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J/ApJ/678/96               Extragalactic H2O masers       (Braatz+, 2008)

The discovery of water maser emission from eight nearby galaxies. Braatz J.A., Gugliucci N.E. <Astrophys. J., 678, 96-101 (2008)> =2008ApJ...678...96B
ADC_Keywords: Active gal. nuclei ; Masers ; Radio sources ; Radial velocities Keywords: galaxies: active - galaxies: nuclei - galaxies: Seyfert - ISM: molecules - masers - radio lines: galaxies Abstract: Using the Green Bank Telescope, we conducted a "snapshot" survey for water maser emission toward the nuclei of 611 galaxies and detected eight new sources. The sample consisted of nearby (v<5000km/s) and luminous (MB←19.5) galaxies, some with known nuclear activity but most not previously known to host AGNs. Our detections include both megamasers associated with AGNs and relatively low luminosity masers probably associated with star formation. The detection in UGC 3789 is particularly intriguing because the spectrum shows both systemic and high-velocity lines indicative of emission from an AGN accretion disk seen edge-on. Based on 6 months of monitoring, we detected accelerations among the systemic features ranging from 2 to 8km/s/yr, the larger values belonging to the most redshifted systemic components. High-velocity maser lines in UGC 3789 show no detectable drift over the same period. Although UGC 3789 was not known to be an AGN prior to this survey, the presence of a disk maser is strong evidence for nuclear activity, and an optical spectrum obtained later has confirmed it. With follow-up observations, it may be possible to measure a geometric distance to UGC 3789. Description: We conducted observations between 2005 September 27 and 2007 April 14 using the Green Bank Telescope (GBT) of the National Radio Astronomy Observatory. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 58 8 H2O masers detected during the Green Bank Telescope (GBT) survey table2.dat 98 648 Galaxies surveyed for water maser emission but not detected
See also: J/AJ/132/1322 : Water maser survey (Gomez+, 2006) J/ApJ/658/1096 : H2O maser classification (Deacon+, 2007) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Name NGC or UGC Source 10- 11 I2 h RAh Hour of right ascension (J2000) 13- 14 I2 min RAm Minute of right ascension (J2000) 16- 19 F4.1 s RAs Second of right ascension (J2000) 21 A1 --- DE- Declination sign (J2000) 22- 23 I2 deg DEd Degree of right ascension (J2000) 25- 26 I2 arcmin DEm Arcminute of right ascension (J2000) 28- 29 I2 arcsec DEs Arcsecond of right ascension (J2000) 31- 34 I4 km/s HVel Heliocentric recession velocity from NED 36- 37 I2 km/s e_HVel HVel uncertainty 39- 41 I3 mJy Speak Peak flux density 43- 47 F5.1 solLum Liso Inferred isotropic luminosity of the maser emission 49- 58 A10 "YYYY/MM/DD" ObsDate Date of observation
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 13 A13 --- Name Source name 15- 16 I2 h RAh Hour of Right Ascension (J2000) 18- 19 I2 min RAm Minute of Right Ascension (J2000) 21- 25 F5.2 s RAs Second of Right Ascension (J2000) 27 A1 --- DE- Sign of the Declination (J2000) 28- 29 I2 deg DEd Degree of Declination (J2000) 31- 32 I2 arcmin DEm Arcminute of Declination (J2000) 34- 37 F4.1 arcsec DEs Arcsecond of Declination (J2000) 39- 43 I5 km/s Vel Recession velocity 45- 54 A10 "YYYY/MM/DD" ObsDate Date of the observation 56- 60 F5.1 K Temp System temperature from first spectral window 62- 63 I2 min Time Integration time 65- 68 F4.1 mJy rms1 RMS noise from first spectral window (1) 70- 74 I5 km/s V1low Lower velocity range covered by first window 76- 80 I5 km/s V1hi Upper velocity range covered by first window 82- 86 F5.1 mJy rms2 RMS noise from second spectral windown (1) 88- 92 I5 km/s V2low Lower velocity range covered by second window 94- 98 I5 km/s V2hi Upper velocity range covered by second window
Note (1): After Hanning smoothing.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 16-Sep-2010
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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