ESA Gaia Expectation for Astroparticle Physics René Hudec

ESA Gaia: Expectation for Astroparticle Physics René Hudec, Vojtěch Šimon, Lukáš Hudec & Collaborators & Gaia CU 7 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: http: //sci. esa. int/gaia/

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 2 including optical counterparts of HE sources.

Gaia: Design Considerations • Astrometry (V < 20): • Photometry (V < 20): – completeness to 20 mag (on-board detection) 109 stars – accuracy: 10– 25 μarcsec 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 Te. V/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 – astrophysical diagnostics (low-dispersion photometry) + chromaticity Teff ~ 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) 3

Gaia: Complete, Faint, Accurate 4

GAIA capabilities <0. 1% for 700 000 stars Distances: <1% for 21 million <10% for 220 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=17 -18 15 -band photometry (250 -950 nm) at ~100 epochs over 4 years Complete survey of the sky to V=20, observing 109 objects: 108 binary star systems (detected astrometrically; 105 orbits) 200 000 disk white dwarfs 50 000 brown dwarfs 50 000 planetary systems 106 -107 resolved galaxies 105 quasars 105 extragalactic supernovae 105 -106 Solar System objects (65 000 presently known)

Satellite and System • ESA-only mission • Launch date: 2011 • Lifetime: 5 years • Launcher: Soyuz–Fregat from CSG • Orbit: L 2 • 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

Schedule 2004 2000 2008 2016 2012 2020 Concept & Technology Study (ESA) ESA acceptance Re-assessment: Ariane-5 Soyuz Technology Development Design, Build, Test Launch Cruise to L 2 Observations Data Analysis Early Data Catalogue 7

Payload and Telescope Two Si. C primary mirrors 1. 45 0. 50 m 2 at 106. 5° Rotation axis (6 h) Basic angle monitoring system Si. C toroidal structure (optical bench) Superposition of two Fields of View (Fo. V) Combined focal plane (CCDs) 8 Figure courtesy EADS-Astrium

Astrometric instrument: Light path 1 2 3 4

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

Photometry Measurement Concept (2/2) RP spectrum of M dwarf (V=17. 3) Red box: data sent to ground White contour: sky-background level Colour coding: signal intensity 11 Figures courtesy Anthony Brown

Figure courtesy Alex Short Focal Plane 104. 26 cm 42. 35 cm Basic Angle Monitor Red Photometer CCDs Wave Front Sensor Blue Photometer CCDs Wave Front Sensor Radial-Velocity Spectrometer CCDs Star motion in 10 s Sky Mapper CCDs Total field: Astrometric Field CCDs Sky mapper: - detects all objects to 20 mag - active area: 0. 75 deg 2 - rejects cosmic-ray events - CCDs: 14 + 62 + 14 + 12 - Fo. V discrimination - 4500 x 1966 pixels (TDI) - pixel size = 10 µm x 30 µm Astrometry: = 59 mas x 177 mas - total detection noise: 6 e- Photometry: - two-channel photometer - blue and red CCDs Spectroscopy: 12 - high-resolution spectra - red CCDs

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 13

Sky Scanning Principle 45 o Spin axis Scan rate: Spin period: 45 o to Sun 60 arcsec/s 6 hours 14 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

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

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

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

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Gaia CU 7 Sub-workpackage on Optical Counterparts of High-Energy Sources René Hudec & Collaborators Leuven, Nov 9 -10, 2006

Motivation of the Gaia CU 7 Subworkpackage 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 22

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. 23

Some examples • LMXRB • HMXRB • Optical Afterglows and Optical Transients of GRB Optical LC of OT of GRB 060116, Jelinek et al. 2006 Long-term optical changes of Sco X-1/V 818 Sco, Hudec 1981 Inactive state optical LC of Her X-1/HZ Her, Hudec and Wenzel 1976 24

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 25

Even gamma-ray sources do have optical counterparts accessible by Gaia Legend - B 1 = 2, 29 - 5 2 = 5 -10 3 = 10 - 15 4 = 15 - 20 5 = 20 - 23 Legend - V 1 = 2, 39 - 5 2 = 5 -10 3 = 10 - 15 4 = 15 - 20 5 = 20 - 21 >90% accessible with Gaia Optical B and V magnitudes of optically identified INTEGRAL gamma-ray sources … most are brighter than mag 20, and more than half are 26

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 27

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 28

Specific colors of OAs of GRBs (Simon et al. , 2001, 2004) Notice the prominent clustering of colors and negligible color evolution during decline. 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 29 OAs (except for

Gaia CU 7 Sub-workpackage on Cataclysmic Variables René Hudec & Collaborators Leuven, Nov 9 -10, 2006

Cataclysmic Variables and Related Objects The objective of the sub-work package: • The investigations and analyses of Cataclysmic Variables and related objects (including supernovae, 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. . . ) 31

SN 1987 A Nova V 1500 Cyg RS Oph Recurrent Nova U Gem Dwarf Nova Z Cam Dwarf Nova Z And Symbiotic Variable 32

Gaia CU 7 Sub-workpackage on AGN

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

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 35

Relation of spectral and photometric variations T. Jarzebowski, 1959 X Cam Mira Variable Spectral Variations M 0 to M 6. 5 Amplitude 1. 4 mag in R 36

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

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 38

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 39

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) 40

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