NEAR-INFRARED OBSERVATIONS OF GQ LUP b USING THE GEMINI INTEGRAL FIELD SPECTROGRAPH NIFS

Journal Article · Tue Oct 20 04:00:00 EDT 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/704/2/1098· OSTI ID:21367364

Lavigne, Jean-Francois; Doyon, Rene ^[1]; Lafreniere, David ^[2]; Marois, Christian ^[3]; Barman, Travis ^[4]

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1. Departement de physique and Observatoire du Mont Megantic, Universite de Montreal, C.P. 6128, Succ. Centre-Ville, Montreal, QC, H3C 3J7 (Canada)
2. Department of Astronomy and Astrophysics, University of Toronto, 50 Street George Street, Toronto, ON, M5S 3H4 (Canada)
3. NRC Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC, V9E 2E7 (Canada)
4. Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States)

We present new JHK spectroscopy (R approx 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 T {sub eff} = 2400 +- 100 K, its gravity to log g = 4.0 +- 0.5, and its luminosity to log(L/L {sub sun}) = -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 M {sub Jup}, 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 Pabeta emission. Our spectra are in excellent agreement with the lower S/N spectra previously published by McElwain and collaborators.

• OSTI ID: 21367364
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 704; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTROPHYSICS
DIMENSIONLESS NUMBERS
DWARF STARS
EMISSION
GRAVITATION
LUMINOSITY
MASS
NOISE
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PHYSICS
SIGNAL-TO-NOISE RATIO
SPECTRA
SPECTROSCOPY
STARS
TELESCOPES