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J/ApJ/647/418       Ground-state OH masers in W3(OH) study   (Fish+, 2006)

A very high spectral resolution study of ground-state OH masers in W3(OH). Fish V.L., Brisken W.F., Sjouwerman L.O. <Astrophys. J., 647, 418-431 (2006)> =2006ApJ...647..418F
ADC_Keywords: Interstellar medium ; Masers Keywords: ISM: individual (W3(OH)) - ISM: molecules - line: profiles - masers - radio lines: ISM Abstract: We present VLBA observations of the ground-state hydroxyl masers in W3(OH) at 0.02km/s spectral resolution. Over 250 masers are detected, including 56 Zeeman pairs. Line shapes are predominantly Gaussian or combinations of several Gaussians, with normalized deviations typically of the same magnitude as in masers in other species. Description: The National Radio Astronomy Observatory's Very Long Baseline Array (VLBA) was used to observe the ground-state OH masers in two massive star-forming regions, W3(OH) and Orion KL. Data were collected starting at approximately 09:00 UT on 2005 September 20 using all 10 antennas. Objects: ---------------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------------- 02 27 04.1 +61 52 22 W3(OH) = GRS 133.90 +01.10 ---------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 58 253 Detected Masers in W3(OH) table2.dat 61 56 Zeeman Pairs in W3(OH)
Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 3 I3 --- [FBS2006b] [1/253] Spot number 5- 8 I4 MHz Freq Frequency 10 A1 --- Pol [LR] Left or Right circular polarization 12- 19 F8.2 mas oRA Right Ascension offset (2) 21- 28 F8.2 mas oDE Declination offset (2) 30- 35 F6.2 km/s Vel Peak emission channel LSR velocity 37- 41 F5.2 Jy Bright Peak brightness in units of Jy/beam (3) 43- 48 F6.3 km/s/mas Grad ? Velocity gradient 50- 53 I4 deg PA [-180/180]? Position angle (4) 55 A1 --- f_PA [f] f: Gradient computed over multiple peaks 57- 58 I2 --- Pair ? Zeeman pair number as listed in Table 2
Note (2): Centroid of Gaussian fit in channel of peak emission. See Section 3 for discussion of relative alignment of maser spots at different frequencies and polarizations. Note (3): Of Gaussian fit in channel of peak emission. Note (4): East of North in direction of increasing line-of-sight velocity across the maser spot.
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 2 I2 --- Pair [1/56] Pair Number 4- 7 I4 MHz Freq Frequency 9- 15 F7.2 mas oRA1 Left circular polarisation (LCP) component Right Ascension offset 17- 24 F8.2 mas oDE1 LCP component Declination offset 26- 31 F6.2 km/s Vel1 LCP component Peak emission channel LSR velocity 33- 39 F7.2 mas oRA2 Right circular polarisation (RCP) component Right Ascension offset 41- 48 F8.2 mas oDE2 RCP component Declination offset 50- 55 F6.2 km/s Vel2 RCP component Peak emission channel LSR velocity 57- 60 F4.1 10-7T B Magnetic field, in mGauss (1) 61 A1 --- n_B [b] Note on B (2)
Note (1): Assumes splitting appropriate for ±1 components for 1612 and 1720MHz transitions. Positive values indicate magnetic fields oriented in the hemisphere pointing away from the observer. Note (2): Large separation between LCP and RCP components. These may be Zeeman cousins as defined in Fish & Reid (2006ApJS..164...99F).
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 08-Jul-2008
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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