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ASCA Guest Observer Facility

ASCA Final Operations Proposals

Submission Statistics

We received 26 ASCA Long-Look Proposals requesting a total of 20.85 Msec.

It will take ASCA about 18 months to perform all the requested observations.

Call for Proposals

We are soliciting suggestions from the US community for long observations during the final months of the ASCA mission.

All data obtained during this phase of the mission will immediately enter the public archive; thus, a successful "proposal" does not imply an exclusive data right, or financial support.

Moreover, the unpredictable nature of the orbital decay (which depends on the solar activities over the next year or so) means that we cannot guarantee that the individual observations based on "accepted" proposals will actually be carried out.

Types of observations

ISAS does not have the human resources to continue to operate ASCA at the current level after the launch of ASTRO-E, currently scheduled for 2000 January 24. Ease of mission planning will therefore be a significant factor in selecting observations. This is particularly true for the first several months of ASTRO-E in orbit; if ASCA is still operational after ASTRO-E operations have become more or less routine, ISAS may be able to operate ASCA in a somewhat less restrictive manner.

In practice, this means:

  • Long observations: a minimum exposure time will be 200 ksec (about 5 day elapsed time); preferred length of observations is 2-3 weeks (elapsed time; 500-750 ksec exposure time), which minimizes operation and opens up a unique phase-space otherwise unavailable to X-ray astronomers. (Each observation will be continuous in the sense of not slewing to other target, interrupted only by Earth occultations and SAA passages.)
  • Time critical observations will not be accepted, except for coordinated observations with other X-ray satellites such as ASTRO-E, Chandra, or XMM.
  • There is a limited scope for raster scans --- a modest raster scan, such as 9 pointings within a 1 x 1 degree area in two weeks, may well be possible --- perhaps several months after the launch of ASTRO-E. However, additional personnel need to be secured for such raster scans to take place. We encourage those who are interested in raster scans to contact colleagues in Japan to see if collaboration can be established with a group with ASCA operations experiences, or consider sending someone to ISAS to help with the operations (This, however, is not an absolute requirement: the GOF will explore various options, if a non-collaborative raster-scan proposal is highly ranked.) The exposure time per poiting within a raster must exceed 40 ksec.
  • We do not solicit target-of-opportunity observations through this channel. However, we will not completely exclude this possibility: in case of an extraordinary celestial event after ASTRO-E launch, and if an ASCA TOO observation appears worthwhile (rather than, or in addition to, TOO observations with other X-ray missions), please follow the current guidelines.

We hope to end up with ~1 year's worth of potential observations, after combining Japanese and US proposals.

How to propose

We have simplified the proposal submission process.

  1. An RPS form must be submitted, either via the web or via the e-mail interface (e-mail to, and follow instructions). The form has been simplified compared with AO-7. Moreover, we no longer require a hardcopy and/or a PostScript version of the form.
  2. Scientific justification and technical feasibility in the form of 1-2 page PostScript file must be submitted electronically. This can be done via the Web interface or FTP. In either case, first submit your RPS form; upon successful submission, you will receive a proposal number, which will be used to identify your scientific justification.
    • Via the Web: Click on the UPLOAD button. You need to supply the local file name (type in the name directly, or use the browse button). If you have just submitted your RPS Form, the PI Last Name and First Initial, and Proposal Number fields will be filled already; if not, you need to type them in. Then press the submit button.
    • To use the FTP: ftp to as an anonymous user. Change directories to /pub/rps/ASCA. Put your file in this directory. To ensure proper post-processing of your uploaded file, we ask that you follow our naming convention: the file name should consist of a concatnation of the three digit proposal number, "_", the PI's first initial, the PI's last name and the correct suffix (.ps, .ps.gz or similar). So, if Jane Doe is the PI and the proposal number is 47, a gzipped postscript file should be uploaded as Note that, for security and confidentiality reasons, you will not be able to list the content of this directory (please contact us if you need to make a correction).
The deadline for proposals was 1999 October 12, 23:59 EDT.

Selection and Implimentation

The US and Japanese submissions will be reviewed indepdendtly first; in the US, this will be done by the NASA headquarters via a peer review panel. Each national review will prepare a rank ordered list, and the two will then be merged into a single list. Selected observations will be carried out on a best-effort basis by the ASCA operations team at ISAS.

The PI of the proposal will be consulted to plan the details of the observations. When the data are received and processed at GSFC, they will be sent to the PI on CD-ROMs (or tapes), but will be placed in the public archive at the same time.

If you have any questions concerning ASCA, visit our Feedback form.

This file was last modified on Wednesday, 13-Oct-1999 15:23:00 EDT

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