J/ApJ/885/64 Amplitude of variability for 150 YSOs in Orion (Ellithorpe+, 2019)
The nature of class I sources: periodic variables in Orion.
Ellithorpe E.A., Duchene G., Stahler S.W.
<Astrophys. J., 885, 64 (2019)>
=2019ApJ...885...64E 2019ApJ...885...64E
ADC_Keywords: YSOs; Stars, pre-main sequence; Infrared
Keywords: Circumstellar matter ; Pre-main sequence stars ; Protostars ;
Starspots ; T Tauri stars ; Herbig Ae/Be stars
Abstract:
We present a quantitative, empirically based argument that at least
some Class I sources are low-mass, pre-main-sequence stars surrounded
by spatially extended envelopes of dusty gas. The source luminosity
arises principally from stellar gravitational contraction, as in
optically visible pre-main-sequence stars that lack such envelopes. We
base our argument on the fact that some Class I sources in Orion and
other star-forming regions have been observed by Spitzer to be
periodic variables in the mid-infrared, and with periods consistent
with T Tauri rotation rates. Using a radiative transfer code, we
construct a variety of dust envelopes surrounding rotating, spotted
stars, to see whether an envelope that produces a Class I spectral
energy distribution at least broadly matches the observed modulations
in luminosity. Acceptable envelopes can be either spherical or
flattened and may or may not have polar cavities. The key requirement
is that they have a modest equatorial optical depth at the Spitzer
waveband of 3.6µm, typically τ3.6∼0.6. The total envelope mass,
based on this limited study, is at most about 0.1M☉, less than a
typical stellar mass. Future studies should focus on the dynamics of
the envelope, to determine whether material is actually falling onto
the circumstellar disk.
Description:
We considered the 150 variable objects in Orion that had newly
identified periods in Morales-Calderon, 2011, J/ApJ/733/50 (Table 4)
to place the amplitude of variability of the Class I sources studied
here in their broader context.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 47 150 Amplitude of variability for 150 YSOs in Orion
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See also:
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
J/ApJS/101/117 : UBVRIJHKLMNQ photometry in Taurus-Auriga (Kenyon+ 1995)
J/AJ/130/1145 : YSO near-infrared properties (Doppmann+, 2005)
J/AJ/140/1214 : Near-IR spectroscopic survey of class I YSOs (Connelley+,2010)
J/ApJ/733/50 : Mid-IR photometric monitoring of ONC (Morales-Calderon+, 2011)
J/AJ/144/192 : Spitzer survey of Orion A & B. I. YSO catalog (Megeath+, 2012)
J/A+A/570/A29 : TBOSS Survey I: Herschel/PACS (Bulger+, 2014)
J/AJ/147/82 : Monitoring of disk-bearing stars in NGC 2264 (Cody+, 2014)
J/AJ/148/122 : YSOVAR: infrared photometry in Lynds 1688 (Gunther+, 2014)
J/AJ/150/118 : YSOVAR IR photometry in IRAS 20050+2720 (Poppenhaeger+, 2015)
J/AJ/150/175 : YSOVAR: infrared photometry in NGC 1333 (Rebull+, 2015)
J/AJ/150/145 : YSOVAR infrared photometry in GGD12-15 (Wolk+, 2015)
J/ApJS/224/5 : The Herschel Orion Protostar Survey: SEDs (Furlan+, 2016)
J/ApJ/821/52 : NIR survey of Spitzer YSOs in Orion Mol. Cloud (Kounkel+,2016)
J/A+A/590/A33 : Class 0 sources continuum subtracted UV-tables (Persson+,2016)
J/ApJ/849/63 : FIR-mm data of YSOs in star-forming regions (Ribas+, 2017)
Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Star Target name
25- 27 A3 --- Class Classification
29- 33 F5.2 d Period [1.05/24.8] Period
35- 39 F5.2 mag alpha [-0.26/0.39] Amplitude of variation at 3.6micron
41- 45 F5.2 mag error [1.06/15.6] Reduced chi square error
47 A1 --- Note Note (1)
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Note (1): Notes as follows:
a = The object is an eclipsing binary, as identified from
its light curve at 3.6microns (2 occurrences).
b = Misclassified in Megeath, 2012, J/AJ/144/192. These
are Class II Objects, based on their SEDs (2 occurrences).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 03-Jun-2021