Observations to be carried out with Chandra during the 12 months of Cycle 15 science operations will be selected from proposals submitted in response to this CfP. Up to 2Ms of Cycle 16 and 1Ms of Cycle 17 observing time may be allocated to time-constrained, multi-cycle observing proposals requesting time that extends beyond Cycle 15.
There are seven types of proposals that may be submitted in response to this CfP; they are detailed in the following sections. In addition, Director’s Discretionary Time (DDT) proposals for observations that cannot be completed in, or cannot wait for, the usual proposal cycle may be submitted at any time (Section 4.8). The CXC reserves the right to reject any approved observation that is in conflict with safety or mission assurance priorities or schedule constraints, or is otherwise deemed to be non-feasible.
There are no restrictions regarding the amount of observing time or the number of targets that may be requested in this category. Proposals may be submitted for single targets with a relatively short observation time, or for larger programs involving multiple targets and/or significant amounts of observing time. All proposals will be reviewed, and a mix of large and small programs will be selected. Proposals requesting observations whose science requires constraints distributed over multiple (up to three) proposal cycles will be considered (Section 3.2.1.14). Observations allocated time in this category will have one year of proprietary time unless a shorter proprietary time interval is requested by the PI.
Large Projects are defined as requiring 300-999 ksec of observing time, regardless of whether they include long-duration observations of single targets or shorter duration observations of many targets. Large Projects must be designated as such by the PI and are encouraged. Up to 4 Msec of the observing time in this Cycle is reserved for Large Projects, subject to the submission of proposals of high scientific merit.
The observations proposed for Large Projects may span up to 3 cycles when required to achieve the scientific goals. In the case of target conflicts with a small proposal, the Selecting Official, based on the recommendation of the peer review, may award the target in question to the smaller proposal. In this case, the proposer of the Large Project may always make use of data taken for the other project once they are made public.
Large Projects are evaluated differently from other proposals. A Large Project is first evaluated and graded along with the other observing proposals by two independent “Topical Science” panels. The graded Large Projects are then passed to the “Big Project” panel which allocates time separately to the LPs and XVPs and makes the final recommendations for an integrated observing plan involving all top-rated proposals to the Selection Official. Although the Big Project panel may recommend shortening a Large Project under exceptional circumstances, it is intended that a Large Project be an all-or-nothing proposition. Observations approved in this category will be allocated one year of proprietary time unless a shorter time is requested by the PI.
X-ray Visionary Projects (XVPs) should describe a major, coherent science program to address key, high-impact, scientific question(s) in current astrophysics and may span up to 3 cycles when required to achieve the scientific goals. We envision that XVPs will result in data sets of lasting value to the astronomical community. We encourage proposers to describe the legacy value of the data and any data products and/or software they expect to release to the community as part of their project.
XVPs are defined as requiring between 1 and 5 Msec of total observing time including long-duration observations of single targets or shorter duration observations of many targets to address major, key questions in current astrophysics. This category is open to all science topics and must be designated as an XVP by the PI. About 5 Msec of the observing time is reserved for X-ray Visionary Projects, subject to the submission of proposals of high scientific merit.
Observations approved as part of an X-ray Visionary Project will have no proprietary time associated with them, and the data will be made public immediately. XVP projects will be allocated a maximum of 2 Msec of observing time on targets situated above 60º ecliptic latitude.
Proposers planning to submit an XVP should send a Notice of Intent to Propose, including the following information: title, PI name, estimated observing time, preliminary list of Co-Is, and short abstract, to the CXC helpdesk (cxchelp@head.cfa.harvard.edu) by 23 Jan 2012. This information on proposals to be submitted will allow the CXC to plan a competent review with minimal conflicts of interest.
Projects that plan to deliver products, such as source catalogs, high fidelity data products, or software to the community are encouraged to outline these plans in the proposal. A modest funding allocation may be requested in the Stage 2 Cost proposal to facilitate the delivery of such products.
X-ray Visionary Projects will be evaluated and graded by an XVP panel at the peer review in addition to the topical panels. The recommendations of all reviewing panels will then be passed to the Big Project Panel which allocates time, separately, to LPs and XVPs and makes the final recommendations for an integrated program involving top-rated proposals to the Selection Official.
Proposals are also solicited for Pre-Approved Targets of Opportunity (TOOs). These are defined to be observations of unanticipated astronomical events, such as a supernova or a gamma-ray burst that must take place in order to trigger the observation. The number of times the Observatory can be used to respond to a TOO is limited by operational considerations with difficulty increasing with rapidity of response. Given the limited availability and high operational impact of TOOs, proposers are asked to carefully consider whether Chandra is the optimal observatory for their particular target(s) and to justify this choice in their proposal. Other X-ray missions, e.g., SWIFT, are more flexible for performing TOO observations on medium/bright targets. SWIFT TOO application information either pre-approved (by peer review) or unanticipated, can be found on the SWIFT website at: http://www.swift.psu.edu/ too.html.
The minimum expected response time for a TOO is 24 hours. It is estimated that the Observatory can support a maximum number of Cycle 15 TOOs by TOO Response Category as shown in the Table 4.1 below.
Table 4.1 TOO Response Category
|
Number of Observations1 |
Category |
Minimum Response Time (days)2 |
|
8 |
Very Fast |
<4 |
|
20 |
Fast |
4 - <15 |
|
26 |
Medium |
15 - <30 |
|
26 |
Slow |
≥ 30 |
Notes:
Proposals may not contain a mixture of TOO and non-TOO targets. Once a TOO has been selected, the observing time is awarded, but not scheduled until the triggering event takes place. It is the responsibility of the PI to alert the CXC to the occurrence of the triggering event. Response time requests in TOO triggers must be within, or longer than, the approved response time window.
Given the high operational impact of TOOs, no constraints or follow-up observations over and above those included in the proposal RPS forms and recommended by the peer review will be accepted. All follow-up observations whose timing depends on events close to the trigger need to be included in the original proposal forms and will be counted as separate TOOs with category determined by the requested time delay between the event and the observation. All trigger criteria must be specified in the appropriate fields on the RPS form. Follow-up observations that have a longer lead time (≥15 days) are classified as constrained observations.
Those proposing for a Pre-Approved TOO should be aware that any such observations awarded for a given observing Cycle, but not accomplished, cannot be carried over to the next Cycle, although they may be re-proposed. Since the CfP is being released prior to the end of this Cycle, there may be a set of selected and Pre-Approved TOOs for this Cycle that have not been triggered. Proposers may choose to assume that these will not have been triggered by the time the next Cycle starts (about December 2013). The PI/Observer should indicate on the RPS form of the new cycle proposal whether/not a trigger of the previous cycle’s TOO would cancel the TOO observation proposed/accepted for the new cycle.
Joint Observing Projects may be proposed as follows with the intent to address those situations where data (not necessarily simultaneous) from more than one facility are required to meet the scientific objectives of the proposal. In addition to time on Chandra, time may be requested and awarded via this CfP on one or more of the facilities described below. It is the proposer’s responsibility to provide a technical justification for all observing facilities included in the proposal. A request for simultaneous or otherwise time-constrained observations must be scientifically justified, and the technical justification must include consideration of the relative visibility of the target by all requested facilities. Please note that coordination with ground-based observatories other than NRAO is only available as a preference and will be carried out on a best-effort basis. No time on the joint facilities will be allocated without accompanying Chandra time on the same target, except where noted. Up to 10% and 5% of the available joint time in Cycles 16 and 17 respectively may be allocated to multi-cycle observing proposals if scientifically justified and subject to the continued availability of that time.
This CfP solicits proposals to allow observers interested in using both the Hubble Space Telescope (HST) and Chandra to achieve their scientific objectives to submit a single proposal in response to either HST or Chandra CfPs. The only criteria above and beyond the usual review criteria are that the project must be fundamentally of a multi-wavelength nature and that both sets of data are required to meet the science goals. Simultaneous Chandra and HST observations should be requested only if necessary to achieve the scientific goals. Proposers responding to this CfP may request, and be awarded, HST observing time in conjunction with their Chandra observations. One hundred orbits of HST observing time are available for this opportunity. Conversely, up to 400 ksec of Chandra observing time are available for award as part of the response to HST research opportunities. However, the Chandra project can award no more than one HST Target of Opportunity (TOO) observation with a turn-around time shorter than two weeks.
Proposers wishing to take advantage of the Chandra-HST arrangements are encouraged to submit their proposal to the Observatory announcement that represents the prime science. The expertise required to best appreciate and evaluate the proposals will be weighted toward the wavelength band of the primary observatory. Demonstration of the technical feasibility for both observatories to produce the necessary data is required, including consideration of the relative visibility of the target(s) to both facilities for the case of time-constrained observations. Technical information about HST is available at http://www.stsci.edu/hst/. General policies for HST observations are described in the latest HST Call for Proposals, available at http://www.stsci.edu/hst/proposing/documents/cp/cp_cover.html. In particular, standard duplication policies described in Section 5.2 apply to HST observations requested as part of Chandra-HST proposals. Known duplications should be justified scientifically. The Space Telescope Science Institute is prepared to assist observers proposing in response to this opportunity. Questions should be addressed to help@stsci.edu.
Any major requested change to the approved HST portion of a Chandra program such as a change of instrument, wavelength settings, the addition of parallel orbits, etc. requires strong scientific justification, is not normally approved, and may jeopardize the Chandra portion.
If a science project requires observations with both XMM-Newton, sponsored by the European Space Agency, and the Chandra X-ray Observatory, then a single proposal may be submitted to request time on both Observatories to either the most recent XMM-Newton Announcement of Opportunity or to this Chandra CfP so that it is unnecessary to submit proposals to two separate reviews.
By agreement with the Chandra Project, the XMM-Newton Project may award up to 400 ksec of Chandra observing time. Similarly, the Chandra Project may award up to 400 ksec of XMM-Newton time. The time will be awarded only for highly ranked proposals that require use of both observatories and shall not apply to usage of archival data. The only criterion above and beyond the usual review criteria is that both sets of data are required to meet the primary science goals. Proposers should take special care in justifying both the scientific and technical reasons for requesting observing time on both missions. Simultaneous Chandra and XMM-Newton observations should be requested only if necessary to achieve the scientific goals. No Targets of Opportunity, either pre-Approved or unanticipated, will be considered for this cooperative program. For this CfP, no XMM-Newton time will be allocated without the need for Chandra time to complete the proposed investigation.
Establishing technical feasibility is the responsibility of the observer, who should review the Chandra and XMM-Newton (http://heasarc.gsfc.nasa.gov/docs/xmm/xmmgof.html) documentation or consult with the CXC HelpDesk (http://cxc.harvard.edu/helpdesk/). For proposals that are approved, both projects will perform detailed feasibility checks. Both projects reserve the right to reject any approved observation that is in conflict with safety or mission assurance priorities or schedule constraints, or is otherwise deemed to be non-feasible. Note that simultaneous longer-duration observations with XMM-Newton that require Chandra satellite pitch angles violating the conditions discussed in Section 2.3 may not be feasible. Any observation(s) deemed to be not performable as indicated above would cause revocation of observations on both facilities.
By agreement with NOAO, proposers interested in making use of observing facilities available through NOAO (including Gemini, CTIO, KPNO, SOAR and WIYN, but not facilities made available through the TSIP or ReSTAR programs) as part of their Chandra science may submit a single observing or archival research proposal in response to this CfP. The award of NOAO time will be made to highly ranked Chandra proposals and will be subject to approval by the NOAO Director.
The primary criterion for the award of NOAO time is that both Chandra and NOAO data are required to meet the scientific objectives of the proposal. Both Chandra observing and archival research proposals are eligible. The highest priority for the award of NOAO time will be given to programs that plan to publicly release the optical data in a timely manner (i.e., shorter than the usual 18-month proprietary period) and that create databases likely to have broad application. NOAO plans to make up to 5% of the public time each semester on each telescope available for this opportunity. Time on the Gemini telescopes will be restricted to no more than 40 hours per year per telescope, and will be scheduled as queue observations. The Gemini queue time is distributed across three priority bands (see http://www.gemini.edu for an explanation of the bands) as follows: NOAO will schedule no more than 15 hours of the Chandra/NOAO time as Band 1, 15 hours as Band 2, and 10 hours as Band 3. In addition, the available observing time is divided roughly equally between the A and B semesters covered by the Chandra cycle, for a maximum of 20 hours per semester on each telescope. Proposers wishing to make use of this opportunity must provide the following additional NOAO-related information as part of their
Chandra proposal:
Demonstration of the technical feasibility of the proposed NOAO observations is the responsibility of the proposer. Detailed technical information concerning NOAO facilities may be found at http://ast.noao.edu/observing. Proposals lacking sufficient detail may not be scheduled by NOAO.
If approved for NOAO time, successful PIs will be required to submit the standard NOAO forms providing detailed observing information appropriate to the telescope and instrument combination(s) awarded. NOAO will perform feasibility checks on the proposed observations and reserves the right to reject any observation determined to be unfeasible for any reason. Such a rejection could jeopardize the entire proposed science program and impact the award of the Chandra observing time as well.
In addition, for NOAO time on Gemini (only), successful PIs will be required to submit a full scientific justification to NOAO on the standard NOAO proposal form. NOAO will review the proposal in order to determine the Gemini queue band into which the observations will be placed. Note that the band awarded may restrict the conditions available for the observations.
By agreement with NRAO, proposers interested in making use of the NRAO Karl G. Jansky Very Large Array (VLA), Very Long Baseline Array (VLBA) and Green Bank Telescope (GBT) facilities as part of their Chandra science may submit a single proposal in response to this CfP. The award of NRAO time will be made to highly ranked Chandra proposals and will be subject to approval by the NRAO Director.
The primary criterion for the award of NRAO time is that both Chandra and NRAO datasets are essential to meet the scientific objectives of the proposal. No NRAO time will be allocated without Chandra time.
NRAO plans to make up to 3% of VLA, VLBA and GBT observing time available for this opportunity with a maximum of 5% in any configuration/time period and including an 18-month period close to the Chandra Cycle 15 such that all VLA configurations are available. A VLA configuration schedule is published at https://science.nrao.edu/facilities/vla/proposing/ configpropdeadlines.
Proposers wishing to make use of this opportunity must provide the following NRAO-related information as part of their Chandra proposal:
Be aware that some Chandra targets might not require new NRAO observations because the joint science goals can be met using:
Detailed technical information concerning the NRAO telescopes can be found at:
http://science.nrao.edu/facilities/vla, http://science.nrao.edu/facilities/vlba, and http://science.nrao.edu/facilities/gbt.
In particular, technical information required for a proposal can be found at:
https://science.nrao.edu/facilities/vla/docs/manuals/oss-2013a,
http://science.nrao.edu/astro.obstatus/current/ (VLBA), and
http://www.gb.nrao.edu/gbtprops/man/GBTpg.pdf (GBT).
If approved for NRAO time, successful PIs will be contacted by the NRAO Scheduling Officers. The successful PIs for GBT projects will be responsible for organizing the project’s information in the GBT Dynamic Scheduling Software and for carrying out their GBT observations. For the VLA and VLBA, the PIs will be responsible for submitting scheduling blocks to the telescope’s dynamic queues. Projects requiring simultaneous NRAO-Chandra observations will be performed on fixed dates. The NRAO Scheduling Officers will tell the PIs those dates and times, and the PIs will be responsible for submitting scheduling blocks two weeks prior to the observations.
NRAO will perform final feasibility checks on the proposed observations and reserves the right to reject any observation determined to be infeasible for any reason. Such a rejection could jeopardize the success of the joint science program.
By agreement with the Suzaku Project, proposers interested in making use of Suzaku time as part of their Chandra science investigation may submit a single proposal in response to this Chandra CfP. The award of Suzaku time will be made to highly ranked Chandra proposals and will be subject to approval by the Suzaku Project.
The primary criterion for the award of Suzaku time is that both Chandra and Suzaku data are required to meet the scientific objectives of the proposal. Suzaku time will not be awarded without accompanying Chandra observing time. The Suzaku Project is making available up to 500 ksec of Suzaku observing time available to such joint science proposals. Coordinated observations are allowed, if judged feasible. Chandra Cycle 15 is expected to overlap with Suzaku Cycle 8 (2013 April through 2014 March) and the possible Cycle 9 (2014 April through 2015 March). Note, however, that there is a possibility that scientific observations with Suzaku may cease sometime during the above period, due to the degradation of the power generation capability of Suzaku.
A maximum of 75 ksec on Suzaku can be time-constrained for science reasons, including coordinated observations, roll, phase or window constraints, or Targets of Opportunity. No TOO requiring less than 4 days response time will be considered.
Proposers wishing to make use of this opportunity must provide the following additional Suzaku-related information as part of their Chandra proposal:
It is the responsibility of the proposer to demonstrate the feasibility of the proposed Suzaku observation. Detailed technical information concerning Suzaku may be found at http://www.astro.isas.jaxa.jp/suzaku/. The Suzaku Guest Observer Facility and Project Scientist will make feasibility assessments of the proposed observations independently of the Chandra review. Proposed Suzaku observations determined to be infeasible will be rejected. Such a rejection could jeopardize the entire proposed science program and impact the award of the Chandra observing time as well.
If Suzaku time is approved, successful PIs will then be required to provide further details of the Suzaku observations to the Suzaku Guest Observer Facility including the observing strategy and instrument configurations in a form amenable to the Suzaku scheduling software.
Suzaku datasets obtained under this agreement will be proprietary to the PI for one year after the performance of the observation, and will subsequently be released publicly via the HEASARC.
If your science project requires observations from both the Spitzer Space Telescope and the Chandra X-ray Observatory, you can submit a single proposal to request time on both observatories to the Chandra Cycle 15 review. This avoids the "double jeopardy" of having to submit proposals to two separate reviews.
Spitzer Cycle-10 will run from approximately October 2013 through September 2014. For Chandra Cycle 15, the CXC will be able to award up to 60 hours of Spitzer time to highly rated proposals. The only criteria above and beyond the usual review criteria are that the project is fundamentally of a multi-wavelength nature and that both sets of data are required to meet the science goals. Spitzer General Observer time will only be awarded in conjunction with Chandra observations and should not be proposed for in conjunction with an Archival Research or Theory/Modeling Proposal.
In the Chandra Cycle 15 review, no more than 20 hours of the 60 hours of Spitzer observing time available will be awarded to an individual proposal. No TOOs will be approved. Highly constrained Spitzer programs are discouraged as joint Chandra-Spitzer proposals. If you require highly constrained Spitzer observations you should submit your proposal to the next Spitzer review. The Cycle-10 call for proposals will be issued in late spring 2013 and the proposal deadline will be in the summer of 2013. If you have questions about constraints for the Spitzer observations, please contact the SSC Helpdesk. Evaluation of the technical feasibility is the responsibility of the observer, who should review the Spitzer documentation: (http://ssc.spitzer.caltech.edu/warmmission/propkit) or consult with the Spitzer Science Center (SSC) Helpdesk (help@spitzer.caltech.edu). For proposals that are approved, the SSC will perform detailed feasibility checks. The SSC reserves the right to reject any approved observation that proves to be non-feasible, impossible to schedule, and/or dangerous to the Spitzer instruments. Any Spitzer observations that prove infeasible or impossible could jeopardize the overall science program and may cause revocation of the corresponding Chandra observations. Duplicate Spitzer observations may also be rejected by the SSC.
Proposers requesting joint Chandra-Spitzer observations must provide a full and comprehensive technical justification for the Spitzer portion of their program. This justification must include:
Technical documentation about the Spitzer Space Telescope is available from the Spitzer Science Center (SSC) website, which also provides access to the Spitzer Helpdesk (email: help@spitzer.caltech.edu). The primary document is the Spitzer Observer's Manual, available, together with other relevant documents, from the Proposal Kit Web Page. Spitzer strongly recommends that observers proposing Spitzer observations estimate the required observing time using Spot, the Spitzer proposal planning software, also available from the on-line proposal kit.
Proposers requesting joint Chandra-Spitzer observations must specify whether they were awarded Spitzer time in a previous cycle for similar or related observations.
Spitzer programs of less than 100 hours are eligible for a maximum of $5,000 in data analysis funding.
By agreement with the Swift Mission Project, proposers interested in making use of Swift time as part of their Chandra science investigation may submit a single proposal in response to this Chandra CfP. The award of Swift time will be made to highly ranked Chandra proposals and will be subject to approval by the Swift Project.
The primary criterion for the award of Swift time is that both Chandra and Swift data are required to meet the scientific objectives of the proposal. Swift time will not be awarded without accompanying Chandra observing time. The Swift Project is making up to 300 ksec of Swift observing time available to such joint science proposals. Coordinated observations are allowed, if judged feasible. Chandra Cycle 15 is expected to overlap with Swift Cycles 9 (2013 April through 2014 March) and 10 (2014 April through 2015 March).
Proposed Swift time may be time-constrained, including coordinated and monitoring observations, and Targets of Opportunity, if full justification is included in the proposal. Note that proposed Swift observing time can include monitoring that precedes, follows and/or (for TOOs) triggers Chandra observing time. Any constraints on the proposed Chandra observations must as usual be specified in Chandra RPS forms, and fully justified in the proposal.
Proposers must clearly describe how their proposal capitalizes on the unique capabilities of Swift. Proposers wishing to make use of this opportunity must provide the following additional Swift-related information as part of their Chandra proposal:
It is the responsibility of the proposer to demonstrate the feasibility of the proposed Swift observation. Detailed technical information concerning Swift may be found at http://heasarc.gsfc.nasa.gov/docs/swift/swiftsc.html. PIs are expected to determine if a target can be viewed by Swift (http://heasarc.gsfc.nasa.gov/Tools/Viewing.html) and whether bright stars prohibit the use of the Swift UVOT (http://heasarc.gsfc.nasa.gov/docs/swift/proposals/ bright_stars/bright_star_checker.html). PIs need to provide a strong justification for the choice of the filters if UVOT filters other than "filter of the day" are requested. If no strong justification is provided, observations will be performed in "filter of the day" mode.
The Swift Guest Observer Facility will make feasibility assessments of the proposed observations independently of the Chandra review. Proposed Swift observations determined to be infeasible will be rejected. Such a rejection could jeopardize the entire proposed science program and impact the award of the Chandra observing time as well.
If Swift time is approved, successful PIs will then be required to submit the standard Swift cover and target forms to the Swift Guest Observer Facility via ARK/RPS (https://heasarc.gsfc.nasa.gov/ark/swiftrps/) to provide the required information about observing strategy and instrument configurations.
Swift data sets obtained under this agreement will not be proprietary to the PI and immediately released publicly via the HEASARC data archive. No funds will be provided from the Swift Project for such joint Chandra/Swift investigations.
Research that is primarily Theoretical/Modeling in nature can have a lasting benefit for current or future observational programs with Chandra, and it is appropriate to propose such programs with relevance to the Chandra mission. Theoretical/Modeling research should be the primary or sole emphasis of such a proposal. Analysis of archival data should not be the goal of the project. Archived data may be used only to show how Chandra observations may be better understood through the results of the proposed Theory/Modeling research. Theory/Modeling proposals must be submitted using the same proposal format as observing proposals, and the proposal type “Theory” should be checked on the electronic submission.
A Theory/Modeling proposal should address a topic that is of direct relevance to Chandra observing programs, and this relevance must be explained in the proposal. (Research that is appropriate for a general theory program should be submitted to the Science Mission Directorate’s Astrophysics Theory Program, solicited in the annual Research Opportunities in Space and Earth Sciences (ROSES) NASA Research Announcement and/or other appropriate funding sources.) The primary criterion for a Theory/Modeling proposal is that the results must enhance the value of Chandra observational programs through their broad interpretation (in the context of new models or theories) or by refining the knowledge needed to interpret specific observational results (for example, a calculation of cross sections). As with all investigations supported through this CfP, the results of the Theoretical/Modeling investigation should be made available to the community in a timely fashion.
A Theory/Modeling proposal must include an estimated amount of funding in the Stage 1 submission and must provide a narrative within the science justification section that describes the proposed use of the funds. Detailed budgets are not requested in Stage 1, however, and are due only in Stage 2.
The scientific justification section of the proposal must describe the proposed theoretical investigation and also the anticipated impact on observational investigations with Chandra. Review panels will consist of observational and theoretical astronomers with a broad range of scientific expertise. The reviewers will not necessarily be specialists in all areas of astrophysics, particularly theory, so the proposals must be written for general audiences of scientists. The proposal should discuss the types of Chandra data that would benefit from the proposed investigation, and references to specific data sets in the Chandra data archive should be given where appropriate. The proposal should also describe how the results of the theoretical investigation will be made available to the astronomical community, and on what time scale the results are expected.
This CfP also includes the opportunity to propose investigations based on data in the Chandra public archive for part or all of the study. Proposals for which archival data is the major focus of the investigation should select the “Archive” category on the RPS form. A PI may link an archival research proposal with an observing proposal to extend an existing sample to perform the same science analysis. There is no restriction on the amount of existing Chandra data that may be proposed for analysis. The Chandra website (http://cxc.harvard.edu/) contains information on the data that are available in the archive. The data currently available from the Chandra Data Archive may be browsed and visualized through the CDA Footprint service (http://cxc.harvard.edu/cda/footprint/cdaview.html). Data becoming publicly available in the future may be browsed through WebChaSeR (http://cda.cfa.harvard.edu/chaser/). The data may also be accessed through this website (see also Section 3.5). All on-orbit calibration data are placed directly in the archive. Data from Director’s Discretionary Time (DDT) observations (Section 4.8) are placed in the archive no later than three months after receipt by the PI, while other proprietary observations are archived no later than one year after receipt by the PI. XVP data have no proprietary period and are placed in the archive coincident with receipt by the PI. A bibliographic interface allows simultaneous browsing of the Chandra Data Archive and the literature (http://cxc.harvard.edu/cgi-gen/cda/bibliography). See Section 6.1.3 for further details on archive browsing.
Archival Research proposals must include an estimated amount of funding in the Stage 1 submission and must provide a brief narrative within the science justification section that describes the proposed use of the funds. Detailed budgets are not requested in Stage 1 and are due in Stage 2.
We will accept archival proposals which make use of the Chandra Source Catalog as all or part of the proposed science program. The current release (1.1) of the catalog includes information about sources detected in a subset of ACIS and HRC-I imaging observations released publicly prior to January 1, 2010. Only point sources, and compact sources, with observed spatial extents ≤30 arcseconds, are included. Highly extended sources, and sources located in selected fields containing bright, highly extended sources, are not included in the current release.
The catalog includes sources detected with flux estimates that are at least 3 times their estimated 1 sigma uncertainties in at least one energy band (typically corresponding to about 10 net source counts on-axis and roughly 20-30 net source counts off-axis). In the current release of the catalog, multiple observations of the same field (if they exist) are not co-added prior to performing source detection. Instead, source detection is performed on each observation individually, so that the flux threshold applies to detections from each observation separately.
Prospective users of the catalog should be aware of the selection effects that restrict the source content of the catalog and which may limit scientific studies that require an unbiased source sample. Users are urged to review the catalog Caveats and Limitations prior to using the CSC for their scientific investigations.
For more information on the Chandra Source Catalog, please refer to the public catalog web pages at http://cxc.harvard.edu/csc. The data used for the CSC, and the area of the sky covered by it, may be visualized with the CDA Footprint Service: http://cxc.harvard.edu/cda/footprint/cdaview.html (Section 6.1.3).
Unanticipated Targets of Opportunity or those that cannot wait for the next proposal cycle may be proposed for observation using Director’s Discretionary Time (DDT) at any time. Proposals for DDT must be submitted electronically through the RPS as described in Section 5.3. Note that the RPS form for DDT is different from that for ordinary proposals. The DDT form may be found on the CXC website by selecting the “Proposer” button and then “Targets of Opportunity” and “Director’s Discretionary Time” (http://cxc.harvard.edu/soft/RPS/Chandra_RfO.html). More information is available in Section 3.2.
