White Dwarf - M Dwarf Pairs in the Sloan Digital Sky Survey (SDSS)
Abstract
Using spectra and color cuts in the Sloan filter system, we have identified 83 White Dwarf - M dwarf pairs in the Sloan Digital Sky Survey (SDSS). The blue portion of the spectrum is fit with white dwarf models as a function of temperature. The best fit is then subtracted off to extract the M-dwarf spectrum. Many of these objects show strong Hα emission, an indicator of M-dwarf chromospheric activity. We have extracted a list of white dwarf temperatures, M-dwarf spectral types, and Hα equivalent widths, and we compare the activity level of these irradiated systems with the field M star population. If a portion of this activity is due to irradiation from the white dwarf companion, then we are studying binaries at a wide range in separations, from loosely bound systems to close binary pre-CVs. This hypothesis is being tested with a spectroscopic follow-up of SDSS objects by looking for (orbital) periodicity in the systems with the highest activity levels, using the ARC 3.5m telescope at Apache Point Observatory (APO).
- Publication:
-
The Future of Cool-Star Astrophysics: 12th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun
- Pub Date:
- October 2003
- Bibcode:
- 2003csss...12..992R
- Keywords:
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- White Dwarf/ M Dwarf pairs;
- Binaries