<i>Gaia</i>Data Release 3

Recio–Blanco, A.; Laverny, P. de; Palicio, P. A.; Kordopatis, G.

doi:10.1051/0004-6361/202243750

“…We also report relatively good agreement in terms of effective temperatures and extinctions between GSP-Phot and ESP-HS for hot stars (T eff > 7500K), which is used for the OB sample definitions in Gaia Collaboration, and Gaia Collaboration, Creevey et al (2022). Recio-Blanco et al (2022) report good agreement between results from GSP-Phot (low-resolution BP/RP spectra) and GSP-Spec (RVS spectra) for effective temperatures and surface gravities. Gaia Collaboration, Creevey et al (2022) demonstrate that when selecting solar-like stars from GSP-Spec results, the colours of the resulting candidates are in good agreement with those of known solar twins for stars where A 0 < 0.001mag according to GSP-Phot.…”

Section: Further Validation Resultssupporting

confidence: 55%

Gaia Data Release 3: Analysis of the Gaia BP/RP spectra using the General Stellar Parameterizer from Photometry

Andrae,

Fouesneau,

Sordo

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

Context. The astrophysical characterisation of sources is among the major new data products in the third Gaia data release (DR3). In particular, there are stellar parameters for 471 million sources estimated from low-resolution BP/RP spectra. Aims. We present the General Stellar Parameterizer from Photometry (GSP-Phot), which is part of the astrophysical parameters inference system (Apsis). GSP-Phot is designed to produce a homogeneous catalogue of parameters for hundreds of millions of single non-variable stars based on their astrometry, photometry, and low-resolution BP/RP spectra. These parameters are effective temperature, surface gravity, metallicity, absolute M G magnitude, radius, distance, and extinction for each star. Methods. GSP-Phot uses a Bayesian forward-modelling approach to simultaneously fit the BP/RP spectrum, parallax, and apparent G magnitude. A major design feature of GSP-Phot is the use of the apparent flux levels of BP/RP spectra to derive, in combination with isochrone models, tight observational constraints on radii and distances. We carefully validate the uncertainty estimates by exploiting repeat Gaia observations of the same source.Results. The data release includes GSP-Phot results for 471 million sources with G < 19. Typical differences to literature values are 110 K for T eff and 0.2-0.25 for log g, but these depend strongly on data quality. In particular, GSP-Phot results are significantly better for stars with good parallax measurements ( /σ > 20), mostly within 2kpc. Metallicity estimates exhibit substantial biases compared to literature values and are only useful at a qualitative level. However, we provide an empirical calibration of our metallicity estimates that largely removes these biases. Extinctions A 0 and A BP show typical differences from reference values of 0.07-0.09 mag. MCMC samples of the parameters are also available for 95% of the sources. Conclusions. GSP-Phot provides a homogeneous catalogue of stellar parameters, distances, and extinctions that can be used for various purposes, such as sample selections (OB stars, red giants, solar analogues etc.). In the context of asteroseismology or ground-based interferometry, where targets are usually bright and have good parallax measurements, GSP-Phot results should be particularly useful for combined analysis or target selection.

show abstract

“…We also report relatively good agreement in terms of effective temperatures and extinctions between GSP-Phot and ESP-HS for hot stars (T eff > 7500K), which is used for the OB sample definitions in Gaia Collaboration, and Gaia Collaboration, Creevey et al (2022). Recio-Blanco et al (2022) report good agreement between results from GSP-Phot (low-resolution BP/RP spectra) and GSP-Spec (RVS spectra) for effective temperatures and surface gravities. Gaia Collaboration, Creevey et al (2022) demonstrate that when selecting solar-like stars from GSP-Spec results, the colours of the resulting candidates are in good agreement with those of known solar twins for stars where A 0 < 0.001mag according to GSP-Phot.…”

Section: Further Validation Resultssupporting

confidence: 52%

“…In Gaia DR3, the Gaia archive provides GSP-Phot results for 471 million sources with apparent magnitude G ≤ 19. We also draw attention to a second module of the CU8 Apsis chain, the General Stellar Parameterizer from Spectroscopy (GSP-Spec; Recio-Blanco et al 2022), which is also designed to characterise single stars in Gaia DR3 but using the higher resolution RVS spectra (Seabroke et al 2022) instead of the low-resolution BP/RP spectra.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

GaiaData Release 3

Andrae¹,

Fouesneau²,

Sordo³

et al. 2023

A&A

View full text Add to dashboard Cite

Context. The astrophysical characterisation of sources is among the major new data products in the third Gaia data release (DR3). In particular, there are stellar parameters for 471 million sources estimated from low-resolution BP/RP spectra. Aims. We present the General Stellar Parameterizer from Photometry (GSP-Phot), which is part of the astrophysical parameters inference system (Apsis). GSP-Phot is designed to produce a homogeneous catalogue of parameters for hundreds of millions of single non-variable stars based on their astrometry, photometry, and low-resolution BP/RP spectra. These parameters are effective temperature, surface gravity, metallicity, absolute M G magnitude, radius, distance, and extinction for each star. Methods. GSP-Phot uses a Bayesian forward-modelling approach to simultaneously fit the BP/RP spectrum, parallax, and apparent G magnitude. A major design feature of GSP-Phot is the use of the apparent flux levels of BP/RP spectra to derive, in combination with isochrone models, tight observational constraints on radii and distances. We carefully validate the uncertainty estimates by exploiting repeat Gaia observations of the same source.Results. The data release includes GSP-Phot results for 471 million sources with G < 19. Typical differences to literature values are 110 K for T eff and 0.2-0.25 for log g, but these depend strongly on data quality. In particular, GSP-Phot results are significantly better for stars with good parallax measurements ( /σ > 20), mostly within 2kpc. Metallicity estimates exhibit substantial biases compared to literature values and are only useful at a qualitative level. However, we provide an empirical calibration of our metallicity estimates that largely removes these biases. Extinctions A 0 and A BP show typical differences from reference values of 0.07-0.09 mag. MCMC samples of the parameters are also available for 95% of the sources. Conclusions. GSP-Phot provides a homogeneous catalogue of stellar parameters, distances, and extinctions that can be used for various purposes, such as sample selections (OB stars, red giants, solar analogues etc.). In the context of asteroseismology or ground-based interferometry, where targets are usually bright and have good parallax measurements, GSP-Phot results should be particularly useful for combined analysis or target selection.

show abstract

“…CU6 therefore used parameters from the preliminary CU8 run. This CU8 run used an earlier version of the GSP-Phot (Andrae et al 2022) and GSP-Spec (Recio-Blanco et al 2022) pipelines. GSP-Phot used DR2 photometric data instead of the better-quality and more detailed DR3 BP/RP data, while GSP-Spec used RVS spectra from the preliminary CU6 run (discussed in Sect.…”

Section: Sta Inputmentioning

confidence: 99%

Gaia Data Release 3: Hot-star radial velocities

Blomme¹,

Fremat²,

Sartoretti³

et al. 2022

Preprint

View full text Add to dashboard Cite

Context. The second Gaia data release, DR2, contained radial velocities of stars with effective temperatures up to T eff = 6900 K. The third data release, Gaia DR3, extends this up to T eff = 14 500 K. Aims. We derive the radial velocities for hot stars (i.e. in the T eff = 6900−14 500 K range) from data obtained with the Radial Velocity Spectrometer (RVS) on board Gaia. Methods. The radial velocities were determined by the standard technique of measuring the Doppler shift of a template spectrum that was compared to the observed spectrum. The RVS wavelength range is very limited. The proximity to and systematic blueward offset of the calcium infrared triplet to the hydrogen Paschen lines in hot stars can result in a systematic offset in radial velocity. For the hot stars, we developed a specific code to improve the selection of the template spectrum, thereby avoiding this systematic offset. Results. With the improved code, and with the correction we propose to the DR3 archive radial velocities, we obtain values that agree with reference values to within 3 km s −1 (in median). Because of the required S/N for applying the improved code, the hot star radial velocities in DR3 are mostly limited to stars with a magnitude in the RVS wavelength band ≤ 12 mag.

show abstract

GaiaData Release 3

Cited by 109 publications

References 59 publications

Gaia Data Release 3: Analysis of the Gaia BP/RP spectra using the General Stellar Parameterizer from Photometry

Gaia Data Release 3: Analysis of the Gaia BP/RP spectra using the General Stellar Parameterizer from Photometry

GaiaData Release 3

Gaia Data Release 3: Hot-star radial velocities

Contact Info

Product

Resources

About