Low-Luminosity Companions to White Dwarfs

By J. Farihi, E. Becklin, B. Zuckerman. 2005

164 citations recorded by the source corpus.

This paper presents results of a near-infrared imaging survey for low-mass stellar and substellar companions to white dwarfs. A wide-field proper-motion survey of 261 white dwarfs was capable of directly detecting companions at orbital separations between ~100 and 5000 AU with masses as low as 0.05 M☉, while a deep near-field search of 86 white dwarfs was capable of directly detecting companions at separations between ~50 and 1100 AU with masses as low as 0.02 M☉. Additionally, all white dwarf targets were examined for near-infrared excess emission, a technique capable of detecting companions at arbitrarily close separations down to masses of 0.05 M☉. No brown dwarf candidates were detected, which implies a brown dwarf companion fraction of <0.5% for white dwarfs. In contrast, the stellar companion fraction of white dwarfs as measured by this survey is 22%, uncorrected for bias. Moreover, most of the known and suspected stellar companions to white dwarfs are low-mass stars whose masses are only slightly greater than the masses of brown dwarfs. Twenty previously unknown stellar companions were detected, five of which are confirmed or likely white dwarfs themselves, while 15 are confirmed or likely low-mass stars. Similar to the distribution of cool field dwarfs as a function of spectral type, the number of cool unevolved dwarf companions peaks at mid-M type. Based on the present work, relative to this peak, field L dwarfs appear to be roughly 2-3 times more abundant than companion L dwarfs. Additionally, there is no evidence that the initial companion masses have been altered by post-main-sequence binary interactions.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/c9b80b90f6ad326eddbe46e8c60fe89a1e64d7ad

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

Citations in the corpus

Can Planets Survive Stellar Evolution? (2007, background): “The wide-field proper-motion survey around 261 white dwarfs by Farihi et al. (2005) was sensitive to 100Y5000 AU with masses down to 52MJ, and their deeper near-field search of 86 white dwarfs could detect 10 MJ at separations between 50 and 1100 AU.”
Debris Disks around White Dwarfs: The DAZ Connection (2006, background): “GD 56 was included in the search by Farihi et al. (2005) for substellar companions around white dwarfs.”
Binary planetary nebulae nuclei towards the Galactic bulge - I. Sample discovery, period distribution, and binary fraction (2009, background): “Some secondaries are expected to have spectral types later than M (de Kool & Ritter 1993; Politano & Weiler 2006), but these are likely to be rare (Farihi et al. 2005).”
AGaiaData Release 2 catalogue of white dwarfs and a comparison with SDSS (2018, background): “…extremes of the mass distribution (Vennes & Kawka 2008; Brown et al. 2010; Hermes et al. 2014), stellar remnants with unresolved low mass companions (Farihi et al. 2005; Girven et al. 2011; Steele et al. 2013), exotic atmospheric compositions (Schmidt et al. 1999; Dufour et al. 2010; Gänsicke et…”
KNOW YOUR NEIGHBORHOOD: A DETAILED MODEL ATMOSPHERE ANALYSIS OF NEARBY WHITE DWARFS (2012, background): “Other contributions from Farihi et al. (2005), Subasavage et al. (2007), and Subasavage et al. (2008) are also worth mentioning in this effort.”
A SPECTROSCOPIC SURVEY AND ANALYSIS OF BRIGHT, HYDROGEN-RICH WHITE DWARFS (2011, background): “It seems that 1015+076 is a DA white dwarf whose spectrum is completely dominated by an unresolved, background G dwarf (Farihi et al. 2005).”
INFRARED SIGNATURES OF DISRUPTED MINOR PLANETS AT WHITE DWARFS (2009, background): “It is worth noting that the white dwarf GD 1400 has an unresolved L7 brown dwarf companion, and the ratio of the 3.6 to 2.2 µm excess there is 1.3 (Farihi et al. 2005b), whereas for PG 1457−086 this value is 0.7, although these ratios are consistent within the uncertainties.”