J/A+A/527/A90 WSRT Virgo HI filament survey (Popping+, 2011)
The WSRT Virgo HI filament survey. I. Total power data.
Popping A., Braun R.
<Astron. Astrophys., 527, A90 (2011)>
=2011A&A...527A..90P 2011A&A...527A..90P
ADC_Keywords: Surveys ; Clusters, galaxy ; Galaxies, radio ; H I data
Keywords: galaxies: evolution - intergalactic medium
Abstract:
Observations of neutral hydrogen can provide a wealth of information
about the kinematics of galaxies. To learn more about the large-scale
structures and accretion processes, the extended environment of
galaxies have to be observed. Numerical simulations predict a cosmic
web of extended structures and gaseous filaments.
To observe the direct vicinity of galaxies, column densities have to
be achieved that probe the regime of Lyman limit systems. Typically,
HI observations are limited to a brightness sensitivity of
NHI∼1019cm-2, but this has to be improved by ∼2 orders of
magnitude.
With the Westerbork Synthesis Radio Telescope (WSRT), we mapped the
galaxy filament connecting the Virgo Cluster with the Local Group.
About 1500 square degrees on the sky was surveyed with Nyquist sampled
pointings. By using the WSRT antennas as single-dish telescopes
instead of the more conventional interferometer, we were very
sensitive to extended emission. The survey consists of a total of
22000 pointings, and each pointing was observed for two minutes
with 14 antennas.
Description:
To obtain the highest possible brightness sensitivity in
cross-correlations, the WSRT (Westerbork Synthesis Radio Telescope)
was configured to simulate a large filled aperture in projection.
Twelve of the 14 WSRT 25m telescopes were positioned at regular
intervals of 144m.
A deep fully-sampled survey of the galaxy filament joining the Local
Group to the Virgo Cluster has been undertaken, extending from 8 to
17h in RA and from -1 to +10 degrees in declination and covering
40MHz of bandwidth with 8km/s resolution.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 97 128 Physical properties of confirmed detections in
the Westerbork Virgo Filament Survey
total-power data
table2.dat 57 20 Source properties of candidate HI detections in
the Westerbork Virgo Filament Survey
notes.dat 80 159 Individual notes
--------------------------------------------------------------------------------
See also:
J/MNRAS/357/819 : Colours and HI line observations in Virgo (Sabatini+, 2005)
J/AJ/133/2569 : ALALFA survey. Northern Virgo HI sources (Giovanelli+, 2007)
J/AJ/136/713 : ALALFA survey. Second Virgo HI sources (Kent+, 2008)
J/A+A/528/A28 : WSRT Virgo HI filament survey. II. (Popping+, 2011)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [WVFS]
6- 14 A9 --- WVFS WVFS name (HHMM+DDMM)
15 A1 --- f_WVFS [*] Correction note (1)
17- 40 A24 --- OName Optical ID
42- 43 I2 h RAh Right ascension (J2000)
45- 46 I2 min RAm Right ascension (J2000)
48- 49 I2 s RAs Right ascension (J2000)
51 A1 --- DE- Declination sign (J2000)
52- 53 I2 deg DEd Declination (J2000)
55- 56 I2 arcmin DEm Declination (J2000)
58- 61 I4 km/s HRV Heliocentric recession velocity
63- 67 F5.1 Jy.km/s SHI Integrated HI flux
69- 71 I3 km/s W20 Width velocity at 20% of the peak flux
72 A1 --- n_W20 [*] edge detection (2)
74- 97 A24 --- ONames Other optical IDs
--------------------------------------------------------------------------------
Note (1): for WVFS 12222+0915 corrected into WVFS 1222+0915 by CDS.
Note (2): * indicates several of the detections are at the edge of the
frequency coverage of the cube. The observed spectrum for these
sources is not complete, which results in only a lower limit to the
integrated flux. We will not consider these sources in our further
analysis.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [WVFS]
6- 14 A9 --- WVFS WVFS name (HHMM+DDMM)
16- 17 I2 h RAh Right ascension (J2000)
19- 20 I2 min RAm Right ascension (J2000)
22- 23 I2 s RAs Right ascension (J2000)
25 A1 --- DE- Declination sign (J2000)
26- 27 I2 deg DEd Declination (J2000)
29- 30 I2 arcmin DEm Declination (J2000)
32- 33 I2 arcsec DEs Declination (J2000)
35- 38 I4 km/s HRV Heliocentric radial velocity
40- 43 F4.1 Jy.km/s SHI Integrated HI flux
45- 47 I3 km/s W20 Width velocity at 20% of the peak flux
49- 52 F4.2 Jy.km/s sigma rms noise level
54- 57 F4.1 --- S/N Signal-to-noise ratio
--------------------------------------------------------------------------------
Byte-by-byte Description of file: notes.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- WVFS WVFS name (HHMM+DDMM)
11- 80 A70 --- Note Text of the note
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Popping & Braun, Paper II 2011A&A...528A..28P 2011A&A...528A..28P, Cat. J/A+A/528/A28
(End) Patricia Vannier [CDS] 28-Jun-2011