J/ApJS/153/523 Starless cores in CS(3-2) and DCO+(2-1) lines (Lee+, 2004)
A survey for infall motions toward starless cores.
III. CS (3-2) and DCO+ (2-1) observations.
Lee C.W., Myers P.C., Plume R.
<Astrophys. J. Suppl. Ser., 153, 523-543 (2004)>
=2004ApJS..153..523L 2004ApJS..153..523L
ADC_Keywords: Interstellar medium ; Surveys ; Line Profiles
Keywords: ISM: globules - ISM: kinematics and dynamics - stars: formation
Abstract:
We present CS(3-2) and DCO+(2-1) observations of 94 starless cores
and compare the results with previous CS(2-1) and N2H+(1-0)
observations to study inward motions in starless cores. Eighty-four
cores were detected in both CS and DCO+ lines. We identify 18 infall
candidates based on observations of CS(3-2), CS(2-1), DCO+(2-1) and
N2H+(1-0). The eight best candidates, L1355, L1498, L1521F, L1544,
L158, L492, L694-2, and L1155C-1, each show at least four indications
of infall asymmetry and no counterindications. Fits of the spectra to
a two-layer radiative transfer model in ten infall candidates suggest
that the median effective line of sight speed of the inward-moving gas
is ∼0.07km/s for CS(3-2) and ∼0.04km/s for CS(2-1).
Description:
We observed both the CS(3-2) and the DCO+(2-1) transitions at
the NRAO 12m telescope in two seasons, 1998 June and October.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 96 94 Starless cores observed in CS(3-2) and/or
DCO+(2-1) lines
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See also:
J/ApJ/526/788 : Survey of infall motions toward starless cores (Lee+, 1999)
J/ApJS/123/233 : Catalog of Optically selected cores (Lee+, 1999)
J/ApJS/152/81 : CO survey toward starless cores (Park+, 2004)
J/ApJ/664/928 : Starless cores in HCN(J=1-0) (Sohn+ 2007)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- [LM99] Observed region name
15- 16 I2 h RAh Central hour of right ascension (B1950)
18- 19 I2 min RAm Central minute of right ascension (B1950)
21- 24 F4.1 s RAs Central second of right ascension (B1950)
26 A1 --- DE- Central declination sign (B1950)
27- 28 I2 deg DEd Central degree of declination (B1950)
30- 31 I2 arcmin DEm Central arcminute of declination (B1950)
33- 34 I2 arcsec DEs Central arcsecond of declination (B1950)
36- 37 A2 --- l_TCS [≤ ] Limit flag on TCS (1)
38- 41 F4.2 K TCS ? Antenna temperature of CS(3-2) line (146.97GHz)
43- 44 A2 --- l_TDCO [≤ ] Limit flag on TDCO (1)
45- 48 F4.2 K TDCO ? Antenna temperature of DCO+(2-1) (144.08GHz)
50- 55 F6.2 km/s VCS ? Velocity of CS(3-2) line (146.97GHz) (2)
57- 60 F4.2 km/s e_VCS ? VCS uncertainty
62- 66 F5.2 km/s VDCO ? Velocity of DCO+(2-1) line (144.08GHz) (2)
68- 71 F4.2 km/s e_VDCO ? VDCO uncertainty
73- 77 F5.2 --- dVCS ? Normalized velocity difference of CS(3-2) (3)
79- 82 F4.2 --- e_dVCS ? dVCS uncertainty
84- 88 F5.2 --- dVDCO ? Normalized velocity difference of
DCO+(2-1) (3)
90- 93 F4.2 --- e_dVDCO ? dVDCO uncertainty
95 I1 --- src [1/2] Source selection (4)
96 A1 --- f_[LM99] [v] Flag for L1271-1 (5)
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Note (1): For undetected lines three σ-values of the observed lines
are given.
Note (2): The velocities of the detected lines were obtained by Gaussian fits of
the lines. All designated errors are 1σ values from the fits.
Note (3): Normalized velocity differences (δV) of CS(3-2) and DCO+ with
respect to N2H+ velocities from Lee et al. 1999,
Cat. J/ApJ/526/788. For example, δVCS32 is defined as
δVCS32=(VCS32-VN2H+)/ΔVN2H+.
The 1σ propagation errors are given at each value of δV.
Note (4): Selection criterion source as follows:
1 = selected from Lee et al. 1999, Cat. J/ApJ/526/788
2 = selected from Lee & Myers, 1999, Cat. J/ApJS/123/233
Note (5): v = L1271-1 source has two more velocity components of
VLSR=-12.87, -6.96km/s.
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History:
From electronic version of the journal
References:
Lee et al. Paper I. 1999ApJ...526..788L 1999ApJ...526..788L. Cat. J/ApJ/526/788.
Lee et al. Paper II. 2001ApJS..136..703L 2001ApJS..136..703L.
(End) Emmanuelle Perret [CDS] 29-Sep-2010