ESA Gaia: Expectation for Astroparticle Physics René Hudec, Vojtěch Šimon, Lukáš Hudec & Collaborators & Gaia CU7 consortium Group of High Energy Astrophysics Astronomical Institute of Academy of Sciences of the Czech Republic, Ondřejov, Czech Republic ISDC Versoix, Switzerland Santa Fe GRB Workshop 2007 Reference:

2 ESA Mission Gaia Unraveling the chemical and dynamical history of our Galaxy Albeit focusing on astrometry, Gaia will also provide spectrophotometry for all objects down to mag 20 over 5 years operation period. Typically 50 to 200 measurements per object including optical counterparts of HE sources.

3 Gaia: Design Considerations Astrometry (V < 20): –completeness to 20 mag (on-board detection)  10 9 stars –accuracy: 10–25 μ arcsec at 15 mag (Hipparcos: 1 milliarcsec at 9 mag) –scanning satellite, two viewing directions  global accuracy, with optimal use of observing time –principles: global astrometric reduction (as for Hipparcos) –non-negligible fraction TeV/VHE sources including OTs and OAs of GRBs will be within the detection limit –dark matter in the Galactic disk study measuring the distances and motions of K giants Photometry (V < 20): –astrophysical diagnostics (low-dispersion photometry) + chromaticity  T eff ~ 200 K, log g, [Fe/H] to 0.2 dex, extinction Radial velocity (V < 16–17): –application: third component of space motion, perspective acceleration dynamics, population studies, binaries spectra: chemistry, rotation –principles: slitless spectroscopy using Ca triplet (847–874 nm)

4 Gaia: Complete, Faint, Accurate

GAIA capabilities Distances: <0.1% for stars <1% for 21 million <10% for 220 million Transverse motions: <0.5% km/s for 44 million <3 km/s for 210 million <10 km/s for 440 million Radial velocities to a few km/s complete to V= band photometry ( nm) at ~100 epochs over 4 years Complete survey of the sky to V=20, observing 10 9 objects: 10 8 binary star systems (detected astrometrically; 10 5 orbits) disk white dwarfs brown dwarfs planetary systems resolved galaxies 10 5 quasars 10 5 extragalactic supernovae Solar System objects ( presently known)

Satellite and System ESA-only mission Launch date: 2011 Lifetime: 5 years Launcher: Soyuz–Fregat from CSG Orbit: L2 Ground station: New Norcia and/or Cebreros Downlink rate: 4–8 Mbps Mass: 2030 kg (payload 690 kg) Power: 1720 W (payload 830 W) Figures courtesy EADS-Astrium

7 Schedule Catalogue ESA acceptance Technology Development Design, Build, Test Launch Observations Data Analysis Early Data Concept & Technology Study (ESA) Re-assessment: Ariane-5  Soyuz Cruise to L2

8 Payload and Telescope Two SiC primary mirrors 1.45  0.50 m 2 at 106.5° SiC toroidal structure (optical bench) Basic angle monitoring system Combined focal plane (CCDs) Rotation axis (6 h) Figure courtesy EADS-Astrium Superposition of two Fields of View (FoV)

Astrometric instrument: Light path

10 Photometry Measurement Concept Figures courtesy EADS-Astrium Blue photometer: 330–680 nm Red photometer: 640–1000 nm

11 Photometry Measurement Concept (2/2) Figures courtesy Anthony Brown RP spectrum of M dwarf (V=17.3) Red box: data sent to ground White contour: sky-background level Colour coding: signal intensity

12 Focal Plane Star motion in 10 s Total field: - active area: 0.75 deg 2 - CCDs: x 1966 pixels (TDI) - pixel size = 10 µm x 30 µm = 59 mas x 177 mas Astrometric Field CCDs Blue Photometer CCDs Sky Mapper CCDs cm Red Photometer CCDs Radial-Velocity Spectrometer CCDs Basic Angle Monitor Wave Front Sensor Basic Angle Monitor Wave Front Sensor Sky mapper: - detects all objects to 20 mag - rejects cosmic-ray events - FoV discrimination Astrometry: - total detection noise: 6 e - Photometry: - two-channel photometer - blue and red CCDs Spectroscopy: - high-resolution spectra - red CCDs 42.35cm Figure courtesy Alex Short

13 On-Board Object Detection Requirements: –unbiased sky sampling (mag, color, resolution) –no all-sky catalogue at Gaia resolution (0.1 arcsec) to V~20 Solution: on-board detection: –no input catalogue or observing programme –good detection efficiency to V~21 mag –low false-detection rate, even at high star densities Will therefore detect: –variable stars (eclipsing binaries, Cepheids, etc.) –supernovae: 20,000 –microlensing events: ~1000 photometric; ~100 astrometric –Solar System objects, including near-Earth asteroids and KBOs –fraction of OTs and OAs of GRBs

14 Sky Scanning Principle Spin axis 45 o to Sun Scan rate: 60 arcsec/s Spin period: 6 hours 45 o Figure courtesy Karen O’Flaherty

Scanning law Observations over 5 months Ecliptic co-ordinates

GAIA and our Galaxy 10  as = 10% distances at 10 kpc 10  as/yr = 1 km/sec at 20 kpc

17 Ingestion, preprocessing, data base + versions, astrometric iterative solution ESAC (+ Barcelona + OATo) Object processing (shell tasks) + Classification CNES, Toulouse Photometry Cambridge (IOC) + Variability Geneva (ISDC) Spectroscopic processing CNES, Toulouse Overall system architecture ESAC Data simulations Barcelona From ground station Community access Data Processing Concept (simplified) Status and contributions to be confirmed

18 * DPAC: Data Processing and Analysis Consortium **DPACE: DPAC Executive

19 Czech Republic expected to join ESA as a full member in Jan 2009

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Gaia CU7 Sub-workpackage on Optical Counterparts of High-Energy Sources René Hudec & Collaborators Leuven, Nov 9-10, 2006

22 Motivation of the Gaia CU7 Sub- workpackage on Optical Counterparts of High-Energy Sources Many of HE&VHE sources (including OAs and OTs of GRBs) have also optical emission, mostly variable and accessible by Gaia Monitoring of this variable optical emission provides important input to understanding the physics of the source Multispectral analyses

23 Optical Counterparts of High Energy Sources The objective of the work package: The investigations and analyses of optical counterparts of high energy astrophysics sources based on Gaia data and complex analyses with additional data. Specifically: For selected targets, multispectral analyses using Gaia and other databases (such as the satellite X-ray and gamma-ray data, optical ground-based data etc) may be feasible. Analyses of long-term light changes and their evolution Analyses of active states and flares The study and understanding of related physical processes. Spectrophotometry, relation of brightness and spectrum/colour. For selected sources, dedicated complex analyses. Statistics of the whole sample of objects.

24 Some examples LMXRB HMXRB Optical Afterglows and Optical Transients of GRB Inactive state optical LC of Her X-1/HZ Her, Hudec and Wenzel 1976 Long-term optical changes of Sco X-1/V818 Sco, Hudec 1981 Optical LC of OT of GRB060116, Jelinek et al. 2006

25 Rapidly evolving light curves of some LMXRB, Muhli et al., 2004 Thermonuclear bursts related to NS? Gaia: Optically faint LMXB often suffer by poor optical coverage/analyses, especially on long-term time scales. Here can Gaia provide important inputs. Ser X-1/MM Ser LMXRB & X-ray burster Wachter 1997 Optical bursts related to X-ray bursts: reprocessing of X-rays in a matter near the NS

26 Legend - B 1 = 2, = = = = Legend - V 1 = 2, = = = = Optical B and V magnitudes of optically identified INTEGRAL gamma-ray sources … most are brighter than mag 20, and more than half are brighter than mag 15 >90% accessible with Gaia Even gamma-ray sources do have optical counterparts accessible by Gaia

27 Gaia and GRBs: Photometry There will be a variety of OTs detected by Gaia The real OTs and OAs of GRBs can be, among these, recognized according to their characteristic power-law fading profie However, the sampling provided by Gaia, is not optimal for these goals, hence not always we can expect realiable and confirmed detection of OT of GRB based only on photometry by Gaia

28 Gaia and GRBs: Spectroscopy The primary strength of Gaia for GRB study is the fine spectro-photometry The OAs of GRBs are known to exhibit quite typical colors, distiguishing them from other types of astrophysical objects (Simon et al. 2001, 2004) Hence a realiable classification of OTs will be possible using this method

29 V-R vs. R-I diagram of OAs of GRBs ( t-T 0 <10.2 days) in observer frame, corrected for the Galactic reddening. Multiple indices of the same OA are connected by lines for convenience. The mean colors (centroid) of the whole ensemble of OAs (except for GRB000131) are marked by the large cross. The colors of SN1998bw are shown only for comparison. The representative reddening paths for E B-V =0.5 are also shown. Positions of the main-sequence stars are included only for comparison. Specific colors of OAs of GRBs (Simon et al., 2001, 2004) Notice the prominent clustering of colors and negligible color evolution during decline.

Gaia CU7 Sub-workpackage on Cataclysmic Variables René Hudec & Collaborators Leuven, Nov 9-10, 2006

31 Cataclysmic Variables and Related Objects The objective of the sub-work package: The investigations and analyses of Cataclysmic Variables and related objects (including supernovae, novae, recurrent novae, nova-like variables, dwarf novae, polars, intermediate polars, symbiotic stars) based on Gaia data (photometry and spectrophotometry) as well as complex analyses with additional data. Some of the CVs are candidates for VHE emission (SNe, AE Aqr, AM Her...)

32 SN 1987A Nova V1500 Cyg RS Oph Recurrent Nova Z Cam Dwarf Nova U Gem Dwarf Nova Z And Symbiotic Variable

Gaia CU7 Sub-workpackage on AGN

Gaia and AGN Gaia will detect all AGN brighter than mag 20 Photometry and spectro-photometry Including TeV AGN/blazars Providing valuable simultaneous and quasi-simultaneous optical data for TeV blazars Automated recognition of AGN by their spectra, searches for spectral changes 34

35 Variability studies based on low dispersion spectra Application of algorithms developed for digitized astronomical archival plates (Hudec L., 2007) on Gaia Simulated low dispersion Gaia spectrum Real low dispersion spectrum from digitized Schmidt spectral plate

36 Relation of spectral and photometric variations T. Jarzebowski, 1959 X Cam Mira Variable Spectral Variations M0 to M6.5 Amplitude 1.4 mag in R

Example spectra of cataclysmic variables & blazars (digitised Hamburg Survey) 37 CV Blazar

38 Novel algorithms for automated analyses of digitized spectral plates Developed by informatics students Automated classification of spectral classes Searches for spectral variability (both continuum and lines) Searches for objects with specific spectra Correlation of spectral and light changes Searches for transients

39 The Motivation The archival spectral plates taken with objective prisma offer the possibility to simulate the Gaia low dispersion spectra and related procedures such as searches for spectral variability and variability analyses based on spectro-photometry Focus on sets of spectral plates of the same sky region covering long time intervals with good sampling

40 Automatic classification of stellar objective prism spectra on digitised plates, a simulation and a feasibilty study for low-dispersion Gaia spectra Left: investigated spectrum Right: Calibration spectrum (Hudec L., 2007)

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42 The End