TY - JOUR A1 - Culpan, Richard A1 - Geier, Stephan A1 - Reindl, Nicole A1 - Pelisoli, Ingrid A1 - Gentile Fusillo, Nicola Pietro A1 - Vorontseva, Alina T1 - The population of hot subdwarf stars studied with Gaia BT - IV. catalogues of hot subluminous stars based on Gaia EDR3 JF - Astronomy and astrophysics : an international weekly journal N2 - In light of substantial new discoveries of hot subdwarfs by ongoing spectroscopic surveys and the availability of the Gaia mission Early Data Release 3 (EDR3), we compiled new releases of two catalogues of hot subluminous stars: the data release 3 (DR3) catalogue of the known hot subdwarf stars contains 6616 unique sources and provides multi-band photometry, and astrometry from Gaia EDR3 as well as classifications based on spectroscopy and colours. This is an increase of 742 objects over the DR2 catalogue. This new catalogue provides atmospheric parameters for 3087 stars and radial velocities for 2791 stars from the literature. In addition, we have updated the Gaia Data Release 2 (DR2) catalogue of hot subluminous stars using the improved accuracy of the Gaia EDR3 data set together with updated quality and selection criteria to produce the Gaia EDR3 catalogue of 61 585 hot subluminous stars, representing an increase of 21 785 objects. The improvements in Gaia EDR3 astrometry and photometry compared to Gaia DR2 have enabled us to define more sophisticated selection functions. In particular, we improved hot subluminous star detection in the crowded regions of the Galactic plane as well as in the direction of the Magellanic Clouds by including sources with close apparent neighbours but with flux levels that dominate the neighbourhood. KW - subdwarfs KW - Hertzsprung-Russell and C-M diagrams KW - binaries: general KW - stars: horizontal-branch KW - catalogs Y1 - 2022 U6 - https://doi.org/10.1051/0004-6361/202243337 SN - 1432-0746 VL - 662 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Raddi, Roberto A1 - Hollands, M. A. A1 - Koester, D. A1 - Hermes, J. J. A1 - Gansicke, B. T. A1 - Heber, Ulrich A1 - Shen, Ken J. A1 - Townsley, D. M. A1 - Pala, Anna Francesca A1 - Reding, J. S. A1 - Toloza, O. F. A1 - Pelisoli, Ingrid Domingos A1 - Geier, Stephan A1 - Fusillo, Nicola Pietro Gentile A1 - Munari, Ullisse A1 - Strader, J. T1 - Partly burnt runaway stellar remnants from peculiar thermonuclear supernovae JF - Monthly notices of the Royal Astronomical Society N2 - We report the discovery of three stars that, along with the prototype LP 40-365, form a distinct class of chemically peculiar runaway stars that are the survivors of thermonuclear explosions. Spectroscopy of the four confirmed LP 40-365 stars finds ONe-dominated atmospheres enriched with remarkably similar amounts of nuclear ashes of partial O- and Si-burning. Kinematic evidence is consistent with ejection from a binary supernova progenitor; at least two stars have rest-frame velocities indicating they are unbound to the Galaxy. With masses and radii ranging between 0.20 and 0.28M(circle dot) and between 0.16 and 0.60 R-circle dot, respectively, we speculate these inflated white dwarfs are the partly burnt remnants of either peculiar Type Iax or electron-capture supernovae. Adopting supernova rates from the literature, we estimate that similar to 20 LP 40-365 stars brighter than 19 mag should be detectable within 2 kpc from the Sun at the end of the Gaia mission. We suggest that as they cool, these stars will evolve in their spectroscopic appearance, and eventually become peculiar O-rich white dwarfs. Finally, we stress that the discovery of new LP 40-365 stars will be useful to further constrain their evolution, supplying key boundary conditions to the modelling of explosion mechanisms, supernova rates, and nucleosynthetic yields of peculiar thermonuclear explosions. KW - stars: individual: LP 40-365 KW - subdwarfs KW - supernovae: general KW - white dwarfs KW - Galaxy: kinematics and dynamics Y1 - 2019 U6 - https://doi.org/10.1093/mnras/stz1618 SN - 0035-8711 SN - 1365-2966 VL - 489 IS - 2 SP - 1489 EP - 1508 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Fusillo, Nicola Pietro Gentile A1 - Tremblay, Pier-Emmanuel A1 - Gänsicke, Boris T. A1 - Manser, Christopher J. A1 - Cunningham, Tim A1 - Cukanovaite, Elena A1 - Hollands, Mark A1 - Marsh, Thomas A1 - Raddi, Roberto A1 - Jordan, Stefan A1 - Toonen, Silvia A1 - Geier, Stephan A1 - Barstow, Martin A1 - Cummings, Jeffrey D. T1 - A Gaia Data Release 2 catalogue of white dwarfs and a comparison with SDSS JF - Monthly notices of the Royal Astronomical Society N2 - We present a catalogue of white dwarf candidates selected from the second data release of Gaia (DR2). We used a sample of spectroscopically confirmed white dwarfs from the Sloan Digital Sky Survey (SDSS) to map the entire space spanned by these objects in the Gaia Hertzsprung–Russell diagram. We then defined a set of cuts in absolute magnitude, colour, and a number of Gaia quality flags to remove the majority of contaminating objects. Finally, we adopt a method analogous to the one presented in our earlier SDSS photometric catalogues to calculate a probability of being a white dwarf (PWD) for all Gaia sources that passed the initial selection. The final catalogue is composed of 486641 stars with calculated PWD from which it is possible to select a sample of ≃260000 high-confidence white dwarf candidates in the magnitude range 8 < G < 21. By comparing this catalogue with a sample of SDSS white dwarf candidates, we estimate an upper limit in completeness of 85 per cent for white dwarfs with G ≤ 20 mag and Teff >7000 K, at high Galactic latitudes (|b| > 20°). However, the completeness drops at low Galactic latitudes, and the magnitude limit of the catalogue varies significantly across the sky as a function of Gaia’s scanning law. We also provide the list of objects within our sample with available SDSS spectroscopy. We use this spectroscopic sample to characterize the observed structure of the white dwarf distribution in the H–R diagram. KW - catalogues KW - surveys KW - white dwarfs Y1 - 2018 U6 - https://doi.org/10.1093/mnras/sty3016 SN - 0035-8711 SN - 1365-2966 VL - 482 IS - 4 SP - 4570 EP - 4591 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Geier, Stephan A1 - Raddi, Roberto A1 - Fusillo, Nicola Pietro Gentile A1 - Marsh, T. R. T1 - The population of hot subdwarf stars studied with Gaia BT - II. The Gaia DR2 catalogue of hot subluminous stars JF - Astronomy and astrophysics : an international weekly journal N2 - Based on data from the ESA Gaia Data Release 2 (DR2) and several ground-based, multi-band photometry surveys we have compiled an all-sky catalogue of 39 800 hot subluminous star candidates selected in Gaia DR2 by means of colour, absolute magnitude, and reduced proper motion cuts. We expect the majority of the candidates to be hot subdwarf stars of spectral type B and O, followed by blue horizontal branch stars of late B-type (HBB), hot post-AGB stars, and central stars of planetary nebulae. The contamination by cooler stars should be about 10%. The catalogue is magnitude limited to Gaia G < 19 mag and covers the whole sky. Except within the Galactic plane and LMC/SMC regions, we expect the catalogue to be almost complete up to about 1.5 kpc. The main purpose of this catalogue is to serve as input target list for the large-scale photometric and spectroscopic surveys which are ongoing or scheduled to start in the coming years. In the long run, securing a statistically significant sample of spectroscopically confirmed hot subluminous stars is key to advance towards a more detailed understanding of the latest stages of stellar evolution for single and binary stars. KW - subdwarfs KW - stars: horizontal-branch KW - catalogs Y1 - 2019 U6 - https://doi.org/10.1051/0004-6361/201834236 SN - 0004-6361 SN - 1432-0746 VL - 621 PB - EDP Sciences CY - Les Ulis ER -