Contents of: VI/111/./abstract/BWILKES_BJWQSO05.abs

The following document lists the file abstract/BWILKES_BJWQSO05.abs from catalogue VI/111.
A plain copy of the file (without headers/trailers) may be downloaded.

We plan to obtain spectrophotometry with ISO to complete multi-wavelength 
observations (180 microns -- 2 keV) of a sample of quasars which, when 
combined with that included in the European Core Program, will fully 
sample the quasar population as we know it. Due to their broad 
bandwidth emission, complete spectral coverage of the continuum is 
essential to understanding the energy generation mechanisms at work in 
these powerful objects. Such data is currently available only for 
low-redshift objects. With these data we will measure the spectral 
energy distributions of the population, search for evolutionary effects
and address specific issues such as the nature of the far-IR turnover and 
the relative importance of thermal and non-thermal emission in the infrared.
Our sample contains a substantial overlap with quasars scheduled for observation
with ROSAT so as to include X-ray information as far as possible.


Filters and AOTs:
The 4--180 micron continuum of the quasars will be observed using PHOT-P and 
PHOT-C, AOTs PHOT03 and PHOT22 respectively. These filter include:
P03: 4.85, 7.3, 11.5, 25, 60, 100; and P22: 135 and 200;  
giving 8 photometric points covering the full 
range of available spectrum. 

Exposure times:
The exposure times have been computed to
obtain S/N of about 10 in each filter and so vary from object to object.
The minimum is 32 secs on source and 32 secs off for a given filter
and the maximum 256 and 256 secs. For those objects where a few filters
reach the maximum exposure time, the S/N will likely be <10 for those

Flux estimation:
Fluxes in the far-IR have been estimated based upon a mean spectral 
energy distribution for quasars at low redshift which extends to 100 
microns. It is based upon 47 low-redshift
quasars and is in press in ApJ Supplements (Elvis etal 199).
Beyond 100 microns, where there is no information for typical
quasars, we assumed a nu cubed law. For the sample of red objects,
no mean energy distribution exists so we have scaled the exposure
times with those of the few IRAS-selected quasars in our sample
which do have data out to 100 microns.

Apertures and chopper:
Apertures are 52" for wavelengths < 25,120 for wavelengths 25,60 microns
and 180 for the remainder.
The chopper throw will be 180" using rectangular chopping mode
for all apertures. For the biggest sources, we use staring mode
with a sky position outside the galaxy.

The samples are split into several proposal files as follows:
				Spring			Fall
				#	Time		#	Time
1. ROSAT-observed quasars	33	78783		38	87240
2. PG quasars			19	35187		24	47306
3. HEAO1 X-ray selected AGN     40	57736		37	52193
4. "Red" quasars 		40	71720		34	55444
			Totals	132    243426		133    242183

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