THE ROLE OF NEWLY BORN MAGNETARS IN GAMMA-RAY BURST X-RAY AFTERGLOW EMISSION: ENERGY INJECTION AND INTERNAL EMISSION

Journal Article · Thu May 20 00:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/715/1/477· OSTI ID:21448733

Yunwei, Yu; Cheng, K S ^[1]

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1. Department of Physics, University of Hong Kong, Pokfulam Road (Hong Kong)

Swift observations suggest that the central compact objects of some gamma-ray bursts (GRBs) could be newly born millisecond magnetars. Therefore, considering the spin evolution of the magnetars against r-mode instability, we investigate the role of magnetars in GRB X-ray afterglow emission. Besides modifying the conventional energy injection model, we pay particular attention to the internal X-ray afterglow emission, whose luminosity is assumed to track the magnetic dipole luminosity of the magnetars with a certain fraction. Following a comparison between the model and some selected observational samples, we suggest that some so-called canonical X-ray afterglows including the shallow decay, normal decay, and steeper-than-normal decay phases could be internally produced by the magnetars (possibly through some internal dissipations of the magnetar winds), while the (energized) external shocks are associated with another type of X-ray afterglows. If this is true, then from those internal X-ray afterglows we can further determine the magnetic field strengths and the initial spin periods of the corresponding magnetars.

• OSTI ID: 21448733
• Journal Information: Astrophysical Journal, Vol. 715, Issue 1; Other Information: DOI: 10.1088/0004-637X/715/1/477; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
AFTERGLOW
COSMIC GAMMA BURSTS
EMISSION
LUMINOSITY
MAGNETIC DIPOLES
MAGNETIC FIELDS
NEUTRONS
STAR EVOLUTION
STARS
X RADIATION
BARYONS
COSMIC RADIATION
DIPOLES
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
EVOLUTION
FERMIONS
HADRONS
IONIZING RADIATIONS
MULTIPOLES
NUCLEONS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PRIMARY COSMIC RADIATION
RADIATIONS