Results

The two sets of data (high resolution 1.5/6km arrays, and low resolution 375/750m arrays) were combined and imaged, and appear on the same scale in figures 1 and 2. It is

$\parbox{8cm}{ \epsfig{file=pres1.c059.con... ...e is from 0 - 0.4 mJy. The central circle is the size of the core at 23''.} }$

Figure: A mosaiced 375 and 750m array image, at 1408MHz, with an approximate $63\times 68$'' beam, and a RMS noise level of $35\mu$Jy. The contours are at the same level as figure 1, so are at $\sim 2.5$, 10, 40$\sigma$, and the range is from 0 - 0.4 mJy.

apparent already that there are some extended sources in the field of the core, in particular the two bright sources near the top left corner, and these do not become subtracted completely, later on. From each day, the 6km only baselines were individually imaged, and one (2000-Dec-27) appears in figure 3. Evident are the two

Figure: Image constructed using only antenna 6 baselines from the 750C configuration on the 2000-Dec-27. The RMS in the image was $50\mu$Jy, but the image quality was quite poor because of the lack of UV coverage, and poorly calibrated. The only contour is at $3 \sigma$, and the range is from 150 to $200 \mu$Jy. Most of the points above the contour are noise, but those points that corresponded to a known pulsar (within a small proportion of the synthesised beam) that were above $3 \sigma$ were modelled by point sources.

constant sources (labelled 142 and 178), and 4 pulsars. The only contour is at $3 \sigma$, so most of the random points are noise, but some may be scintillating pulsars. The central circle (radius 23'') is the size of the core of the cluster. Table 2 lists each of the pulsars, and the two constant

Table: Fluxes of each resolved pulsar. The lack of data for the 2000-Dec-25 is because of observing problems - this data is as yet unused. The column labelled ``Only 6km'' is the raw fitted (for a point source) flux from the individual 6km baseline map, and ``Rescaled'' is after the source 142 is scaled to be the same as in McConnell and Ables' (2000) 6km mosaic ($643 \mu$Jy)

30.01cm	30.85cmSource/ Pulsar name	30.85cmCamilo et. al.[1] flux	Observation Date
			99-Jan-25		00-May-05		00-Dec-23		00-Dec-25		00-Dec-27
			Only 6km	Rescaled	Only 6km	Rescaled	Only 6km	Rescaled	Only 6km	Rescaled	Only 6km	Rescaled
80.45cmFlux ($\mu$Jy)$\;$	142				564	643	839	643	761	643	715	643
	178				285		218		270		313
	C	360					172	132	202	171	178	160
	D	220			244	278	311	238			285	256
	E	210									365	328
	F	150							318	268
	J	540							175	148	268	241
	Q	50					287	220

sources (source 142 and 178) fluxes, and the scaled value. Since source 142 is $643 \mu$Jy in the high resolution map, we scale it to be $643 \mu$Jy on all days, and all the others as appropriate. Source 178 is similarly always left (ie, not scaled) as the $226\mu$Jy that is was in the high resolution map. Due to persistent problems during the 1999-Jan-25 observation, culminating in the loss of one antenna for most of the day, this data had to be discarded. It is seen in table 2, that some of the mean fluxes from the antenna 6 baselines are a lot lower than Camilo et. al.[1] claim (particlularly pulsar J), and this is as yet unexplained. Subtracting the point sources in the masked high resolution image, the two constant sources manually, and the 4 significant pulsars from the 2000-Dec-27 data yields the image in figure 4. The

Figure: Image from 2000-Dec-27 that shows both the pulsars and the two constant sources, 142 and 178, removed. This then forms part of the image in figure 6. The range is from 0 to $400 \mu$Jy, and the contours are at 3, 6, 12, 24 ...$\times$ the RMS from figure 1. Since the RMS of this image is $50\mu$Jy, the contours are at 1.7, 3.4, 6.8$\sigma$. The peak of the core in this image is $380 \mu$Jy.

process was repeated for the other days, and the result was combined to yield figure 6. The combined image was also produced

$\parbox{8cm}{ \epsfig{file=pres1.rem.kno... ...0 \mu$Jy/beam, and the integrated flux is $\sim 810$Jy (fitted for gaussian)} }$

Figure: This is all the days data combined, with all point sources away from the core, the two constant sources, 142 and 178, and the pulsars, subtracted. The contours are at 3, 6, 12, 24 ...$\times$ the RMS from figure 1. Since the RMS of this image is $60 \mu$Jy, the contours are at 1.4, 2.8, 5.6 ...$\sigma$. The range of the image is 0 to $400 \mu$Jy. The peak of the core in this image is $280 \pm 60 \mu$Jy/beam, and the integrated flux is $\sim 415 \mu$Jy (fitted for Gaussian)

without subtracting the pulsars in figure 5 - only subtracting the two constant sources. The integrated flux within the core of figure 5 is only $810 \pm 60 \mu$Jy, which is much lower than the expected 4mJy. Similarly, after subtracting the pulsars to give figure 6, we are left with much lower than the 2mJy expected - only $415 \pm 60 \mu$Jy. The errors quoted are the image RMS (fitted using IMSAD from the region surrounding the core). Note that this error is typically 3 times larger, for all the images created in this analysis, than the theoretical RMS quoted by INVERT, and the difference is attributed to image confusion.