J/ApJS/264/38 NEOWISE variability of Gaia Herbig Ae/Be & Be stars (Mei+, 2023)
NEOWISE variability of the new Gaia Herbig Ae/Be and classical Be stars-
variability sample and statistical analysis.
Mei Y., Song S.-M., Liu J.-T., Hyland L.J., Chen X.
<Astrophys. J. Suppl. Ser., 264, 38 (2023)>
=2023ApJS..264...38M 2023ApJS..264...38M
ADC_Keywords: Stars, Be; Stars, pre-main sequence; YSOs; Stars, giant;
Photometry, infrared; Stars, variable; Optical
Keywords: Young stellar objects ; Herbig Ae/Be stars ; B(e) stars ;
Pre-main sequence stars ; Protoplanetary disks ; Protostars
Abstract:
Light variability is an essential attribute of young stellar objects
(YSOs) at the pre-main-sequence (PMS) stage, which can be treated as
an indicator to trace star formation. We present a statistical study
on the infrared NEOWISE variability of new and large-sized PMS stars
as well as Herbig Ae/Be (HAeBe) and classical Be (CBe) stars
identified from Gaia Data Release 2. A total of 3792 (including
714 HAeBe), 417, and 473 NEOWISE variable sources were detected from
the catalog of 8470 PMS (including 1361 HAeBe), 693 CBe, and
1309 uncertain (possibly belonging to either HAeBe or CBe) stars,
respectively. We found that 80% of the PMS variables are dominated by
irregular infrared variability, whereas variables in the CBe and
uncertain categories exhibit comparable contributions from secular
(linear, curved, and periodic) and stochastic (burst, drop, and
irregular) variables. This, in combination with infrared W1-W2 colors,
W4 luminosities, and the spectral energy distribution slope at near-
and mid-infrared wavelengths, suggests different evolutionary stages
of the PMS (including HAeBe), uncertain, and CBe stars, from less to
more evolved. A statistical analysis of variable source properties
(e.g., period and fractional amplitude) further reveals a potential
sequence possibly associated with disk evolution for different types
of light curves (from linear, to curved, periodic, stochastic, and
nonvariable stars). Possible mechanisms for the variable sources are
suggested to be related to either extinction via circumstellar matter,
or contribution of multiple systems surrounding the YSOs, as opposed
to variable accretion (e.g., episodic accretion or accretion burst).
Description:
In this study, the samples of HAeBe, CBe, and PMS stars were adopted
from those compiled by Vioque+ (2020, J/A+A/638/A21). They applied an
artificial neural network (ANN) to identify HAeBe stars and CBe stars
from 4,150,983 sources resulting from the crossmatching of Gaia DR2,
2MASS, WISE, IPHAS, and VPHAS+. When the threshold of the
classification probability was set to be larger than 50%, the
resulting catalogs include 8470 pre-main-sequence (PMS) candidates,
693 classical Be (CBe) candidates, and 1309 sources that may belong to
either of the two categories (named as "either" in their work, but
renamed as "uncertain" in our study).
In 2013 September, WISE began the NEOWISE monitoring working at the
3.4 (W1) and 4.6um (W2) bands. NEOWISE is currently in operation and
implements observations every 6 months. The latest released data (the
NEOWISE 2022 data-released in 2022 March) consists of 7.5yr W1 and
W2 photometric observations. See Section 2.2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 58 92173 Multi-epoch NEOWISE Photometry for the PMS sample
tablea2.dat 58 14457 Multi-epoch NEOWISE Photometry for the Uncertain
sample
tablea3.dat 58 9027 Multi-epoch NEOWISE Photometry for the CBe sample
tableb1.dat 102 72 Parameters of linear light curve sources for the
PMS sample
tableb2.dat 102 55 Parameters of linear light curve sources for the
Uncertain sample
tableb3.dat 102 91 Parameters of linear light curve sources for the
CBe sample
tablec1.dat 118 433 Parameters of sin light curve sources for the PMS
sample
tablec2.dat 118 93 Parameters of sin light curve sources for the
Uncertain sample
tablec3.dat 118 94 Parameters of sin light curve sources for the
CBe sample
tabled1.dat 133 253 Parameters of sin+linear variable sources in the
PMS sample
tabled2.dat 133 76 Parameters of sin+linear variable sources for
in Uncertain sample
tabled3.dat 133 92 Parameters of sin+linear variable sources in
the CBe sample
tablee1.dat 96 3913 Related parameters of stochastic variable sources
in the PMS sample
tablee2.dat 96 353 Related parameters of stochastic variable sources
in the Uncertain sample
tablee3.dat 96 182 Related parameters of stochastic variable sources
in the CBe sample
tablef1.dat 122 88 Parameters of the AGB candidate variables
(see Section 4.4)
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See also:
J/A+A/349/619 : UBVRI light curves of AA Tau in 1995 (Bouvier+, 1999)
J/AJ/121/3160 : JHK photometry near the Trapezium region (Carpenter+, 2001)
J/A+A/379/564 : Vega-type & PMS stars UBVRI phot-polarimetry (Oudmaijer+ 2001)
J/AJ/131/1574 : Infrared photometry of IC348 members (Lada+, 2006)
J/ApJ/638/897 : IR phot. in Trumpler 37 and NGC 7160 (Sicilia-Aguilar+, 2006)
J/AJ/136/2413 : Galactic midplane Spitzer red sources (Robitaille+, 2008)
J/MNRAS/386/313 : IR observations of Mira variables (Whitelock+, 2008)
J/A+A/557/A77 : VR light curves of AA Tau in 2007-2013 (Bouvier+, 2013)
J/AJ/147/82 : Monitoring of disk-bearing stars in NGC 2264 (Cody+, 2014)
J/ApJ/792/30 : NEOWISE magnitudes for near-Earth objects (Mainzer+, 2014)
J/A+A/610/A77 : Orion Integral Filament ALMA+IRAM30m N2H+(1-0) (Hacar+, 2018)
J/A+A/620/A128 : Gaia DR2 study of Herbig Ae/Be stars (Vioque+, 2018)
J/ApJ/877/110 : SPIRITS cat. of IR long period variables (Karambelkar+, 2019)
J/A+A/638/A21 : New Herbig Ae/Be & classical Be stars catalog (Vioque+, 2020)
J/ApJ/920/132 : NEOWISE 6.5yr variability in YSOs (Park+, 2021)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- ID [1/8470] Identifier (G1)
6- 12 F7.1 d Epoch [56640/59560.5] Observation epoch; JD-2400000
14- 19 F6.3 mag W1mag [1.37/15.81] NEOWISE 3.4um band magnitude
21- 25 F5.3 mag e_W1mag [0.001/2.3] Uncertainty in W1mag
27- 35 F9.2 mJy W1Flux [0.15/87453] NEOWISE 3.4um band flux density
37- 42 F6.3 mag W2mag [0.3/15.2] NEOWISE 4.6um band magnitude
44- 48 F5.3 mag e_W2mag [0.001/2.3] Uncertainty in W2mag
50- 58 F9.2 mJy W2Flux [0.14/128668] NEOWISE 4.6um band flux density
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Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- ID [1/1309] Identifier (G1)
6- 12 F7.1 d Epoch [56640.2/59560.5] Observation epoch; JD-2400000
14- 19 F6.3 mag W1mag [0.84/15.9] NEOWISE 3.4um band magnitude
21- 25 F5.3 mag e_W1mag [0.001/1.7] Uncertainty in W1mag
27- 35 F9.2 mJy W1Flux [0.14/142108] NEOWISE 3.4um band flux density
37- 42 F6.3 mag W2mag [0.66/15.31] NEOWISE 4.6um band magnitude
44- 48 F5.3 mag e_W2mag [0.001/2] Uncertainty in W2mag
50- 58 F9.2 mJy W2Flux [0.13/93023] NEOWISE 4.6um band flux density
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Byte-by-byte Description of file: tablea3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- ID [1/693] Identifier (G1)
6- 12 F7.1 d Epoch [56642/59560.4] Observation epoch; JD-2400000
14- 19 F6.3 mag W1mag [2.23/13.6] NEOWISE 3.4um band magnitude
21- 25 F5.3 mag e_W1mag [0.002/1.4] Uncertainty in W1mag
27- 35 F9.2 mJy W1Flux [1/39560] NEOWISE 3.4um band flux density
37- 42 F6.3 mag W2mag [1.79/14.8] NEOWISE 4.6um band magnitude
44- 48 F5.3 mag e_W2mag [0.0/1.7] Uncertainty in W2mag
50- 58 F9.2 mJy W2Flux [0.2/33006] NEOWISE 4.6um band flux density
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Byte-by-byte Description of file: tableb[123].dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- ID [20/8463] Identifier (G1)
6- 13 E8.1 --- Slope [-0.0006/0.0008] Fitted slope
15- 21 E7.1 --- e_Slope [1.6e-6/9.8e-5] Uncertainty in Slope
23- 26 F4.2 --- R2 [0.56/1] The goodness of fitting value
28- 33 F6.3 mag W1mag [6/14.3] Mean NEOWISE 3.4 micron band magnitude
35- 39 F5.3 mag e_W1mag [0.009/1] Uncertainty in W1mag
41- 46 F6.3 mag W2mag [3.9/13] Mean NEOWISE 4.6 micron band magnitude
48- 52 F5.3 mag e_W2mag [0.016/0.7] Uncertainty in W2mag
54- 58 F5.3 mag Delta [0.05/1.9] W2 band magnitude difference between
maximum & minimum
60- 64 F5.1 --- SI [11.3/604] Stetson index
66- 69 F4.1 --- SD/sig [1.4/43] W2 band flux density curve
SD/σ value
71- 76 F6.3 mag W4mag [-1.6/9.5] Vioque+ (2020, J/A+A/638/A21) WISE
22.2um band magnitude
78- 84 F7.1 pc Dist [114/13800]? Vioque+ (2020, J/A+A/638/A21)
extracted distance
86- 88 A3 --- HAeBe Source is a HAeBe star? (only for PMS; Table B1)
90- 92 A3 --- Var Source is variable? (only for PMS; Table B1)
94- 98 F5.2 --- alpha [-2.3/2.11] SED slope
100- 102 A3 --- Stage Evolutionary stage classification from alpha
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Byte-by-byte Description of file: tablec[123].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- ID [1/8433] Identifier (G1)
6- 12 F7.1 d Per [632/29942] Fitted period
14- 19 F6.1 d e_Per [11/7848] Uncertainty in Per
21- 26 F6.3 mag Amp [-7.6/9.5] Fitted amplitude
28- 32 F5.3 mag e_Amp [0.002/1.4] Uncertainty in Amp
34- 37 F4.2 --- R2 [0.4/1] The goodness of fitting value
39- 44 F6.3 mag W1mag [5.8/14.3] Mean NEOWISE 3.4um band magnitude
46- 50 F5.3 mag e_W1mag [0.008/1] Uncertainty in W1mag
52- 57 F6.3 mag W2mag [4.7/14] Mean NEOWISE 4.6um band magnitude
59- 63 F5.3 mag e_W2mag [0.01/1] Uncertainty in W2mag
65- 69 F5.3 mag Delta [0.04/4] W2 band magnitude difference between
maximum & minimum
71- 76 F6.1 --- SI [-16.3/1741] Stetson index
78- 81 F4.1 --- SD/sig [1/62] W2 band flux density curve SD/σ
value
83- 88 F6.3 mag W4mag [-2.5/9.5] Vioque+ (2020, J/A+A/638/A21) WISE
22.2um band magnitude
90- 96 F7.1 pc Dist [124.8/27700]? Vioque+ (2020, J/A+A/638/A21)
extracted distance
98- 100 A3 --- HAeBe Source is a HAeBe star? (only for PMS; Table C1)
102- 104 A3 --- Var Source is variable? (only for PMS; Table C1)
106- 108 A3 --- ES Source is an evolved star?
(only for PMS; Table C1) (G2)
110- 114 F5.2 --- alpha [-2.5/1.98] SED slope
116- 118 A3 --- Stage Evolutionary stage classification from alpha
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Byte-by-byte Description of file: tabled[123].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- ID [7/8464] Identifier (G1)
6- 12 F7.1 d Per [371/20000] Fitted period (1)
14- 19 F6.1 d e_Per [3/4181] Uncertainty in Per
21- 26 F6.3 mag Amp [-1.5/16.5] Fitted amplitude (1)
28- 32 F5.3 mag e_Amp [0.002/5.8] Uncertainty in Amp
34- 41 E8.1 --- Slope [-0.005/0.0008] Fitted slope (2)
43- 49 E7.1 --- e_Slope [2.2e-6/0.4] Uncertainty in Slope
51- 54 F4.2 --- R2 [0.49/1] The goodness of fitting value
56- 61 F6.3 mag W1mag [6.6/14.3] Mean NEOWISE 3.4um band magnitude
63- 67 F5.3 mag e_W1mag [0.01/0.9] Uncertainty in W1mag
69- 74 F6.3 mag W2mag [5.3/13.5] Mean NEOWISE 4.6um band magnitude
76- 80 F5.3 mag e_W2mag [0.01/0.8] Uncertainty in W2mag
82- 86 F5.3 mag Delta [0.04/2.8] W2 band magnitude difference between
maximum & minimum
88- 92 F5.1 --- SI [4.6/783] Stetson index
94- 97 F4.1 --- SD/sig [1.2/59.5] W2 band flux density curve
SD/σ value
99- 103 F5.3 mag W4mag [0.9/9.5] Vioque+ (2020, J/A+A/638/A21) WISE
22.2um band magnitude
105- 111 F7.1 pc Dist [106/11100]? Vioque+ (2020, J/A+A/638/A21)
extracted distance
113- 115 A3 --- HAeBe Source is a HAeBe star? (only for PMS; Table D1)
117- 119 A3 --- Var Source is variable? (only for PMS; Table D1)
121- 123 A3 --- ES Source is an evolved star
(only for PMS; Table D1) (G2)
125- 129 F5.2 --- alpha [-2.5/2.16] SED slope
131- 133 A3 --- Stage Evolutionary stage classification from alpha
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Note (1): Of the sin function portion of the sin+linear light curves.
Note (2): Of the linear portion of the sin+linear light curves.
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Byte-by-byte Description of file: tablee[123].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- ID [1/8470] Identifier (G1)
6- 11 F6.3 mag W1mag [2.69/15.2] Mean NEOWISE 3.4um band magnitude
13- 17 F5.3 mag e_W1mag [0.01/1.1] Uncertainty in W1mag
19- 24 F6.3 mag W2mag [1/14.1] Mean NEOWISE 4.6um band magnitude
26- 30 F5.3 mag e_W2mag [0.013/1.8] Uncertainty in W2mag
32- 36 F5.3 mag Delta [0.04/5.5] W2 band magnitude difference between
maximum & minimum
38- 43 F6.1 --- SI [20/1015.3] Stetson index
45- 49 F5.1 --- SD/sig [0.6/107.5] W2 band flux density curve
SD/σ value
51- 59 A9 --- St-Var Type of stochastic variable
(burst, drop, and irregular)
61- 66 F6.3 mag W4mag [-3.31/9.7] Vioque+ (2020, J/A+A/638/A21) WISE
22.2um band magnitude
68- 74 F7.1 pc Dist [81.9/17289]? Vioque+ (2020, J/A+A/638/A21)
extracted distance
76- 78 A3 --- HAeBe Source is a HAeBe star? (only for PMS; Table E1)
80- 82 A3 --- Var Source is variable? (only for PMS; Table E1)
84- 86 A3 --- ES Source is an evolved star
(only for PMS; Table E1) (G2)
88- 92 F5.2 --- alpha [-2.6/3.3] SED slope
94- 96 A3 --- Stage Evolutionary stage classification from alpha
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Byte-by-byte Description of file: tablef1.dat
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Bytes Format Units Label Explanations
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1 A1 --- f_ID E: Identifier from "either" table in
Vioque+ 2020, J/A+A/638/A21 (otherwise
from "pms")
2- 5 I4 --- ID Identifier (G1)
7- 12 F6.1 d Per [325.4/1792.5] Fitted period (1)
14- 17 F4.1 d e_Per [1.6/90.5] Uncertainty in Per
19- 24 F6.3 mag Amp [-0.93/1.3] Fitted amplitude (1)
26- 30 F5.3 mag e_Amp [0.015/0.15] Uncertainty in Amp
32- 39 E8.1 --- Slope [-0.0004/0.00013]? Fitted slope (2)
41- 47 E7.1 --- e_Slope [1.3e-5/8.2e-5]? Uncertainty in Slope
49- 52 F4.2 --- R2 [0.5/1] The goodness of fitting value
54- 59 F6.3 mag W1mag [2.8/14.1] Mean NEOWISE 3.4um band magnitude
61- 65 F5.3 mag e_W1mag [0.02/1.1] Uncertainty in W1mag
67- 72 F6.3 mag W2mag [1/13.6] Mean NEOWISE 4.6um band magnitude
74- 78 F5.3 mag e_W2mag [0.09/0.9] Uncertainty in W2mag
80- 84 F5.3 mag Delta [0.3/3.4] W2 band magnitude difference between
maximum & minimum
86- 90 F5.1 --- SI [-8.2/662.2] Stetson index
92- 95 F4.1 --- SD/sig [1/41.7] W2 band flux density curve SD/σ
value
97- 102 F6.3 mag W4mag [-0.55/9.5] Vioque+ (2020, J/A+A/638/A21) WISE
22.2um band magnitude
104- 110 F7.1 pc Dist [277/11554]? Vioque+ (2020, J/A+A/638/A21)
extracted distance
112- 114 A3 --- HAeBe Source is a HAeBe star?
116- 118 A3 --- Var Source is variable?
120- 122 A3 --- ES Source is an evolved star (G2)
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Note (1): Of the sin function portion of the sin+linear light curves.
Note (2): Of the linear portion of the sin+linear light curves.
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Global notes:
Note (G1): ID is numbered according to the source sequence number (recno)
of the PMS (Table 7), uncertain (Table 8), classical Be (Table 9)
sample in Vioque+ (2020, J/A+A/638/A21 -
tables D1 (pms), either, and, D2 (cbe); respectively).
Note (G2): Identified from Gaia measurements extracted from
Vioque+ (2020, J/A+A/638/A21).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 08-Mar-2023