There are two major parts to "GCN": Notices and Circulars.
(1) The Notices part is the automated
system which distributes "TOKEN: value(s)"-format notices of GRBs detected
by the Fermi, Swift, HETE, INTEGRAL, RXTE-PCA/ASM, IPN, MILAGRO
to sites via sockets, emails, pagers, etc (note that the socket method uses
binary packets -- not the "TOKEN: value" format of the email-based methods).
(2) The Circulars part distributes prose-style
messages about optical/radio/x-ray/gamma-ray follow-up observations
via email to people.
(3) The Reports part distributes final reports on each burst by the follow-up
observing team.
The two distribution lists are separate because of the different needs of the users and the requirements of the system. Please read the discusion of those requirements and needs below. When you have decided which (or both) you want to sign up for, please send me email with the information and to which service you want.
We actively invite new sites and instruments to become part of the GCN network. We encourage any and all band-passes: radio, IR, optical, UV, X & Gamma rays, neutrino, and gravity waves also. Many times in the past, we have modified GCN to accommodate the requirements of new sites and we will continue to do so. No matter what your needs may be, we are sure there is a way that we can accomodate them within the GCN system.
For those people who have read these GCN web pages and have a pretty good idea that they want to receive GCN Notices, the 13 pieces of information listed below are required to create an entry in the "sites.cfg" file and make a site active. And if you haven't read the web pages yet, then these items below provide a hint about how GCN works, its capabilities and limitations, and what to look for when reading the web pages to make an initial specification for your site's configuration.
THE BASIC ITEMS NEEDED FOR EACH NEW SITE (or person):
1) Site Name:
Used for identification to quickly and uniquely indentify each site.
This name should be used in all future communications with GCN OPS.
Something short (less than 12 characters).
2) Longitude and Latitude of the instrument:
Needed if the visibility, night-time or some custom filters are used.
Also needed for the "world map" graphic to show the site's location.
Decimal degrees is preferred (eg 127.35, -35.51); 127d21m17s,-35d30m19s
also accepted.
3) What filter?
All, visible, night, custom, etc. For the details see parts '2a' & '2b'.
4) What intensity threshold? (Obsolete)
This is sometimes used to reject the weaker events whose location
uncertainties are larger than the site's FOV. It applies only to the
BATSE-derived locations (obsolete).
5) Do you want Error_Box_Size filtering?
This will reject notices that have uncertaintites on their locations
larger that the amount specified (the default is 360.1 degrees,
ie there will be no rejection based on error box size as there can be
no box diameter larger than 360 degrees). Sites typically choose a value
which is comparable to the FOV of your instrument or as large
as the amount of tiling you are willing to perform.
6) Do you want Time_Delay filtering?
This will reject notices that have distributions time delays after
the burst longer than the specified number of hours (the default is
999.9 hours, which is esentially an eternity in this business).
You need to specify the maximum number of hours between the burst
and when the Notice becomes available for distribution; ie you don't
anything older than X.X hours.
7) Do you want Trigger_ID filtering?
This will reject notices that are not identified to be GRBs (e.g. hard
x-ray transients, known variable sources, negative-curvature bkg intevals, etc).
It is ~80% accurate, and
applies only to the Swift-BAT-derived locations.
The other mission-based sources of locations (e.g. INTEGRAL, HETE, RXTE, IPN, etc)
are always describing real GRBs. For the details see part '6'.
8) What source(s) of GRB, X-ray Transient, and/or extreme-UV Transient Notices
do you want to receive?
The choices are: Swift, HETE, INTEGRAL, RXTE-PCA/-ASM, IPN, MILAGRO, COUNTERPART, etc.
For the details or more details see part '1'.
9) What Notice sub-types within each source do you want?
For Fermi, there are different types, the details.
For Swift, there are many different types, the details.
The RXTE-PCA has "Alert-will", "Alert-won't", "Observed-saw", and "Observed-nosaw".
HETE has ALERT, UPDATE, FINAL, and GROUND_ANALYSIS subtypes.
INTEGRAL has POINTDIR, SPIACS, WAKEUP, REFINED, and OFFLINE subtypes.
Currently, IPN does not have any subdivision of types.
For the details see part '1'.
10) Do you want Test Notices enabled?
GCN can generate test notices (automatically and manually). Some sites
find these useful for testing/exercising their systems & procedures.
For the details.
11) The distribution method?
The choices are:
Internet sockets, e-mail, and cell/pager (1 long form or 3 different
short forms). Automated instruments tend to choose the socket method
because of its speed and manual instruments tend to opt
for the e-mail and pager methods. Cellphone recipients can request
an alias for their destination_address if they do not want their cell number
to appear on the website copy of the sites.cfg file
For the details.
And if you choose the full-email format, then for the Swift-based Notices,
do you want the lightcurve, image, and spectrum attachments (or none).
And what format do you want them in: FITS, GIF, JPEG, PDF, PostScript?
12) The "address" of the "instrument":
If you select the sockets method, then we need a "machine.domain".
If you want e-mail or pager, then "account@machine.domain" for each
person to receive the notices.
13) Sites using the Internet socket method of communication need to choose
if they want to receive the "socket disconnected notices" (& how often) and
the "daily socket reports". For the details.
Now that you have read the above 13 questions, you can build your configuration request
by selecting #1 on this page.
And for those people that are uncertain if GCN can fill their needs, we encourage you to contact us ( scott@lheamail.gsfc.nasa.gov) to discuss your situation. GCN is a wide and varied system, and some productive accomodation can usually be achieved.
It is also useful for us to know something about your system/instrument. If you could have the basic numbers describing your system handy during the initial discussion, it would help us to make appropriate suggestions to fine tune the interaction with your system. The basic numbers are the aperture (collecting area), FOV, position resolution, detector type, sensitivity (lim mag, flux, etc), band pass, whether it is an automated or manual system, and response time (instrument response time and human response time). If there is a web-page for your system, then please pass along the URL.
This operation is much simplier in its actions and sign-up requirements than the Notices. Prose-style messages submitted by list-members are re-distributed to the "Circulars" distribution list. There are seven pieces of information needed to sign-up for the GCN Circulars:
1) Your full name: John Doe
2) Your institutional and/or project affiliation: NOAO
3) The email address you want to receive the Circulars: jdoe@sirus.noao.edu or John.Doe.1@noao.edu
4) Your login account name you will be using to submit: jdoe
5) Your domain from which you will be submitting: noao.edu
6) Whether you want to receive or not the Circulars -- 1 to receive, 0 not to.
7) Whether you want to receive or not the Reports -- 1 to receive, 0 not to.
Items 4 & 5 may seem like a duplication of item 3. Item 3 can be different than from where you will be submitting. Also, some institutions use email routers/servers that allow for a generic email address such that email can be delivered to a person no matter how their true account name/machine moves or changes. Items 4 and 5 are used in the validation process for circular submissions. Typically, the domain used in item 5 is reduced down to the institutional level (i.e. no machine name included) to allow for people to submit from more than one machine within their institution. Item 6 allows for people to have more than one entry if they find they will be submitting from more than one account/machine names, but they only want to receive one copy of the outgoing circulars. So only one of their entries in the list would have a "true" value for this flag. For more information on the GCN Circulars. Item 7 allows people to choose not to receive the announement emails on each new GCN Report.
When you sign up for the Circulars (above), then you need to specify if you want to receive the announcements of each new Report. For more information on the GCN Reports.
The main contact is: Scott Barthelmy,
scott@lheamail.gsfc.nasa.gov, 301-286-3106