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4.4 Overview of the Scientific Programme

The scientific programme for ISO consisted of more than 1000 individual proposals from nearly 600 principal investigators from the world-wide astronomical community.

Figure 4.8: ISO made more than 30000 observations, covering all fields of astronomy, literally from comets to cosmology. The observation pointings are depicted in this figure, an Aitoff projection in galactic coordinates. The scientific category of the associated observing proposals are: solar system (black), stellar physics (red), interstellar medium (green), extragalactic (blue) and cosmology (magenta). Noticeable features are e.g., the zodiacal light scans, and the Magellanic Clouds. Due to the stringent pointing constraints ISO was in principle precluded to observe the Orion region, but thanks to the extended lifetime, observations could be done on Orion (l$\approx$$-$150$^{\circ}$, b$\approx$$-$20$^{\circ}$) towards the end of the mission.

About 10% of ISO's time was used for Solar System studies, 23% for the Interstellar Medium (ISM), 29% on Stellar/Circumstellar topics, 27% for Extragalactic observations and 11% for Cosmology (see Figure 4.8).

The full list of accepted and performed proposals is given in Appendix B.

4.4.1 Large survey programmes

There were no restrictions on the duration nor the size of the programmes except those set by the technical constraints of the mission, e.g. sky visibility and the orbit.

The OTAC considered each proposal on its scientific merits without any, a priori, preference for programmes of any specific size.

Taking advantage of this, some ISO programmes were proposed by observers and approved by the OTAC requesting a large amount of observing time. They intended to produce homogenous data sets on large samples of sources in a variety of scientific areas.

Table 4.1 gives an overview of the largest survey programmes.

Table 4.1: The largest ISO observing programmes, each with 1% or more of ISO's observing time and together amounting to 15% of the total time available.

Programme PI

European Large Area ISO Survey (ELAIS) Rowan-Robinson
Spectroscopy of Bright Galactic Nuclei Genzel
ISOCAM Survey of the Inner Galaxy (ISOGAL) Omont
ISOCAM Deep Survey Programme Cesarsky
ISM of Normal Galaxies Helou
Dust Debris Around Solar Mass Stars Becklin
Exploring the Full Range of Quasar/AGN Properties Wilkes
Structure of the FIR Background Puget

More details of the survey programmes can be found in `ISO Surveys of a Dusty Universe' (Lemke et al. 1999, [112]).

4.4.2 Target of opportunity programmes

In order to maximise ISO's scientific return from unpredictable astronomical events some of which needed rapid reaction times, a number of small teams were also set up to define and prepare the necessary ISO observations for likely Targets of Opportunity (ToO), such as supernovae, novae, bright comets, etc.

These teams prepared generic observations in advance, stored pre-planned observation sequences in the SOC's databases, fine tuned them as needed and were responsible for publishing the data to the community as quickly as possible. Such observations were executed only in the event that the specified phenomenon actually occured and it was the responsibility of the Principal Investigator of the team to inform the SOC of the occurrence of the phenomenon. Time for any such ToO observations came from the general Open Time.

These ToO proposals were reviewed by OTAC in the same way as other observing proposals. Each selected team contained, ex officio, one or more SOC astronomers. These were either included in the original proposal or were added to selected teams. The roles of these SOC staff included co-ordination during definition, responsibility for maintaining the appropriate observations in the SOC's databases and, being the focus at the SOC, during any execution of these observations.

Table 4.2 gives a summary of the performed ToO programmes. These proposals are also contained in Appendix B under Open Time proposals.

Table 4.2: Summary of all performed ToO programmes.

Programme PI Observed Targets

Observations of Novae during the ISO Mission Barlow Nova Cas 95,
    Nova Aql 95
    Nova Cru 96,...

The Nature of the Superluminal Galactic
Source GRS 1915+105: ISO Monitoring of the Most    
Powerful Source in the Galaxy Castro-Tirado GRS 1915+105

The Nature of the Superluminal Galactic Source
GRS 1915+105: ISO Observations during the Oct 1997    
X-Ray and Radio Outburst Castro-Tirado GRS 1915+105

New Soft Gamma-Ray Repeater (SGR 1814$-$1340):
A New IR-Source? Castro-Tirado SGR 1814$-$1340

Studies of High Mass X-ray Binary Systems: Multi-
waveband Investigations of such Systems in Outburst Coe 4U1145$-$619,

Observations of Unexpected Comets
Crovisier P/Hale-Bopp

Spectroscopic Observations of Comets
Crovisier P/Hale-Bopp

ISO Observations of Cygnus X-3 in Outburst:
Infrared Studies of a Flaring Microquasar Fender Cyg X-3

Observations of New Novae in Outburst
Physics Characteristics and Contributions to the ISM Gehrz Nova Aql 95,
    LMC1 1995,
    Nova Oph 94,
    Nova Sco 97,...

ISOPHOT Observations of a Bright Comet Coma:
Composition and Dust Production Grün P/Hale-Bopp

ISOPHOT Observations of a New Comet:
Coma Composition and Dust Production Grün P/Hale-Bopp

The Nucleus of a New Bright Comet
Lamy P/Hale-Bopp,
    P/Hartley 2

Observations of Low-Mass X-ray Binaries
Naylor V404 Cyg,

Cometary Comae in the IR:
Dimensions, Structures and Composition Peschke P/Hale-Bopp

Evolution of the Circumstellar Environment during
an FU Ori or EX Lup Outburst Prusti FU Ori in Serpens

Dust Formation around R CrB Type Stars at their
Minima: Search for Fullerenes Tanabe LR Sco, V Cra

The Infrared Counterpart of GRS 1915+105:
Observations of Outbursts Winkler GRS 1915+105

4.4.3 Discretionary time programmes

ISO made new and unexpected discoveries and, in many cases, ISO itself was the only facility capable of follow-on investigations of these discoveries. Additionally, compelling new observations became apparent during ISO's in-orbit life. Thus, a small pool of `discretionary time' was kept available, outside the normal `Call-Proposal-Review' cycle, for observations that could not have been foreseen at the time of proposal submission. An average of 30 minutes of discretionary time observations per day was foreseen.

To use this discretionary time, a request had to be made to the scientific head of the Observatory, the Project Scientist. Whenever possible, the Chairman of the OTAC was consulted by the Project Scientist before any additional observations were authorised. The Project Scientist reported to the next meeting of OTAC on all discretionary time observations.

Over 150 discretionary time proposals were received during the ISO operational lifetime, 40% of them in the last four months of the mission.

Following a recommendation of the OTAC, after a meeting held on 16 September 1997 where the overall status of the ISO scientific programme was reviewed, recommendations were made concerning use of the extra-time available as a consequence of the longer lifetime of ISO.

The principal conclusions were: that the amount of discretionary time should be significantly increased for the rest of the mission; that an additional $\sim$200 hours should be made available to the previously-approved large surveys; and that some 300 hours should be devoted to observations of `general interest' which should be placed in the public domain without the usual 12 months proprietary period. Thus, about 20 additional proposals on specific topics were solicited to the community; these can be recognised in the ISO Data Archive as the programme names all start with `ZZ'.

4.4.4 Parallel and serendipity programmes

The parallel and serendipity modes were not available to proposers. The data from these modes needed to be taken and reduced in a systematic and completely different manner. This was done by the respective instrument consortia, in collaboration with the SOC, and the data are available now through the ISO Data Archive. Table 4.3 gives an overview of all performed parallel and serendipity programmes of ISO. The parallel data were obtained while other instruments were prime, the serendipity data were taken during slews of the satellite.

Table 4.3: Summary of all performed parallel and serendipity programmes.
Programme Wavelength No. of observations / sky coverage
ISOCAM Parallel 6.0, 6.7, 14.3$\mu $m $>$ 40000 observations
ISOCAM Serendipity 6.0, 6.7, 14.3$\mu $m $\approx$ 10 to 15% sky coverage
ISOPHOT Serendipity 170$\mu $m $\approx$ 15% sky coverage
LWS Parallel 10 wavelengths: 46 to 178$\mu $m $>$ 17000 obs. $\approx$ 1% sky coverage
LWS Serendipity 10 wavelengths: 46 to 178$\mu $m $\approx$ 10% sky coverage

Most of the parallel and serendipity programmes are explained in detail in `ISO Surveys of a Dusty Universe' (Lemke et al. 1999, [112]).

next up previous contents index
Next: 4.5 Overview of Satellite Up: 4. ISO Operations Previous: 4.3 Observing with ISO
ISO Handbook Volume I (GEN), Version 2.0, SAI/2000-035/Dc