J/ApJS/226/8 Spitzer/IRS survey of Class II objects in Orion A. I. (Kim+, 2016)
The Spitzer Infrared Spectrograph survey of protoplanetary disks in Orion A.
I. Disk properties.
Kim K.H., Watson D.M., Manoj P., Forrest W.J., Furlan E., Najita J.,
Sargent B., Hernandez J., Calvet N., Adame L., Espaillat C., Megeath S.T.,
Muzerolle J., McClure M.K.
<Astrophys. J. Suppl. Ser., 226, 8-8 (2016)>
=2016ApJS..226....8K 2016ApJS..226....8K (SIMBAD/NED BibCode)
ADC_Keywords: YSOs ; Spectral types ; Equivalent widths ; Stars, masses ;
Stars, distances ; Surveys
Keywords: accretion, accretion disk; infrared: stars; protoplanetary disks;
stars: pre-main sequence; surveys
Abstract:
We present our investigation of 319 Class II objects in Orion A
observed by Spitzer/IRS. We also present the follow-up observations of
120 of these Class II objects in Orion A from the Infrared Telescope
Facility/SpeX. We measure continuum spectral indices, equivalent
widths, and integrated fluxes that pertain to disk structure and dust
composition from IRS spectra of Class II objects in Orion A. We
estimate mass accretion rates using hydrogen recombination lines in
the SpeX spectra of our targets. Utilizing these properties, we
compare the distributions of the disk and dust properties of Orion A
disks with those of Taurus disks with respect to position within Orion A
(Orion Nebular Cluster [ONC] and L1641) and with the subgroups by the
inferred radial structures, such as transitional disks (TDs) versus
radially continuous full disks (FDs). Our main findings are as
follows. (1) Inner disks evolve faster than the outer disks. (2) The
mass accretion rates of TDs and those of radially continuous FDs are
statistically significantly displaced from each other. The median mass
accretion rate of radially continuous disks in the ONC and L1641 is
not very different from that in Taurus. (3) Less grain processing has
occurred in the disks in the ONC compared to those in Taurus, based on
analysis of the shape index of the 10µm silicate feature
(F11.3/F9.8). (4) The 20-31µm continuum spectral index tracks
the projected distance from the most luminous Trapezium star,
θ1 Ori C. A possible explanation is UV ablation of the outer
parts of disks.
Description:
We present 319 Class II disks observed with Spitzer/IRS in the Orion A
star-forming region. We described the Spitzer/IRS and IRTF/SpeX
observations and data reduction process in Kim+ (2013, J/ApJ/769/149).
The Orion A objects in this paper were selected based on the
identification of young stars with disks by IRAC/Two Micron All Sky
Survey (2MASS) color-color diagrams (Megeath+ 2012, J/AJ/144/192). We
observed them using Spitzer/IRS during campaigns 36, 39, 40, and 44
between 2006 November and 2007 October. To this group we added 16
additional objects (5 in the ONC; 11 in L1641) that were reclassified
as Class II from Class 0/I sources observed in the Orion A protostar
survey by C. Poteet et al. (2016, in preparation); 14 of these 16 were
observed during campaigns 39 and 40, but 2 sources were observed in
campaign 56 (see table 1).
Of our IRS targets observed in both SL and LL modules in Orion A with
Spitzer/IRS, we observed 120 at near-IR (0.8-2.4um) wavelengths with
the medium-resolution spectrograph SpeX, on the NASA IRTF on Mauna Kea
during the 2010A, 2011A, and 2011B semesters (see table 3).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 97 319 Observation and reduction log of IRS spectra
table2.dat 94 319 Identifications of the objects
table3.dat 34 124 Observation log of SpeX spectra
table4.dat 122 301 Spectral type and extinction
table6.dat 56 310 Basic stellar properties and mass accretion rate
table7.dat 74 301 Spectral indices
table8.dat 82 301 Grain properties
table11.dat 35 298 n20-31 and the projected distance
from θ1 Ori C
refs.dat 139 26 References (for table 4)
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See also:
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
II/171 : Parenago Catalog of Stars in Orion Nebula (Parenago 1954)
J/ApJS/224/5 : Herschel Orion Protostar Survey (HOPS): SEDs (Furlan+, 2016)
J/AJ/146/85 : Spectral types of optical stars in ONC (Hillenbrand+, 2013)
J/ApJS/208/9 : Intrinsic colors and temperatures of PMS stars (Pecaut+, 2013)
J/ApJS/207/5 : YSOs in LDN 1641 with Hectochelle spectra (Fang+, 2013)
J/ApJ/769/149 : IR spectroscopy in Orion A: transitional disks (Kim+, 2013)
J/ApJ/767/36 : APEX observations of HOPS protostars (Stutz+, 2013)
J/ApJ/764/114 : BVRI photometry of stars in Orion A (Hsu+, 2013)
J/AJ/144/192 : Spitzer survey of Orion A & B. I. YSO catalog (Megeath+, 2012)
J/ApJ/752/59 : Low-mass population in L1641 (Hsu+, 2012)
J/AJ/139/950 : JHKs photometry in ONC (Robberto+, 2010)
J/ApJS/183/261 : Optical photometry of the ONC (Da Rio+, 2009)
J/MNRAS/400/603 : New variables in ONC (Parihar+, 2009)
J/ApJ/703/1964 : Spectra of three nearby star-forming regions (Furlan+, 2009)
J/A+A/504/461 : YSOs in L1630N and L1641 (Fang+, 2009)
J/ApJ/697/1103 : Kinematics of Orion Nebula Cluster (Tobin+, 2009)
J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)
J/ApJ/693/L81 : Extinction in star-forming regions (McClure, 2009)
J/A+A/489/1409 : IR photometry and spectroscopy in L1641N (Galfalk+, 2008)
J/ApJ/677/401 : Xray properties of protostars in ONC (Prisinzano+, 2008)
J/ApJ/676/1109 : Velocities of stars in Orion Nebula Cluster (Furesz+, 2008)
J/ApJ/671/1784 : Ori OB1 IRAC/MIPS observations (Hernandez+, 2007)
J/A+A/461/183 : Variability of classical T Tauri (Grankin+, 2007)
J/ApJ/601/979 : vsini of Orion low-mass stars (Wolff+, 2004)
J/AJ/121/1676 : ONC low-mass stars photometry (Rebull+, 2001)
J/ApJ/540/236 : KH photometry of Orion Nebula Cluster (Hillenbrand+, 2000)
J/AJ/119/3026 : Circumstellar disk candidates in Orion (Rebull+, 2000)
J/AJ/113/1733 : Orion Nebula Cluster population (Hillenbrand 1997)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Running sequence number (G1)
5- 16 A12 --- IRS IRS identifier (2)
18 I1 h RAh [5] Hour of Right Ascension (J2000)
20- 21 I2 min RAm [33/43] Minute of Right Ascension (J2000)
23- 27 F5.2 s RAs Second of Right Ascension (J2000)
29 A1 --- DE- [-] Sign of the Declination (J2000)
30 I1 deg DEd [4/8] Degree of Declination (J2000)
32- 33 I2 arcmin DEm Arcminute of Declination (J2000)
35- 39 F5.2 arcsec DEs Arcsecond of Declination (J2000)
41- 48 I8 --- AORID Spitzer AORID observation identifier
50- 51 I2 --- Camp IRS Campaign number (36, 39, 40, 44 or 56)
53- 63 A11 "Y/M/D" Date Date of the observation
65- 68 A4 --- Mod Module used in the observation (SL or SLLL)
70- 78 A9 --- Reg Observation region (L1641, ONC or Trapezium)
80- 93 A14 --- Red Reduction used (3)
95 A1 --- f_Red Flag on Red (4)
97 A1 --- n_AORID Extra note on the IRS program ID (5)
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Note (2): These are used to identify objects often in other works. The IRS
names come from the position of each object.
Note (3): Indicates the methods of source extraction to get the SEDs in
Figure 7 and Figure 8.
ECO = an automated tapered column extraction in SMART with off-nod
or off-order sky subtraction; man: a manual tapered column
extraction in SMART with a constant or linear sky subtraction;
man = a manual tapered column extraction in SMART with a constant or
linear sky subtraction;
AdOpt = an optimal source extraction using an empirical point response
function (PRF) in SMART;
opse = an optimal source extraction using an analytical PRF.
Note (4): Flag on Reduction used as follows:
a = SL & LL1: opse; LL2: AdOpt
b = SL: man; LL: AdOpt
c = SL: AdOpt; LL:opse
d = SL & LL1: AdOpt; LL2:man
e = SL & LL2: man; LL1: opse
f = SL: opse; LL:AdOpt
g = SL & LL2: AdOpt; LL1:opse
h = SL & LL2: AdOpt; LL1: ECO
i = SL: AdOpt; LL:ECO
j = SL: opse; LL2: AdOpt; LL1: man
k = SL: opse; LL:man
l = SL & LL2: AdOpt; LL1:man
m = SL2: AdOpt; SL1:man
Note (5): Extra note as follows:
n = The IRS program ID 30859
o = The IRS program ID 50374
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Running sequence number (G1)
5- 16 A12 --- IRS IRS identifier (DDddddd+Dddd; J2000) (2)
18- 33 A16 --- 2MASS 2MASS identifier (HHMMSSss+DDMMSSs; J2000)
35- 92 A58 --- OName Other name(s) selected (3)
94 A1 --- f_OName Flag on OName (4)
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Note (2): These are used to identify objects often in other works. The IRS
names come from the position of each object.
Note (3): The sources of selected objects names:
Parenago = Parenago, 1954, II/171 (<Parenago NNNN> in Simbad);
[FHM2008] = Furesz et al., 2008, J/ApJ/676/1109
(<[FHM2008] SN-apNNN or FNN-apNNN> in Simbad);
HBC = Herbig & Bell Catalog, 1988, V/73 ( in Simbad)
HOPS = Herschel Orion Protostar Survey (Megeath+ 2010AAS...21544013M;
see also Furlan+, 2016, J/ApJS/224/5)
Other = V indicate the General Catalogue of Variable Stars (GCVS;
Kukarkin et al. 1971GCVS3.C......0K 1971GCVS3.C......0K; see B/gcvs).
Note (4): Flag as follows:
a = The coordinate of HBC 497 (DL Ori/G3) does not exactly matched to
the IRS coordinate of OriA-270.
b = A 2MASS source is 2-3 arcsec away from the target.
c = JHK photometry is from Robberto et al. (2010, J/AJ/139/950).
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/303] Running sequence number (G1)
4 A1 --- m_Seq Component identifier (1)
6- 16 A11 "Y/M/D" Date UT date of the observation
18- 20 F3.1 arcsec Width [0.3/0.8] Slit width
22- 25 I4 s Tint [80/2520] Total integration time
27- 32 F6.2 deg PA [-55/90]? Position angle of slit
34 A1 --- Note Binary system note (2)
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Note (1): When an object was revealed having a nearby companion and it was
observed separately from the target object with SpeX,
we add "a" and "b".
Note (2): Note as follows:
a = system where the primary and secondary were observed separately;
b = system where the primary and secondary were observed simultaneously
and extracted their spectra separately;
c = system suspected to have a secondary, but the spectrum of each
component was not resolved, and the spectrum is the composite spectrum
of a primary and a secondary.
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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- 3 I3 --- Seq Running sequence number (G1)
5- 16 A12 --- IRS IRS identifier (DDddddd+Dddd; J2000 or
HOPS-NNN)
18- 79 A62 --- SpTl Literature spectral types (see refs.dat file
for references in parenthesis)
81- 84 A4 --- SpT Adopted MK spectral type
86- 91 F6.1 0.1nm EWHa [-263/49]? Equivalent width of Hα;
in Angstroms (3)
93- 95 F3.1 0.1nm EWLi [0/2]? Equivalent width of Li line;
in Angstroms (3)
97-101 F5.2 mag Av [0/35]? Adopted V band extinction
103-107 F5.2 mag e_Av [0/32]? Lower uncertainty in Av
109-113 F5.2 mag E_Av [0/12]? Upper uncertainty in Av
115-122 A8 --- n_Av Method used to determine the adopted Av (4)
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Note (3): From Hernandez (2008), private communication;
Hernandez & Tobin (2009), private communication;
Hsu et al. (2012, J/ApJ/752/59).
Note (4): The method for estimating visual extinction (Av) toward our targets
is described in detail in Kim et al. (2013, J/ApJ/769/149).
To derive the color excess, E(λ1-λ2), we take J, H, and
K bands from 2MASS and I and J bands from DENIS and adopt I-J, J-H,
and H-K photospheric colors from
Pecaut & Mamajek (2013, J/ApJS/208/9). For sources without available
SpT information, we adopt an intrinsic color from J-H and H-K of the
Classical T Tauri Star (CTTS) locus of colors from
Meyer et al. (1997AJ....114..288M 1997AJ....114..288M).
See section 3.2 for further explanations.
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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 A1 --- Type [ab] Observation type (1)
3- 5 I3 --- Seq Running sequence number (G1)
7- 18 A12 --- IRS IRS identifier (DDddddd+Dddd; J2000 or
HOPS-NNN)
20- 23 I4 K Teff [2610/9700]? Effective temperature
25- 30 F6.2 Lsun L* [0.01/195]? Stellar luminosity
32- 35 F4.2 Msun M* [0.09/4.5]? Stellar mass
37- 40 F4.2 Msun e_M* [0.02/0.3]? Error in M*
42 A1 --- l_dM/dt Limit flag on dM/dt
43- 49 F7.2 10-9Msun/yr dM/dt [0.1/1376]? Accrection rate
51- 56 F6.2 10-9Msun/yr e_dM/dt [0.04/572]? Error in dM/dt
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Note (1): Observation type as follows:
a = a Class II object.
b = a companion observed by SpeX.
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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- 3 I3 --- Seq Running sequence number (G1)
5- 8 A4 --- Mod Module used (SL or SLLL)
10- 14 F5.2 --- nK-6 [-3/4]? K band (2.17um) to 5.4-6.0um
spectral index
16- 19 F4.2 --- e_nK-6 [0.03/1.3]? Uncertainty in nK-6
21- 25 F5.2 --- n6-13 [-4/1]? 5.4-6.0 to 12.8-14.0um spectral index
27- 30 F4.2 --- e_n6-13 [0.03/5]? Uncertainty in n6-13
32- 36 F5.2 --- n13-31 [-2.5/3]? 12.8-14.0 to 30.3-31.0um spectral index
38- 41 F4.2 --- e_n13-31 [0.02/3]? Uncertainty in n13-31
43- 47 F5.2 --- n5-12 [-5.1/1]? 5.2-5.54 to 12.8-14.0um spectral index
49- 52 F4.2 --- e_n5-12 [0.02/2.1]? Uncertainty in n5-12
54- 58 F5.2 --- n12-20 [-2.2/4]? 12.7-13.1 to 19.7-19.95um spectral index
60- 63 F4.2 --- e_n12-20 [0.02/5]? Uncertainty in n12-20
65- 69 F5.2 --- nK-25 [-2/1]? K band (2.17um) to 24.5-25.5um
spectral index
71- 74 F4.2 --- e_nK-25 [0.01/0.3]? Uncertainty in nK-25
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq Running sequence number (G1)
5- 8 A4 --- Mod Module used (SL or SLLL)
10- 16 F7.3 um EW10 [-13/528]? Equivalent width of 10um feature
18- 23 F6.3 um e_EW10 [0.05/54]? Uncertainty in EW10
25- 30 F6.3 um EW20 [-1/20]? Equivalent width of 20um feature
32- 36 F5.3 um e_EW20 [0.2/1]? Uncertainty in EW20
38- 44 F7.3 10-15W/m2 F10 [-6/249]? Integrated 10um feature flux (2)
46- 51 F6.3 10-15W/m2 e_F10 [0.003/16]? Uncertainty in F10
53- 58 F6.3 10-15W/m2 F20 [-0.1/58]? Integrated 20um feature flux (2)
60- 65 F6.3 10-15W/m2 e_F20 [0.01/29]? Uncertainty in F20
67- 72 F6.2 --- F11.3/F9.8 [-26/26]? Ratio of 11.3 to 9.8um flux (3)
74- 79 F6.2 --- e_F11.3/F9.8 [0/190]? Uncertainty in F11.3/F9.8
81- 82 A2 --- TDFD ? Disk type: FD=full disk (189 sources) or
TD=Transitional disk (65 sources)
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Note (2): In units of 1e-12erg/s/cm2.
Note (3): Continuum-subtracted and normalized.
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Byte-by-byte Description of file: table11.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Running sequence number (G1)
5- 11 F7.2 --- n20-31 [-4/3]?=-999 19.7-19.95 to 30.3-31.0um
spectral index
13- 19 F7.2 --- e_n20-31 [0.02/6]?=-999 Uncertainty in n20-31
21- 27 F7.1 arcsec d [102/12986] Projected angular distance (2)
29- 32 F4.1 pc Dist [0.2/27] Projected linear distance (2)
34- 35 A2 --- Sec Section (3)
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Note (2): From θ1 Ori C.
Note (3): The region for each section is indicated in Figure 1.
L indicates L1641 in Figure 2.
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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 (as in table 4)
6- 24 A19 --- BibCode ADS/SIMBAD bibcode if any
26- 49 A24 --- Aut First author's name(s)
51-139 A89 --- Comm Comment
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Global notes:
Note (G1): Numbers in this column are from the number sequence of 303 Class II
objects observed in the IRS program ID 30706 and additional
16 Class II objects candidates identified from Herschel Orion
Protostar Survey.
We use these numbers to identify objects conveniently. This number
sequence will be used consistently in other future papers dealing
with the objects in this work.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 25-Oct-2016