Autonomous Disentangling for Spectroscopic Surveys

Abstract

A suite of spectroscopic surveys is producing vast sets of stellar spectra with the goal of advancing stellar physics and Galactic evolution by determining their basic physical properties. A substantial fraction of these stars are in binary systems, but almost all large-survey modeling pipelines treat them as single stars. For sets of multi-epoch spectra, spectral disentangling is a powerful technique to recover or constrain the individual components' spectra of a multiple system. So far, this approach has focused on small samples or individual objects, usually with high resolution ($R\gtrsim 10.000$) spectra and many epochs ($\gtrsim 8$). Here, we present a disentangling implementation that accounts for several aspects of few-epoch spectra from large surveys: that vast sample sizes require automatic determination of starting guesses; that some of the most extensive spectroscopic surveys have a resolution of only $\approx 2,000$; that few epochs preclude unique orbit fitting; that one needs effective regularisation of the disentangled solution to ensure resulting spectra are smooth. We describe the implementation of this code and show with simulated spectra how well spectral recovery can work for hot and cool stars at $R\approx 2000$. Moreover, we verify the code on two established binary systems, the ``Unicorn'' and ``Giraffe''. This code can serve to explore new regimes in survey disentangling in search of massive stars with massive dark companions, e.g. the $\gtrsim 200,000$ hot stars of the SDSS-V survey.

Accepted to MNRAS

References in corpus (22)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• The Sloan Digital Sky Survey: Technical Summary
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• Binary interaction dominates the evolution of massive stars
• GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo During the Second Part of the Third Observing Run
• Mind your Ps and Qs: the Interrelation between Period (P) and Mass-ratio (Q) Distributions of Binary Stars
• The First Data Release (DR1) of the LAMOST general survey
• The 'hidden' companion in LB-1 unveiled by spectral disentangling
• A Unicorn in Monoceros: the $3M_{\odot }$ dark companion to the bright, nearby red giant V723 Mon is a non-interacting, mass-gap black hole candidate
• Is HR 6819 a triple system containing a black hole? -- An alternative explanation
• An X-ray quiet black hole born with a negligible kick in a massive binary within the Large Magellanic Cloud
• Identifying quiescent compact objects in massive Galactic single-lined spectroscopic binaries
• The Tarantula Massive Binary Monitoring VI: Characterisation of hidden companions in 51 single-lined O-type binaries, a flat mass-ratio distribution, and black-hole binary candidates
• Unicorns and Giraffes in the binary zoo: stripped giants with subgiant companions
• HR 6819 is a binary system with no black hole -- revisiting the source with infrared interferometry and optical integral field spectroscopy
• The "Giraffe": Discovery of a stripped red giant in an interacting binary with a $\sim 2M_{\odot }$ lower giant
• TIRAVEL - Template Independent RAdial VELocity measurement
• Spectral disentangling with Spectangular

Cited by in corpus (3)

• HIP 15429: A newborn Be star on an eccentric binary orbit
• Millions of Main-Sequence Binary Stars from Gaia BP/RP Spectra
• Looking for Signs of Unresolved Binarity in the Continuum of LAMOST Stellar Spectra