CDROM/APJS/V106/P463 SiO Maser Sources (Jiang+ 1996) ================================================================================ SiO Maser Sources in the Outer Disk of the Galaxy B. W. Jiang, S. Deguchi, I. Yamamura, Y. Nakada, S. H. Cho, and T. Yamagata <1996, ApJS, 106, 463> =1996ApJS..106..463J ================================================================================ Abstract: The observations in the 28SiO J = 1-0 v = 1, J = 1-0 v = 2 lines and the 29SiO J = 1-0, v = 0 lines were simultaneously made toward 181 color-selected IRAS sources in the outer disk of the Galaxy (at longitudes between 90 deg and 250 deg). The 28SiO lines were detected in 63 sources (56 new) and the 29SiO line in 11 sources (9 new). Most of the detections are optically variable stars, mainly Mira-type variables and a few semiregular variables. The detection rate (35%) is much lower than that of the bulge survey performed by the same observational system - the 45 m telescope at Nobeyama Radio Observatory. The lower detection rate of SiO maser emission is partly attributed to the increase of contaminations by stars with C-rich circumstellar envelopes and young stellar objects in the outer disk sample. The kinematical implications of the observational results are also discussed. The luminosity distances to the SiO maser sources are estimated from their IRAS fluxes at 12 um and colors. By combining the SiO radial velocity and the luminosity distance, the rotation curve of the outer Galactic disk is found to be slightly falling within the Galactocentric distance between 8.5 and 12 kpc. The sources located within 20 deg from the Galactic anticenter direction are used to check for a peculiar motion of the local standard of rest. Keywords: Galaxy: kinematics and dynamics -- ISM: molecules -- masers -- stars: variables: other (long-period variables) File Summary: -------------------------------------------------------------------------------- File Name Lrecl Records Explanations -------------------------------------------------------------------------------- table1a.dat 74 123 Line parameters of Gaussian components of the v=1 and v=2 detections table2a.dat 74 46 Line parameters of Gaussian components of the 29SiO detections table3.dat 103 117 Infrared properties and observation parameters of the nondetections -------------------------------------------------------------------------------- Byte-per-byte Description of file: table1a.dat table2a.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1-10 A10 --- IRAS IRAS PSC name 11-17 F7.3 K TA1 *[]? Peak antenna temperature 18 A1 --- n_TA1 *No data flag for TA1 19-24 F6.3 K rms1 *[]? 1 sigma noise level of line observation 25-33 F9.3 km/s Vlsr1 *[]? Velocity in Local Standard of Rest 34 A1 --- n_Vlsr1 *No data flag for Vlsr1 35-41 F7.3 km/s FWHM1 *[]? Full width at half maximum 42 A1 --- n_FWHM1 *No data flag for FWHM1 43-49 F7.3 K TA2 *[]? Peak antenna temperature 50 A1 --- n_TA2 *No data flag for TA2 51-56 F6.3 K rms2 *[]? 1 sigma noise level of line observation 57-65 F9.3 km/s Vlsr2 *[]? Velocity in Local Standard of Rest 66 A1 --- n_Vlsr2 *No data flag for Vlsr2 67-73 F7.3 km/s FWHM2 *[]? Full width at half maximum 74 A1 --- n_FWHM2 *No data flag for FWHM2 -------------------------------------------------------------------------------- Notes for file: table1a.dat table2a.dat -------------------------------------------------------------------------------- IRAS: If this field is blank, the data are continuations for the previous object. TA1, rms1, Vlsr1, FWHM1: Gaussian components for SiO v = 1 J = 1-0 line. TA2, rms2, Vlsr2, FWHM2: Gaussian components for SiO v = 2 J = 1-0 line. n_TA1, n_Vlsr1, n_FWHM1, n_TA2, n_Vlsr2, n_FWHM2: No data flags. These are to distinguish from the blank fields for rms1 and rms2, which are only given on the first line of data for each object. -------------------------------------------------------------------------------- Byte-per-byte Description of file: table3.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1-10 A10 --- IRAS IRAS PSC name 11-17 F7.1 deg GLon Galactic longitude 18-23 F6.1 deg GLat Galactic latitude 24-31 F8.3 Jy F_12 IRAS flux at 12 microns 32-38 F7.2 --- C_12 IRAS color C_12 (log F_25/F_12) 39-45 F7.2 --- C_23 IRAS color C_23 (log F_60/F_25) 46-48 I3 --- Var IRAS variability index 49-52 I4 --- LRS []? IRAS Low Resolution Spectrum class 53-54 I2 --- Id []? ID status; 1=identified; 0=unidentified 55-61 F7.3 K rms1 1-sigma level for SiO maser v=1 line obs. 62-68 F7.3 K rms2 1-sigma level for SiO maser v=2 line obs. 69 1X --- --- Blank 70-77 A8 --- Date Date of SiO maser observation, yymmddhh 78 1X --- --- Blank 79-103 A25 --- Other *Result of obs. in other molecular lines -------------------------------------------------------------------------------- Notes for file: table3.dat -------------------------------------------------------------------------------- Other: Results of observations in other molecular lines, '+' means positive result and '-' means negative, number in parentheses are reference numbers, as follows: 1. te Lintel Hekkert et al., 1990, A&AS, 90, 327 2. Le Sequeren et al., 1992, A&A, 254, 133 3. Eder et al., 1988, ApJS, 66, 183 4. Lewis et al., 1990, ApJ, 362, 634 5. Chengalur et al., 1993, ApJS, 89, 189 6. Lewis, 1994, ApJS, 93, 549 7. Loup et al., 1993, A&AS, 99, 291 8. Wouterlout et al., 1989, A&AS, 80, 149 9. Sivagnanam et al., 1990, A&A, 233, 112 10. Galt et al., 1989, AJ, 98, 2182 11. Nyman et al., 1993, A&A, 280, 551 12. Benson et al., 1990, ApJS, 74, 911 13. Kastner et al., 1993, A&A, 275, 163 -------------------------------------------------------------------------------- ================================================================================ (End) Lee Brotzman [ADS] 09-Nov-96