September 8, 2008
Announcement of Opportunity (AO-4) of Suzaku
Kazuhisa Mitsuda (Project manager, ISAS/JAXA),
Tadayuki Takahashi (Project sub-manager, ISAS/JAXA)
Hideyo Kunieda (Project scientist, Nagoya University)
1. Overview
The X-ray Astronomy satellite Suzaku was developed under collaboration of Japan and the United States, and was launched by ISAS/JAXA on 2005 July 10. Suzaku has successfully carried out astronomical observations using the X-ray Imaging Spectrometer (XIS) and the Hard X-ray Detector (HXD). After the initial operation for instrument calibration and performance verification, which confirm the wide-bandpass, high-sensitivity, moderate spectral resolution capabilities of Suzaku, we entered the international AO phase of the mission in 2006 April, performing observations based on proposals received from the astronomical community world-wide. We plan to start AO-4 observations in 2009 April, and hereby solicit submission of observing proposals.
Changes made since the last AO can be summarized as follows:
(1) “Long Program” which was introduced in AO-3 is combined into a more general “Key Project”, for which we spend 2000 ksec in total. The AO for Key Project will be issued separately.
(2) The upper limit of the exposure time, which was set 300 ksec until the last AO, is removed.
Note that the data taken in the Key Project program and those of ordinary proposals with an exposure time ³300 ksec are to be opened immediately after the initial data processing is completed and no proprietary is rewarded to the proposer.
Note:
US based scientists should consult the parallel announcement at
while scientists in ESA member countries should consult the version at
http://www.rssd.esa.int/Suzaku
Present version is applicable to scientists based in all other countries.
2. The Suzaku observatory
The Suzaku satellite carries four modules of the X-Ray Telescope (XRT) that focuses X-rays up to ~10 keV with a high efficiency. In the focal plane of each XRT is mounted an X-ray CCD camera (XIS) module. The XIS has a high sensitivity and moderate spatial resolution, which is especially advantageous in scrutinizing extended sources, as well as good spectral resolution for the soft X-ray below 0.8 keV, which is superior to that of Chandra and XMM-Newton. Moreover, we have applied so-called Spaced-row Charge Injection technique for the XIS since AO-2 to suppress degradation of energy resolution. The HXD has unprecedented sensitivity in the wide energy range up to 600 keV, although it has no imaging capability. The wide bandpass coverage of 0.2 keV through 600 keV with the XIS and the HXD is an important characteristic of the Suzaku mission.
3. Mission phases and time allocation
The Suzaku mission has been developed and maintained under collaboration of Japan and US, and the Science Working Group (SWG) that consist of researchers involved in the development and the operation oversees the project overall. Since the end of the SWG phase of the mission (2006 March), all observation time except
(1) Observatory Time (3%): for satellite maintenance and related purposes,
(2) Calibration time (5%): for calibration of the instruments,
(3) Director's Discretionary Time (DDT: 5%): for gamma-ray bursts or any genuinely unpredictable events, and other important observations granted at the discretion of the mission director,
has exclusively been dedicated for AO observations. The AO-4 program (1 year period starting on 2009 April) will be run under the same policy. The remaining 87% of the total time, which amounts to 360 d ´ 38 ksec/d ´ 0.87 = 11902 ksec, is open to the AO-4 program, and is distributed among Japan, US, ESA and other countries as follows.
(1) Japan time 5451 ksec (ESA 909 ksec, Japan and others 4542 ksec)
(2) US time 3963 ksec
(3) Joint Japan-US time 488 ksec
(4) Key project time 2000 ksec
Here the Japan time includes joint Japan-ESA time, which amounts to 909 ksec. Accordingly, the remaining 4541 ksec is the time for Japanese scientists in AO-4. All proposals out of Japan, US and ESA should be submitted to the Japan time. Note, however, that the total approved exposure time of proposals whose PIs are not Japanese nor researchers from ESA member states is decided not to exceed the joint Japan-ESA time. The joint Japan-US time will be used if proposals for the same targets are accepted both in Japan and US, and if both PIs accept such merging (the proposal form has a check box for the PI to indicate whether he/she accepts the merging).
4. Constraints to be noticed for preparing proposals
(1) The complete list of the targets accepted by AO-3 can be found at the following URL.
http://www.astro.isas.ac.jp/suzaku/accept/
Observations of the priority A and B targets are guaranteed. New proposals for these targets are difficult to be approved except for a strong justification for an additional observation, such as much longer exposure, different pointing position on the same extended object, or a different phase of a variable object. On the other hand, some of the priority C targets and ToO targets are not observed. This can be checked at the following URL.
http://www.astro.isas.jaxa.jp/suzaku/log/
Anyone can submit proposals for the C or ToO targets that are unobserved. It must be noted, however, that these unobserved C targets or ToO targets are possible to be observed by the end of March 2009. In this case, the observations of the C targets are regarded as being completed if the exposure time exceeds 70% of the proposed time. If the exposure time is less than 70 %, on the other hand, an additional observation will be carried out to fill the remaining time only if a proposal for the same target from the same PI is accepted at a higher priority (A or B) in AO-4. Otherwise the observation carried out in AO-3 is ignored, and the target is open for competition in AO-4.
(2) The exposure time of the observation should be justified based on the specific scientific objectives, preferably using simulations. However, we set the minimum exposure time of a single pointing observation at 10 ksec, considering the efficiency of satellite operation. On the other hand, we set no upper limit on the exposure time for a long observation. A longer observation is, however, required stronger scientific justification. Note also that any observations based on a proposal whose approved total observation time exceeds 300 ksec are to be opened to public as soon as the data are ready to analyze (No proprietary is rewarded to the proposer).
(3) In AO-4, we revise the Long program (L), which is introduced in the previous AO allowing observation with an exposure between 300 ksec and 1Msec, and combine it into the new category “Key project”. The announcement of opportunity of the Key project will be issued separately. There is no observing time limitation on the Key project. This will provide a unique opportunity to carry out various projects, such as an extremely long observation of a single object, mapping observation of a certain area of the sky, a long term monitoring observation of an object over several years, and so on, by fully utilizing unique capabilities of Suzaku. The dead line of the Key project proposals are the same as that of the ordinary proposals (solicited by this announcement), 2008 Dec 5. They are sent to the initial refereeing process in Japan and US separately. The principal investigators of the proposals survived the initial refereeing process are requested to make a presentation in the Japan-US merging committee, which finally selects the project proposals for the AO-4 Key project. Note that the data based on the Key project proposals are opened immediately after the data are ready for analysis.
(4) Submission of the same proposals both to the Key project and the ordinary observation is strictly prohibited. If the same researchers are found in the Co-I lists of both proposals, they are rejected without being sent to the refereeing process.
(5) Target of opportunity (ToO) proposals are allowed for short-lived events on known objects whose timing is uncertain. This category is referred to as “Reserved ToO observation”. In this case, condition to trigger the observation, estimated probability of the event to take place during the AO-4 period, and the expected duration of the event should be specified in the proposal as well as other information required for the ordinary observation proposals. Any proposal without specifying a target name, such as “Observation of a forthcoming nearby supernova”, or “Next nova explosion in M31” , is not to be accepted. The number of targets that is allowed to be written in the target list is limited at most 5 per proposal. It is requested to specify in the scientific justification how many targets should be observed to fulfill the scientific goal of the proposal. If the total exposure time to complete the requested number of targets is equal to or larger than 300 ksec, the data will be opened to public as soon as the first observation is finished. See (2) above.
(6) It is possible to submit proposals specifying the time of observations as TC (Time Critical) Observations. These include observations of a certain binary phase, coordinated observations with other wavebands, monitoring a target several times with certain time intervals, roll-angle-constraint observation of diffuse sources, and so on. The Suzaku operation team will do their best to perform the observations as requested. In all these cases, the PI has to activate the TC flag in the application form. Even if the coordination with other instruments is not planned in detail at the time of the proposal submission, the PI is requested to check the TC box if he/she would like to do so after the approval of the proposal. The observation without a TC flag is treated as non-TC observation, and the coordinate observation should be carried out in the style that the other instruments follow the Suzaku schedule.
(7) Any genuinely unpredictable events such as, gamma-ray bursts and supernovae and so on, can be observed as part of the DDT. This category is referred to as a “realtime ToO observation”. The observation proposals of this category are received at any time and are refereed out of the ordinary proposal selection process. Any proposer who would like to propose a realtime ToO observation is requested to fill the form
http://www.astro.isas.jaxa.jp/suzaku/planning/gtoo/
and send it to the Suzaku manager by e-mail
suzaku_managers@astro.isas.jaxa.jp
The proposer has no proprietary on the realtime ToO observation data. Realtime ToO observations on gamma-ray bursts will be planned by the Suzaku Science Working Group, referring to information from various other observation networks.
5. Schedule of the reviewing process
(1) Researchers who affiliate with Japanese institutions or who do not belong to US nor ESA institutions should submit their proposals to ISAS/JAXA according to this AO document. The deadline of proposal submission is at noon of 2008 December 5 (JST). All proposals submitted to ISAS/JAXA are to be reviewed in the same process in Japan. Selection of proposal will be made in February 2009 in Japan side. The ESA-selected proposals are merged at this stage. The Japan-US merging committee will be convened in March 2009. The final observing program of AO-4 will be published soon thereafter.
(2) Accepted proposal are classified into three categories according to their priorities (A, B, and C) which are assigned on the basis of their mark given by the referees. Priority A targets will be preferentially observed during the AO-4 period (2009 Apr to 2010 Mar), and the observation is regarded as completed if the exposure time is more than 90% of the requested time. Priority B targets are tried to be observed during AO-4 period. This is on the best-effort basis, and hence, they may be carried over to the following AOs. Observations of the priority B targets are regarded as completed if the observation covers more than 70% of the requested time. Priority C targets will be scheduled as fillers if there remains a room in the time line after scheduling the priority A and B targets. Of the total available time T (=11902 ksec = 360 d ´ 38 ksec/d ´ 0.87), we will accept 0.6T (= 7141 ksec) for Key+A (Key project time is at most 2000 ksec), 0.3T (= 3571 ksec) for B, and 0.5T (= 5951 ksec) for C proposals. This implies the oversubscription fraction of 40%. The oversubscribed targets will be scheduled if observing time remains after the observatory time, the calibration time, and DDT are assigned.
(3) Reserved ToOs and TC observations pose constraint on scheduling observations. Hence total fraction of them is limited to some 15% of the total available time.
6. Data right
The data taken in the ordinary observation program are immediately delivered to the proposer. The proposer has proprietary to the data for 1 year after the data are ready for scientific analysis. This does not apply to the data based on the ordinary observation proposals whose total exposure time is equal to or more than 300 ksec, those based on Key project proposals and realtime ToO proposals.
================== Call for Proposals of the Suzaku AO-4 period ===================
1. Observations solicited in AO-4
We call for X-ray observations with the Suzaku observatory from April 2009 through March 2010.
2. Applicant eligibility for submitting proposals to the Japan time
Principal investigators (PI’s) who plan to submit their proposals to ISAS/JAXA have to affiliate with institutions or universities located in Japan. Graduate students can apply the AO as a PI, but they must include their supervisor as a Co-I. PIs belonging to US institutions or to ESA member state institutions should submit to NASA and ESA, respectively. NASA and ESA researchers who spend most of their time during AO-4 period in Japan can submit their proposals to ISAS/JAXA. PIs in the other countries should submit their proposals to ISAS/JAXA Japan. The proposals submitted to ISAS/JAXA can include US/ESA researchers as Co-Is. It is not allowed to submit identical proposals to both ISAS/JAXA and NASA. They will be ignored on both sides.
3. Due date of proposals
The observation proposals should be submitted by 12:00 JST (03:00 UT) on December 5, 2008. Only electronic submission through the Remote Proposal-submission System (RPS) is allowed. The RPS will be ready for use around October, 2008.
4. Proposal submission
The forms summarized in the next section should be submitted electronically with the Remote Proposal-submission System (RPS). The RPS will be ready for use in early October.
5. Proposal form
The proposal form consists of
(1) Cover Page: general information including investigators’ name, title and abstract of the proposal.
(2) Target Form: information on the proposed targets including target name, its celestial coordinates, expected counting rate, and preferred observation mode. The target information in this form is automatically registered in the observation database and utilized for making the long-term observation time line of AO-4. The proposers are therefore strongly required to provide accurate information.
(3) Target Constraints: constraints for planning the observation should be specified in this form, which include phase constraint, roll-angle constraint, condition for monitoring observations etc. This form is required only for reserved ToO and TC observations.
(4) Target Remarks: Any additional constraints for performing observations can be written in this form. This form is required only for reserved ToO and TC observations.
(5) Scientific Justification: Background of the proposal, scientific issues to be resolved, and technical feasibility of the proposed observation should be summarized within 4 pages including text, figures, charts, tables, and references.
Of them, the forms (1) and (2) ((1) through (4) in the case of reserved ToO and TC observations) should be created electronically by logging in
http://rps.astro.isas.jaxa.jp/
The form (5) can be made off-line. The proposers can use any editors/word processors they like. It should be in fhe format either of pdf or ps at the time of submission. The allowed language for (5) is either Japanese or English. In submitting a proposal, the proposer should submit the forms (1) and (2) ((1) through (4) in the case of reserved ToO and TC observations) through the RPS, and after acceptance of them, the form (5) is allowed to be uploaded. Note that paper submission is no longer required in AO-4.
6. Supplement Information
Detailed information on the Suzaku instrumentation, such as capabilities of scientific instruments, is summarized in the Technical Description (TD) document, which can be found at
http://www.astro.isas.jaxa.jp/suzaku/doc/suzaku_td
We plan to update the TD document, as well as the proposal planning tools, in early October, 2008. Until then, the proposers are advised to use existing versions of them. For those who are not familiar with Suzaku data, we summarize how to “walk through Suzaku analysis” and a few set of test data (of Crab and other typical X-ray objeccts) at
http://www.astro.isas.jaxa.jp/suzaku/pub/20051201.html
7. Contact point
Feel free to contact
suzaku_ao4@astro.isas.jaxa.jp
if you have any question on AO-4.