A COMPREHENSIVE STUDY OF CLOSE DOUBLE WHITE DWARFS AS GRAVITATIONAL WAVE SOURCES: EVOLUTIONARY CHANNELS, BIRTH RATES, AND PHYSICAL PROPERTIES

Journal Article · Fri Aug 20 04:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/719/2/1546· OSTI ID:21457078

Jinzhong, Liu; Zhanwen, Han; Fenghui, Zhang

Close double white dwarfs (CDWDs) are believed to dominate the Galactic gravitational wave (GW) radiation in the frequency range 10{sup -4} to 0.1 Hz, which will be detected by the Laser Interferometer Space Antenna (LISA) detector. The aim of this detector is to detect GW radiation from astrophysical sources in the universe and to help improve our understanding of the origin of the sources and their physical properties (masses and orbital periods). In this paper, we study the probable candidate sources in the Galaxy for the LISA detector: CDWDs. We use the binary population synthesis approach of CDWDs together with the latest findings of the synthesis models from Han, who proposed three evolutionary channels: (1) stable Roche lobe overflow plus common envelope (RLOF+CE), (2) CE+CE, and (3) exposed core plus CE. As a result, we systematically investigate the detailed physical properties (the distributions of masses, orbital periods, and chirp masses) of the CDWD sources for the LISA detector, examine the importance of the three evolutionary channels for the formation of CDWDs, and carry out Monte Carlo simulations. Our results show that RLOF+CE and CE+CE are the main evolutionary scenarios leading to the formation of CDWDs. For the LISA detectable sources, we also explore and discuss the importance of these three evolutionary channels. Using the calculated birth rate, we compare our results to the LISA sensitivity curve and the foreground noise floor of CDWDs. We find that our estimate for the number of CDWD sources that can be detected by the LISA detector is greater than 10,000. We also find that the detectable CDWDs are produced via the CE+CE channel and we analyze the fraction of the detectable CDWDs that are double helium (He+He), or carbon-oxygen plus helium (CO+He) WD binary systems.

• OSTI ID: 21457078
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 719; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTROPHYSICS
CALCULATION METHODS
COMPUTERIZED SIMULATION
DWARF STARS
ELEMENTS
FLUIDS
GALAXIES
GASES
GRAVITATIONAL WAVES
HELIUM
INTERFEROMETERS
MEASURING INSTRUMENTS
MONTE CARLO METHOD
NONMETALS
PHYSICS
POTENTIALS
RARE GASES
ROCHE EQUIPOTENTIALS
SIMULATION
STARS
UNIVERSE
WHITE DWARF STARS