Choose timezone
Your profile timezone:
Powered by Indico
v3.3.5
Gaia ESA Mission launched in 2013 is releasing a number of Focused Products on Tuesday 10 October 2023. The first part of the talk will provide information about the mission status and present a brief overview of the new products. The data become available from the Gaia Archive (and from Gaia's partner data centres). The Gaia Focused Product Release contains five sets of data: 1) Astrometry and photometry from engineering images taken in the omega Centauri region; 2) The first results of quasars' environment analysis for gravitational lenses search; 3) Extended radial velocity epoch data for Long Period Variables; 4) Diffuse Interstellar Bands from aggregated RVS spectra; 5) Updated astrometry for Solar System objects . The products are build partly on the data period that went into Gaia's Data Release 3 , but in case of the Solar System objects extends the stretch of time that forms the basis for the FPR data product.
The second part of the presentation will focus on the Long-period variables (LPVs) radial velocity time series. LPVs represent the late evolutionary stages of low- to intermediate-mass stars (on the Asymptotic Giant Branch) or massive stars (Red Supergiants).
They display periodic variability due to pulsation in several modes of low radial order, possibly at the same time. Understanding their variability is crucial to study their evolution and the mass-loss process that leads to their death and to the enrichment of the interstellar medium by their nucleosynthesis products.
The second Gaia Data Release (Gaia DR2) in 2016 delivered photometric time series for over 150'000 long-period variable (LPV) candidates based on 22 months of observations.
Last year, with Gaia DR3, this number increased to more than 2.3 millions, extending the span of the time series up to 34 months. As part of this Gaia Focused Product Release (FPR), we take a step further and deliver radial velocity time series for a selection of the LPVs published in DR3 having high-quality observations.
While measuring the mean radial velocity of a star is a key ingredient to understand the dynamics of the Galaxy's stellar content, Gaia's multi-epoch observations allow to monitor radial velocity variability - in parallel to photometric variability.
Stars can thus be characterized much better allowing to identify subsamples of stars in a specific evolutionary stage like long period variables.
These new data expand substantially the availability of epoch radial velocity data for long-period variables, and are expected to be highly valuable for investigating the variability of evolved red giants.
In this seminar, I will describe the construction of this FPR catalog, describe its content, and discuss its value as a tool for the astrophysical community to prepare for the upcoming Gaia DR4.
Elisabetta Rigliaco