Radial velocities from Gaia BP/RP spectra

The Gaia mission has provided us full astrometric solutions for over $1.5$B sources. However, only the brightest 34M of those have radial velocity measurements. As a proof of concept, this paper aims to close that gap, by obtaining radial velocity estimates from the low-resolution BP/RP spectra that Gaia now provides. These spectra are currently published for about 220M sources, with this number increasing to the full $\sim 2$B Gaia sources with Gaia Data Release 4. To obtain the radial velocity measurements, we fit Gaia BP/RP spectra with models based on a grid of synthetic spectra, with which we obtain the posterior probability on the radial velocity for each object. Our measured velocities show systematic biases that depend mainly on colours and magnitudes of stars. We correct for these effects by using external catalogues of radial velocity measurements. We present in this work a catalogue of about $6.4$M sources with our most reliable radial velocity measurements and uncertainties $<300$ km s$^{-1}$ obtained from the BP/RP spectra. About 23% of these have no previous radial velocity measurement in Gaia RVS. Furthermore, we provide an extended catalogue containing all 125M sources for which we were able to obtain radial velocity measurements. The latter catalogue, however, also contains a fraction of measurements for which the reported radial velocities and uncertainties are inaccurate. Although typical uncertainties in the catalogue are significantly higher compared to those obtained with precision spectroscopy instruments, the number of potential sources for which this method can be applied is orders of magnitude higher than any previous radial velocity catalogue. Further development of the analysis could therefore prove extremely valuable in our understanding of Galactic dynamics.Comment: 14 pages, 17 figures, submitted to A&A, comments welcom

Gaia XP radial velocity catalogues

&lt;p&gt;Here we provide the radial velocities we measured from the Gaia XP spectra.&lt;/p&gt

: A pipeline to search for UV transients with

Despite the prevalence of transient-searching facilities operating across most wavelengths, the ultraviolet (UV) transient sky remains to be systematically studied. Therefore, we recently initiated the Transient Ultraviolet Objects (TUVO) project, with which we search for serendipitous UV transients in data obtained using currently available UV instruments with a strong focus on the UV and Optical (UVOT) telescope aboard the Neil Gehrels Swift Observatory (an overview of the project is described in a companion paper). Here, we describe the pipeline (named TUVOpip