Models for Low-Mass X-Ray Binaries in the Elliptical Galaxies NGC3379 and NGC4278: Comparison with Observations

التفاصيل البيبلوغرافية
العنوان: Models for Low-Mass X-Ray Binaries in the Elliptical Galaxies NGC3379 and NGC4278: Comparison with Observations
المؤلفون: Fragos, T., Kalogera, V., Belczynski, K., Fabbiano, G., Kim, D. -W., Brassington, N. J., Angelini, L., Davies, R. L., Gallagher, J. S., King, A. R., Pellegrini, S., Trinchieri, G., Zepf, S. E., Zezas, A.
سنة النشر: 2008
المجموعة: Astrophysics
مصطلحات موضوعية: Astrophysics
الوصف: We present theoretical models for the formation and evolution of populations of low-mass X-ray binaries (LMXB) in the two elliptical galaxies NGC 3379 and NGC 4278. The models are calculated with the recently updated StarTrack code (Belczynski et al., 2006), assuming only a primordial galactic field LMXB population. StarTrack is an advanced population synthesis code that has been tested and calibrated using detailed binary star calculations and incorporates all the important physical processes of binary evolution. The simulations are targeted to modeling and understanding the origin of the X-ray luminosity functions (XLF) of point sources in these galaxies. For the first time we explore the population XLF down to luminosities of 3X10^36 erg/s, as probed by the most recent observational results (Kim et al., 2006). We consider models for the formation and evolution of LMXBs in galactic fields with different CE efficiencies, stellar wind prescriptions, magnetic braking laws and initial mass functions. We identify models that produce an XLF in excellent agreement with the observations both in shape and absolute normalization. We also find that the treatment of the outburst luminosity of transient systems remains a crucial factor for the determination of the XLF since the modeled populations are dominated by transient X-ray systems.
Comment: 54 pages, 22 figure, submitted to The Astrophysical Journal
نوع الوثيقة: Working Paper
DOI: 10.1086/588456
URL الوصول: http://arxiv.org/abs/0801.1122
رقم الأكسشن: edsarx.0801.1122
قاعدة البيانات: arXiv