The MUCHFUSS project - Searching for hot subdwarf binaries with massive unseen companions: Survey, target selection and atmospheric parameters

Abstract

The project Massive Unseen Companions to Hot Faint Underluminous Stars from SDSS (MUCHFUSS) aims at finding sdBs with compact companions like supermassive white dwarfs (M>1.0 Msun), neutron stars or black holes. The existence of such systems is predicted by binary evolution theory and recent discoveries indicate that they are likely to exist in our Galaxy. A determination of the orbital parameters is sufficient to put a lower limit on the companion mass by calculating the binary mass function. If this lower limit exceeds the Chandrasekhar mass and no sign of a companion is visible in the spectra, the existence of a massive compact companion is proven without the need for any additional assumptions. We identified about 1100 hot subdwarf stars from the SDSS by colour selection and visual inspection of their spectra. Stars with high velocities have been reobserved and individual SDSS spectra have been analysed. In total 127 radial velocity variable subdwarfs have been discovered. Binaries with high RV shifts and binaries with moderate shifts within short timespans have the highest probability of hosting massive compact companions. Atmospheric parameters of 69 hot subdwarfs in these binary systems have been determined by means of a quantitative spectral analysis. The atmospheric parameter distribution of the selected sample does not differ from previously studied samples of hot subdwarfs. The systems are considered the best candidates to search for massive compact companions by follow-up time resolved spectroscopy.

15 pages, 13 figures, A&A, accepted

References in corpus (9)

• Post Common Envelope Binaries from SDSS. I: 101 white dwarf main sequence binaries with multiple SDSS spectroscopy
• Hot subdwarfs from the ESO Supernova Ia Progenitor Survey: II. Atmospheric parameters of subdwarf O stars
• The hot subdwarf B + white dwarf binary KPD 1930+2752 - a Supernova Type Ia progenitor candidate
• An ultra-massive fast-spinning white dwarf in a peculiar binary system
• A possible solution for the lack of EHB binaries in globular clusters
• Population synthesis of Galactic subdwarf B stars
• The Hyper-MUCHFUSS project: probing the Galactic halo with sdB stars
• Massive unseen companions to hot faint underluminous stars from SDSS (MUCHFUSS) - Analysis of seven close subdwarf B binaries
• First Attempt at Spectroscopic Detection of Gravity Modes in a Long-Period Pulsating Subdwarf B Star -- PG 1627+017

Cited by in corpus (72)

• Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
• Hot subluminous stars
• A selection of hot subluminous stars in the GALEX survey II. Subdwarf atmospheric parameters
• The fastest unbound star in our Galaxy ejected by a thermonuclear supernova
• Mass-accreting white dwarfs and type Ia supernovae
• Hot subdwarf binaries from the MUCHFUSS project - Analysis of 12 new systems and a study of the short-period binary population
• The population of hot subdwarf stars studied with Gaia II. The Gaia DR2 catalogue of hot subluminous stars
• A progenitor binary and an ejected mass donor remnant of faint type Ia supernovae
• Origin of apparent period variations in eclipsing post-common-envelope binaries
• The orbits of subdwarf-B + main-sequence binaries. II. Three eccentric systems; BD+29 3070, BD +34 1543 and Feige 87
• The population of hot subdwarf stars studied with Gaia -- IV. Catalogues of hot subluminous stars based on Gaia EDR3
• The shortest period sdB plus white dwarf binary CD-30 11223 (GALEX J1411-3053)
• The first ultracompact Roche lobe-filling hot subdwarf binary
• Three ways to solve the orbit of KIC11558725: a 10 day beaming sdB+WD binary with a pulsating subdwarf
• He-accreting carbon-oxygen white dwarfs and type Ia supernovae
• New binaries among UV-selected, hot subdwarf stars and population properties
• Testing eccentricity pumping mechanisms to model eccentric long period sdB binaries with MESA
• The catalogue of radial velocity variable hot subluminous stars from the MUCHFUSS project
• Alone but not lonely: Observational evidence that binary interaction is always required to form hot subdwarf stars
• A stripped helium star in the potential black hole binary LB-1
• Hot subdwarf stars in close-up view - III. Metal abundances of subdwarf B stars
• The orbital period -- mass ratio relation of wide sdB+MS binaries and its application to the stability of RLOF
• Hot subdwarfs in close binaries observed from space I: orbital, atmospheric, and absolute parameters and the nature of their companions
• Binaries discovered by the MUCHFUSS project: SDSS J162256.66$+$473051.1 - An eclipsing subdwarf B binary with a brown dwarf companion
• Hot subdwarf stars in close-up view - II. Rotational properties of single and wide binary subdwarf B stars
• PG1018-047: the longest period subdwarf B binary
• A new class of Roche lobe-filling hot subdwarf binaries
• Hot Subdwarf Stars Observed in LAMOST DR1 - Atmospheric parameters from single-lined spectra
• KIC7668647: a 14 day beaming sdB+WD binary with a pulsating subdwarf
• New hot subdwarf stars identified in Gaia DR2 with LAMOST DR5 spectra
• Hot subdwarf stars observed in Gaia DR2 and LAMOST DR5
• PTF1 J082340.04+081936.5: A hot subdwarf B star with a low mass white dwarf companion in an 87 minute orbit
• EC 10246-2707: a new eclipsing sdB + M dwarf binary
• Discovery of a double detonation thermonuclear supernova progenitor
• A quantitative in-depth analysis of the prototype sdB+BD system SDSS J08205+0008 revisited in the Gaia era
• The helium-rich subdwarf CPD-20 1123: a post-common envelope binary evolving onto the extended horizontal branch
• A Radial Velocity Study of Composite-Spectra Hot Subdwarf Stars with the Hobby-Eberly Telescope
• Using large spectroscopic surveys to test the double degenerate model for Type Ia supernovae
• The OmegaWhite survey for short-period variable stars - V. Discovery of an ultracompact hot subdwarf binary with a compact companion in a 44 minute orbit
• Orbital properties of an unusually low-mass sdB star in a close binary system with a white dwarf
• Orbital solutions of eight close sdB binaries and constraints on the nature of the unseen companions
• The subdwarf B star SB 290 - A fast rotator on the extreme horizontal branch
• Short-period pulsating hot-subdwarf stars observed by TESS I. Southern ecliptic hemisphere
• PG 1610$+$062: a runaway B star challenging classical ejection mechanisms
• Two New Long-Period Hot Subdwarf Binaries with Dwarf Companions
• Two candidate brown dwarf companions around core helium-burning stars
• The MUCHFUSS photometric campaign
• Radial Velocity Confirmation of a Binary Detected from Pulse Timings
• Hot subdwarfs in close binaries observed from space II: Analysis of the light curves
• An in-depth reanalysis of the alleged type Ia supernova progenitor Henize 2-428
• Hot Subdwarf Stars Identified in Gaia DR2 with Spectra of LAMOST DR6 and DR7. II. Kinematics
• The Unseen Population of F to K-type Companions to Hot Subdwarf Stars
• A search for new hot subdwarf stars by means of Virtual Observatory tools II
• K2 observations of the pulsating subdwarf B star EQ Piscium: an sdB+dM binary
• Searching for Hot Subdwarf Stars in LAMOST DR1-II. Pure spectroscopic identification method for hot subdwarfs
• Quantitative spectral analysis of the sdB star HD 188112: a helium-core white dwarf progenitor
• A spectroscopic and kinematic survey of fast hot subdwarfs
• Evolutionary Constraints on the Long-period Subdwarf B Binary PG 1018-047
• Constraints on the winds of hot subdwarf stars from X-ray observations of two sdB binaries with compact companions: CD -30 11223 and PG 1232-136
• Confirming new white dwarf-ultracool dwarf binary candidates
• The first massive compact companion in a wide orbit around a hot subdwarf star
• Identification of new hot subdwarf binary systems by means of Virtual Observatory tools
• Advanced Classification of Hot Subdwarf Binaries Using Artificial Intelligence Techniques and Gaia DR3 data
• Hot subdwarfs - Small stars marking important events in stellar evolution
• Hot Subdwarf Formation: Confronting Theory with Observation
• Hot subluminous Stars: Highlights from the MUCHFUSS and Kepler missions
• Candidate Hα emission and absorption line sources in the Galactic Bulge Survey
• Identifying and characterising the population of hot sub-luminous stars with multi-colour MeerLICHT data
• MUCHFUSS - Massive Unseen Companions to Hot Faint Underluminous Stars from SDSS
• Onset of common envelope evolution during a core helium flash by rapid envelope expansion
• Stars on the ascending helium giant branch I. From white dwarf merger to helium giant: the evolutionary state of the rapidly rotating hot subdwarf HE 1518-0948
• X-ray emission from hot subdwarfs with compact companions