Low frequency QPOs and possible change in the accretion geometry during the outbursts of Aquila X−-1

We have studied the evolution of the Low Frequency Quasi-Periodic Oscillations (LFQPOs) during the rising phase of seven outbursts of the neutron star Soft X-ray Transient (SXT) Aql X$-$1 observed with the \textit{Rossi X-ray Timing Explorer (RXTE)}. The frequency correlation between the low frequency break and the LFQPO sampled on the time scale of $\sim$2 days was seen. Except for the peculiar 2001 outburst, the frequency of the LFQPOs increased with time before the hard-to-soft state transition up to a maximum $\nu_{max}$ at $\sim$31 Hz, a factor of $\sim$5 higher than those seen in black hole transients such as GX 339$-$4, making the maximum QPO frequency a likely indicator of the mass of the central compact object. The characteristic frequencies increased by around ten percent per day in the early rising phase and accelerated to nearly one hundred percent per day since $\sim$2 days before the hard-to-soft state transition. We examined the dependence of the frequency $\nu_{LF}$ on the source flux $f$ and found an anti-correlation between the maximum frequency of the LFQPOs and the corresponding X-ray luminosity of the hard-to-soft transition (or outburst peak luminosity) among the outbursts. We suggest that X-ray evaporation process can not be the only mechanism that drives the variation of the inner disk radius if either of the twin kHz QPO corresponds to the Keplerian frequency at the truncation radius.Comment: 8 pages, 8 figures, 1 table; accepted for publication in Ap

Energy dependent power spectral states and origin of aperiodic variability in black hole binaries

We found the black hole candidate MAXI J1659-152 showed distinct power spectra, i.e., a power-law noise (PLN) vs. band-limited noise (BLN) plus quasi-periodic oscillations (QPOs), below and above about 2 keV respectively, in the observations with the Swift and the RXTE during the 2010 outburst, indicating a high energy cut-off of the PLN and a low energy cut-off of the BLN and the QPOs around 2 keV. The emergence of the PLN and the fading of the BLN and the QPOs initially took place from below 2 keV when the source entered the hard intermediate state and finally settled in the soft state three weeks later. The evolution was accompanied by the emergence of the disk spectral component and decreases in the amplitudes of variability in the soft X-ray and the hard X-ray bands. Our results indicate that the PLN is associated with the optically thick disk in both hard and intermediate states, and power spectral state is independent of the X-ray energy spectral state in a broadband view. We suggest that in the hard and the intermediate state, the BLN and the QPOs emerge from the innermost hot flow subjected to Comptonization, while the PLN originates from the optically thick disk further out. The energy cut-offs of the PLN and the BLN or QPOs then follow the temperature of the seed photons from the inner edge of the optically thick disk, while the high frequency cut-off of the PLN follows the orbital frequency at the inner edge of the optically thick disk as well.Comment: 5 pages, 6 figures, accepted for publication in Ap

PARTISIPASI POLITIK MASYARAKAT DALAM PEMBANGUNAN INFRASTRUKTUR DISTRIK KANGGIME KABUPATEN TOLIKARA PROVINSI PAPUA

ABSTRAK Pembangunan infrastruktur merupakan salah satu kewajiban dari pemerintah. Karena pembangunan infrastruktur memiliki multiplier effect yang sangat besar terutama bagi peningkatan kesejahteraan masyarakat. Namun pembangunan infrastruktur sebenarnya tidak semata tanggung jawab pemerintah, namun juga memerlukan keterlibatan masyarakat secara langsung. Keterlibatan masyarakat itu diharapkan akan menumbuhkan rasa memiliki terhadap infrastruktur yang dibangun dan tentunya harapan selanjutnya mereka akan memelihara dan menjaganya. Namun masih banyak dalam pembangunan infrastruktur keterlibatan masyarakat masih minim. Hal itu disebabkan karena pemerintah kurang melibatkan masyarakat atau masyarakatnya yang tidak mau terlibat. Untuk itu penelitian ini mengidentifikasi permasalahan terkait keterlibatan masyarakar hasil di distrik Kanggime kabuaten Tolikara dalam pembangunan infrastruktur di wilayah tersebut. Dari hasil penelitian di identifikasi bahwa minimnya partisipasi masyarakat dalam pembangunan infrastruktur banyak disebabkan ketidakpercayaan mereka terhadap pemimpin mereka dan juga terhadap wakil mereka yang duduk di kursi legislative karena merasa sering dibohongi. Selain itu juga disebabkan karena seringkali program pembangunan yang ditetapkan tidak sesuai dengan apa yang mereka inginkan.  Kata Kunci : Partisipasi Masyarakat; Pembangunan Infrakstruktur COMMUNITY POLITICAL PARTICIPATION IN DEVELOPING KANGGIME DISTRICT INFRASTRUCTURE, TOLIKARA DISTRICT, PAPUA PROVINCE  ByNuwen Wenda ABSTRACT Infrastructure development is one of the obligations of the government. Because infrastructure development has a very large multiplier effect, especially for improving the welfare of the community. However, infrastructure development is not only the responsibility of the government, but also requires direct community involvement. It is hoped that community involvement will foster a sense of belonging to the infrastructure being built and of course hope that in the future they will maintain and maintain it. However, there is still a lot of community involvement in infrastructure development. This is because the government does not involve the community or society who do not want to be involved. For this reason, this study identifies problems related to the involvement of the results community in Kanggime district, Tolikara district in infrastructure development in the region. From the research results, it is identified that the lack of community participation in infrastructure development is largely due to their distrust of their leaders and also to their representatives who sit in the legislative seats because they feel they are often cheated. In addition, it is also caused by the fact that the development programs that are set do not match what they want. Keywords: Community Participation; Infrastructure Developmen