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J/ApJ/664/928       Starless cores in HCN(J=1-0)                   (Sohn+ 2007)

Probing inward motions in starless cores using the HCN(J = 1-0) hyperfine transitions: a pointing survey toward central regions. Sohn J., Lee C.W., Park Y.-S., Lee H.M., Myers P.C., Lee Y. <Astrophys. J., 664, 928-941 (2007)> =2007ApJ...664..928S
ADC_Keywords: Globules ; Interstellar medium ; Radio lines Keywords: ISM: globules - ISM: kinematics and dynamics - ISM: molecules - stars: formation Abstract: We have carried out a survey toward the central regions of 85 starless cores in HCN(J=1-0) to study inward motions in the cores. Sixty-four cores were detected with HCN lines. The infall asymmetry in the HCN spectra is found to be more prevalent, and more prominent than in any other previously used infall tracers such as CS(J=2-1), DCO+(J=2-1), and N2H+(J=1-0). We have found a close relation between the intensities of the HCN and N2H+ lines. Description: We have conducted single-pointing observations for 85 starless cores in HCN(J=1-0) with the 13.7m telescope of the Taeduk Radio Astronomical Observatory (TRAO) in Korea. Observations were carried out during 2002 January, February, November, and December and 2003 January to May. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 138 85 The line parameters of the starless cores observed in HCN and H13CN J=1-0 lines table2.dat 37 68 Line asymmetry colors of starless cores
Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Name Source name 10 A1 --- f_Name [a] double peaked sources (1) 12- 13 I2 h RAh Hour of Right Ascension (J2000) (2) 15- 16 I2 min RAm Minute of Right Ascension (J2000) (2) 18- 21 F4.1 s RAs Second of Right Ascension (J2000) (2) 23 A1 --- DE- Sign of the Declination (J2000)(2) 24- 25 I2 deg DEd Degree of Declination (J2000) (2) 27- 28 I2 arcmin DEm Arcminute of Declination (J2000) (2) 30- 31 I2 arcsec DEs Arcsecond of Declination (J2000) (2) 33 A1 --- l_T.HCN The 3σ limit flag on T.HCN 34- 39 F6.2 K T.HCN Antenna temperature of HCN J=1-0 (F=2-1) 41 A1 --- l_T.H13CN The 3σ limit flag on T.H13CN 42- 47 F6.2 K T.H13CN ? Antenna temperature of H13CN J=1-0 49- 53 F5.2 km/s V(F=0-1) ? Peak HCN J=1-0(F=0-1) intensity velocity 55- 58 F4.2 km/s e_V(F=0-1) ? Error in V(F=0-1) 60- 64 F5.2 km/s V(F=1-1) ? Peak HCN J=1-0(F=1-1) intensity velocity 66- 69 F4.2 km/s e_V(F=1-1) ? Error in V(F=1-1) 71- 75 F5.2 km/s V(F=2-1) ? Peak HCN J=1-0(F=2-1) intensity velocity 77- 80 F4.2 km/s e_V(F=2-1) ? Error in V(F=2-1) 82- 86 F5.2 km/s VN2H ? The N_2_H+ velocity (3) 88- 92 F5.2 km/s e_VN2H ? Error in VN2H 94- 97 F4.2 km/s W(N2H) ? The FWHM of N_2_H+ (3) 99-102 F4.2 km/s e_W(N2H) ? Error in d(N2H) 104-109 F6.3 --- d(F=0-1) ? Normalized HCN J=1-0(F=0-1) velocity difference 111-114 F4.2 --- e_d(F=0-1) ? Error in d(F=0-1) 116-121 F6.3 --- d(F=1-1) ? Normalized HCN J=1-0(F=1-1) velocity difference 123-126 F4.2 --- e_d(F=1-1) ? Error in d(F=1-1) 128-133 F6.3 --- d(F=2-1) ? Normalized HCN J=1-0(F=2-1) velocity difference 135-138 F4.2 --- e_d(F=2-1) ? Error in d(F=2-1)
Note (1): a = These sources have double peaks in HCN spectra whose intensity ratios are close to 1.0 within error. The HCN peak velocities for such sources were obtained by the Gaussian fit after masking a fainter peak between two components. The δV values of these sources are not used in our statistical analysis of δV. Note (2): Coordinates observed toward the sources which are from the Lee & Myers (1999, Cat. J/ApJS/123/233) catalog. Note (3): Taken from Lee & Myers (1999, Cat. J/ApJS/123/233) by slightly shifting them from the original values using the new frequency of N2H+ J=1-0 taken from Lee, Myers & Tafalla (2001ApJS..136..703L).
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Name Source name 10- 11 I2 --- d(VF=2-1) ? Normalized velocity difference line asymmetry diagnostic for HCN(1-0)F=2-1 (1) 13- 14 I2 --- d(VCS2-1) ? Normalized velocity difference line asymmetry diagnostic for HCN(1-0)CS(2-1) (1) 16- 17 I2 --- d(VCS3-2) ? Normalized velocity difference line asymmetry diagnostic for HCN(1-0)CS(3-2) (1) 19- 20 I2 --- d(VDCO) ? Normalized velocity difference line asymmetry diagnostic for HCN(1-0)DCO+(2-1) (1) 22- 23 I2 --- Tb/Tr(F=2-1) ? Blue to Red ratio line asymmetry diagnostic for HCN(1-0)F=2-1 (1) 25- 26 I2 --- Tb/Tr(CS2-1) ? Blue to Red ratio line asymmetry diagnostic for HCN(1-0)CS(2-1) (1) 28- 29 I2 --- Tb/Tr(CS3-2) ? Blue to Red ratio line asymmetry diagnostic for HCN(1-0)CS(3-2) (1) 31- 32 I2 --- Tb/Tr(DCO) ? Blue to Red ratio line asymmetry diagnostic for HCN(1-0)DCO+(2-1) (1) 34 I1 --- Tb/Tr(N2H) ? Blue to Red ratio line asymmetry diagnostic for HCN(1-0)N2H+ (1) 36- 37 I2 --- Total Total color code
Note (1): The δV value is flagged as follows: 1 = δV≤-5σ(δV) 0 = |δV|<5σ(δV) -1 = δV≥-5σ(δV) A good infall candidate should be given a number "1". In a similar way the intensity ratio is also flagged with: 1 = Tb/Tr>1+σ(Tb/Tr), 0 = 1-σ(Tb/Tr)<Tb/Tr<1+σ(Tb/Tr), -1 = Tb/Tr<1-σ(Tb/Tr), where the values of Tb and Tr were obtained from Gaussian fits of blue and red components of the profile. Again, a dense core flagged with 1 should be considered to be an infall candidate. The above criteria used for selecting infall candidates are similar to those used by LMT99 (J/ApJS/123/233) and LMP04 (J/ApJS/123/233), but have more data from this HCN study.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 29-Aug-2009
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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