Statistics

The two panels show how the allocated time of each of the EIS observing runs for the EIS-WIDE survey has been distributed in technical downtime, unused time because of bad weather and time actually used for observations.

The upper panel shows in the red column the total number of allocated hours in that particular run. The lightblue is the downtime because of technical problems, the blue column is the downtime because of bad weather and the green one is the number of hours used for observations.

The lower panel has the same columns but this time is shown the fraction of the total time in the different categories. Note that runs 1, 2, 9 and 10 were half-nights.   

Weather Conditions

The plot compares the average weather conditions at La Silla during the last five years to what the EIS observers have experienced during the EIS-WIDE survey observations.

The red line is the percentage of clear nights for the given month. The green line is the percentage of photometric nights. The black squares are the percentage of the allocated EIS time used for observations. Note that runs 1, 2, 9 and 10 were half-nights.

 

Seeing Distribution

The plot summarizes the seeing distribution obtained from EIS I-band images. The plot includes the data taken up to the end of year 1997 only. Each patch (A, B, C and D) is displayed separately.

The blue vertical lines indicate the median value (solid one) and the 25% and 75% quartiles (dotted ones) of the distribution.

 

Seeing tables

Here are tables reporting the pointing coordinates (Ra and Dec in degrees), the EIS row number, the EIS column number and the seeing value for the EIS images available in the four patches.  

To avoid inconsistencies we provide the seeing value as it is computed from the image during data processing. This means that the following tables include only data taken in 1997.  

N.B. The EIS mosaic consists of frames with significant overlaps (a quarter of an EMMI frame). The easiest way of visualizing the geometry of the EIS mosaic is to picture two independent sets of tiles (referred to as A(i,j), where i - the EIS row number - refers to the row along right ascension and j - the EIS column number - to columns in declination) forming a contiguous grid (normally referred to as odd and even depending on the value of j) superposed and shifted in right ascension and declination by half the length of an EMMI frame. The 6 square degrees patches designed for the EIS survey can then be covered by a mosaic of 600 EMMI frames (15 EIS rows x 40 EIS columns).

patch A, band I 

patch A, band V 

patch B, band I 

patch B, band V 

patch B, band B 

patch C, band I 

patch D, band I 

 

Limiting Magnitude/Isophote Distribution

The two plots show the limiting isophote (mag per sq. arcsec.) and the limiting magnitude distributions obtained for patch A I-band.

The blue vertical lines indicate the median value (solid one) and the 25% and 75% quartiles (dotted ones) of the distribution.

Four frames taken in very bad extinction conditions have been excluded from the plots.

 

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Send comments to <eisadm@eso.org>  Last update: Nov 16, 2000