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The Chandra HRC View of the Subarcsecond Structures in the Nuclear Region of NGC 1068
Elvis, Martin; Risaliti, Guido; Karovska, Margarita +2 more
We have obtained a high spatial resolution X-ray image of the nucleus of NGC 1068 using the High Resolution Camera (HRC-I) on board the Chandra X-ray Observatory, which provides an unprecedented view of the innermost 1 arcsec radius region of this galaxy. The HRC image resolves the narrow-line region into X-ray emission clumps matching bright emis…
Characteristic Size of Flare Kernels in the Visible and Near-infrared Continua
Xu, Yan; Cao, Wenda; Jing, Ju +1 more
In this Letter, we present a new approach to estimate the formation height of visible and near-infrared emission of an X10 flare. The sizes of flare emission cores in three wavelengths are accurately measured during the peak of the flare. The source size is the largest in the G band at 4308 Å and shrinks toward longer wavelengths, namely the green…
How the inclination of Earth's orbit affects incoming solar irradiance
Cheung, M. C. M.; Kretzschmar, M.; Dudok de Wit, T. +3 more
The variability in solar irradiance, the main external energy source of the Earth's system, must be critically studied in order to place the effects of human-driven climate change into perspective and allow plausible predictions of the evolution of climate. Accurate measurements of total solar irradiance (TSI) variability by instruments onboard sp…
Rest-frame stacking of 2XMM catalog sources. Properties of the Fe Kα line
Nandra, K.; Merloni, A.; Comastri, A. +3 more
Aims: The aim of this work is to characterize the average Fe K emission properties of active galactic nuclei (AGNs) in the source rest-frame.
Methods: We selected a sample of 248 AGNs from the 2XMM catalog, covering a wide redshift range 0 < z < 5 and with the EPIC-PN net 2-10 keV rest-frame counts ≥ 200 and power law photon indice…
Properties of Umbral Dots from Stray Light Corrected Hinode Filtergrams
Ichimoto, Kiyoshi; Ravindra, B.; Mathew, Shibu K. +3 more
High-resolution blue continuum filtergrams from Hinode are employed to study the umbral fine structure of a regular unipolar sunspot. The removal of scattered light from the images increases the rms contrast by a factor of 1.45 on average. Improvement in image contrast renders identification of short filamentary structures resembling penumbrae tha…
Planetary transit candidates in the CoRoT-SRc01 field
Mazeh, T.; Aigrain, S.; Alapini, A. +52 more
Context. The space mission CoRoT is devoted to the analysis of stellar variability and the photometric detection of extrasolar planets.
Aims: We present the list of planetary transit candidates detected in the first short run observed by CoRoT that targeted SRc01, towards the Galactic center in the direction of Aquila, which lasted from April…
The origin of hot white dwarf circumstellar features
Barstow, M. A.; Redfield, S.; Welsh, B. Y. +4 more
We have analysed a sample of 23 hot DAs to better understand the source of the circumstellar features reported in previous work. Unambiguous detections of circumstellar material are again made at eight stars. The velocities of the circumstellar material at three of the white dwarfs are coincident with the radial velocities of interstellar medium (…
Chromospheric jets around the edges of sunspots
Morton, R. J.
Aims: Evidence is beginning to be put forward that demonstrates the role of the chromosphere in supplying energy and mass to the corona. We aim to assess the role of chromospheric jets in active region dynamics.
Methods: Using a combination of the Hinode/SOT Ca II H and TRACE 1550 Å and 1600 Å filters we examine chromospheric jets situat…
Observation of standing kink waves in solar spicules
Zhelyazkov, I.; Zaqarashvili, T. V.; Ebadi, H.
We analyze the time series of Ca II H-line obtained from Hinode/SOT on the solar limb. The time-distance analysis shows that the axis of spicule undergos quasi-periodic transverse displacement at different heights from the photosphere. The mean period of transverse displacement is ∼180 s and the mean amplitude is 1 arc sec. Then, we solve the disp…
A Suzaku Observation of Mkn 590 Reveals a Vanishing Soft Excess
Rivers, Elizabeth; Markowitz, Alex; Rothschild, Richard +1 more
We have analyzed a long-look Suzaku observation of the Seyfert 1.2 Mkn 590. We aimed to measure the Compton reflection strength, Fe K complex properties, and soft excess emission as had been observed previously in this source. The Compton reflection strength was measured to be in the range 0.2-1.0 depending on the model used. A moderately strong F…