Virtual Observatory Current trends and development

Xiaowei LiuPeking University

University College London

Topics

● (Practical) Efforts towards a VO (sci., tech.)● European activities and reaction to the concept

of VOs● SRM - conferences on VOs● Data-mining (a common problem)

➔ Archive Research proposals

➔ Legacy Archive Research proposals (cycle 11)– The project should perform a homogeneous analysis of a well-

defined subset of data in the HST Archive.

– The main goal should be to provide a homogeneous set of calibrated data and/or ancillary data products (catalogs, software tools, web interfaces etc.) to the scientific community.

– The results of the project should enable a variety of new and important types of scientific investigations.

Infrared Space Observatory (ISO)

ISO carried out 26000 observations during its 28 months lifetime.

First look

Whole archive downloaded

twice!

Approaching space-borne obs. mode: ➢Standardisation of data taking➢ Service observations➢ P2PP - Observation blocks

ESO VLT

Trends and conclusions

● Large data set from space borne mission, ● Standardisation of ground-based observations

and systematically data archiving

Data-mining becomes a very important aspect of research

New sciences possible VOs

National Virtual Observatory

Graphics from US NVO project

Astrovirtel An European Project

Approved Astrovirtel proposals

First significant discovery based on Astrovirtel

First discovered by Millis R., Elliot J. L., Wasserman L H., NOAO PR01-10, 2 July 2001,with an estimated R = 960 km.

Latest estimate using Astrovirtel yields:d = 43 AU, R = 1200 km (Hahn G, et al., ESO PR 23 Aug. 2001)

Astrophysical Virtual Observatory➢ Proposal submitted to EC in February 2001➢ Consortium: ESO, ESA/ST-ECF, CDS Strassbourg, terapix IAP Paris, Astrogrid UK, Jodrell Bank➢ Activities - AVO science - Archive interoperability - Technological infrastructure➢ Phase A - Realistic test bed for GRID-type distributed infrastructures - Address and verify against existing archive for: Quality and availability of calib. pipelines & calib. data Characterisation of the PSF or seeing over the filed of the images Limiting magnitudes and surface brightness Photometrical conditions, astrometry characterisation - Analysis tools for large distributed data set - Policy: Open on-line facility or Controlled infrastructure with dedicated funds or specialised assistance, selection via standard "Call for proposals" - Phase B design

AVO Science Working GroupPiero Benvenuti (ST-ECF)Email: Piero.Benvenuti@eso.orgDeadline: September 21st 2001

UK PPARC -Long Term Science Review

AstroGrid projectAstroGrid project

• developed during LTSR• proposal to PPARC October 2000• three year project• one year Phase A study

– community consultation– science requirements analysis– benchmark tests– pilot database federations

• we need use-cases....

NAM 2001 Andy Lawrence

Cambridge

Phase B - preliminaryPhase B - preliminary

• uniform AstroGrid interface• data-mining machines connected in grid• tool for simultaneous browsing

– plus advanced visualisation, links to spectra etc.

• tools for advanced database analysis– advanced querying, mixture fitting, statistical manipulations etc.

• tools for on-line data analysis– statistics, model fitting

• system for uploading code

NAM 2001 Andy Lawrence

Cambridge

Conferences on Virtual Observatories➢ VOs of the Future (SRM for NVO) (Caltech, Pasadena, June 13 - 16, 2000) - Explore the possibilities for new astronomy with large digital sky surveys - Define the technical needs and the mandate for the future NVO (GVO) Overviews of existing efforts; New science with a VO; Hardware & network; Statistics & data mining; Data format & visualization, archive interoperability; Education & public outreach

➢ Mining the Sky (MPA/ESO/MPE Garching, German, July 31 - August 4, 2000) - Numerical and statistical analysis of large astronomical datasets - Large-scale computer simulations - Data mining

➢ Astronomical Data Analysis Software & Systems X (SAO, Boston, November 12-15, 2000) - Astronomy technologies; Sky surveys; Public outreach - Software development history, methodologies & technologies - Science data pipelines; IRAF, DS9, AIPS++, FITS, IDL, Linux, Cobra

Conferences on Virtual Observatories➢ Theoretical Data in Virtual Observatories (Tucson, Mar. 20-21, 2001) ➢ New Astrophysics and Cosmology with a Virtual Observatory Science with Wide-Field Survey Telescopes (Aspen Center for Physics, May 27-June 10, 2001)

➢ Statistical Challenges in Modern Astronomy III (Penn State, July 18-21, 2001)

➢ SPIE 46th Ann. Meeting, Conf. 4477 on Astron. Data Analysis (San Diego, July 29-August 3, 2001) - Data Mining: Sky Survey Data Analysis, Detection, Classification - Data Modeling, Background Estimation, Cosmic Ray Removal, ... - Data Analysis and Statistical Methods - Image Compression, Databases, Information Retrieval,... - Virtual Observatory, Computational Grids - Autonomous Agents, Distributed Computing Environments,...

Conferences on Virtual Observatories➢ Joint European and National Astronomical Meeting Joint Discussion 2: Virtual Observatory (Munich, September 10-15, 2001) - What is a virtual observatory? - Why do we need a virtual observatory? - Virtual Observatory activities in Europe, JAPAN, and USA - Oral and Poster Contributions - General Discussion

Virtual Observatories - New Opportunity, New Challenge

● The ever-increasing amount of high-quality scientific data stored in various astronomical archives is becoming a `source' that can be utilised by research teams in an equivalent fashion to observing with a `physical' telescope at a ground or space-based observatory

– "Observatory": A connected and interoperating set of astron. archives

– "Telescopes": Network of archives

– "Instruments": Suite of software tools to query and analyse the data

● Case for a Chinese National Virtual Observatory

– Unavoidable

– Observations driven and oriented, more balanced researches

– Fast track, Cost-effective

– SRM or SWG