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Top > Suzaku > Proposal > AO1 > Announce

2005 November

First Announcement of Opportunity(AO-1) for observations with the X-ray astronomy satellite "Suzaku"

1. Overview

This announcement solicit proposal for observations using the ISAS (Institute of Space and Astronautical Science)/JAXA (Japan Aerospace Exploration Agency) X-ray astronomy satellite "Suzaku," which was successfully launched into orbit on 2005 July 10.

During the course of commissioning, all helium cryogen was lost from the X-Ray Spectrometer (XRS), the highest resolution X-ray spectrometer to date. The XRS team believes they have identified the immediate cause of the cryogen loss, but the underlying cause is being investigated by committees both in Japan and in the US. The remaining instruments, 4 X-ray CCD cameras (X-ray Imaging Spectrometer, XIS) and the Hard X-ray Detector (HXD) have been commissioned successfully by mid August. Since then, we have performed calibration and verification observations, which confirms that Suzaku has high sensitivity over a wide energy range as planned. This has already published on newspapers, on ISAS/JAXA web pages

and on other venues. The current strengths of Suzaku can be summarized as (1) highest sensitivity to date for hard X-rays (10-300 keV); and (2) higher sensitivity and spectral resolution in the soft X-ray band (0.3-0.8 keV) using a new generation backside-illuminated CCD chip. We have already started normal observations in September; we plan to begin open observations starting in 2006 April, after roughly 7 month of performance verification observations.

Although Suzaku (then called Astro-E2) observing proposals were solicited, selected, and announced in 2004, the selection process emphasized the use of the XRS. The selected proposals may or may not represent the best use of the HXD and the XIS, and the observation parameters may or may not be optimized for these instruments. We are therefore starting anew with this solicitation; the results of the earlier solicitation will be disregarded.

This first announcement of opportunity is for a one year period starting 2006 April. The deadline and other details are described below in the web pages accessed from the followig URL.

We invite application from researchers in a wide range of field.

This is one of three parallel announcements, and solicit proposals from researchers in Japan and in countries other than the US and ESA member countries. Researchers based in the US should consult the parallel announcement at Researchers in ESA member countries should consult the version at:

2. The Suzaku X-ray Observatory

The Suzaku satellite carries five X-Ray Telescopes (XRTs) that focus X-rays up to 12 keV with a high efficiency, and one unit of XRS and 4 units of XIS (X-ray CCD Cameras) at their foci. Although we have unfortunately lost the use of the XRS, one unit of XIS has a high sensitivity and good spectral resolution for soft X-rays below 0.8 keV, a capability that is superior to those of Chandra and XMM-Newton. At the same time, the HXD has unprecedented sensitivity in the wide energy range up to several hundred keV. The wide bandpass coverage with the XIS and the HXD is an important characteristic of the Suzaku mission, so we invite observing proposals that make strong use of their sensitivities. The details of the instruments (Technical Description document:under preparation), list of targets that have been observed or will be observed within the SWG time, will be published on the Suzaku home page ( in the very near future.

3. Mission Phases and Time Allocation

The Suzaku mission has been developed as a Japanese-US collaboration, and the Science Working Group (SWG) that consist of researchers involved in the development and operation oversees the project overall.

The mission is divided into three phases.
I) Phase 0, from the launch through end of 2005 August, when the mission operation focused on in-orbit check-out of the spacecraft including the attitude control system, and the initial operations of the scientific instruments.
II) Phase I, from 2005 September through 2006 March, is the performance verification phase. During Phase I, observation program is chosen exclusively by the SWG, to verify the performance of Suzaku instruments, and to observe typical targets.
III) Phase II refers to the period after 2006 April, in which observing time is 100% open to the community. We plan to solicit proposals once a year. The time is divided into three categories, Japan, US, Joint Japan/US times. Proposals from all non-US contries will be accepted within the Japan time, in particular, a fraction of Japan time is allocated to European (ESA) solicitation.

The following summarizes the time allocation.

Mission Phase SWGJapanUS J/US
Phase-0(-2005 Aug.) 0% 0 % (0 %) 0%0 %
Phase-I (2005 Sep-2006 Mar) 100 % 0 % (0 %) 0 %0 %
AO-1 (2006 Apr.-2007 Mar) 0 % 50 % (8 %) 37.5 %12.5 %
AO-2 (2007 Apr.-2008 Mar)

The total time available for proposals is calculated after subtracting Observatory Time (4%; for satellite maintenance and other similar purposes), 3% set aside for ongoing calibration observations, as well as Director's Discretionary Time (5%; for gamma-ray bursts or any genuinely unpredictable events, and other important observations granted at the discretion of the mission director).

During AO-1, the available (88% of total) time will be divided into (1) 50% for Japanese observations; (2) 37.5% for US observations; and (3) 12.5% for joint Japanese-US observations. The joint time will be used if proposals were received for the same target both in Japan and in the US, and if both PIs accept such merging (the proposal form will have a check box for the PI to indicate yes or no). This allocation is based on an ISAS-NASA agreement. Additionally, 8% of the observing time is allocated to proposals submitted to ESA as joint Japan-ESA observations, thus the purely Japanese time is 42%. This means that the total available to Japanese researchers is 4923 ks plus 1465 ks for joint Japan-US observations, assuming 37 ks of good time per day and 360 days of operation per year. Proposals from non-US, non-ESA countries will be accepted within the Japanese time up to the ESA portion.

4. Observing Constraints

The Suzaku Science Working Group (SWG) have decided the target list of observations during Phase I. Proposals to observe targets in this list is allowed, but must include a justification for an additional observation, such as a much longer exposure, different pointing within an extended object, or different observing window of a variable object.

The length of the observation should be justified based on the specific scientific objectives, preferably using simulations. However, we set the minimum observing time at 10 ksec, considering the efficiency of satellite operation. There is no upper limit to for the observing time, but longer observations will naturally require stronger scientific justifications.
It is possible to specify the time of observations (time critical observations) to observe specific phases or for simultaneous observations.

Target of opportunity (TOO) proposals are allowed for short-lived events on known objects whose timing is uncertain. The name and coordinates of the object(s) as well as the triggering conditions must be specified. We also require the estimated probability during AO-1 of such an event, as well as its duration. Generic TOOs without a specific target (such as "a nearby supernova") will not be accepted.
Gamma-ray bursts or any genuinely unpredictable events may be observed outside the proposal process, as part of the 5% Director's Time. Details mechanism for applying for such observations will be published later. Data from such observations will not have a proprietary period.

5. Review Process and schedule

The deadline is 2006 January 7 12:00 JST for proposals submitted to ISAS (including those from non-US, non-ESA countries). After the Japanese program is determined, the ESA program will be folded in. We will then convene a Japan-US merging committee in March and publish the list of accepted proposals.

Accepted proposal will be classified into three categories. Priority A targets will be preferentially observed during the AO-1 period (2006 Apr to 2007 Mar). Priority B targets will be scheduled in this period as far as possible, but may be carried over to the following AOs. Priority C targets will be used as fillers when there are gaps in the schedule. For the total available time T, we will adopt 0.5T, 0.4T, and 0.5T as As, Bs, and Cs (for a total oversubscription by 40%). If the actual amounts of observatory, calibration, and director's times add up to less than 12% that is set aside, then the remainder will be used to observe additional C targets.
TOOs and time critical observations will be accepted only as priority A targets.

6. Data rights

Observers will have exclusive rights to the data for a 1 year period after receipt of data, after processing. This, however, does not apply to realtime TOO observations and for Gamma-ray burst data. We will deem an observation complete if 90% (for A targets) or 70% (for B targets) of the proposed time is obtained with either the XIS or HXD, to be specified by the observer; however, this is subject to revision with experience.

We are looking forward to receiving many proposals to enhance outcome of the Suzaku observations as much as possible.

With best wishes,
Kazuhisa Mitsuda(Suzaku Project Manager)
Hideyo Kunieda*(Suzaku Project Scientist)
Tadayuki Takahashi(Suzaku Deputy Manger)

Proposal Submission

1. Observations:

X-ray observations of astronomical objects using ISAS/JAXA X-ray astronomy satellite, Suzaku, for a 1 year period starting 2006 April

2. Who May Propose to ISAS/JAXA:

Researchers affiliated with non-US, non-ESA institutions can apply. US-based researchers should submit their proposals to NASA, and those in ESA member countries should propose through ESA.

Principal investigators (PIs) affiliated with universities and institutions are eligible. Graduate students are allowed to apply, but their thesis advisors or similar researchers must be involoved as a co-investigator. Long-term visitors to Japanese institutions from abroad qualify. There is no restrictions on inclusion of co-investigators from outside Japan. Japanese researchers stations overseas on Japanese funds can apply to Japanese or foreign time, but not both.

3. Proposal Deadline:

12:00 JST on Saturday, 2006 January 7. This will be strictly enforced for e-mail and web submission. Hardcopies should be postmarked no later than January 7. Applications from outside Japan should ensure that hardcopies arrive in Japan by January 7.

4. Proposal format:

The following two materials are both required

(a) RPS (Remote Proposal Submission system) submission. The data entered into RPS, such as position and observation parameters will be used in operations of Suzaku, so care must be taken to ensure accuracy.
(b) Paper submission: 7 set of hardcopies must be mailed to:

Prof. Kazuhisa Mitsuda,
3-1-1- Yoshinodai,
229-8510 Kanagawa,
Envelope should be marked "Suzaku Observing Proposal" in red.

5. Hardcopies

The hardcopies should consist of

(1) Cover Page (1 page),
(2) Target Form (1 page),
(3) Scientific Justification (scientific problem and technical feasibility)
(maximum 4 pages; includes text, figures, charts, and tables),

6. Supplemental information:

Following information are being prepared to be found on the Suzaku home page at
(1) Technical description of Suzaku
(2) Public data of typical sources
(3) Simple manual of analysis
(4) Link to ISAS RPS

If you have further questions, please contact:
Prof. Kazuhisa Mitsuda
Suzaku Project Manager

ISAS/JAXA Department of High Energy Astrophysics

Last Modified: Friday, 01-Sep-2006 23:30:31 JST