J/ApJ/646/297 Spitzer observations of pre-main-sequence stars (Rebull+, 2006)
A correlation between pre-main-sequence stellar rotation rates and IRAC excesses
in Orion.
Rebull L.M., Stauffer J.R., Megeath S.T., Hora J.L., Hartmann L.
<Astrophys. J., 646, 297-303 (2006)>
=2006ApJ...646..297R 2006ApJ...646..297R
ADC_Keywords: Clusters, open ; Stars, pre-main sequence ; Infrared sources
Keywords: open clusters and associations: individual (Orion) - stars: rotation
Abstract:
Early observations of T Tauri stars suggested that stars with evidence
of circumstellar accretion disks rotated slower than stars without
such evidence, but more recent results are not as clear. Near-IR
circumstellar disk indicators, although the most widely available, are
subject to uncertainties that can result from inner disk holes and/or
the system inclination. Mid-infrared observations are less sensitive
to such effects, but until now, these observations have been difficult
to obtain. The Spitzer Space Telescope now easily enables mid-infrared
measurements of large samples of PMS stars covering a broad mass range
in nearby star-forming regions. Megeath and collaborators surveyed the
Orion Molecular Clouds (1Myr) with the IRAC instrument (3.6, 4.5, 5.8,
8um) as part of a joint IRAC and MIPS GTO program. We examine the
relationship between rotation and Spitzer mid-IR fluxes for 900 stars
in Orion for stars between 3 and 0.1M☉. We find in these Spitzer
data the clearest indication to date that stars with longer periods
are more likely than those with short periods to have IR excesses
suggestive of disks.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 87 464 Stars detected in 3.6 and 8 microns with periods
from the literature
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Star name (1)
12- 13 I2 h RAh Hour of Right Ascension (J2000)
15- 16 I2 min RAm Minute of Right Ascension (J2000)
18- 21 F4.1 s RAs Second of Right Ascension (J2000)
23 A1 --- DE- Sign of the Declination (J2000)
24- 25 I2 deg DEd Degree of Declination (J2000)
27- 28 I2 arcmin DEm Arcminute of Declination (J2000)
30- 33 F4.1 arcsec DEs Arcsecond of Declination (J2000)
35- 39 F5.2 mag F3.6um IRAC 3.6 micron magnitude (see text)
41- 45 F5.3 mag e_F3.6um Error in F3.6um
47- 51 F5.2 mag F4.5um IRAC 4.5 micron magnitude (see text)
53- 57 F5.3 mag e_F4.5um Error in F4.5um
59- 63 F5.2 mag F5.8um ? IRAC 5.8 micron magnitude (see text)
65- 69 F5.3 mag e_F5.8um ? Error in F5.8um
71- 75 F5.2 mag F8um IRAC 8 micron magnitude (see text)
77- 81 F5.3 mag e_F8um Error in F8um
83- 87 F5.2 d Per Period
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Note (1): Acronyms used are:
R01 = numbers come from Rebull (2001, Cat. J/AJ/121/1676),
[R2001] NNNN in Simbad
HBC = numbers from Herbig & Bell (1988, Cat. V/73),
HBC NNN in Simbad
Par = numbers from Parenago (1954, Cat. II/171),
Parenago NNNN in Simbad
CHS = numbers from Carpenter et al. (2001, Cat. J/AJ/121/3160),
[CHS2001] NNNNN in Simbad
H97 = numbers from Hillenbrand (1997, Cat. J/AJ/113/1733),
[H97b] NNNNa in Simbad
HBJM = numbers from Herbst et al. (2001ApJ...554L.197H 2001ApJ...554L.197H)
[H97b] NNNN in Simbad
JW = numbers come from Jones & Walker (1988AJ.....95.1755J 1988AJ.....95.1755J)
JW NNNN in Simbad
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 02-May-2008