Related papers: The atoll source 4U 1608-52 is not a Z source

The low-mass X-ray binary pulsar 4U 1626-67 shows 0.048 Hz quasi-periodic oscillations (QPOs) and red noise variability as well as coherent pulsations at the 0.130 Hz neutron star spin frequency. Power density spectra of observations made…

We selected a sample of 437 BL Lac objects, taken from the RomaBZCat catalogue, for which spectroscopic information and SDSS photometry is available. We propose a new classification of BL Lacs in which the sources' type is not defined only…

Two flares with a duration of several hours are reported for the low-mass X-ray binary 4U 1636-53. The characteristics of these flares (i.e., decay time scales, spectral softening, fluences) are very similar to the very long type-I X-ray…

In many pattern forming systems that exhibit traveling waves, sources and sinks occur which separate patches of oppositely traveling waves. We show that simple qualitative features of their dynamics can be compared to predictions from…

We present a systematic spectral analysis with Suzaku of six AGNs detected in the Swift/BAT hard X-ray (15--200 keV) survey, Swift J0138.6-4001, J0255.2-0011, J0350.1-5019, J0505.7-2348, J0601.9-8636, and J1628.1-5145. This is considered to…

The different timing results of the magnetar Swift J1822.3-1606 is analyzed and understood theoretically. It is pointed that different timing solutions are caused not only by timing noise, but also that the period derivative is decreasing…

We have conducted a 3-month program of simultaneous optical, soft and hard X-ray monitoring of the LMXB 4U1636-536/V801 Ara using the SMARTS 1.3m telescope and archival RXTE/ASM and Swift/XRT data. 4U1636-536 has been exhibiting a large…

Aims. The blazars Mrk 421 and Mrk 501 have shown multiwavelength variability on all observed timescales, and have been well studied at high energies on short timescales. We aim to characterise the long-term temporal behaviour of these…

We present the results of a detailed timing and spectral analysis of the quasi-regular modulation (QRM) phenomenon in the black hole X-ray binary 4U 1630--47 during its 1998 outburst observed by Rossi X-ray Timing Explore (RXTE). We find…

We report the first X-ray and radio polarimetric results of the neutron star (NS) low-mass X-ray binary (LMXB) atoll-source 4U 1728-34 using the Imaging X-ray Polarimetry Explorer (IXPE) and Australia Telescope Compact Array (ATCA). We…

We present results from 16 snapshots of Aql X-1 with RXTE during the rising phase of its recent outburst. The observations were carried out at a typical rate of once or twice per day. The source shows interesting spectral evolution during…

The source CGRaBS~J0211$+$1051 (MG1 J021114+1051, z=0.20) flared up on 2011 January 23 in high-energy $\gamma$-rays as reported by {\it Fermi}/LAT. This event was followed by the increased activity at the UV, optical and radio frequencies…

We report results of X-ray timing analyses for the low-field magnetar CXOU~J164710.2$-$455216 which exhibited multiple outbursts. We use data taken with NICER, NuSTAR, Chandra, and Neil-Gehrels-Swift telescopes between 2017 and 2018 when…

We have investigated the dipping activity observed in the high-mass X-ray binary 4U 1907+09 and shown that the source continues to pulsate in the "off" state, noting that the transition between the "on" and "off" states may be either…

We report results from a long-term monitoring data set obtained with the Rossi X-ray Timing Explorer (RXTE) from the bright globular cluster binary source 4U 1820-30. During this monitoring, the source intensity varied from a flux of 2.9E-9…

We investigate the behavior of the high frequency quasi-periodic oscillations (QPOs) in 4U 0614+091, combining timing and spectral analysis of RXTE observations. The energy spectra of the source can be described by a power law (alpha ~ 2.8)…

Here we present a new bowshock blue-shifted source in the close vicinity of Sgr A* that we name X8. We use data-sets that are based on SINFONI observations with the Very Large Telescope. We can trace the source between 2006 and 2016 in the…

We report on results from a 2003 February INTEGRAL observation of the black hole candidate (BHC) 4U 1630-47 and the high energy sources in the Norma Region of the Galaxy and on RXTE and radio observations of 4U 1630-47. To date, there have…

Recent results from IceCube regarding TXS 0506+056 suggest that it may be useful to test the hypothesis of multiple neutrino flares, where each flare is not necessarily accompanied by a corresponding gamma-ray flare. An untriggered,…

Since November 2004, the Burst Alert Telescope on board Swift is producing a monitoring of the entire sky in the 15-150 keV band, recording the timing and spectral behavior of the detected sources. Here we study the properties of the HMXB…