We provide an overview of the GLAST Guest Investigator (GI) program, which will support basic research relevant to the GLAST mission in yearly cycles beginning approximately two months after launch. Current details about the GLAST GI program will always be posted on the GLAST Science Support Center (GSSC) website: http://glast.gsfc.nasa.gov/ssc/

Band, David L.

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THE GLAST GUEST INVESTIGATOR PROGR~LM 
David L. Band*>? and the GLAST SSC* 
*Code 661, NASMGSFC, Greenbelt, MD 20771 
+ C R E S S T ~ M B C  
Abstract. We provide an overview of the GLAST Guest Investigator (GI) program, which will support basic research relevant 
to the GLAST mission in yearly cycles beginning approximately two months after launch. Current details about the GLAST 
GI program will always be posted on the GLAST Science Support Center (GSSC) website: http://glast.gsfc.nasa.gov/ssc/. 
Keywords: Gamma-Ray Missions 
PACS: 95.55.Ka; 95.85.P~; 98.70.R~ 
INTRODUCTION 
The GLAST Guest Investigator (GI) program will support the scientigc community's participation in the GLAST 
mission by funding GLAST-related data analysis and research, by providing simultaneous observations through joint 
observing programs with other astronomical facilities, and by modifying GLAST's observing program. Because the 
GI program will change from year to year, here we provide an overview of the less ephemeral aspects of the program. 
The GLAST Science Support Center (GSSC) is the mission's interface with the scientiEc community, and the GSSC 
website (http://glast.gsfc.nasa.gov/ssc/) will always provide specifcs regarding the GI program. 
THE GLAST DATA AND TNE DATA RELEASE POLICY 
To understand the opportunities afforded by the GI program, the nature of the GLAST data and the policies guiding 
its release must be considered. The LAT is a wide Eeld-of-view (FOV) detector (most analyses will include data up 
to 65" off-axis) that will usually scan the sky. In addition the relatively large (compared to other wavelength bands) 
point-spread function (< 3.5" at 100 MeV, < 0.15" at >I0  GeV) will require the simultaneous analysis of aII the 
sources in a region --10-15" around the source of interest. Because the LAT will usually accumulate data on a large 
fraction (-30%) of the sky at any time, and the scan pattern will provide uniform sky coverage on ~3 hour eimescales, 
pointed observations will rarely be scientifcally warranted: the more rapid accumulation of exposure for one source 
will disrupt the exposure accumulation for sources over the rest of the sky. Therefore, the LAT event data will not 
easily be broken into observations of individual sources, as is done for narrow FOV instruments. 
Consequently, the general policy is that the GLAST data will be released publicly as soon as they have been 
processed by the instrument teams and loaded into the GSSC's databases (a latency of less than two days). However, 
during the Erst year of scientigc operations, which coincides with the GIprogram's Erst cycle, the LAT instrument team 
will be calibrating the LAT, &ne-tuning the analysis software, and preparing a point source to guide future analysis. 
Therefore, during this frst year LAT event data will be proprietary to the LAT instrument team. During this period the 
LAT team will make public nuxes, spectra and lightcurves of detected transients and -20 selected sources (the list 
is posted on the GSSC website). At the end of the &rst year, all Cycle 1 and subsequent LAT event data will become 
publicly available. GBM science data will be released from the beginning of science operations. 
Thus in general GIs may propose to analyze all GLAST scientiEc data without a proprietary period. However during 
Cycle 1 GIs may not propose to analyze LAT event data, but may propose to study all other released data. 
GUEST INVESTIGATOR PROGRAM BASICS 
The annual 'cycles' of the GLAST GI Program will be announced in NASASS Research Opportunities in Space and 
Earth Science (ROSES); for example, Cycle 1 was announced in the 2007 ROSES. This announcement is the deEnitive, 
https://ntrs.nasa.gov/search.jsp?R=20070034812 2019-08-30T01:50:25+00:00Z
legal deEnition of the program. The GSSC will administer this program for NASA Headquarters. 
Investigators may propose the following investigation types: 
- The analysis of released LAT scientiEc data. Note that during Cycle 1 this includes nuxes, spectra and lightcurves 
of transients and a list of -20 interesting sources, as well as a preliminary source list that will be released half-way 
through the cycle. After the Erst year all LAT event data will be public without a proprietary period. 
The analysis of burst data from the GBM. 
Multiwavelength observations with other instruments and observatories that are directly relevant to GLAST 
science objectives. Observations on other astronomical facilities may be awarded through joint programs between 
GLAST and these facilities. 
Development of data analysis techniques applicable to the data provided by the GLAST instruments. 
Theoretical investigations that will advance the mission science return of GLAST. Up to 10% of GLAST GI 
funding may be devoted to such theoretical efforts. 
- Changes in the observing plan (e.g., pointed observations), after the Erst year. However, most scientiEc objectives 
will be met by the default survey mode. Note that in Cycle 1 GI proposals cannot modify the observing plan. 
Further information can be found on the GSSC website. 
There will be two proposal classes. Regular proposals will provide research plans that can be completed in one year. 
Large proposals will have research plans that are more expansive and may take up to three years to complete. The 
number of large projects funded, and corresponding budgets awarded in any given year, will be limited. Large projects 
will be reviewed each year to determine if appropriate progress is being made. PIS of approved large projects must 
submit a annual progress report. 
The Cycle 1 program will (tentatively) fund -40-50 regular and - 4 large proposals. The GI program in subsequent 
years will be approximately twice as large. 
PIS at institutions outside the US may submit proposals, but cannot be funded by NASA (positive evaluations may 
be useful for obtaining funding from non-US funding agencies). US Co-Is of proposals submitted by foreign PIS may 
be funded commensurate with their level of effort. 
The 61 program will include a GLAST Fellows Program with a schedule similar to the Hubble and Chandra Fellows 
programs. 
More ~nformation available from GSSC website: http://glast.gsfc.nasa.gov/ssc/ Assistance is available from the 
GSSC helpdesk: http:Nglast.gsfc.nasa.gov/ssc/help/. 
PROPOSAL SUBMlISSION 
A two stage proposal process will be used in Cycle 1, and is planned for subsequent cycles. First, proposers will submit 
their 4 page science proposals that will be evaluated by peer panels. Second, those GIs whose scientigc proposals are 
tentatively selected will then submit the proposal~s funding portion. Proposers will submit the maximum funding 
request (a single number) with the science proposals, but will submit a detailed budget only if the science proposal has 
been tentatively accepted. For Cycle 1 the science proposals will be submitted through the Remote Proposal System 
(WS) at Goddard Space Flight Center. If the science proposal has been tentatively accepted, the budgets will be 
submitted through the NASA Solicitation and Proposal Integrated Review and Evaluation System (NSPIRES). 
To assist scientists prepare GI proposals, the GSSC will provide methods to estimate the detectability of LAT point 
sources (e.g., the time required for the 5 0  detection of a source). The GSSC will also provide a GLAST version of 
Webspec, a web-based tool that simulates spectra by running XSPECSS fakeit command; thus scientists can simulate 
and &t C;BM or LAT spectra. A technical handbook will be posted on the GSSC website. 
In the second and subsequent cycles scientists will be able to simulate data using the tools in the Science Analysis 
Environment (SAE), the set of tools that will be provided to analyze GLAST data. A spatial-spectral source model 
can be folded through the LAT instrument response functions to simulate an observation. The simulated data can then 
be analyzed with the SAE tools. Because during the £rst cycle LAT count data will not be released and GIs cannot 
propose observations, the relevant SAE tools will not be available for the Erst round of proposals. 


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