scientific abstract 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. observation summary 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 filters. 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. samples: the samples are split into several proposal files as follows: \t\t\t\tspring\t\t\tfall \t\t\t\t#\ttime\t\t#\ttime 1. rosat-observed quasars\t33\t78783\t\t38\t87240 2. pg quasars\t\t\t19\t35187\t\t24\t47306 3. heao1 x-ray selected agn 40\t57736\t\t37\t52193 4. red quasars \t\t40\t71720\t\t34\t55444 einstein, \t high-z,bals..\t\t \t\t\t\t-------------------------------------- \t\t\ttotals\t132 243426\t\t133 242183 \t\t\t\t
Instrument
PHT03 , PHT22
Temporal Coverage
1996-02-20T03:31:06Z/1996-10-27T17:29:19Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the worlds first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
European Space Agency, Wilkes et al., 1999, 'Exploring the Full Range of Quasar\/AGN Properties ', 1.0, European Space Agency, https://doi.org/10.5270/esa-39wf8fx
