Discovery of a Quasi-Periodic Oscillation in the Ultraluminous X-ray Source IC 342 X-1: XMM-Newton Results

We report the discovery of a quasi-periodic oscillation (QPO) at 642 mHz in an {\it XMM-Newton} observation of the ultraluminous X-ray source (ULX) IC 342 X-1. The QPO has a centroid at $\nu_{QPO} = 642 \pm 20$ mHz, a coherence factor of $Q = 11.6$, and an amplitude (rms) of 4.1\% with significance of $3.6\sigma$. The energy dependence study shows that the QPO is stronger in the energy range 0.3 - 5.0 keV. A subsequent observation (6 days later) does not show any signature of the QPO in the power density spectrum. The broadband energy spectra (0.3 - 40.0 keV) obtained by quasi-simultaneous observations of {\it XMM-Newton} and {\it NuSTAR} can be well described by an absorbed {\it diskbb} plus {\it cutoffpl} model. The best fitted spectral parameters are power-law index ($\Gamma$) $\sim$ 1.1, cutoff energy ($E_c$) $\sim$ 7.9 keV and disc temperature ($kT_{in}$) $\sim$ 0.33 keV, where the QPO is detected. The unabsorbed bolometric luminosity is $\sim$ 5.34$\times$ 10$^{39}$ erg~s$^{-1}$. Comparing with the well known X-ray binary GRS 1915+105, our results are consistent with the mass of the compact object in IC 342 X-1 being in the range $\sim 20 - 65 ~ M_\odot$. We discuss the possible implications of our results.Comment: 7 pages, 3 figures (2 colour), in press (MNRAS

Kashmir: Lest We Forget

From a time when Kashmir was regarded as the epitome of communal amity and the unequivocal support that the people of the state gave to the idea of India, to the past three decades of relative inversion of opinions, even if of a segment of the community, the state has travelled a long distance in a small span of its timeless history. All relevant parties to the Kashmir questions have had a role to play in this quagmire of intrigue and deceit. Any resolution is only conceivable if there is acceptance of the role that each has played in bringing the situation to the current pass and taking magnanimous steps in undoing the errors that have given rise to ill- perceptions on all sides. This paper seeks to highlight some of the most glaring issues that have bred distrust and suggest a way forward