Publications (41)
Exogeological inferences from white dwarf pollutants: the impact of stellar physics
Andrew M. Buchan, Pier-Emmanuel Tremblay, Antoine Bédard +2
Many white dwarfs have accreted material from their own planetary systems. These objects can be used to infer the composition of exoplanetary material and identify evidence for key…
Initial-final mass relation from white dwarfs within 40 pc
Tim Cunningham, Pier-Emmanuel Tremblay, Mairi O'Brien
We present an initial-final mass relation derived from the spectroscopically-complete volume-limited 40 pc sample of white dwarfs. The relation is modelled using population synthes…
Core crystallization and pile-up in the cooling sequence of evolving white dwarfs
Pier-Emmanuel Tremblay, Gilles Fontaine, Nicola Pietro Gentile Fusillo +7
White dwarfs are stellar embers depleted of nuclear energy sources that cool over billions of years. These stars, which are supported by electron degeneracy pressure, reach densiti…
The Galactic White Dwarf Population
Santiago Torres, Roberto Raddi, Alberto Rebassa-Mansergas +15
The ESA Gaia mission has revolutionized our understanding of the white dwarf population, delivering an unprecedented census of these nearby remnants and revealing previously unseen…
A white dwarf accreting planetary material determined from X-ray observations
Tim Cunningham, Peter J. Wheatley, Pier-Emmanuel Tremblay +4
The atmospheres of a large proportion of white dwarf stars are polluted by heavy elements that are expected to sink out of visible layers on short timescales. This has been interpr…
Detection of a weak magnetic field in the Balmer emission line white dwarf WDJ1653-1001
Abbigail Elms, Stefano Bagnulo, Pier-Emmanuel Tremblay +8
The small DAHe and DAe spectral classes comprise isolated, hydrogen-dominated atmosphere white dwarfs that exhibit variable photometric flux and Balmer line emission. These mysteri…
The entry geometry and velocity of planetary debris into the Roche sphere of a white dwarf
Dimitri Veras, Nikolaos Georgakarakos, Alexander J. Mustill +3
Our knowledge of white dwarf planetary systems predominately arises from the region within a few Solar radii of the white dwarfs, where minor planets break up, form rings and discs…
From Hydrogen to Helium: The Spectral Evolution of White Dwarfs as Evidence for Convective Mixing
Tim Cunningham, Pier-Emmanuel Tremblay, Nicola Pietro Gentile Fusillo +2
We present a study of the hypothesis that white dwarfs undergo a spectral change from hydrogen- to helium-dominated atmospheres using a volume-limited photometric sample drawn from…
Horizontal spreading of planetary debris accreted by white dwarfs
Tim Cunningham, Pier-Emmanuel Tremblay, Evan B. Bauer +8
White dwarfs with metal-polluted atmospheres have been studied widely in the context of the accretion of rocky debris from evolved planetary systems. One open question is the geome…
Comparison of methods used to derive the Galactic star formation history from white dwarf samples
Emily K. Roberts, Pier-Emmanuel Tremblay, Mairi W. O'Brien +4
We compare three methods of deriving the local Galactic star formation history, using as a benchmark the Gaia-defined 40 pc white dwarf sample, currently the largest volume complet…
White dwarfs within 13 pc: Insights from ultraviolet spectroscopy
Mairi W. O'Brien, Pier-Emmanuel Tremblay, Boris T. Gaensicke +9
We present a comprehensive multi-wavelength spectroscopic and photometric analysis of the 44 confirmed white dwarfs within 13 pc of the Sun. Combining flux-calibrated ultraviolet (…
Double White Dwarf Binaries in SDSS-V DR19 : A catalog of DA white dwarf binaries and constraints on the binary population
Gautham Adamane Pallathadka, Vedant Chandra, Nadia L. Zakamska +17
The fifth-generation Sloan Digital Sky Survey (SDSS-V) includes the first large-scale spectroscopic survey of white dwarfs (WDs) in the era of Gaia parallaxes. SDSS-V collects mult…
Double White Dwarf Binaries in SDSS-V DR19 : The discovery of a rare DA+DQ white dwarf binary with 31 hour orbital period
Gautham Adamane Pallathadka, Vedant Chandra, Boris T. Gansicke +13
Binaries of two white dwarfs (WDs) are an important class of astrophysical objects that are theorized to lead to Type Ia supernovae and are also used to gain insight into complex p…
Spectral analysis of ultra-cool white dwarfs polluted by planetary debris
Abbigail K. Elms, Pier-Emmanuel Tremblay, Boris T. Gänsicke +5
We identify two ultra-cool ( K) metal-polluted (DZ) white dwarfs WDJ21474035 and WDJ19220233 as the coolest and second coolest DZ stars known to date w…
Spectroscopic and Photometric Periods of Six Ultracompact Accreting Binaries
Matthew J. Green, Thomas R. Marsh, Philip J. Carter +19
Ultracompact accreting binary systems each consist of a stellar remnant accreting helium-enriched material from a compact donor star. Such binaries include two related sub-classes,…
The life cycle of stars and their planets from the high energy perspective
Lia Corrales, Keivan G. Stassun, Tim Cunningham +19
One of the key research themes identified by the Astro2020 decadal survey is Worlds and Suns in Context. The Advanced X-ray Imaging Satellite (AXIS) is a proposed NASA APEX mission…
The DBL Survey I: discovery of 34 double-lined double white dwarf binaries
James Munday, Ingrid Pelisoli, P. E. Tremblay +8
We present the first discoveries of the double-lined double white dwarf (DBL) survey that targets over-luminous sources with respect to the canonical white dwarf cooling sequence a…
Circumstellar interaction in the extreme white dwarf merger remnant ZTF\,J1901+1458: A new class of white dwarf merger remnants with X-ray emission
Aayush Desai, Ilaria Caiazzo, Stephane Vennes +31
Double degenerate white dwarf (WD) mergers can exhibit extreme magnetic fields exceeding G and rapid rotation, but their spectral-energy distributions and high-energy emis…
MESA Isochrones and Stellar Tracks (MIST) III. The White Dwarf Cooling Sequence
Evan B. Bauer, Aaron Dotter, Charlie Conroy +3
We present a substantial update to the MESA Isochrones and Stellar Tracks (MIST) library, extending the MIST model grids and isochrones down the white dwarf (WD) cooling sequence w…
Expansion properties of the young supernova type Iax remnant Pa 30 revealed
Tim Cunningham, Ilaria Caiazzo, Nikolaus Z. Prusinski +14
The recently discovered Pa 30 nebula, the putative type Iax supernova remnant associated with the historical supernova of 1181 AD, shows puzzling characteristics that make it uniqu…
PEWDD: A database of white dwarfs enriched by exo-planetary material
Jamie Williams, Boris Gaensicke, Andrew Swan +4
We present the Planetary Enriched White Dwarf Database (PEWDD), a collection of published photospheric abundances of white dwarfs accreting planetary debris alongside additional in…
A Data Release 2 catalogue of white dwarfs and a comparison with SDSS
Nicola Pietro Gentile Fusillo, Pier-Emmanuel Tremblay, Boris T. Gänsicke +11
We present a catalogue of white dwarf candidates selected from the second data release of (DR2). We used a sample of spectroscopically confirmed white dwarfs from the Sloan…
Sloan Digital Sky Survey-V: Pioneering Panoptic Spectroscopy
Juna A. Kollmeier, Hans-Walter Rix, Conny Aerts +217
The Sloan Digital Sky Survey-V (SDSS-V) is pioneering panoptic spectroscopy: it is the first all-sky, multi-epoch, optical-to-infrared spectroscopic survey. SDSS-V is mapping the s…
white dwarfs within 40 pc II: the volume-limited northern hemisphere sample
Jack McCleery, Pier-Emmanuel Tremblay, Nicola Pietro Gentile Fusillo +6
We present an overview of the sample of northern hemisphere white dwarfs within 40 pc of the Sun detected from Data Release 2 (DR2). We find that 521 sources are spectroscop…
Convective Overshoot and Macroscopic Diffusion in Pure-Hydrogen Atmosphere White Dwarfs
Tim Cunningham, Pier-Emmanuel Tremblay, Bernd Freytag +2
We present a theoretical description of macroscopic diffusion caused by convective overshoot in pure-hydrogen DA white dwarfs using three-dimensional (3D), closed-bottom, radiation…
A super-Chandrasekhar mass type Ia supernova progenitor at 49 pc set to detonate in 23 Gyr
James Munday, Ruediger Pakmor, Ingrid Pelisoli +9
Double white dwarf binaries are a leading explanation to the origin of type Ia supernovae, but no system exceeding the Chandrasekhar mass limit (1.4 M) has been found that…
Helium escaping from the atmosphere of a nearby rocky exoplanet orbiting in a habitable zone
Collin Cherubim, Shreyas Vissapragada, Tim Cunningham +13
The study reports the detection of helium escaping from the atmosphere of the rocky exoplanet LHS 1140b using near‑infrared transit spectroscopy, showing time‑variable escape and s…
Spectroscopic Monitoring of Metal Lines in Polluted White Dwarfs
Laura K. Rogers, Michael M. Shara, Amy Bonsor +12
The disruption and accretion of planetary material onto white dwarfs is expected to be inherently dynamic and stochastic, potentially driving variability in the accretion rate and…
Astro 2020 Science White Paper: Evolved Planetary Systems around White Dwarfs
Boris Gaensicke, Martin Barstow, Amy Bonsor +25
Practically all known planet hosts will evolve into white dwarfs, and large parts of their planetary systems will survive this transition - the same is true for the solar system be…
The dearth of high-mass hydrogen-atmosphere metal-polluted white dwarfs within 40 pc
Tim Cunningham, Pier-Emmanuel Tremblay, Mairi O'Brien +7
We present a population synthesis model which addresses the different mass distributions of the metal-polluted and non-metal-polluted hydrogen-atmosphere white dwarfs identified in…
From Hubble to HWO: Bridging the Frontier of White Dwarf Exoplanet Science
Laura K. Rogers, Siyi Xu, Martin Barstow +20
White dwarf stars, the endpoint of stellar evolution for 97% of stars in our Milky Way, offer a unique and powerful window into the bulk elemental composition of rocky exoplanetary…
White Dwarfs in Wide Binary Systems as Reliable Age Calibrators
Alberto Rebassa-Mansergas, Roberto Raddi, Anna F. Pala +13
Deriving precise stellar ages is a challenging task. Consequently, age-dependent relations - such as the age-metallicity and age-velocity dispersion relations of the Milky Way, or…
A Minute-Cadence Deep Bulge Survey: First Data Release of DREAMS
Hongjing Yang, Weicheng Zang, Francisco Valdes +31
The DECam Rogue Earths and Mars Survey (DREAMS), a NOIRLab survey program, has been conducting a three-year survey covering a 5 deg area in the Galactic bulge (roughly spanning…
The Effects of Magnetic Accretion on the Spatial Extent of White Dwarf Pollution
Dang Pham, Aster G. Taylor, Tim Cunningham
Many white dwarfs are polluted by metals, which are generally understood to be the accreted remnants of a planetary system. Modeling these systems typically assumes that the metal…
A half-ring of ionized circumstellar material trapped in the magnetosphere of a white dwarf merger remnant
Andrei A. Cristea, Ilaria Caiazzo, Tim Cunningham +31
Many white dwarfs are observed in compact double white dwarf binaries and, through the emission of gravitational waves, a large fraction are destined to merge. The merger remnants…
The Future of Evolved Planetary Systems
Roberto Raddi, Anna F. Pala, Alberto Rebassa-Mansergas +19
Understanding the formation, evolution, and chemical diversity of exoplanets are now central areas of astrophysics research. White dwarfs provide a uniquely sensitive laboratory fo…
A network of cooler white dwarfs as infrared standards for flux calibration
Abbigail K. Elms, Nicola Pietro Gentile Fusillo, Pier-Emmanuel Tremblay +6
The accurate flux calibration of observational data is vital for astrophysics and cosmology because absolute flux uncertainties of stellar standards propagate into scientific resul…
White Dwarf Binaries: Probes of Future Astrophysics
Anna F. Pala, Roberto Raddi, Alberto Rebassa-Mansergas +25
White dwarf binaries are fundamental astrophysical probes. They represent ideal laboratories to test the models of binary evolution, which also apply to the sources of gravitationa…
The DBL Survey II: towards a mass-period distribution of double white dwarf binaries
James Munday, Ingrid Pelisoli, Pier-Emmanuel Tremblay +14
Double white dwarf binaries are an important remnant of binary evolution as they are possible type Ia supernova progenitors and strong sources of gravitational waves in the low-fre…
Discovery of two new polars evolved past the period bounce
Tim Cunningham, Ilaria Caiazzo, Gracjan Sienkiewicz +13
We report the discovery of two new magnetic cataclysmic variables with brown dwarf companions and long orbital periods ( and min). This discovery incr…
A hot white dwarf merger remnant revealed by an ultraviolet detection of carbon
Snehalata Sahu, Antoine Bédard, Boris T. Gänsicke +7
Atmospheric carbon has been detected in the optical spectra of six hydrogen-rich ultra-massive white dwarfs, revealing large carbon abundances (log C/H > 0.5) attributable to th…