Related papers: Anomalous Entropic Behavior Observed in Quasar 3C …
We report on our Chandra Cycle 9 program to observe half of the 60 (unobserved by Chandra) 3C radio sources at z<0.3 for 8 ksec each. Here we give the basic data: the X-ray intensity of the nuclei and any features associated with radio…
We present the results of a systematic search for quasars in the Catalina Real-time Transient Survey exhibiting both strong photometric and spectroscopic variability over a decadal baseline. We identify 73 sources with specific patterns of…
We report on quasar outflow properties revealed by analyzing more than 60 composite outflow spectra built from $\sim 60\,000$ CIV absorption troughs in the SDSS-III/BOSS DR12QBAL catalog. We assess the dependences of the equivalent widths…
Using an unprecedented cadence of 30 minutes provided by the Transiting Exoplanet Survey Satellite (TESS), we have examined the optical light curves (LCs) of the blazar S5 0716+714 obtained from its Sectors 40, 47, and 53 over a period of…
We report Cousins R-band monitoring of the high-redshift (z=4.40) radio quiet quasar Q 2203+292 from May 1999 to October 2007. The quasar shows maximum peak-to-peak light curve amplitude of ~0.3 mag during the time of our monitoring, and…
We present the analysis of serendipitous sources in a deep, 500 ksec, hard X-ray observation of the Coma cluster region with the IBIS instrument onboard INTEGRAL. In addition to the Coma cluster, the final 20-50 keV image contains 12…
Elliptic ($v_2$) and triangular ($v_3$) anisotropic flow coefficients for inclusive and identified charged hadrons (~$\pi^\pm$, $K^\pm$, $p$, $\bar{p}$~) at midrapidity in Au+Au collisions, measured by the STAR experiment in the Beam Energy…
We statistically study the physical properties of a sample of narrow absorption line (NAL) systems looking for empirical evidences to distinguish between intrinsic and intervening NALs without taking into account any a priori definition or…
We present an analysis of the effects of luminosity on the shape of the mid-infrared spectral energy distributions (SEDs) of 234 radio-quiet quasars originally presented by Richards et al. In quasars without evident dust extinction, the…
Microquasars have been expected to emit high energy gamma-rays due to their general similarities to the gamma-ray emitting blazars (evidences of relativistic jets, non-thermal radio to X-ray emission). In fact, the first source of this…
With close pairs of quasars at different redshifts, a background quasar sightline can be used to study a foreground quasar's environment in absorption. We used a sample of 17 Lyman limit systems with column density N_HI > 10^19 cm^-2…
Anomalous behaviour of the excess entropy ($S_e$) and the associated scaling relationship with diffusivity are compared in liquids with very different underlying interactions but similar water-like anomalies: water (SPC/E and TIP3P models),…
We investigate Extremely Red Quasars (ERQs), a remarkable population of heavily-reddened quasars at redshift z$\sim$2 - 3 that might be caught during a short-lived 'blow-out' phase of quasar/galaxy evolution. We perform a near-IR…
In the course of a large intervening MgII survey of 25 quasars, the CIV emission lines of six (three radio-loud and three radio-quiet) were observed serendipitously. In four of these six quasars, we detected associated narrow absorption…
X-ray spectra of many accreting pulsars exhibit significant variations as a function of flux and thus of mass accretion rate. In some of these pulsars, the centroid energy of the cyclotron line(s), which characterizes the magnetic field…
We report the detection of extended X-ray emission around several powerful 3CR quasars with redshifts out to 0.73. The ROSAT HRI images of the quasars have been corrected for spacecraft wobble and compared with an empirical point-spread…
We present images from five observations of the quasar 3C 273 with the Chandra X-ray Observatory. The jet has at least four distinct features which are not resolved in previous observations. The first knot in the jet (A1) is very bright in…
We present preliminary results of BeppoSAX AO1 observations of 3C 273 performed in January 1997. We also present a close comparison with data obtained during the satellite SVP, in July 1996. On average, the AO1 flux is about a factor 2…
An analysis of the high-energy emission from IGR J16393-4643 (=AX J1639.0-4642) is presented using data from INTEGRAL and XMM-Newton. The source is persistent in the 20-40 keV band at an average flux of 5.1x10^-11 ergs/cm2/s, with…
The interstellar scattering responsible for pulsar parabolic arcs, and for intra-day variability of compact radio quasars, is highly anisotropic in some cases. We numerically simulate these observed phenomena using totally anisotropic,…