Massive OB stars as seen by Gaia

Transcription

1 Massive OB stars as seen by Gaia Y.Frémat Royal Observatory of Belgium Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 1 / 17

2 OB stars in the Gaia Universe Model Robin et al., 2012, A&A, 543, 100 gaia.am.ub.es/gums-10/main.html Luri et al., 2014, A&A, 566, A % Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 2 / 17

3 OB stars in the Gaia Universe Model Robin et al., 2012, A&A, 543, 100 gaia.am.ub.es/gums-10/main.html Luri et al., 2014, A&A, 566, A % 0.3 % Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 2 / 17

4 OB stars in the Gaia Universe Model Robin et al., 2012, A&A, 543, 100 gaia.am.ub.es/gums-10/main.html Luri et al., 2014, A&A, 566, A % 0.3 % Represent to B stars, to O stars Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 2 / 17

5 Introduction Astrometry Photometry Spectroscopy Sampling Other output Release scenario Image of the Week NGC HD66259 HD65987 Y.Fre mat, EWASS SP7 Massive OB stars as seen by Gaia 3 / 17

6 Instruments on-board Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 4 / 17

7 Astrometry cosmos.esa.int/web/gaia/science-performance Average of 70 transits 100 σ π µas (B1V) µas (V < 12) 26 µas (V = 15) 600 µas (V = 20) 0 <1 <0.2 <0.05 σ µ α,δ µas yr 1 σ π /π Percentage (%) Expected from Gaia O Stars B Stars Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 5 / 17

8 Astrometry cosmos.esa.int/web/gaia/science-performance Luri et al., 2014, A&A, 566, A119 Average of 70 transits σ π µas (B1V) 5-16 µas (V < 12) 26 µas (V = 15) 600 µas (V = 20) <1 <0.2 <0.05 σ µ α,δ µas yr 1 σ π /π Percentage (%) 50 Expected from Gaia O Stars B Stars Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 5 / 17

9 Astrometry Gaia vs Hipparcos cosmos.esa.int/web/gaia/science-performance Luri et al., 2014, A&A, 566, A119 Hipparcos Expected from Gaia 73 O & 885 B stars with σ π π < O & 8826 B stars with σ π π < 1 Percentage (%) σ µ α,δ 1 mas yr 1 0 <1 <0.2 < open clusters in the input catalogue O Stars σ π /π B Stars Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 6 / 17

10 Photometry cosmos.esa.int/web/gaia/science-performance Jordi et al., 2010, A&A, 523, A48 B1V Star, G=15-20 BP: 330 to 680 nm, σ 4 to 51 mmags RP: 640 to 1000 nm, σ 4 to 110 mmags G: σ 1 to 6 mmag Average of 70 transits Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 7 / 17

11 Photometry G vs V Jordi et al., 2010, A&A, 523, A48 Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 8 / 17

12 Photometry Colour-Magnitude Diagrams Johnson Cousins photometry from WEBDA Conversion: Jordi et al., 2010, A&A, 523, A48 Parameters: Kharchenko et al., 2013, A&A, 558, 53 Isochrones: Girardi et al. Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 9 / 17

13 Photometry Dispersed Photometry BP: 4 to 32 nm/pixel, 330 to 680 nm RP: 7 to 15 nm/pixel, 640 to 1000 nm SNR: from 250 (G= 6 to 12) to < 20 (G=20), Bailer-Jones et al. (2013, Fig.2) OB AP relative errors (G = 10-15): T eff = 17 %, log g = 31 %, A 0 = 12 % Upper fig.: Bailer-Jones et al., 2013, A&A, 559, 74 Lower fig.: Liu et al., 2012, MNRAS, 426, 2463 Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 10 / 17

14 Spectroscopy Coverage: 845 to 872 nm ; 3 CCDs Resolution: to (D.Katz & O. Marchal) Single and multiple transit RV measurements Average of 40 transits Figure from: ESA/Gaia/DPAC/CU6/Observatoire de Paris-Meudon/ Olivier Marchal, Carine Babusiaux & David Katz Taken from: cosmos.esa.int/web/gaia/iow_ Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 11 / 17

15 Spectroscopy Expected SNR SNR values from cosmos.esa.int/web/gaia/sn-rvs G RVS to V conversion following Jordi et al., 2010, A&A, 523, A48 T eff calibration from Worthey & Lee, 2011ApJS, 193, 1 End-of-mission SNR: (V=8), (V=12) Transit spectrum:. 65 (V=8),. 7 (V=11) Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 12 / 17

16 Spectroscopy Expected end-of-mission error on radial velocity cosmos.esa.int/web/gaia/science-performance fig. provided by R.Blomme End-of-Mission, error on combined spectrum: 1 to 15 km/s (B stars, V < 11) Expected minimum error on epoch RVs: Strongly depends on V.sin(i) Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 13 / 17

17 Data Sampling End-of-mission Nb of transits in the direction of 371 open clusters taken from Dias et al. (2012) Time-sampling Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 14 / 17

18 Additional Products Gaia photometric alerts: Variability classification (CU7, L.Eyer et al.). (from release 4 on) Multiple system classification (CU4, D.Pourbaix et al.). (from release 3 on) Stellar classification (CU8, C.Bailer-Jones et al.): astrophysical parameters, identification of emission-line stars. (from release 3 on) Auxiliary data & software. Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 15 / 17

19 Conclusion Release Scenario Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 16 / 17

20 Thank you Y.Frémat, EWASS SP7 Massive OB stars as seen by Gaia 17 / 17