FAR-ULTRAVIOLET SPECTROSCOPY OF THE NOVA-LIKE VARIABLE KQ MONOCEROTIS: A NEW SW SEXTANTIS STAR?

Journal Article · Sat Jun 01 04:00:00 EDT 2013 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/145/6/168· OSTI ID:22118806

Wolfe, Aaron; Sion, Edward M. ^[1]

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1. Astronomy and Astrophysics, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085 (United States)

New optical spectra obtained with the SMARTS 1.5 m telescope and archival International Ultraviolet Explorer (IUE) far-ultraviolet (FUV) spectra of the nova-like variable KQ Mon are discussed. The optical spectra reveal Balmer lines in absorption as well as He I absorption superposed on a blue continuum. The 2011 optical spectrum is similar to the KPNO 2.1 m IIDS spectrum we obtained 33 years earlier except that the Balmer and He I absorption is stronger in 2011. Far-ultraviolet IUE spectra reveal deep absorption lines due to C II, Si III, Si IV, C IV, and He II, but no P Cygni profiles indicative of wind outflow. We present the results of the first synthetic spectral analysis of the IUE archival spectra of KQ Mon with realistic optically thick, steady-state, viscous accretion-disk models with vertical structure and high-gravity photosphere models. We find that the photosphere of the white dwarf (WD) contributes very little FUV flux to the spectrum and is overwhelmed by the accretion light of a steady disk. Disk models corresponding to a WD mass of {approx}0.6 M {sub Sun }, with an accretion rate of order 10{sup -9} M {sub Sun} yr{sup -1} and disk inclinations between 60 Degree-Sign and 75 Degree-Sign , yield distances from the normalization in the range of 144-165 pc. KQ Mon is discussed with respect to other nova-like variables. Its spectroscopic similarity to the FUV spectra of three definite SW Sex stars suggests that it is likely a member of the SW Sex class and lends support to the possibility that the WD is magnetic.

• OSTI ID: 22118806
• Journal Information: Astronomical Journal (New York, N.Y. Online), Journal Name: Astronomical Journal (New York, N.Y. Online) Journal Issue: 6 Vol. 145; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION SPECTRA
ABSORPTION SPECTROSCOPY
ACCRETION DISKS
ASTRONOMY
ASTROPHYSICS
BALMER LINES
CARBON IONS
EMISSION SPECTROSCOPY
FAR ULTRAVIOLET RADIATION
GRAVITATION
HELIUM IONS
NOVAE
PHOTOSPHERE
SILICON IONS
VISIBLE RADIATION
WHITE DWARF STARS