Academic Journal
AND
| العنوان: | AND |
|---|---|
| المؤلفون: | Peter G. Jonker, Deepto Chakrabarty, Adrienne M. Juett |
| المساهمون: | The Pennsylvania State University CiteSeerX Archives |
| المصدر: | http://arxiv.org/pdf/0706.3421v1.pdf. |
| سنة النشر: | 2008 |
| المجموعة: | CiteSeerX |
| الوصف: | We report on our analysis of 300 ks of Chandra observations of the neutron star soft X–ray transient 1H 1905+000 in quiescence. We do not detect the source down to a 95 % confidence unabsorbed flux upper limit of 2 × 10 −16 erg cm −2 s −1 in the 0.5–10 keV energy range for an assumed Γ = 2 power law spectral model. A limit of 1.4 × 10 −16 erg cm −2 s −1 is derived if we assume that the spectrum of 1H 1905+000 in quiescence is described well with a black body of temperature of 0.2 keV. For the upper limit to the source distance of 10 kpc this yields a 0.5–10 keV luminosity limit of 2.4×10 30 erg s −1 / 1.7×10 30 erg s −1 for the abovementioned power law or black body spectrum, respectively. This luminosity limit is lower than the luminosity of A 0620–00, the weakest black hole soft X–ray transient in quiescence reported so far. Together with the uncertainties in relating the mass transfer and mass accretion rates we come to the conclusion that the claim that there is evidence for the presence of a black hole event horizon on the basis of a lower quiescent luminosity for black holes than for neutron stars is unproven. We also briefly discuss the implications of the low quiescent luminosity of 1H 1905+000 for the neutron star equation of state. Using deep Magellan images of the field of 1H 1905+000 obtained at excellent observing conditions we do not detect the quiescent counterpart of 1H 1905+000 at the position of the outburst optical counterpart down to a magnitude limit of i ′> 25.3. This can be converted to a |
| نوع الوثيقة: | text |
| وصف الملف: | application/pdf |
| اللغة: | English |
| Relation: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.250.3245; http://arxiv.org/pdf/0706.3421v1.pdf |
| الاتاحة: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.250.3245 http://arxiv.org/pdf/0706.3421v1.pdf |
| Rights: | Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
| رقم الانضمام: | edsbas.BA6E8A37 |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |