flux (2MASS)
34- 39 F6.2 mJy FK ? K flux (2MASS)
41- 47 F7.2 mJy F3.6 ? 3.6um flux (SPITZER)
49- 55 F7.2 mJy F4.5 ? 4.5um flux (SPITZER)
57- 63 F7.2 mJy F5.8 ? 5.8um flux (SPITZER)
65- 71 F7.2 mJy F8.0 ? 8.0um flux (SPITZER)
74- 81 F8.2 mJy F24 ? 24um flux (SPITZER)
83- 92 F10.2 mJy F70 ? PACS 70um flux (Herschel)
94-103 F10.2 mJy F160 ? PACS 160um flux (Herschel)
105-110 I6 mJy F250 ? SPIRE 250um flux (Herschel)
112-117 I6 mJy F350 ? SPIRE 350um flux (Herschel)
119-124 I6 mJy F500 ? SPIRE 500um flux (Herschel)
126-131 I6 mJy F870 ? APEX 870um flux
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- Source Source name
21- 26 F6.2 --- chi2 Chi square fit
28- 31 F4.2 --- s_chi2 Chi square fit standard deviation
33- 37 F5.2 mag Av ISM extinction
39- 43 F5.2 mag s_Av ISM extinction standard deviation
45- 49 F5.2 Msun M Mass of the Envelope
51- 54 F4.2 Msun s_M Mass of the Envelope standard deviation
56- 60 F5.2 [Msun/yr] logdM/dt Envelope accretion rate
62- 66 F5.2 [Msun/yr] s_logdM/dt [] Envelope accretion rate
standard deviation
68- 72 F5.2 [Msun] logMd Disk mass
74- 78 F5.2 [Msun] s_logMd [] Disk mass standard deviation
80- 84 F5.2 [Msun/yr] logdMd/dt Disk accretion rate
86- 90 F5.2 [Msun/yr] s_logdMd/dt [] Disk accretion rate standard deviation
92- 95 F4.2 [Lsun] logL Luminosity
97-101 F5.2 [Lsun] s_logL [] Luminosity standard deviation
103-106 F4.2 [yr] logAge Age
108-111 F4.2 [yr] s_logAge Age standard deviation
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Acknowledgements:
Guilherme Teixeira, guilhermedcteixeira(at)mail.com
(End) G. Teixeira [IA - Porto, Portugal], P. Vannier [CDS] 10-Sep-2018