IGR J17480-2446: a new class of accreting binaries?
Abstract
Context. The recent discovery of long-period, low magnetic field pulsars in low-mass X-ray binaries (LMXBs) represents a challenge for the standard evolutionary scenario. These pulsars have a magnetic field strength comparable to that of millisecond pulsars (~108-109 G), but their period is at least an order of magnitude longer.
Aims: We discuss the origin of this new class of pulsars within the standard picture of LMXBs formation and apply our results to the case of IGR J17480-2446.
Methods: The magnetothermal evolution of the binary system is studied numerically by taking into account the effect of different accretion rates during the Roche-lobe overflow in the framework of the minimal cooling scenario.
Results: We show that, in addition to standard millisecond pulsars, long-period low magnetic field pulsars should also be expected as a possible outcome of the binary evolution, depending on the strength of the accretion rate during the Roche-lobe overflow. In particular, we argue that IGR J17480-2446 belongs to this new class of objects.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- February 2015
- DOI:
- 10.1051/0004-6361/201424524
- arXiv:
- arXiv:1412.6425
- Bibcode:
- 2015A&A...574A..63B
- Keywords:
-
- stars: magnetic field;
- pulsars: individual: IGR J17480-2446;
- X-rays: binaries;
- accretion;
- accretion disks;
- stars: neutron;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 5 pages, 2 figures. Astronomy and Astrophysics, to appear