Optical Identification of He White Dwarfs Orbiting Four Millisecond Pulsars in the Globular Cluster 47 Tucanae

Abstract

We used ultra-deep UV observations obtained with the Hubble Space Telescope to search for optical companions to binary millisecond pulsars (MSPs) in the globular cluster 47 Tucanae. We identified four new counterparts (to MSPs 47TucQ, 47TucS, 47TucT and 47TucY) and confirmed those already known (to MSPs 47TucU and 47TucW). In the color magnitude diagram, the detected companions are located in a region between the main sequence and the CO white dwarf cooling sequences, consistent with the cooling tracks of He white dwarfs of mass between 0.15 Msun and 0.20 Msun. For each identified companion, mass, cooling age, temperature and pulsar mass (as a function of the inclination angle) have been derived and discussed. For 47TucU we also found that the past accretion history likely proceeded in a sub-Eddington rate. The companion to the redback 47TucW is confirmed to be a non degenerate star, with properties particularly similar to those observed for black widow systems. Two stars have been identified within the 2-sigma astrometric uncertainty from the radio positions of 47TucH and 47TucI, but the available data prevent us from firmly assessing whether they are the true companions of these two MSPs.

arXiv comment27 pages, 7 figures, Accepted for publication by ApJ

References in corpus (70)

• A Massive Pulsar in a Compact Relativistic Binary
• Neutron Star Structure and the Equation of State
• The Fourth US Naval Observatory CCD Astrograph Catalog (UCAC4)
• A Radio Pulsar/X-ray Binary Link
• The relativistic pulsar-white dwarf binary PSR J1738+0333 II. The most stringent test of scalar-tensor gravity
• The ACS Survey of Galactic Globular Clusters. XII. Photometric Binaries along the Main-Sequence
• Swings between rotation and accretion power in a millisecond binary pulsar
• A Comprehensive Spectroscopic Analysis of DB White Dwarfs
• Dynamical Formation of Close Binary Systems in Globular Clusters
• The giant, horizontal and asymptotic branches of galactic globular clusters. I. The catalog, photometric observables and features
• Distances and ages of NGC 6397, NGC 6752 and 47 Tuc
• Twenty-One Millisecond Pulsars in Terzan 5 Using the Green Bank Telescope
• A Young White Dwarf Companion to Pulsar 1620-26: Evidence for Early Planet Formation
• New evolutionary sequences for extremely low mass white dwarfs: Homogeneous mass and age determinations, and asteroseismic prospects
• The cluster Terzan 5 as a remnant of a primordial building block of the Galactic bulge
• A state change in the low-mass X-ray binary XSS J12270-4859
• Multiple stellar populations in 47 Tucanae
• Observations of 20 millisecond pulsars in 47 Tucanae at 20 cm
• Formation of millisecond pulsars with CO white dwarf companions - II. Accretion, spin-up, true ages and comparison to MSPs with He white dwarf companions
• Dynamical age differences among coeval star clusters as revealed by blue stragglers
• Astrometry and photometry with HST WFC3. II. Improved geometric-distortion corrections for 10 filters of the UVIS channel
• Relativistic Binaries in Globular Clusters
• Detection of ionized gas in the globular cluster 47 Tucanae
• Formation of black widows and redbacks -- two distinct populations of eclipsing binary millisecond pulsars
• The masses of the millisecond pulsar J1012+5307 and its white-dwarf companion
• The relativistic pulsar-white dwarf binary PSR J1738+0333 I. Mass determination and evolutionary history
• Chandra X-Ray Observations of Nineteen Millisecond Pulsars in the Globular Cluster 47 Tucanae
• An Age Difference of 2 Gyr between a Metal-Rich and a Metal-Poor Globular Cluster
• Formation of Short-Period Binary Pulsars in Globular Clusters
• Chandra Study of a Complete Sample of Millisecond Pulsars in 47Tuc and NGC6397
• The formation of low-mass helium white dwarfs orbiting pulsars: Evolution of low-mass X-ray binaries below the bifurcation period
• The White Dwarf Distance to the Globular Cluster 47 Tucanae and its Age
• The bright optical companion to the eclipsing millisecond pulsar in NGC 6397
• The masses of PSR J1911-5958A and its white dwarf companion
• Multi-telescope timing of PSR J1518+4904
• On the disruption of pulsar and X-ray binaries in globular clusters
• Blue Stragglers, Young White Dwarfs and UV-excess stars in the core of 47 Tuc
• Discovery of another peculiar radial distribution of Blue Stragglers in Globular Clusters: The case of 47 Tuc
• Spin-Down of Radio Millisecond Pulsars at Genesis
• An X-ray Variable Millisecond Pulsar in the Globular Cluster 47 Tucanae: Closing the Link to Low Mass X-ray Binaries
• Another Non-segregated Blue Straggler Population in a Globular Cluster: the Case of NGC 2419
• Understanding the evolution of close binary systems with radio pulsars
• Radio Searches of Fermi LAT Sources and Blind Search Pulsars: The Fermi Pulsar Search Consortium
• The puzzling dynamical status of the core of the globular cluster NGC 6752
• X-ray Sources and their Optical Counterparts in the Globular Cluster M4
• The Orbit and Companion of Probable gamma-ray Pulsar J2339-0533
• Blue Straggler Stars in the Unusual Globular Cluster NGC 6388
• PSR J1740-5340: accretion inhibited by radio-ejection in a binary millisecond pulsar in the Globular Cluster NGC 6397
• The light curve of the companion to PSR B1957+20
• Optical Detection of a Variable Millisecond Pulsar Companion in 47 Tucanae
• The Spectral Energy Distributions of White Dwarfs in 47 Tucanae: The Distance to the Cluster
• Three Binary Millisecond Pulsars in NGC 6266
• A Millisecond Pulsar Optical Counterpart with Large-Amplitude Variability in the Globular Cluster 47 Tucanae
• The Helium White Dwarf orbiting the Millisecond Pulsar in the halo of the Globular Cluster NGC 6752
• Evolution and colors of helium-core white dwarf stars with high-metallicity progenitors
• The optical counterpart to the X-ray transient IGR J18245-2452 in the globular cluster M28
• Optical Counterparts of Two Fermi Millisecond Pulsars: PSR J1301+0833 and PSR J1628-3205
• The optical companion to the binary millisecond pulsar J1824-2452H in the globular cluster M28
• Black Widow Pulsars: the Price of Promiscuity
• Accurate mass ratio and heating effects in the dual-line millisecond binary pulsar in NGC 6397
• The complex Halpha line profile of the bright companion to PSR J1740-5340 in NGC 6397
• A puzzling millisecond pulsar companion in NGC 6266
• A Shapiro delay detection in the binary system hosting the millisecond pulsar PSR J1910-5959A
• New clues on the nature of the companion to PSR~J1740-5340 in NGC6397 from XSHOOTER spectroscopy
• The puzzling properties of the Helium White Dwarf orbiting the millisecond pulsar PSR J1911-5958A in NGC 6752
• Optical identification of the companion to PSR J1911-5958A, the pulsar binary in the outskirts of NGC 6752
• Radio Timing and Optical Photometry of the Black Widow System PSR J1953+1846A in the Globular Cluster M71
• The chemical composition of the peculiar companion to the millisecond pulsar in NGC 6397
• Radial velocities from VLT-KMOS spectra of giant stars in the globular cluster NGC 6388
• The optical companion to the intermediate mass millisecond pulsar J1439-5501 in the Galactic field

Cited by in corpus (26)

• Models of low-mass helium white dwarfs including gravitational settling, thermal and chemical diffusion, and rotational mixing
• Long-term observations of the pulsars in 47 Tucanae - II. Proper motions, accelerations and jerks
• On the classification of GRBs and their occurrence rates
• Long-term observations of the pulsars in 47 Tucanae. I. A study of four elusive binary systems
• Discovery of three new millisecond pulsars in Terzan 5
• Chandra studies of the globular cluster 47 Tucanae: A deeper X-ray source catalogue, five new X-ray counterparts to millisecond radio pulsars, and new constraints to r-mode instability window
• An extremely low-mass He white dwarf orbiting the millisecond pulsar J1342+2822B in the globular cluster M3
• PSR J1641+3627F: a low-mass He white dwarf orbiting a possible high-mass neutron star in the globular cluster M13
• Radial variation of the stellar mass functions in the globular clusters M15 and M30: clues of a non-standard IMF?
• The Optical Counterpart to the Accreting Millisecond X-ray Pulsar SAX J1748.9-2021 in the Globular Cluster NGC 6440
• Orbital Evolution of Neutron-Star -- White-Dwarf Binaries by Roche-Lobe Overflow and Gravitational Wave Radiation
• GRB 170817A-GW170817-AT 2017gfo and the observations of NS-NS, NS-WD and WD-WD mergers
• High-resolution extinction map in the direction of the bulge globular cluster NGC 6440
• On the rate and on the gravitational wave emission of short and long GRBs
• The ultracool helium-atmosphere white dwarf companion of PSR J0740+6620?
• Induced Gravitational Collapse, Binary-Driven Hypernovae, Long Gramma-ray Bursts and Their Connection with Short Gamma-ray Bursts
• A young white dwarf orbiting PSR J1835-3259B in the bulge globular cluster NGC 6652
• Identifying the brightest Galactic globular clusters for future observations by H.E.S.S. and CTA
• On the vanishing orbital X-ray variability of the eclipsing binary millisecond pulsar 47 Tuc W
• White Dwarf Stars
• Detection of a white dwarf orbiting a Carbon-Oxygen depleted blue straggler in 47 Tucanae
• On the effect of pulsar evaporation on the cooling of white dwarfs
• Possible tidal dissipation in millisecond pulsar binaries
• High Energy Radiation from Spider Pulsars
• PSR J0024$-$7204ai: a massive, eccentric binary system in the globular cluster 47 Tucanae
• Formation of Extremely Low-mass White Dwarf Binaries Undergoing Enhanced Angular Momentum Loss