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Last updated: Tue Nov 25 16:55:47 CET 2008 muehle@jive.nl

General Comments. ( Brief data summary and scan listing )
C band (5 GHz) global VLBI experiment, observed on 10 June 2008. The data rate was 512 Mbps (4 x 16 MHz subbands, dual polarization, two-bit sampling). The target source 'Arp220' was calibrated using the phase-reference source 'J1532+2344'. 'J1613+3412' served as fringe finder. 'J1516+1932' was also observed as a calibrator. Ef served as reference antenna. The plots show baselines to either Ef or Sc.
17 stations were scheduled in this experiment: Ef, Wb, Jb2, On85, Mc, Nt, Tr, Sc, Hn, Nl, Fd, La, Pt, Kp, Ov, Br and Ar. Ef experienced recording problems at 2:35 - 3:28 UT. Wb observed in phased-array mode. At Jb, the MkII Telescope was used for these observations. Strong wind prevented On from observing. The disk-pack that contains the Mc data of 15:49 - 03:27 UT is missing. Pt could not observe due to a bad Azimuth drive wheel. Hn reported several power glitches and reboots. At Ar, observations had to be terminated at ~3:20 UT due to a drive system failure.

The EVN reliability indicator (ERI) for this experiment was ERI = 0.50 . ERI* = 0.71 . (Ef=0.93, Wb=1, Jb=1, On=0, Mc=0.15, Nt=1, Tr=1, Ar=0.76)

Plots of the autocorrelations
Comments.
stable bandpasses; Nt: IF2/L shows severe ringing or is missing; Wb: IF4/L has a spiky, but stable bandbass; Sc/Br: IF1/R has at times a spiky, but stable bandbass, probably due to an playback-related issue, seems ok after calibration; 939 pages

plots of the uncalibrated amplitude and phase against time
Comments.
nothing unusual detected; 56 pages

Plots of the uncalibrated amplitude and phase against frequency channel
Comments.
some trouble at startup; after 15:22 UT phases fine, only occasionally bad phases in individual (subbands)/baselines/scans; in general, stable bandpasses; Nt: IF2/L missing or bad phases; Fd, Kp: noisy phases in first ~30-40 minutes of observations; Hn: temporary drop in amplitudes at ~01:00 UT; increased phase rate in IF4/R after 02:30 UT; 1174 pages

The uncalibrated amplitude and phase of the crosshand correlations against frequency channel (not available)
Comments.

TSYS against time
Comments.
Ef: significant drop in T_sys after first pointing (19:20-19:29 UT); Nt: IF4/L shows unusual T_sys data compared to the other subbands in the first hour of observations; Wb: occasional outliers in the first 2 hours of observations; rain at Hn after 03:00 UT; Fd, Kp, Ov: high system temperatures during the first 30-60 minutes of observations; 12 pages

Telescope sensitivities from the a priori TSYS and Gain curves (the square of this number gives the antenna noise (SEFD) in Jy - the smaller the better).
Comments.
nothing unusual detected, curves of gains vs. time match closely those of T_sys vs. time; 12 pages

Fringe-fit phase solutions (including Parallactic Angle correction).
Comments.
reference antenna: Ef, drift in phases reflects the parallactic angle correction; many stations have instances of fast phase rotation in the first hour of the observations, possibly due to low source elevation; 12 pages

Fringe-fit delay solutions
Comments.
reference antenna: Ef; delays of the order of (tens of) nanoseconds, very few outliers; Hn: IF/4R shows jump of >100nsec in delay at ~ 02:20 UT; 12 pages

Fringe-fit rate solutions
Comments.
reference antenna: Ef; nothing unusual detected, rates of the order of mHz; 12 pages

Telescope bandpasses
Comments.
reference antenna: Ef; bandpasses look good, phases close to zero; 4 pages

Calibrated amplitude and phase against time (a priori amplitude calibration and fringe-fit solutions applied).
Comments.
Jb: second scan of fringe finder bad in IF4/RR; 56 pages

Calibrated amplitude and phase against frequency channel
Comments.
in general, stable bandpasses; frequently high (phase) noise level in the first scans of a station, probably due to high system temperature, later ok; Tr: temporary drop in amplitude in IF2/L around 22:30 UT; Hn: drop in amplitude, loss of phase stability in scan 303; 1145 pages

Naturally weighted dirty map (not useful for bright sources) produced before self-cal of:
J1532+2344: pdf (not available) , or FITS (not available) .
ARP220: pdf , or FITS .
J1516+1932: pdf (not available) , or FITS (not available) .
J1613+3412: pdf (not available) , or FITS (not available) .
Comments.
The cores of Arp220 are located 400 milliarcsec from the pointing centre (see cover letter of the schedule).

Uniformly weighted dirty map (not useful for bright sources) produced before self-cal of:
J1532+2344: pdf (not available) , or FITS (not available) .
ARP220: pdf , or FITS .
J1516+1932: pdf (not available) , or FITS (not available) .
J1613+3412: pdf (not available) , or FITS (not available) .
Comments.
The cores of Arp220 are located 400 milliarcsec from the pointing centre (see cover letter of the schedule).

Phase corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
J1532+2344 .
ARP220 (not available) .
J1516+1932 .
J1613+3412 .
Comments.
refant: Ef; phase corrections look reasonable, few outliers; 12 pages per source

Amplitude corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
J1532+2344: pdf , or text file , or statistical summary .
ARP220: pdf (not available) , or text file (not available) , or statistical summary (not available) .
J1516+1932: pdf , or text file , or statistical summary .
J1613+3412: pdf , or text file , or statistical summary .
Comments.
Ef: jump in gain amplitude after first pointing (see "TSYS against time"); Jb: low gains in IF3/R+L and IF4/R+L, very few and suspiciously high gains in IF4/R for J1613+3412; 12 pages per source

Telescope sensitivities (the total AMP gain applied during both a priori and self calibration; the square of this number gives the antenna noise (SEFD) in Jy).
Comments.
few outliers; Sc: slightly increased gain in IF1/R in the first 5 hours of observations; 12 pages

Residual closure phase (visibility closure phase with model closure phase subtracted) for:
J1532+2344 .
ARP220 (not available) .
J1516+1932 .
J1613+3412 .
Comments.
some outliers, but nothing unexpected; 30-44 pages per source

Calibrated visibilities and the source model of:
J1532+2344 .
ARP220 (not available) .
J1516+1932 .
J1613+3412 .
Comments.
in general, very good agreement between data and models; J1613+3412: in the second scan, slight deviations in the baselines to Sc and Ar; 55-56 pages per source

Calibrated visibilities against u,v distance for:
J1532+2344: pdf , or png .
ARP220: pdf , or png .
J1516+1932: pdf , or png .
J1613+3412: pdf , or png .
Comments.

u,v coverage for:
J1532+2344: pdf , or png .
ARP220: pdf , or png .
J1516+1932: pdf , or png .
J1613+3412: pdf , or png .
Comments.

Crude maps of sources:
J1532+2344: pdf , or FITS .
ARP220: pdf , or FITS .
J1516+1932: pdf , or FITS .
J1613+3412: pdf , or FITS .
Comments.
The cores of Arp220 are located 400 milliarcsec from the pointing centre (see cover letter of the schedule).