J/ApJ/703/1964 Spectra of three nearby star-forming regions (Furlan+, 2009)
Disk evolution in the three nearby star-forming regions of Taurus, Chamaeleon,
and Ophiuchus.
Furlan E., Watson D.M., McClure M.K., Manoj P., Espaillat C., D'Alessio P.,
Calvet N., Kim K.H., Sargent B.A., Forrest W.J., Hartmann L.
<Astrophys. J., 703, 1964-1983 (2009)>
=2009ApJ...703.1964F 2009ApJ...703.1964F
ADC_Keywords: Molecular clouds ; Spectra, infrared ; YSOs
Keywords: circumstellar matter - infrared: stars - stars: formation -
stars: pre-main sequence
Abstract:
We analyze samples of Spitzer Infrared Spectrograph spectra of T Tauri
stars in the Ophiuchus, Taurus, and Chamaeleon I star-forming regions,
whose median ages lie in the <1-2Myr range. The median mid-infrared
spectra of objects in these three regions are similar in shape,
suggesting, on average, similar disk structures. When normalized to
the same stellar luminosity, the medians follow each other closely,
implying comparable mid-infrared excess emission from the
circumstellar disks. We use the spectral index between 13 and 31um and
the equivalent width of the 10um silicate emission feature to identify
objects whose disk configuration departs from that of a continuous,
optically thick accretion disk. Based on their medians and fraction of
evolved disks, T Tauri stars in Taurus and Chamaeleon I are very
alike.
Description:
Our Taurus, Chamaeleon I, and Ophiuchus targets were observed as part
of an IRS guaranteed-time program during IRS campaigns 3, 4, 12, 19,
20, 21, 22, 23, 29, and 30, which were scheduled from 2004 February to
2006 April. The objects (table 5) were originally selected from
infrared catalogs of YSOs in these regions that were compiled before
the launch of the Spitzer Space Telescope in 2003. All targets were
observed with either the two low-resolution IRS modules (Short-Low
(SL) and Long-Low (LL), 5.2-14um and 14-38um, respectively) or the SL
module and the two high-resolution modules (Short-High (SH) and
Long-High (LH), 10-19um and 19-37um, respectively). In this way, we
obtained the full mid-infrared spectrum from 5 to 40um for each target.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 45 63 Properties of the targets in the Ophiuchus core
region
table2.dat 45 85 Properties of the targets in the Taurus region
table3.dat 45 69 Properties of the targets in the Chamaeleon I
region
table4.dat 43 15 Properties of the targets in the Ophiuchus
off-core region
table5.dat 46 233 Target names and coordinates
table6a.dat 40 310 Ophiuchus core median (H normalization)
table6b.dat 40 310 Chamaeleon I median (H normalization)
table6c.dat 40 310 Taurus median (H normalization)
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/156 : IRAS Faint Source Catalog, |b| > 10, Version 2.0 (Moshir+ 1989)
V/73 : Emission-Line Stars of the Orion Population (Herbig+ 1988)
J/A+A/519/A34 : YSOs in DROXO (Deep rho Oph XMM obs.) (Pillitteri+, 2010)
J/A+A/515/A75 : Low-mass population in ρ Oph cloud (Alves de Oliveira+,
2010)
J/ApJ/692/973 : Protostars in Perseus, Serpens and Ophiuchus (Enoch+, 2009)
J/PASJ/60/209 : Faint companions around YSOs in TMC (Itoh+, 2008)
J/ApJ/683/822 : Star formation in Ophiuchus and Perseus II. (Jorgensen+, 2008)
J/ApJS/173/104 : Stellar population in Chamaeleon I (Luhman, 2007)
J/A+A/452/245 : Near-IR photometry of PMS stars in rho Oph (Natta+, 2006)
J/A+A/460/695 : Search for Associations Containing Young stars (Torres+, 2006)
J/AJ/130/1733 : Optical spectroscopy of ρ Oph stars (Wilking+, 2005)
J/AJ/126/2971 : UBVRI photometry of 131 Herbig Ae/Be (Vieira+, 2003)
J/A+A/372/173 : ISOCAM observations of the rho Ophiuchi cloud (Bontemps+,
2001)
J/A+A/357/219 : ISOCAM observations in Cha I. (Persi+, 2000)
J/ApJS/112/109 : Rho Oph Near-IR Positions and Photometry (Barsony+, 1997)
J/ApJS/101/117 : UBVRIJHKLMNQ photometry in Taurus-Auriga (Kenyon+ 1995)
Byte-by-byte Description of file: table1.dat table2.dat table3.dat table4.dat
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Bytes Format Units Label Explanations
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1- 20 A20 --- Name Target name
22- 26 A5 --- SpT Adopted MK spectral type (1)
28- 31 F4.1 --- Av ? Optical extinction AV (assuming RV=3.1) (2)
33- 37 F5.2 um EW ? The 10um equivalent width in um
39- 43 F5.2 --- n13-31 ? The 13-31um spectral index (n13-31)
45 A1 --- Med [x]? x: the object was used in the median
calculation
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Note (1): Spectral types were taken from references below:
* In table 1: from Brandner & Zinnecker (1997A&A...321..220B 1997A&A...321..220B);
Luhman & Rieke (1999ApJ...525..440L 1999ApJ...525..440L);
Wilking et al. (2005, Cat. J/AJ/130/1733);
Natta et al. (2006, Cat. J/A+A/452/245);
McClure et al. (2010ApJS..188...75M 2010ApJS..188...75M);
* In table 2: from Kenyon et al. (1990AJ.....99..869K 1990AJ.....99..869K);
Hartigan et al. (1994ApJ...427..961H 1994ApJ...427..961H);
Strom & Strom (1994ApJ...424..237S 1994ApJ...424..237S);
Kenyon & Hartmann (1995, Cat. J/ApJS/101/117);
Torres et al. (1995AJ....109.2146T 1995AJ....109.2146T);
Kenyon et al. (1998AJ....115.2491K 1998AJ....115.2491K);
Briceno et al. (1998AJ....115.2074B 1998AJ....115.2074B);
Luhman (2000ApJ...544.1044L 2000ApJ...544.1044L);
White & Ghez (2001ApJ...556..265W 2001ApJ...556..265W);
Hartigan & Kenyon (2003ApJ...583..334H 2003ApJ...583..334H);
White & Basri (2003ApJ...582.1109W 2003ApJ...582.1109W);
White & Hillenbrand (2004ApJ...616..998W 2004ApJ...616..998W);
Calvet et al. (2004AJ....128.1294C 2004AJ....128.1294C);
Furlan et al. (2006ApJS..165..568F 2006ApJS..165..568F).
* In table 3: spectral type and, where available, extinction information
were taken from Luhman (2004ApJ...602..816L 2004ApJ...602..816L) and Gomez & Mardones
(2003AJ....125.2134G 2003AJ....125.2134G). For objects without published or with uncertain
extinction values, the optical extinction AV was derived using the
observed optical/near-infrared colors and intrinsic colors based on
the spectral type or a typical CTTS excess (see the text for details).
* In table 4: spectral types were taken from Herbig & Bell (1988, Cat. V/73);
Chen et al. (1995ApJ...445..377C 1995ApJ...445..377C);
Preibisch et al. (1998, Cat. J/A+A/333/619);
Vieira et al. (2003, Cat. J/AJ/126/2971);
Torres et al. (2006, Cat. J/A+A/460/695);
McClure et al. (2010ApJS..188...75M 2010ApJS..188...75M).
Note (2): Uncertainties in AV are detailing below:
* In table 1: uncertainties in AV, ranging from 1% to 30% of the AV value
(McClure et al. 2010ApJS..188...75M 2010ApJS..188...75M), account for ∼25% of the error
bars of EW(10um) and n13-31.
* In table 2: uncertainties in AV, assumed to be 0.3mag (Kenyon & Hartmann
1995, Cat. J/ApJS/101/117), account for ∼15% and 1% of the error bars
of EW(10um) and n13-31, respectively.
* In table 3: uncertainties in AV, assumed to be 0.46mag (Luhman 2007,
Cat. J/ApJS/173/104), account for ∼10% and 2% of the error bars of
EW(10um) and n13-31, respectively.
* In table 4: uncertainties in AV, which are typically 0.3mag
(McClure et al. 2010ApJS..188...75M 2010ApJS..188...75M), account for ∼10% and 1% of the
error bars of EW(10um) and n13-31, respectively.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 20 A20 --- Name Target name
23- 24 I2 h RAh Hour of Right Ascension (J2000) (3)
26- 27 I2 min RAm Minute of Right Ascension (J2000)
29- 33 F5.2 s RAs Second of Right Ascension (J2000)
36 A1 --- DE- Sign of the Declination (J2000) (3)
37- 38 I2 deg DEd Degree of Declination (J2000)
40- 41 I2 arcmin DEm Arcminute of Declination (J2000)
43- 46 F4.1 arcsec DEs Arcsecond of Declination (J2000)
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Note (3): Objects with 4h<RA<5.5h are in Taurus,
objects with 10h<RA<12h are in Chamaeleon I,
objects with 16h<RA<17h are in Ophiuchus.
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Byte-by-byte Description of file: table6[abc].dat
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Bytes Format Units Label Explanations
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1- 4 F4.1 um lambda Wavelength in micron
8- 16 E9.3 mW/m2 nuFnu Median flux density νFν (1)
20- 28 E9.3 mW/m2 e_nuFnu Lower quartile in nuFnu (1)
32- 40 E9.3 mW/m2 E_nuFnu Upper quartile in nuFnu (1)
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Note (1): These are the median, lower quartile, and upper quartile for the
Ophiuchus core (L1688), Chamaeleon I and Taurus calculated using the
IRS spectra of 28, 28 and 52 Class II objects, respectively, with
K5-M2 spectral types, normalized at their 2MASS H-band fluxes.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 02-Nov-2011