IVOA Time Domain Interest Group
Working Group Chair:
John Swinbank
Vice Chair:
Mike Fitzpatrick
Chairs Emeritus:
Roy Williams,
Rob Seaman,
Matthew Graham
Vice Chairs Emeritus:
Alasdair Allan,
Roy Williams,
John Swinbank
Charter
The time domain is the emerging field of astronomical research, as recognized in the European ASTRONET and 2010 US National Research Council Decadal Survey of Astronomy and Astrophysics. Planned facilities for the next decade and beyond, both ground-based, such as the LSST and SKA, and space-based, such as CHEOPS,
EChO and PLATO, will revolutionize our understanding of the universe with nightly searches of large swathes of sky for changing objects and networks of robotic telescopes ready to follow up in greater detail selected interesting sources. This will impact essentially every area of astronomy, from the Solar System to cosmology, and from stellar evolution to extreme relativistic phenomena, making it a very rich area for scientific exploration and discovery, and extending beyond the traditional electromagnetic spectrum into neutrino and gravitational wave astronomy. Moreover, many interesting phenomena, e.g., supernovae and other types of cosmic explosions, can only be studied in the time domain. The challenges lie in the automated distribution, processing, classification, and archiving of vast streams of triggers. The VO is well-placed to support and facilitate research in this area.
The IVOA Time Domain Interest Group has evolved from the IVOA VOEvent Working Group recognizing that the mechanics of celestial event notification are now broadly resolved within the VO but that broader representation of the emerging time domain community has become necessary.
It will:
- Provide a forum for discussing time domain specific issues in a VO context.
- Contribute to other IVOA working groups to ensure that time domain specific requirements are included.
- Incorporate standard approaches defined in these groups when designing and implementing services on time domain archives.
- Define standard services relevant for time domain archives.
- Promote development of services for comparing theoretical results to observations and vice versa.
- Define relevant milestones and assign specific tasks to interested parties.
VOEvent
VOEvent defines the content and meaning of a standard information packet for representing, transmitting, publishing and archiving information about a transient celestial event, with the implication that timely follow-up is of interest.
VOEvent 2.0 was published as an IVOA Recommendation on 11 July 2011. The
VOEvent 2.0 wiki, which was used to discuss the evolution of the standard, is still available.
Introductory Material
The VOEvent book,
"Hotwiring the Transient Universe", provides an introduction to the VOEvent system and related infrastructure. It is available in printed form from
Lulu. A
Kindle version is also available: do a "download file as" and drag to the documents directory on your Kindle via USB.
SkyAlert provides a web-based interface for exploring and collating VOEvents and defining personalised event alert schemes.
Dakota and
Comet provide tools for connecting to high-speed TCP streams of VOEvents.
NASA Gamma-ray Coordinates Network provides a VOEvent stream of GRB and transient notices, including example source code for tools to receive messages.
VOEvent Transport
VOEvent is deliberately transport-agnostic. However, the
VOEvent Transport Protocol (VTP) may be used to distribute streams of VOEvents across the internet with a relatively low latency. The following "brokers" provide access to such streams. A tool such as Dakota or Comet, below, is required to subscribe.
Tools and Libraries
Since VOEvents are XML documents, they can be manipulated with a wide range of standard tools. In addition, the following libraries and tools may be useful.
Generating, Reading and Manipulating VOEvents
- VOEventLib is a Python library for working with VOEvent documents.
- voevent-parse is a lightweight Python library for parsing, manipulating, and generating VOEvents.
Working with the VOEvent Transport Protocol
- The Dakota VOEvent Tools are a cross-platform, open source set of tools which fully implement the VOEvent Transport 1.1 protocol for subscriber, publisher, and broker-to-broker operations. The Dakota tools are written in portable C#.
- Comet is a Python implementation of the VOEvent Transport Protocol. It is capable of receiving events either by subscribing to one or more remote brokers or by direct connection from authors, and can then both process those events locally and forward them to its own subscribers. In addition, Comet provides a tool for publishing VOEvents to a remote broker.
VOEventStream: Metadata for Collections of Events
VOEventStream-0.2.html
Time Series Data
SimpleTimeseries is an XML format, developed outwith the IVOA, for representing time-series data.
Mailing-list
- General working-group discussion archive.
Future Events
Past Events
- VAO All-hands meeting requires login - Charlottesville, VA, Sep 30 - Oct 1, 2010
- SPIE AT&I, especially Obs. Ops. session 4, Orlando, May 24 - 31, 2006
- VOEvent session at the IVOA Interoperability Meeting in Madrid, October 6 - 7, 2005
- VOEvent session at the IVOA Interoperability Meeting in Kyoto, May 16-20, 2005
Links
Gamma-ray Burst Coordinate Network (GCN)
Astronomer's Telegram
RTML - Remote Telescope Markup Language and
Twiki here
Real Time Virtual Observatory
Space-Time Coordinate Metadata for the Virtual Observatory (STC)
Schema for IAU Telegram Discovery Report
Unified Content Descriptors, and
more here
Resource Metdata for the Virtual Observatory
Pairitel Project
eSTAR Project
AAVSO
Discussion leading up to the VOEvent Recommendation