J/ApJS/265/16 Statistical study of NEOWISE 6.7GHz methanol masers (Song+, 2023)
Sample and statistical analysis of the Near-Earth Object Wide-field Infrared
Survey Explorer variability of the 6.7GHz methanol maser sources.
Song S.-M., Chen Xi, Shen Z.-Q., Wang Y.-X., Yang K., Miao D., Wu J.-H.,
Liu J.-T., Zhang Y.-K.
<Astrophys. J. Suppl. Ser., 265, 16 (2023)>
=2023ApJS..265...16S 2023ApJS..265...16S
ADC_Keywords: Masers; Photometry, infrared; YSOs; Stars, distances
Keywords: Young stellar objects ; Massive stars ; Interstellar masers ;
Infrared photometry
Abstract:
We present a statistical study of infrared variability using the
Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE)
database for a sample consisting of 1085 high-mass young stellar
objects (YSOs) related to 6.7GHz methanol masers. A total of
383 maser sources were identified as NEOWISE variables and classified
in two variability behavior classifications: 204 secular (linear,
curved, and periodic) and 179 stochastic (burst, drop, and irregular)
variables. Statistical analysis of the properties of these variables
(e.g., the dust temperature, bolometric luminosity, hydrogen column
density, W4 luminosity, and W1-W2 color) has revealed a potential
evolutionary sequence among different light-curve types of variables.
There is a possible general evolutionary (from less to more evolved)
trend between the three variable types from secular to stochastic to
nonvariable. For the specific classifications, the evolutionary trend
for secular variables is linear to sin to sin+linear, and for
stochastic variables it is burst to irregular to drop. These sequences
may reflect the evolution of the envelope or accretion disk of
high-mass YSOs, from large to small radii due to gravitational
collapse. Although no significant variability correlation was
established between the 6.7GHz methanol maser and the W2-band emission
based on the data collected so far, a number of candidates were found
for further investigating the accretion burst events via future
variability monitoring programs of both mid-infrared emission and
masers.
Description:
WISE began the NEOWISE monitoring project at the 3.4um (W1) and 4.6um
(W2) bands in 2013 September. NEOWISE is currently operating and
implementing observations every six months. The latest released data
(the NEOWISE 2022 data --released in 2022 March) consist of 7.5yr W1-
and W2-band photometric measurements. NEOWISE is primarily sensitive
to the magnitude range of 2.0-14.5. See Section 2.2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 98 8359 Multi-epoch NEOWISE photometry for the 6.7GHz
methanol maser sample
table4.dat 233 206 Parameters of secular light curve variables
table5.dat 172 179 Parameters of stochastic light curve sources
table6.dat 147 156 Parameters of the no variability sources
refs.dat 151 37 References
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See also:
VIII/96 : 6-GHz methanol multibeam maser catalogue (Caswell+, 2010-12)
J/A+AS/110/81 : Methanol masers towards IRAS sources (van der Walt+ 1995)
J/MNRAS/291/261 : Methanol maser of IRAS-selected sources (Walsh+ 1997)
J/A+AS/134/115 : Medicina 6.7GHz methanol masers survey (Slysh+ 1999)
J/A+AS/143/269 : 6.7GHz methanol maser emission survey (Szymczak+, 2000)
J/AJ/121/3160 : JHK phot. near the Trapezium region (Carpenter+, 2001)
J/A+A/432/737 : 6.7GHz Methanol Masers (Pestalozzi+, 2005)
J/MNRAS/377/571 : GLIMPSE methanol masers non-detections (Ellingsen+, 2007)
J/ApJ/656/255 : Arecibo methanol maser Gal. plane survey (Pandian+, 2007)
J/other/PASA/26.454 : Precise positions of methanol masers (Caswell, 2009)
J/ApJ/733/50 : MIR phot. monitoring of the ONC (Morales-Calderon+, 2011)
J/MNRAS/424/1925 : Spectrocopic Binarity of O & B type stars (Chini+, 2012)
J/AN/333/634 : Torun methanol source catalogue (Szymczak+, 2012)
J/A+A/557/A77 : VR light curves of AA Tau in 2007-2013 (Bouvier+, 2013)
J/AJ/147/82 : Disk-bearing stars in NGC 2264 (Cody+, 2014)
J/ApJ/792/30 : NEOWISE mag. for near-Earth objects (Mainzer+, 2014)
J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)
J/A+A/563/A130 : GLIMPSE/BGPS 6.7GHz methanol maser survey (Sun+, 2014)
J/ApJ/846/160 : 6.7GHz Class II methanol maser survey (Yang+, 2017)
J/MNRAS/473/1059 : Complete sample of Galactic clumps (Urquhart+, 2018)
J/AJ/155/99 : IR var. among YSOs in Serpens South cluster (Wolk+, 2018)
J/ApJS/241/18 : Methanol maser survey. II. |b|<2° (Yang+, 2019)
J/A+A/634/A41 : G107.298+5.639 multi-frequency maser LCs (Olech+, 2020)
J/ApJ/920/132 : NEOWISE 6.5yr variability in YSOs (Park+, 2021)
J/A+A/667/A44 : LAMOST DR8 early-type stars statistics (Guo+, 2022)
J/A+A/661/A114 : Periodic flares in two methanol masers (Olech+, 2022)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- ID [2/1085] Yang+ 2019, J/ApJS/241/18, Table 6
sequence number
6- 23 A18 --- Name Source name (L.lll+B.bbb; Galactic) as in
Yang+ 2019, J/ApJS/241/18, Table 6
25- 31 F7.1 d Epoch [56649.1/59556.6] Averaged Modified Julian Date
of observation
33- 38 F6.3 mag W1mag [2.45/16.12] NEOWISE 3.36um band mean magnitude
40- 44 F5.3 mag e_W1mag [0.012/0.5] Uncertainty in W1mag
46- 54 F9.3 mJy FW1 [0.1/32164] NEOWISE 3.36um band flux density
56- 64 F9.3 mJy e_FW1 [0.03/10743] Uncertainty in FW1
66- 71 F6.3 mag W2mag [0.2/13.5] NEOWISE 4.62um band mean magnitude
73- 77 F5.3 mag e_W2mag [0.007/0.4] Uncertainty in W2mag
79- 88 F10.3 mJy FW2 [0.69/140848] NEOWISE 4.62um band flux density
90- 98 F9.3 mJy e_FW2 [0.07/32367] Uncertainty in FW2
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- ID [26/1083] Yang+ 2019, J/ApJS/241/18, Table 6
sequence number
6- 23 A18 --- Name Source name (L.lll+B.bbb; Galactic) as
in Yang+ 2019, J/ApJS/241/18, Table 6
25- 28 A4 --- Type Variable type (1)
30- 36 F7.1 d Per [544/22036]? Fitted period (2)
38- 45 F8.1 d e_Per [4/272396]? Uncertainty in Per
47- 52 F6.3 mag Amp [-2/2]? Amplitude (2)
54- 59 F6.3 mag e_Amp [0.003/49]? Uncertainty in Amp
61- 66 F6.3 --- Frac [-0.85/5.31]? Fractional amplitude (2)
68- 76 E9.2 --- Slope [-0.001/0.0006]? Slope (2)
78- 85 E8.2 --- e_Slope [2.4e-6/0.003]? Uncertainty in Slope
87- 90 F4.2 --- R2 [0.42/0.98] Goodness of fitting
92- 97 F6.3 mag W1mag [4.38/16] NEOWISE 3.36um band mean magnitude
99- 103 F5.3 mag e_W1mag [0.03/0.9] Uncertainty in W1mag
105- 110 F6.3 mag W2mag [1.1/13.4] NEOWISE 4.62um band magnitude
112- 116 F5.3 mag e_W2mag [0.03/0.7] Uncertainty in W2mag
118- 122 F5.3 --- DelW2 [0.06/1.92] Difference between W2 max and min
magnitudes (G4)
124- 129 F6.3 --- SD/sig [1/31.3] Standard deviation divided by mean
uncertainty
131- 136 F6.3 mag W4mag [-3.6/5.3]? WISE 22.2 micron band magnitude
138- 142 F5.3 mag e_W4mag [0.001/0.3]? Uncertainty in W4mag
144- 148 F5.2 kpc Dist [0.8/17.46] Kinematic distance (G1)
150- 153 F4.2 kpc e_Dist [0.03/7.4] Uncertainty in Dist
155- 158 F4.2 pc Rad [0/5.1]? Clump radius (G2)
160- 163 F4.1 K Tdust [14/35]? Dust temperature (G2)
165- 169 F5.2 [Lsun] logLb [-0.3/5.8]? Log bolometric luminosity (G2)
171- 175 F5.2 [Msun] logMc [-1/4.25]? Log clump mass (G2)
177- 181 F5.2 [cm2] logNH2 [21.9/23.4]? Log hydrogen column density (G2)
183- 187 F5.1 Jy FMax [0/607] Maximum flux density (G3)
189- 193 F5.1 Jy FMin [0/243] Minimum flux density (G3)
195- 198 F4.1 --- Var [1/40.1] Maser variation index
200 I1 --- N [1/8] Number of previous 6.7GHz maser
observations
202- 233 A32 --- Ref Previous observation reference codes
(see refs.dat file)
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Note (1): Variable type as follows:
Line = Linear (12 occurrences)
Sin = (77 occurrences)
SL = Sin + Linear (117 occurrences)
Note (2): From the fitting results of the W2 magnitude light curves.
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- ID [2/1085] Yang+ 2019, J/ApJS/241/18, Table 6
sequence number
6- 18 A13 --- Name Source name (L.lll+B.bbb; Galactic) as in
Yang+ 2019, J/ApJS/241/18, Table 6
20- 28 A9 --- Type Variable type (1)
30- 35 F6.3 mag W1mag [3.3/13.74] NEOWISE 3.36um band mean magnitude
37- 41 F5.3 mag e_W1mag [0.015/0.4] Uncertainty in W1mag
43- 48 F6.3 mag W2mag [0.7/11.7] NEOWISE 4.62um band magnitude
50- 54 F5.3 mag e_W2mag [0.01/0.2] Uncertainty in W2mag
56- 60 F5.3 --- DelW2 [0.06/3.9] Difference between W2 max and min
magnitudes (G4)
62- 67 F6.3 --- SD/sig [1/21] Standard deviation divided by mean
uncertainty
69- 74 F6.3 mag W4mag [-6.5/6.1]? WISE 22.2 micron band magnitude
76- 80 F5.3 mag e_W4mag [0.001/0.3]? Uncertainty in W4mag
82- 86 F5.2 kpc Dist [0.9/17.1] Kinematic distance (G1)
88- 91 F4.2 pc Rad [0.01/3.8]? Clump radius (G2)
93- 96 F4.1 K Tdust [15.4/46.4]? Dust temperature (G2)
98- 101 F4.2 [Lsun] logLb [0/5.93]? Log bolometric luminosity (G2)
103- 107 F5.2 [Msun] logMc [-0.7/4.4]? Log clump mass (G2)
109- 113 F5.2 [cm2] logNH2 [21.69/24]? Log hydrogen column density (G2)
115- 120 F6.1 Jy FMax [0.2/3880] Maximum flux density (G3)
122- 127 F6.1 Jy FMin [0.2/3275] Minimum flux density (G3)
129- 132 F4.1 --- Var [1/18.2] Maser variation index
134 I1 --- N [1/9] Number of previous 6.7GHz maser
observations
136- 172 A37 --- Ref Previous observation reference codes
(see refs.dat file)
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Note (1): Type as follows:
Irregular = 133 occurrences,
Burst = 14 occurrences
Drop = 32 occurrences
see Section 3.2.
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Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- ID [12/1076] Yang+ 2019, J/ApJS/241/18, Table 6
sequence number
6- 18 A13 --- Name Source name (L.lll+B.bbb; Galactic) as in
Yang+ 2019, J/ApJS/241/18, Table 6
20- 25 F6.3 mag W1mag [3.9/13.92] NEOWISE 3.36um band mean magnitude
27- 31 F5.3 mag e_W1mag [0.014/0.4] Uncertainty in W1mag
33- 38 F6.3 mag W2mag [1.12/12.04] NEOWISE 4.62um band mean magnitude
40- 44 F5.3 mag e_W2mag [0.009/0.11] Uncertainty in W2mag
46- 51 F6.3 mag W4mag [-3.8/6.6]? WISE 22.2 micron band magnitude
53- 57 F5.3 mag e_W4mag [0.001/0.3]? Uncertainty in W4mag
59- 62 F4.2 pc Rad [0.04/3.2]? Clump radius (G2)
64- 67 F4.1 K Tdust [16.3/35.4]? Dust temperature (G2)
69- 72 F4.2 [Lsun] logLb [1.76/5.72]? Log bolometric luminosity (G2)
74- 77 F4.2 [Msun] logMc [0.96/4.1]? Log clump mass (G2)
79- 83 F5.2 [cm2] logNH2 [21.87/23.92]? Log hydrogen column density (G2)
85- 89 F5.2 kpc Dist [1.2/18.1] Kinematic distance (G1)
91- 96 F6.1 Jy FMax [0/3544] Maximum flux density (G3)
98- 103 F6.1 Jy FMin [0/2721] Minimum flux density (G3)
105- 108 F4.1 --- Var [1/10.3] Maser variation index
110 I1 --- N [1/9] Number of previous 6.7GHz maser
observations
112- 147 A36 --- Ref Previous observation reference codes
(see refs.dat file)
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Ref Reference code
6- 24 A19 --- BibCode Bibcode of the reference
26- 45 A20 --- Auth Author's name(s)
47-151 A105 --- Comm Comment
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Global notes:
Note (G1): Derived from the model of BeSSLe project proposed in
Reid+ (2016ApJ...823...77R 2016ApJ...823...77R).
Note (G2): Of the matched 850um ATLASGAL clumps which are extracted
from Urquhart+ (2018, J/MNRAS/473/1059).
Note (G3): From the 6.7GHz methanol maser information extracted
from Ladeyschikov+ (2019AJ....158..233L 2019AJ....158..233L).
Note (G4): as the measurement of fractional flux change between the
faintest and brightest epochs.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 19-Apr-2023