Near-infrared observations of GQ lup B using the gemini integral field spectrograph nifs

Jean Francois Lavigne, Rene Doyon, David Lafrenière, Christian Marois, Travis Barman

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


We present new JHK spectroscopy (R ∼ 5000) of GQ Lup b, acquired with the Near-Infrared Integral Field Spectrograph and the adaptive optics system ALTAIR at the Gemini North telescope. Angular differential imaging was used in the J and H bands to suppress the speckle noise from GQ Lup A; we show that this approach can provide improvements in signal-to-noise ratio (S/N) by a factor of 2-6 for companions located at subarcsecond separations. Based on high-quality observations and Global Astrometric lnterferometer for Astrophysics synthetic spectra, we estimate the companion effective temperature to Teff = 2400 ± 100 K, its gravity to log g = 4.0 ± 0.5, and its luminosity to log(L/L) = -2.47 ± 0.28. Comparisons with the predictions of the DUSTY evolutionary tracks allow us to constrain the mass of GQ Lup b to 8-60 MJup, most likely in the brown dwarf regime. Compared with the spectra published by Seifahrt and collaborators, our spectra of GQ Lup b are significantly redder (by 15%-50%) and do not show important Paβ emission. Our spectra are in excellent agreement with the lower S/N spectra previously published by McElwain and collaborators.

Original languageEnglish (US)
Pages (from-to)1098-1106
Number of pages9
JournalAstrophysical Journal
Issue number2
StatePublished - Oct 20 2009


  • High angular resolution - techniques
  • Individual (GQ Lup) - stars
  • Low-mass, brown dwarfs - stars
  • Planetary systems - stars
  • Pre-main sequence - techniques
  • Spectroscopic

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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