GALAXY EVOLUTION EXPLORER (GALEX)
GUEST
INVESTIGATOR PROGRAM - Cycle 5
1.Guest
Investigator (GI) Program Description
1.1 Overview
1.2 Program
Types
1.2.1 New
Observations
1.2.2 Archival
Investigations
1.2.3 Unscheduled Observing Time – Targets of Opportunity and
Discretionary Time
1.3 Mission Capabilities and
Constraints – Cycle 5
1.4 General Guidelines and
Policies
1.4.1 Proposal Process
1.4.2 Who May Propose
1.4.3 Late Proposals
1.5 Data Rights and
Distribution
1.7 Proposal Evaluation and
Selection
1.8 Funding for US
Investigators
1.9 Education and Public Outreach
2. Proposal Preparation and Submission
2.1 General Information on
NASA Proposals
2.2 Notice of Intent
2.4 Cover Page
2.5 Proposal Format and
Content
2.6 Proposal Template, Examples
and Instructions
3.1 Mission Overview
3.3 Satellite Operations and
Observation Planning
3.3.1 Observation Modes
3.3.2 Brightness Limits
3.4 Data Processing,
Calibration, and Distribution
3.4.1 Pipeline Processing and
Calibration
3.4.2 Data distribution
GALEX GUEST INVESTIGATOR PROGRAM - Cycle 5
1 Guest Investigator (GI)
Program Description
This program element (D.5)
of the 2008 ROSES solicits proposals for the
acquisition and analysis of new scientific data from the Galaxy Evolution
Explorer (GALEX). GALEX operates in two broad bands, Far-UV (FUV,
1350-1800 Å) and Near-UV (NUV, 1800-2800 Å), providing wide-field (1.2 degree)
imaging and low resolution (R = 150-300) grism spectroscopy, with sufficient
sensitivity to study a wide variety of objects within and outside of our
Galaxy. GALEX was launched on April 28, 2003.
During calendar year 2009,
the scientific capabilities of GALEX will be available to the astronomical
community for scientific investigations that do not duplicate the GALEX team
investigations. This solicitation is for Cycle 5 of the GALEX Guest
Investigator (GI) Program, to be carried out beginning on January 1, 2009, and
lasting approximately 12 months. Section 2 contains instructions for proposal
preparation. A brief description of the GALEX mission is in Section 3; a more detailed description can be
found at http://www.caltech.edu/researcher/techdocs.html/.
Proposals will be accepted
for both new observations and for archival research. Proposed scientific
investigations should not duplicate GALEX primary science investigations, or
already accepted GI Programs (see http://galexgi.gsfc.nasa.gov/science/index.html
). Guest Investigations may be proposed for fields already observed by
the GALEX science team, as long as the science investigation is clearly
different. Many projects may be best addressed as archival
investigations, using the data already collected for the primary mission; all
publicly available GALEX data in the Multimission Archive at Space Telescope (MAST) will be available for archival
investigations. Potential proposers are strongly encouraged to examine
the descriptions of the GALEX primary science investigations before proposing. Examples of GALEX science may be found in the
list of publications (http://www.galex.edu/researcher/data.html).
Proposals submitted in
response to this program may be for new observations with GALEX, or for
analysis of existing GALEX data. Approximately 1500 ksec (1/3 of the
available observing time) is expected to be available to the community for new
observations in Cycle 5. There are four proposal categories: 1) Standard, 2) Legacy, and 3) Snap proposals are for new
observations; while 4) Archival proposals are for investigations
using the rich GALEX archival data set. Mixed proposals may be
submitted that include some new observations and some archival work, provided
the archival work is not expected to comprise more than ~1/3 of the
investigation's effort; these should be submitted as the relevant type of
observing proposal. If more than ~1/3 of a combined investigation is expected
to comprise work with archival data, and the investigators wish to request
funding for the archival work, then two separate proposals (one new
observing, one archival) should be submitted and the connection noted in each
proposal. More information on the different proposal types may be found in the
following sections.
For the first three
categories, proposals submitted in response to this NRA constitute the first
phase of the GALEX GI proposal process. The following information is
required: a scientific justification, a description of the proposed
observations, a discussion of the technical feasibility, astronomical target
data, exposure time estimates, and any special operational requirements (e.g.,
orientation constraints, timing considerations, etc.). Section 1.3
describes important capabilities and constraints that affect how GI programs
will be evaluated and implemented in Cycle 5. After selection by NASA,
successful GI programs will undergo a
detailed Phase 2 review, so that safety checks, assessments, feasibility
assessment, and observation scheduling can be performed. No Phase 2 review will
be required for successful archival proposals.
There are two types of
unscheduled observing time that can be made available, with the approval of the
GALEX Mission Scientist. The first deals with major Targets of
Opportunity (ToO), such as supernovae, novae, and comets. The second
type, called Discretionary Observing Time (DOT), is intended for observations
of an urgent nature requiring a small amount of observing time and of
sufficiently high scientific priority that they should not be delayed to the
next observing cycle (See Section
1.2.3 for more details).
1.2.1 New Observations: Program Categories and Time
Allocation
Observing Program Categories - Each GALEX observing
proposal must be designated in one of three proposal categories at the time of
submission - Standard, Legacy, or Snap - and this category must apply to all
targets in the proposal. Approximately 1/3 of the available observing
time during Cycle 5 (~ 1500ksec) is expected to be available to the community
for new observations. GALEX observing
time is allocated in orbital nights (orbits).
Proposals should request only the time needed for scientific
exposures.
1. Standard proposals provide
the opportunity to observe targets specified by the proposer. These
may include shallow or deep imaging, shallow or deep grism observations,
repeated visits to observe time-variable phenomena, or mapping of regions of
the sky not observed by the GALEX primary science surveys. NASA
intends to execute all observations associated with accepted Standard
proposals. These programs typically
require less than 100 ksec. observing time.
2. Legacy proposals provide the opportunity for large coherent
projects of general and lasting importance to a wide astrophysical
audience. These proposals typically
require a minimum of 100 orbits. Legacy programs are expected to use GALEX
to enhance significantly the overall scientific contribution of the
mission. They are expected to provide
value-added data products, to offer immediate data access, to make available
ancillary data, or otherwise enhance the resulting dataset. NASA intends to execute all observations
associated with the allocated observing time for accepted Legacy proposals. NASA anticipates that at
least 25% of the GI observing time in Cycle 5 will be allocated to Legacy
proposals.
3.
Snap proposals are intended to maximize
the science return of GALEX and to provide scheduling flexibility by providing
a large pool of targets to the mission schedulers; they will receive lower
priority in target scheduling. Snap programs provide the opportunity for
observations of a class of objects to be undertaken without the requiring that
any specific object in the class be observed. It is unlikely that all
targets in an accepted Snap program will be observed. Although there is no
assurance that any specific target in a Snap program will be observed, NASA
expects that data will be obtained for many targets in this category.
Following the evaluation of
submitted proposals, some proposals submitted but not accepted by NASA under
the Standard category may be recommended for inclusion in the Snap
category. It will be the proposer's option to accept or reject such
reprogramming of a submitted Standard proposal.
Observing Program
Constraints – Standard
and Snap proposals may only request observations using GALEX standard observing
modes. These are described briefly in Section 3.3.1 and in more detail in the GALEX Observers Guide. In Cycle 5,
Legacy proposals will be accepted for programs using non-standard GALEX
observing or data-processing modes, IF the GI proposal team includes one or
more GALEX team experts to be responsible for the non-standard operations as
part of the proposed investigation (this should be explained in the feasibility
section of the proposal).
Program Execution and
Carryover -
NASA intends that all observations for non-ToO Standard and Legacy observing
programs will be performed. If necessary, observations not executed
during the current cycle will be carried over into the following cycle.
GIs do not need to re-propose for these observations, and any such programs
will be given priority for execution in the next cycle. ToO
programs will not be carried over into the next Cycle. ToO programs that
are not activated and executed within the nominal one-year observing cycle must
be re-proposed in order to be considered in the next observing year.
Unobserved targets in Snap programs must also be re-proposed each Cycle.
Proposals will be accepted
for scientific investigations based on any data in the GALEX public archive at
MAST (http://galex.stsci.edu). Search tools and lists of completed and
planned non-AIS GALEX observations may be found at http://galexgi.gsfc.nasa.gov/targets.
Investigators considering an Archival proposal should pay close attention to
the GALEX primary science investigations.
Although Archival proposals may be based on any data released in the
GALEX data releases, they may not duplicate the science goals of type 1 PI
science team investigations or already accepted GI programs.
1.2.3 Unscheduled Observing
Time
Targets of
The lack of a real-time
observing capability constrains the speed with which a ToO observation can be
implemented. The GALEX ToO response time is expected to be no
less than 7 days during Cycle 5. ToO proposals must clearly state the
required response time. The PI of an
accepted ToO proposal must negotiate an agreement on what will constitute a
“trigger” for the TOO with the
Discretionary Observing Time
-- Discretionary
Observing Time (DOT) is intended for observations of an urgent nature for which
no approved observing program exists, and that are of sufficiently high
scientific merit and priority that they should not be delayed to the next
observing cycle. The total amount of DOT available during Cycle 5 is
extremely limited. The GALEX Mission Scientist may approve DOT in those
cases where the scientific timeliness of the project is such that it should be
done quickly, the need for the observation could not have been foreseen and
proposed for in the current observing cycle, and the observation does not
duplicate or infringe on PI or approved GI programs. A proposal for DOT
may be submitted to the Mission Scientist in the form of a letter (printed
or electronic) and should describe the scientific objectives, reason(s) for
requiring GALEX, the proposed observations and their feasibility, and should
explain why DOT should be granted in lieu of consideration during the next
proposal cycle. All requests for DOT will be reviewed for scientific
merit and technical feasibility.
1.3 Mission Capabilities and Constraints During
Cycle 5
This section summarizes
GALEX capabilities that should be considered by all GALEX proposers.
Complete information on the GALEX instrument and other topics is available from
the GALEX Mission homepage http://www.galex.caltech.edu/researcher/techdocs.html.
Sensitivity Limits – There are fundamental
detector performance limitations which preclude observations of individual
bright targets, of target fields containing bright stars, and of bright or
crowded fields (section 3.3.2).
Proposers should pay particular attention to this issue in the “Feasibility”
section of their proposal. Further
information on brightness limits may be found in and at the GALEX Mission
homepage, http://www.galex.caltech.edu/researcher/techdocs.html
and a field brightness checker tool may be found at http://sherpa.caltech.edu/gips/tools.
Please note: For Cycle 5,
brightness limits preclude Magellanic cloud observations within 3.75 degrees of
the LMC center, or 2.0 degrees of the SMC center. Proposals for
such observations will not be reviewed.
Observing Modes - GALEX has two observing
modes, broad-band imaging and grism spectroscopy. The exposure time alone
defines the achievable signal-to-noise ratio for a given image or
spectrum. Imaging observations are typically done either “normal”
mode (observe one field for one orbital night), or in “petal pattern
mode” (observe several mostly-overlapping fields centered on the proposed
field center – in this mode full exposure depth will be obtained for a region 1
degree in diameter, used for fields with containing stars very near the brightness
limits). Grism spectroscopy is done in multiple orbits, with a different
grism orientation used for each orbital night. Observations are
generally obtained in both FUV and NUV bands simultaneously. Further
information on observing modes may be found in Section 3.3.1 and at http://galexgi.gsfc.nasa.gov/documents/MissionOverview.html.
Targets of
1.4 General Guidelines and
Policies
Notices of Intent are
strongly encouraged, but are not required. Proposals should provide a strong
scientific justification and careful feasibility analysis, which will form the
basis for selection by NASA, and an overview of planned observations and
targets. Proposals that are awarded observing time based on the
evaluation process described in Section
1.7 subsequently will be required to undergo a more detailed
technical safety review before final acceptance (Phase 2) following guidelines
provided by the GALEX Project.
Successful U.S. proposers and U.S. Co-Is of successful non-US proposers
will be invited to submit a budget based on funding guidelines provided by NASA
(section 1.8) when
the proposal is accepted. Proposal submission steps are
summarized in Section 2.4.
The most up-to-date proposal submission checklist may be found at http://galexgi.gsfc.nasa.gov/propforms/ProposalChecklist.html;
this list may be updated during the proposal period.
Participation in the GALEX
GI Program is open to individuals associated with all categories of
Consistent with NASA policy,
a late proposal may be considered only if it is judged to be in the best
interests of the Government. However, a proposal submitted after the published
deadline is unlikely to be considered of uniquely greater value to NASA than
proposals submitted on time. A proposal is considered “on time” only
if all necessary components, (Cover page, Target forms and Scientific
Justification pdf file) are submitted by the proposal deadline. Finally,
please note that processing delays due to (but not limited only to) network
failures, denial-of-service attacks, hard disk crashes, power outages, Internet
delays, or hungry dogs, do not excuse late submission of a proposal.
1.5 Data Rights and
Distribution
GIs will be notified electronically when their data
are available from the archive. Data rights for GALEX GI observations
(Legacy, Standard and Snap programs) reside solely with each observing
program's Principal Investigator for a period of six months following
availability of the processed data at the GALEX data archive in MAST (http://galex.stsci.edu/GR4/ After this period, the data become available
for public access through MAST. Investigators, particularly for Legacy
Proposals, are encouraged to consider waiving the proprietary period for their
data.
Observations of calibration
targets/fields generally have no proprietary period and will be released
through the GALEX archive as soon as the processed data products are available.
The GALEX Project reserves the right to use any GALEX observation to assist in
assessing the performance of the instrument, but the confidentiality of data
obtained for scientific programs will be maintained.
During QA checking, UV
Variable objects are noted and shared with the community through an alerts
page. If this occurs in a GI observation,
the position of the variable object and its light curve is published but all other aspects of the
data remain confidential for the 6 month proprietary time.
The Cycle 5 observing
opportunity primarily seeks to identify new targets for observation with the
GALEX satellite or to obtain significantly deeper exposures of already-observed
targets. Search tools and lists of all targets
observed or planned for observation (excluding AIS fields, including
previous cycle GI targets) may be found at (http://galexgi.gsfc.nasa.gov/targets
). Each target's name and celestial coordinates (right ascension and
declination, epoch J2000) will be considered when judging any potential target
duplications.
Target Duplication – By design, the GALEX
prime mission will obtain moderate exposures of a large fraction of the sky in
the All-Sky Imaging Survey (AIS), a .
Many GI projects may be well suited to archival investigations using the
data collected for the primary mission.
Any target duplication between Cycle 5 GI observing programs and those
observed (or expected to be observed) by the GALEX primary mission, or by
previous cycle GIs, must be strongly justified in the proposal (e.g.,
expected variability, need for deeper exposures, etc.). Review panels
will receive a summary of any perceived duplications between pending and
existing observations and those proposed for Cycle 5. The panels will also
receive a summary of target duplications between different Cycle 5
proposals. In general, a given pointing center will be allocated to only
one observing program. Failure to provide accurate target data in the
proposal may result in disallowing a target if a conflict with another program
is discovered after proposal acceptance and the target conflict was missed as a
result of the inaccurate target data.
Target List Modifications - After selection of Cycle
5 programs, small changes to a program's target list may be permitted only with
the approval of the GALEX Mission Scientist. Any new target must be
consistent with the program's scientific objectives and must not already be
allocated to another program. Large-scale target list changes will not be
accepted.
Calibration Targets - Astronomical targets are
used for photometric and wavelength calibration. Most of the calibration
objects (Appendix, In-Flight Calibration Guide) will be observed
for calibration purposes. GI's are allowed to include calibration targets
as scientific targets in their programs. The GALEX Project may continue
to use these objects for calibration, even if the target is allocated to a GI
program.
1.7 Proposal Evaluation and Selection Process
Proposals submitted to NASA
in response to this opportunity will be evaluated in a competitive peer review conducted
by NASA Headquarters, using review panels organized by scientific research
area. Upon completion of the review by the individual panels, a
final cross-discipline panel review chaired by a NASA HQ representative will
synthesize the results of the individual panels. Legacy proposals will be
reviewed with other GALEX proposals in the same scientific discipline as well
as in other disciplines (e.g., stellar evolution, ISM, large scale structure,
etc). Each scientific panel will have the option to forward a small
number of Legacy proposals for final evaluation by the chairs of the GALEX peer
panels; this panel of chairs will formulate the final recommendations to NASA
for the Cycle 5 observing program. Based on these results, the GALEX
Program Scientist will then develop a recommendation for the total program to
be submitted to the Selection Official. The final proposal selection will
be made by the director of the Astrophysics Division of NASA's Science Mission
Directorate. The following factors, listed in descending order of importance,
will be used in evaluating proposals for their scientific merit and technical
feasibility for the GALEX Guest Investigator Program:
1. The overall scientific merit of the proposed
investigation;
2. The suitability and feasibility of using the
GALEX observatory or GALEX data for the proposed investigation;
3. The likelihood of accomplishing the
objectives of the investigation;
4. The degree to which the investigation uses
the unique capabilities of GALEX;
5. The feasibility and scope of the data
analysis plans;
6. The relevance to NASA’s goals.
Legacy proposals will also
be evaluated on:
7. Provisions to provide legacy data to the
community in a timely fashion (possibly waiving the proprietary period) and/or
plans to provide enhanced data products to the community.
Scientific review panels
will be given an assessment of the technical feasibility of each proposal,
determined by the GALEX science operations team. After acceptance
of an observing program by NASA, successful proposers must work with the
Caltech SOC to prepare detailed (Phase 2) evaluation & observing
plans. Should there be any question
regarding the safety or feasibility of individual observations, the GALEX PI,
in consultation with the GALEX Mission Scientist, will make the final decision
as to whether or not to attempt or postpone a particular observation, based on
the latest information available regarding the satellite’s on-orbit
performance. NASA reserves the right to select only a portion of a proposed
investigation, in which case the investigator will be given the opportunity to
accept or decline such partial selection.
1.8 Funding for
Limited funds for awards under
this NRA are expected to be available to investigators at
1.9 Education and Public Outreach
The policy of NASA’s Science Mission
Directorate (SMD) continues to encourage the participation by
the space science community in education and public outreach activities, with
the goal of enhancing the Nation’s formal education system and contributing to
the broad public understanding of science, mathematics, and technology. A
significant national program in space science education and outreach is now
underway, and SMD’s demonstrated contributions to education and outreach have
now become an important part of the broader justification for the public
support of space science (for further details see the SMD’s “Education
and Public Outreach” page (http://science.hq.nasa.gov/research/epo.htm). Guest Investigators selected for GALEX Cycle
5 will have an opportunity to submit a supplemental E/PO element to their
research proposal in conjunction with the budget phase of the proposal
process. E/PO proposals will be due 60 days after the date of the
selection letter for the Cycle 5 science proposal. Information
about and instructions for preparing and submitting E/PO proposals is available
in Section (b) of the ROSES-2008 NRA Summary of Solicitation.
2. General Information on NASA
Proposals
General information
on the preparation and submission of research proposals to NASA may be found in
the 2008 NASA HQ NRA Proposers Guidebook
http://www.hq.nasa.gov/office/procurement/nraguidebook/proposer2008.pdf OR
http://www.hq.nasa.gov/office/procurement/nraguidebook/proposer2008.doc
If you have questions about
the general nature of NASA NRAs, or questions or problems with submitting NOIs
or Phase 2 Budget proposals, please consult the NASA HQ Proposal Submission FAQ
page, or send technical support questions to proposals@hq.nasa.gov.
Questions about the GALEX
Guest Investigator Program, or about the GALEX Cycle 5 GI proposal submission
process should be directed to the GALEX
GI help desk (send email to galexhelp@galexgi.gsfc.nasa.gov).
In order to expedite the
proposal review process and the timely selection of scientific peer review panels,
investigators intending to submit proposals for participation in this program
are encouraged to submit a Notice of Intent (NOI) to propose by April 25, 2008.
The NOI Web site will request the tentative title
of the investigation, name and affiliation of the PI and any Co-I's, and a
brief summary of the proposed investigation. Although NOI’s are encouraged,
they are not required.
GALEX Cycle 5 proposal
submission is all-electronic, and uses the Remote Proposal Submission (ARK/RPS) system of the
HEASARC. Proposers will need to establish an account with the Astrophysics Research Knowledgebase
(ARK/RPS) to submit proposals. A proposal submission checklist
can be found at http://galexgi.gsfc.nasa.gov/propforms/ProposalChecklist.html,
with links to more detailed instructions. A complete proposal submission
consists of the following steps:
1. Fill out the ARK/RPS cover sheet
information and target form(s).
2. Verify the ARK/RPS form, using the
“Verify” button.
3. Submit the ARK/RPS form (the
“Submit” button will not appear until the form has passed
verification. (An acknowledgment of receipt will be sent to the
proposal submitter by return e-mail if requested in your ARK/RPS account
setup.)
4. Upload the .pdf file of your Scientific
Justification.
You may re-submit and
re-upload as often as needed. All
steps must be completed by
16:30
pm EDT on 20 June, 2008
in order to be included in
the proposal review for this cycle of the GALEX Guest Investigator
program.
2.4 Cover Pages and Target Information.
Cover pages and Target
information are submitted directly into ARK/RPS (Remote Proposal System) of the
HEASARC, see Section 2.3).
Cover page information
includes Title, PI information, Co-I’s and affiliations, and basic
information about the proposal (type, science area, time requested etc.)
In all cases, including Archival
Proposals, a target list must be submitted. More information on
target submission can be found in the help file for the
GALEX RPS forms.
2.5 Science Justification -
Format and Content
Proposals must be written
concisely, in English. The length of each section of the proposal should
not exceed the page limits indicated below. Proposals must be printed
with a font size no smaller than 11 points (about 6 characters per cm) throughout
(References and figure captions may be 10pt). Margins should be 1 inch
(2.54cm). Proposals should be single spaced on 8.5x11 or A4 paper.
Reviewers will be instructed to base their review only on the portion of each
proposal that complies with the page limits given below in this NRA; excess
pages will be rejected before being sent to the reviewers.
Illustrations contained in the printed proposal may be in black and white or
color. Proposals will be sent to reviewers as .pdf files, and may be
printed out on the reviewer’s printer, so proposers would be prudent to verify
that any color entries are also legible in black and white.
A GALEX proposal Science
Justification requires the following sections, which should be included in the
order indicated. Page limits for each section are indicated
below. Total page limits are: 8 pages for Standard or Snap observing
proposals, 10 pages for Legacy proposals, and 6 pages for Archival proposals
(including figures, tables and references).
1. Scientific Justification (not to exceed
3 pages for Standard, Survey or Archival proposals, or 5 pages for Legacy
proposals):
Fully describe the scientific objectives of the proposed investigation, clearly
stating its goals, its significance to astronomy, why GALEX data are essential
to the investigation, and the relevance to NASA goals. The page limit
includes all text, figures, tables, and references for this Section. The
proposed scientific investigation should not duplicate GALEX primary science
investigations or accepted GI programs (http://galexgi.gsfc.nasa.gov/science);
any cases where overlap might be perceived should be clearly justified.
GI investigations may be proposed for targets or fields observed by the GALEX
science team, as long as the science goals of the investigation are clearly
different.
2. Description of Observations (no more than 1
page, not required for archival proposals): Describe the desired
observations. All observing constraints (e.g., Time-Critical (coordinated
observations, phase coverage, contiguous orbits etc.), Target of Opportunity,
Low Zodiacal Light, Moving Target), and/or Special Requirements
(non-standard data products, FUV-only observations, brightness waivers,
specified grism orientation, etc.) must be explained and justified.
Triggering events for Targets of Opportunity should be defined clearly.
Actual ephemeris data for Solar System targets are not required for this phase
of the proposal process, but a discussion of when and where should be
provided (Proposers wishing to observe moving targets should be aware
that they will need to request receive time-tagged photon data and will need to
reconstruct these into images themselves).
3. Feasibility (not to exceed 1 page, not
required for archival proposals): Feasibility and Safety: The proposed program
must justify the need for the requested exposure time for each target, noting
the required signal-to-noise ratio (S/N) and spectral resolution, expected
flux, and any other information relevant to the observation (e.g., wavelength,
region of interest, spectral flux distribution, emission line
intensities). This section forms the basis for technical assessment of
the feasibility of the proposed observations. Although a safety check is not required for
Cycle 5 Phase 1, proposers are advised to verify that their targets can be
safely observed and to explain any questionable cases in the Feasibility
discussion. Proposers requesting time-critical observations are advised to
verify that their targets are visible to the GALEX spacecraft at the desired
times. Safety concerns, target visibility through the year, zodiacal
light background, etc. may be checked using several tools available at http://sherpa.caltech.edu/gips/tools/index.html;
an exposure simulator may be accessed at the same site.
4. Additional Information (up to 1 page,
required for archival proposals): This Section may be used to provide
any relevant information concerning data analysis plans, modeling capabilities,
corollary data from other telescopes, etc. A data analysis plan is
required for Archival proposals or for mixed new observation & archival
proposals.
2.6 Templates, Examples, and Instructions
GALEX proposal Scientific
Justifications must be submitted as .pdf files, which are uploaded by
Submission procedures are
described in Section 2.3.
GALEX is a NASA Small
Explorer (SMEK), developed in collaboration by Caltech in
The GALEX PI is
responsible for achieving the scientific objectives of the primary
mission. GALEX’s primary objectives are to map the global history and
probe the causes of star formation over the redshift range 0 < z <
2. This time span traces 80% of the life of the universe, the period over
which galaxies have evolved dramatically, and the time that most stars,
elements, and galaxy disks had their origins. GALEX uses the space ultraviolet
(l < 3000 Å) to simultaneously measure redshift (using emission lines and
the Lyman Break), extinction (using the UV spectral slope), and star formation
rate (using the UV luminosity, which is proportional to the instantaneous star
formation rate). Other scientific objectives supporting this overarching
goal are: 1) Determining the UV properties of local galaxies and how their
rest-UV properties, measured at high redshift by other missions, relate to star
formation rate, extinction, metallicity, and burst history; 2) Measuring
the star formation and metal production history of galaxies over the redshift
range 0 < z < 2; 3) Determining the time and location of the
origins of the stars and elements we see today, and connecting this to
the evolution between 0 < z < 2; and 4) Identifying the global
(galaxy-wide) factors that drive star formation and evolution in galaxies. Goals of the GALEX extended missions expand
on the primary mission goals.
The GALEX prime mission
addresses these objectives by performing complementary imaging and
spectroscopic surveys. Approximately 2000 orbits were devoted to each
survey. Details of the GALEX primary mission science plan, and how itl
uses these surveys, can be found at http://galexgi.gsfc.nasa.gov/Documents. Approximately70% of the primary mission
survey data will be available for GI archival proposals in Cycle 5.
Imaging surveys: these use two bands (FUV
(1350-1800 Å) and NUV (1800-2800 Å) ) to image the sky with ~5 arcsec\
resolution, a 1.2 degree field-of-view, and <1 arcsec astrometric
accuracy. These surveys will detect millions of galaxies in the
local universe and many thousands in the more distant universe over the redshift
range 0.5 < z < 2. More detailed information may be found in Table
1, or at
http://www.galex.caltech.edu/researcher/data.html
Medium deep spectroscopic survey: uses a slitless grism with
spectral resolution of R=150-300. These surveys will measure
approximately 100,000 galaxies over a wide range of luminosities and star
formation rates, over the redshift range of 0 < z < 2.
Approximately
2/3 of the observing time during Cycle 5 will be used by the PI Team for survey
observations
The wide field-of-view and
spectral bandpasses provided by GALEX permits the study of many important
astrophysical subjects besides galaxy evolution. These include, but are
not limited to: stellar winds and outflows, post-main-sequence stellar
evolution, binary/multiple star evolution, globular cluster structure and
evolution, massive stars, supernova remnants, reflection nebulae, interstellar
dust, structure of the ISM / IGM, the UV background, nearby galaxy populations,
galaxy clusters, intergalactic material, QSO evolution, and large scale
structure.
GALEX is now
conducting several Legacy Surveys, which will be delivered to the scientific
community as quickly as possible. These
include:
GALEX is a 50cm UV-optimized
telescope that obtains images simultaneously in two bands: 1350-1800Å (far-UV,
FUV) and 1800-2800Å (near-UV, NUV). The circular field of view is 1.2
degrees in diameter and the angular resolution is ~4.5 arcsec. GALEX can
also obtain slitless spectroscopy (same field of view and spatial resolution)
with spectral resolution of R=200-350 (FUV) and 80-150 (NUV). The
telescope has one primary 50 cm mirror, which feeds light through either an
imaging window or an imaging grism, to a dichroic beamsplitter, and into two
sealed-tube microchannel-plate photon-counting detectors. The
effective area is ~35 cm2 for the FUV channel and
~65 cm2 for the NUV channel. The high throughput results
from an optical design utilizing a high-efficiency beam splitter, a
high–efficiency CaF2 grism, and multilayer reflective coatings
optimized for wavelength coverage in the GALEX range. Further details on
the GALEX instrument can be found at http://www.galex.caltech.edu/researcher/techdocs.html,
Instrument Status paper , the GALEX Mission
and Instrument Summary, the GALEX Observer’s Guide, and the GALEX Detector Handbook at http://www.galex.caltech.edu/researcher/techdocs.html
and in the GALEX Calibration Papers at http://galexgi.gsfc.nasa.gov/docs/galex/instrument.html.
3.3 Satellite Operations and Observation
Planning
GALEX is in a nearly circular
orbit with a mean altitude of 690 km, an orbital inclination of 29o,
and an orbital period of 98 minutes with ~2100 sec orbital nights. The
plane of the orbit precesses with a period of 60 days. Typically, GALEX
is in contact with the ground station for 8-12 minutes per orbit for 10
consecutive orbits, followed by five orbits with no contact. All GALEX
scientific observations are conducted autonomously by the onboard instrument
data system, from week-long observing plans. Science observations are made only
during orbital nights, with a typical time of ~1500 sec/orbit available for
science observations. Observations are scheduled in units of
1.5ksec.
All science data collection
uses a spiral dither, to prevent bright-star-induced fatigue of localized
regions on the detectors and to improve image flat-fielding. In “normal”
(or “stare/dither”) mode, only one field center is observed for the entire
eclipse. In “petal pattern mode”, several (typically 10-12) largely-overlapping
field centers are observed during one orbital night, such that full-depth
exposure is obtained for a field approximately 1 degree in diameter – this is
done for fields containing stars near the brightness limits and is done to
avoid damaging the detectors.
Grism observations are
always done at a single grism orientation for each orbit; multiple observations
are during multiple orbits made at different grism orientations. Grism
images require a “pre-image” (may be an existing GALEX image if the field
centers are within 15 arcmin); the pre-image is used as a “finding chart” for
spectral extractions, and requires an exposure time at least 5% that of
the proposed grism observations for proper spectral extraction. In
Cycle 5, all pre-images require a full orbit, i.e., AIS fields may not be used
as pre-images. All GALEX science data is
sent down as time-tagged photon lists, allowing ex-post-facto aspect
determination and image reconstruction.
Proposers may request
time-tagged photon data, but should be aware that there is currently no data
analysis or pipeline support for data reduction.
GI observations may use only
these standard GALEX observing modes except for Legacy proposals with PI team
membership. We hope in future cycles to offer a “short pre-image + long
grism in a single orbit” option but this is not available in Cycle 5.
There are detector
brightness limits that, because of the wide field of view, significantly affect
flexibility of mission planning when choosing targets. Fundamental detector
safety requirements limit observations of bright targets. Currently,
point sources, with flat spectra, may not be observed (imaging or grism) that
are brighter than:
|
||||||
• |
FUV |
5,000cps |
or |
mAB = 9.5 |
or |
Flux = 7 x 10-12 erg cm-2 s-1 Å-1 |
• |
NUV |
30,000cps |
or |
mAB = 8.9 |
or |
Flux = 6 x 10-12 erg cm-2 s-1 Å-1 |
• |
Bright and / or crowded fields may not be observed if they exceed total brightness levels of: |
|||||
• |
FUV |
15,000cps |
or |
|
|
Flux = 2.0 x 10-11 erg cm-2 s-1 Å-1 |
• |
NUV |
50,000cps |
or |
|
|
Flux = 1.6 x 10-11 erg cm-2 s-1 Å-1 |
POINTING CENTERS |
||||||
· |
0.75° |
for an object with |
Flux _NUV = 1 x 10-12, |
or |
or mAB = 10.8 |
(5,000 cps) |
· |
0.88° |
for an object with |
Flux _NUV = 1 x 10-11, |
or |
or mAB = 8.3 |
(50,000 cps) |
· |
1.00° |
for an object with |
Flux _NUV = 4 x 10-11, |
or |
or mAB = 6.8 |
(200,000 cps) |
· |
1.50° |
for an object with |
Flux _NUV = 1 x 10-10, |
or |
or mAB = 5.8 |
(500,000 cps) |
· |
2.00° |
for an object with |
Flux _NUV = 2 x 10-10, |
or |
or mAB = 5.0 |
(1,000,000 cps) |
|
(Fluxes and magnitudes in NUV band (~ 2300 Å), |
Flux in ergs cm-2 s-1 Å-1 ) |
||||
3.4 Data Processing, Calibration, and Distribution
Data pipeline processing is
done at the GALEX SOC, including image construction from time-tagged photon
lists, flat-fielding, background subtraction, photometric calibration, image
rectifying, astrometric solution, and transformation into North-up FITS
images. Multiple visits to the same target are stacked.
In the case of imaging observations (both single visit and stacked images), the
pipeline detects objects in the field, extracts object properties, and collects
the objects and their properties into catalogues. In the case of grism
observations, for each object in the field, a subimage of the spectrum is cut
out, the subimages are rotated and stacked, and individual source spectra are
extracted, wavelength calibrated, corrected for spectral response, and
collected into catalogues The
astrometric accuracy of the resulting images is ~0.6 arcsec
RMS (slightly worse at the edge of the field). The current photometric accuracy
is routinely 3% / 5% (NUV / FUV), although there are systematics of
similar order. The wavelength accuracy of the spectral ranges is 1-2 Å
relative, 2-4 Å absolute. More details may be found in the http://www.journals.uchicago.edu/ApJ/journal/contents/ApJL/v619n1.html
and all other documents at http://galexgi.gsfc.nasa.gov/Documents).
The GALEX pipeline produces
a series of image and spectroscopic products in addition to the images and
spectra. These are delivered, with the images and spectra, in GALEX Data
Releases (GRs). The fourth public data release (http://galex.stsci.edu/GR4/) occurred
in January to May 2008; it contains approximately 96% of the data for the GALEX
primary mission surveys. All data in the GALEX archive may be used in
GALEX Cycle 5 archival proposals.
The GALEX data is
permanently archived at the Multimission Archive at Space Telescope (MAST) (http://galex.stsci.edu/). Guest Investigators access their data through
MAST, and MAST provides selective access to proprietary data. Access
procedures for public and proprietary data are similar to those for Hubble
Space Telescope data. Only the PI of each GI program (and their
designees) can access that program's data during the proprietary period.
GALEX data distribution is by electronic file transfer from MAST.
Observations of calibration targets generally have no proprietary period.
See Section 1.5 for
additional information about GALEX data rights.
GALEX Cycle 5 Guest Investigator Proposals
NRA Release – 15 February, 2008
Notices of Intent
4:30pm, EDT, 25 April, 2008 (NOIs are encouraged but not required.)
Proposal Deadline
4:30pm, EDT, 20 June 2008
Cycle 5 Observations
1 January 2009 through 31 December 2009
Scientific and technical
questions concerning the GALEX GI Program should be directed to:
Dr.
Susan Neff
GALEX
Laboratory
for Observational Cosmology, Code 665
National
Aeronautics and Space Administration
Telephone:
301-286-5137
Facsimile:
301-286-1753
E-mail:
Susan.G.Neff@nasa.gov
Programmatic information may
be obtained from:
Dr.
Zlatan Tsvetanov
GALEX
Program Officer
Universe
Division, Code SZ
Science
National
Aeronautics and Space Administration
Telephone:
202-358-0810
Facsimile:
202-358-3096
E-mail:
Zlatan.Tsvetanov@nasa.gov
Technical information about
the GALEX mission or proposal preparation and submission may be obtained from:
GALEX
Help Desk
Laboratory
for Observational Cosmology, Code 665
National
Aeronautics and Space Administration
Telephone:
301-286-5689
Facsimile:
301-286-1753
E-mail:
galexhelp@galexgi.gsfc.nasa.gov
Responsible NASA Official:
Susan G. Neff
Curators: Dorothy Appleman