ESA Gaia: Expectation

for Astroparticle Physics

René Hudec, Vojtěch Šimon, Lukáš Hudec

& Collaborators & Gaia CU7 consortiumGroup of High Energy Astrophysics

Astronomical Institute of Academy of Sciences of the Czech

Republic, Ondřejov, Czech Republic

ISDC Versoix, SwitzerlandSanta Fe GRB Workshop 2007

Reference: http://sci.esa.int/gaia/

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ESA Mission Gaia

Unraveling the chemical and dynamical history of our Galaxy

Albeit focusing on astrometry, Gaia will also providespectrophotometry 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.

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Gaia: Design Considerations

• Astrometry (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 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

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)

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Gaia: Complete, Faint, Accurate

Hipparcos Gaia

Magnitude limit 12 20 mag Completeness 7.3 – 9.0 20 mag Bright limit 0 6 mag Number of objects 120 000 26 million to V = 15 250 million to V = 18 1000 million to V = 20 Effective distance limit

1 kpc 1 Mpc Quasars None 5 x 105

Galaxies None 106 – 107 Accuracy 1 milliarcsec 7 µarcsec at V = 10 10-25 µarcsec at V = 15 300 µarcsec at V = 20 Photometry photometry

2-colour (B and V) Low-res. spectra to V = 20 Radial velocity None 15 km/s to V = 16-17 Observing programme

Pre-selected Complete and unbiased

GAIA capabilitiesDistances:

<0.1% for 700 000 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=17-1815-band photometry (250-950nm) 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: 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

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Schedule

Catalogue

2000 2004 2008 2012 2016 2020

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

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Payload and Telescope

Two SiC primary mirrors1.45 0.50 m2 at 106.5°

SiC toroidalstructure

(optical bench)

Basic anglemonitoring system

Combinedfocal plane

(CCDs)

Rotation axis (6 h)

Figure courtesy EADS-Astrium

Superposition of two Fields of View

(FoV)

Astrometric instrument: Light path1 2

3 4

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Photometry Measurement Concept

Figures courtesy EADS-Astrium

Blue photometer:330–680 nm

Red photometer:640–1000 nm

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Photometry Measurement Concept (2/2)

Figures courtesy Anthony Brown

Blue photometer

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RP spectrum of M dwarf (V=17.3)Red box: data sent to ground

White contour: sky-background levelColour coding: signal intensity

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Focal Plane

Star motion in 10 s

Total field: - active area: 0.75 deg2

- CCDs: 14 + 62 + 14 + 12 - 4500 x 1966 pixels (TDI) - pixel size = 10 µm x 30 µm

= 59 mas x 177 mas

Astrometric Field CCDs

Blue P

hotometer C

CD

s

Sky Mapper CCDs

104.26cm

Red P

hotometer C

CD

s 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 discriminationAstrometry: - total detection noise: 6 e-

Photometry: - two-channel photometer - blue and red CCDsSpectroscopy: - high-resolution spectra - red CCDs

42.3

5cm

Figure courtesy Alex Short

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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

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Sky Scanning Principle

Spin axis 45o to SunScan rate: 60 arcsec/sSpin period: 6 hours

45o

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

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Ingestion, preprocessing,data base + versions,

astrometric iterative solutionESAC (+ Barcelona + OATo)

Object processing(shell tasks)

+ ClassificationCNES, Toulouse

PhotometryCambridge (IOC)

+ VariabilityGeneva (ISDC)

Spectroscopicprocessing

CNES, Toulouse

Overall system architecture

ESACData 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

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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 SourcesRené Hudec & Collaborators

Leuven, Nov 9-10, 2006

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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

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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.

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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

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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

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B magnitudy

1% 13%

40%38%

8% 1

2

3

4

5

V magnitudy

1% 17%

43%

34%

5% 1

2

3

4

5

Legend - B1 = 2,29 - 52 = 5 -103 = 10 - 154 = 15 - 205 = 20 - 23

Legend - V1 = 2,39 - 52 = 5 -103 = 10 - 154 = 15 - 205 = 20 - 21

Optical B and V magnitudes of optically identified INTEGRAL Optical B and V magnitudes of optically identified INTEGRAL gamma-ray sources … most are brighter than mag 20, and gamma-ray sources … most are brighter than mag 20, and more than halfmore than half are brighter are brighter than mag 15 than mag 15

>90% accessible with Gaia

Even gamma-ray sources do have optical counterparts

accessible by Gaia

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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

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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

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V-RV-R vs. vs. R-IR-I diagram diagram of of OAs OAs of GRBs of GRBs ((t-Tt-T00 <10.2 <10.2 daysdays) in ) in observer frameobserver frame,, corrected for corrected for tthehe Galactic reddening. Multiple indices of the same OA are connected by lines forGalactic reddening. Multiple indices of the same OA are connected by lines forconvenience. The mean colors (convenience. The mean colors (centroidcentroid) of the whole ensemble of OAs (except for) of the whole ensemble of OAs (except forGRB000131) are marked by the large cross. The colors of SN1998bw are shown GRB000131) are marked by the large cross. The colors of SN1998bw are shown onlyonly for for compcomparison. The representative reddening paths for arison. The representative reddening paths for EEB-VB-V=0.5=0.5 are also shown. are also shown.

Positions of the main-sequence stars are included Positions of the main-sequence stars are included only only for comparison.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 VariablesRené Hudec & Collaborators

Leuven, Nov 9-10, 2006

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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...)

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SN 1987ANova 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

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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

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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)

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psconvert_setup.exe

CV

CV CV

CV

Blazar

Blazar

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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

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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

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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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The End