152 research outputs found

    CHEERS results on Mrk 573: Study of deep Chandra observations

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    We present results on Mrk 573 obtained as part of the CHandra survey of Extended Emission-line Regions in nearby Seyfert galaxies (CHEERS). Previous studies showed that this source features a biconical emission in the soft X-ray band closely related with the Narrow Line Region as mapped by the [O iii] emission line and the radio emission, though on a smaller scale; we investigate the properties of soft X-ray emission from this source with new deep Chandra observations. Making use of the subpixel resolution of the Chandra/ACIS image and PSF-deconvolution, we resolve and study substructures in each ionizing cone. The two cone spectra are fitted with photoionization model, showing a mildly photoionized phase diffused over the bicone. Thermal collisional gas at about ~ 1.1 keV and ~ 0.8 keV appears to be located between the nucleus and the "knots" resolved in radio observations, and between the "arcs" resolved in the optical images, respectively; this can be interpreted in terms of shock interaction with the host galactic plane. The nucleus shows a significant flux decrease across the observations indicating variability of the AGN, with the nuclear region featuring higher ionization parameter with respect to the bicone region. The long exposure allows us to find extended emission up to ~ 7 kpc from the nucleus along the bicone axis. Significant emission is also detected in the direction perpendicular to the ionizing cones, disagreeing with the fully obscuring torus prescribed in the AGN unified model, and suggesting instead the presence of a clumpy structure.Comment: 38 pages, 15 figures, 8 tables, accepted for publication on Ap

    Transrectal ultrasonography of the adrenal glands in donkeys (Equus asinus)

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    Little information is available for medical imaging in donkeys and no report about adrenal glands ultrasonography can be found in scientific literature. The feasibility of transrectal ultrasonography of the adrenal glands was tested on 30 healthy donkeys using a 10 MHz linear transducer. Mean age of animals was 10.7 ±4.8 years, mean weight 275.0 ±62.9 Kg and mean height 126.7 ±7.1 cm. The left adrenal gland was visualized in all donkeys. The right gland ultrasonography was not feasible in seven animals with a height less than 116 cm. The left gland was visualized as a linear or slightly curved structure, the right gland was most often S-shaped. In both glands, an hypechoic peripheral zone was identified as the cortex with an inner, hyperechoic medulla. The length was 5.49 ±1.90 cm and 5.15 ±1.10 cm for right and left gland, respectively. Right gland whole and medullary thickness were 0.71 ±0.11 cm and 0.24 ±0.09 cm, 0.65 ±0.13 cm and 0.21 ±0.07 cm, 0.56 ±0.17 cm and 0.25 ±0.07 cm for cranial pole, middle point and caudal pole respectively. Left gland whole and medullary thickness were 0.69 ±0.13 cm and 0.25 ±0.09 cm, 0.66 ±0.13 cm and 0.23 ±0.09 cm, 0.57 ±0.15 cm and 0.26 ±0.09 cm for cranial pole, middle point and caudal pole respectively. There was a significant correlation between height and the entire length of the left gland. Ultrasonography of the adrenal glands is a suitable tool for evaluation of both adrenal glands in most of the donkey. The size is a limiting factor for proper visualization of the right gland

    Mapping Seyfert and LINER Excitation Modes in the Inner kpc of NGC 3393

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    We have mapped the extended narrow line region (ENLR) of NGC 3393 on scales of r4r\lesssim4^{\prime\prime} (1\sim1\,kpc) from the nucleus using emission line images of Hαλ6563\alpha\,\lambda6563, [O III]λ5007\lambda5007, and [S II]λλ6717,6731\lambda\lambda6717,6731 taken with HST as part of the CHandra survey of Extended Emission line Regions in nearby Seyfert galaxies (CHEERS). By mapping these lines onto a spatially resolved Baldwin-Phillips-Terlevich (BPT) diagram, we investigate the impact of feedback from a Compton-thick AGN on its circumnuclear ISM. We find the expected Seyfert-like emission within the ionization bicone (3\lesssim3^{\prime\prime}; 770 pc). We also find a new, figure 8 shaped LINER cocoon enveloping the bicone and defining a sharp (100  \lesssim100\;pc) transition between higher and lower ionization zones. These data illustrate the morphological dependence of ionization states of the ENLR relative to bicone and host gas geometries.Comment: Accepted by ApJ and published (2016, ApJ, 829, 46). Updated to reflect the accepted versio

    Flaring Patterns in Blazars

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    Blazars radiate from relativistic jets launched by a supermassive black hole along our line of sight; the subclass of FSRQs exhibits broad emission lines, a telltale sign of a gas-rich environment and high accretion rate, contrary to the other subclass of the BL Lacertae objects. We show that this dichotomy of the sources in physical properties is enhanced in their flaring activity. The BL Lac flares yielded spectral evidence of being driven by further acceleration of highly relativistic electrons in the jet. Here we discuss spectral fits of multi-lambda data concerning strong flares of the two flat spectrum radio quasars 3C 454.3 and 3C 279 recently detected in gamma rays by the AGILE and Fermi satellites. We find that optimal spectral fits are provided by external Compton radiation enhanced by increasing production of thermal seed photons by growing accretion. We find such flares to trace patterns on the jet power - electron energy plane that diverge from those followed by flaring BL Lacs, and discuss why these occur.Comment: 6 pages, 3 figures, accepted for publication in The Astrophysical Journa

    Transrectal ultrasonography of the adrenal glands in donkeys (Equus asinus)

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    Little information is available for medical imaging in donkeys and no report about adrenal glands ultrasonography can be found in scientific literature. The feasibility of transrectal ultrasonography of the adrenal glands was tested on 30 healthy donkeys using a 10 MHz linear transducer. Mean age of animals was 10.7 ±4.8 years, mean weight 275.0 ±62.9 Kg and mean height 126.7 ±7.1 cm. The left adrenal gland was visualized in all donkeys. The right gland ultrasonography was not feasible in seven animals with a height less than 116 cm. The left gland was visualized as a linear or slightly curved structure, the right gland was most often S-shaped. In both glands, an hypechoic peripheral zone was identified as the cortex with an inner, hyperechoic medulla. The length was 5.49 ±1.90 cm and 5.15 ±1.10 cm for right and left gland, respectively. Right gland whole and medullary thickness were 0.71 ±0.11 cm and 0.24 ±0.09 cm, 0.65 ±0.13 cm and 0.21 ±0.07 cm, 0.56 ±0.17 cm and 0.25 ±0.07 cm for cranial pole, middle point and caudal pole respectively. Left gland whole and medullary thickness were 0.69 ±0.13 cm and 0.25 ±0.09 cm, 0.66 ±0.13 cm and 0.23 ±0.09 cm, 0.57 ±0.15 cm and 0.26 ±0.09 cm for cranial pole, middle point and caudal pole respectively. There was a significant correlation between height and the entire length of the left gland. Ultrasonography of the adrenal glands is a suitable tool for evaluation of both adrenal glands in most of the donkey. The size is a limiting factor for proper visualization of the right gland
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