Work

Spectral Features in the Thermal Emission from Isolated Neutron Stars: Dependence on Magnetic Field Strengths

Year: 2004

Type: article

Abstract: We study several effects that influence the strength of the proton cyclotron and atomic features in the thermal spectra of magnetic neutron stars. We show that it is possible for vacuum polarization to strongly suppress the spectral lines when the magnetic field B ≳ 10 14 G. For weaker fields ( B ≲ 7 × 10 13 G), the surface spectrum is unaffected by vacuum polarization; thus, the proton cyclotron absorption line can have a large equivalent width. Using an approximate calculation of the synthetic spectra, we show that variation of magnetic fields over the neutron star surface leads to broadening of the line. The recently detected absorption features from the isolated neutron stars RX J1308.6+2127, RX J1605.3+3249, and RX J0720.4-3125 can plausibly be explained by the proton cyclotron resonance, with possible blending due to atomic transitions, in the atmosphere of the star.

Source: The Astrophysical Journal

DOI: 10.1086/383341

Authors: Wynn C. G. Ho, Dong Lai

Institutions: Cornell University, SLAC National Accelerator Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Stanford University

Language: English

Topic: Pulsars and Gravitational Waves Research

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: bronze

Funders: National Science Foundation, National Aeronautics and Space Administration

Awards: Magnetically Driven Warping, Precession and Resonances in Accretion Disks, Matter and Radiation in Superstrong Magnetic Fields of Neutron Stars, THERMAL RADIATION FROM STRONGLY MAGNETIZED NEUTRON STARS