SDSSJ143244.91+301435.3 at VLBI: a compact radio galaxy in a narrow-line Seyfert 1

We present VLBI observations, carried out with the European Very Long Baseline Interferometry Network (EVN), of SDSSJ143244.91+301435.3, a radio-loud narrow-line Seyfert 1 (RLNLS1) characterized by a steep radio spectrum. The source, compact at Very Large Array (VLA) resolution, is resolved on the milliarcsec scale, showing a central region plus two extended structures. The relatively high brightness temperature of all components (5x10^6-1.3x10^8 K) supports the hypothesis that the radio emission is non-thermal and likely produced by a relativistic jet and/or small radio lobes. The observed radio morphology, the lack of a significant core and the presence of a low frequency (230 MHz) spectral turnover are reminiscent of the Compact Steep Spectrum sources (CSS). However, the linear size of the source (~0.5kpc) measured from the EVN map is lower than the value predicted using the turnover/size relation valid for CSS sources (~6kpc). This discrepancy can be explained by an additional component not detected in our observations, accounting for about a quarter of the total source flux density, combined to projection effects. The low core-dominance of the source (CD<0.29) confirms that SDSSJ143244.91+301435.3 is not a blazar, i.e. the relativistic jet is not pointing towards the observer. This supports the idea that SDSSJ143244.91+301435.3 may belong to the "parent population" of flat-spectrum RLNLS1 and favours the hypothesis of a direct link between RLNLS1 and compact, possibly young, radio galaxies.Comment: 8 pages, 3 figures, accepted for publication in MNRA

Performing edge detection by difference of Gaussians using q-Gaussian kernels

In image processing, edge detection is a valuable tool to perform the extraction of features from an image. This detection reduces the amount of information to be processed, since the redundant information (considered less relevant) can be unconsidered. The technique of edge detection consists of determining the points of a digital image whose intensity changes sharply. This changes are due to the discontinuities of the orientation on a surface for example. A well known method of edge detection is the Difference of Gaussians (DoG). The method consists of subtracting two Gaussians, where a kernel has a standard deviation smaller than the previous one. The convolution between the subtraction of kernels and the input image results in the edge detection of this image. This paper introduces a method of extracting edges using DoG with kernels based on the q-Gaussian probability distribution, derived from the q-statistic proposed by Constantino Tsallis. To demonstrate the method's potential, we compare the introduced method with the traditional DoG using Gaussians kernels. The results showed that the proposed method can extract edges with more accurate details.Comment: 5 pages, 5 figures, IC-MSQUARE 201

Detecting Extrasolar Planets with Integral Field Spectroscopy

Observations of extrasolar planets using Integral Field Spectroscopy (IFS), if coupled with an extreme Adaptive Optics system and analyzed with a Simultaneous Differential Imaging technique (SDI), are a powerful tool to detect and characterize extrasolar planets directly; they enhance the signal of the planet and, at the same time, reduces the impact of stellar light and consequently important noise sources like speckles. In order to verify the efficiency of such a technique, we developed a simulation code able to test the capabilities of this IFS-SDI technique for different kinds of planets and telescopes, modelling the atmospheric and instrumental noise sources. The first results obtained by the simulations show that many significant extrasolar planet detections are indeed possible using the present 8m-class telescopes within a few hours of exposure time. The procedure adopted to simulate IFS observations is presented here in detail, explaining in particular how we obtain estimates of the speckle noise, Adaptive Optics corrections, specific instrumental features, and how we test the efficiency of the SDI technique to increase the signal-to-noise ratio of the planet detection. The most important results achieved by simulations of various objects, from 1 M_J to brown dwarfs of 30 M_J, for observations with an 8 meter telescope, are then presented and discussed.Comment: 60 pages, 37 figures, accepted in PASP, 4 Tables adde

A new beach topography-based method for shoreline identification

The definition of shoreline is not the same for all contexts, and it is often a subjective matter. Various methods exist that are based on the use of different instruments that can determine and highlight a shoreline. In recent years, numerous studies have employed photogrammetric methods, based on different colours, to map the boundary between water and land. These works use images acquired by satellites, drones, or cameras, and differ mainly in terms of resolution. Such methods can identify a shoreline by means of automatic, semi-automatic, or manual procedures. The aim of this work is to find and promote a new and valid beach topography-based algorithm, able to identify the shoreline. We apply the Structure from Motion (SfM) techniques to reconstruct a high-resolution Digital Elevation Model by means of a drone for image acquisition. The algorithm is based on the variation of the topographic beach profile caused by the transition from water to sand. The SfM technique is not efficient when applied to reflecting surfaces like sea water resulting in a very irregular and unnatural profile over the sea. Taking advantage of this fact, the algorithm searches for the point in the space where a beach profile changes from irregular to regular, causing a transition from water to land. The algorithm is promoted by the release of a QGIS v3.x plugin, which allows the easy application and extraction of other shorelines

Trophic Status of the Bandar Kayangan Lembah Sari Reservoir, Rumbai Pesisir Sub-district, Pekanbaru Based on Nitrate and Phosphate Concentration

As a basis to determine the trophic status of the waters. A research aims tounderstand the trophic status of the waters of the Bandar Kayangan Lembah Sarireservoir was conducted in Mach-April 2016.There were 4 stations, namely St 1 (in theinlet from Ambang River), St 2 (in the inlet from Merbau River), St3 (in the middle ofthe lake) and St 4 (in the dam). Samplings were conducted 3 times, once/ week. Watersamples were taken from the water surface.Results shown that nitrate concentration was ranged from 0.075 – 0.096 mg/L,phosphate from 0.208 – 0.293 mg/L, temperature 31-32°C, transparency 56.8 – 60.2 cm,depth 219.3 – 378.7 cm, velocity0.25 – 0.40 cm/s, pH was4, dissolved oxygen (DO)5.38 – 8.31mg/L. Based on nitrate concentration, the trophic status of the BandarKayangan Lembah Sari reservoir was categorized as oligotrophic, whereas based onphosphate concentration, it can be categorized as eutrophic

Aqueous Humor Biomarkers of M\ufcller Cell Activation in Diabetic Eyes.

PURPOSE: To identify early biomarkers of retinal M\ufcller cell activation in diabetic eyes with or without clinically detectable signs of diabetic retinopathy (DR). METHODS: This study was a cross-sectional comparative case series. The aqueous humor (AH) of 34 eyes was collected in 12 healthy controls, 11 diabetic patients without DR, and 11 diabetic patients with nonproliferative DR. Full ophthalmic examination and spectral-domain optical coherence tomography were performed in all eyes. Glial fibrillary acidic protein (GFAP), aquaporin 1 (AQP1), and aquaporin 4 (AQP4) were quantified in AH samples as biomarkers of M\ufcller cell activity by ELISA. Statistical analysis was performed with ANOVA followed by Tukey-Kramer post hoc test. RESULTS: There was no significant difference in the age among the three groups. Mean concentration of GFAP, AQP1, and AQP4 significantly increased in diabetic eyes versus controls (P < 0.05, for each comparison). Glial fibrillary acidic protein and AQP1 showed an approximate 2-fold increase, whereas AQP4 showed an approximate 25-fold increase in diabetics with DR versus controls. In diabetics without DR, AQP4 showed an approximate 6-fold increase versus controls. CONCLUSIONS: Glial fibrillary acidic protein, AQP1, and AQP4-biomarkers of M\ufcller cell activity-are significantly increased in human eyes with diabetes, confirming that M\ufcller cells are precociously affected by diabetes mellitus

Exploring the parent population of beamed NLS1s: from the black hole to the jet

The aim of this work is to understand the nature of the parent population of beamed narrow-line Seyfert 1 galaxies (NLS1s), by studying the physical properties of three parent candidates samples: steep-spectrum radio-loud NLS1s, radio-quiet NLS1s and disk-hosted radio-galaxies. In particular, we focused on the black hole mass and Eddington ratio distribution and on the interactions between the jet and the narrow-line region.Comment: 6 pages, 2 figures, to appear in Proceedings of High Energy Phenomena in Relativistic Outflows (HEPRO) V, Workshop Series of the Argentinian Astronomical Societ

Unveiling the parent population of beamed narrow-line Seyfert 1s

Narrow-line Seyfert 1 galaxies (NLS1s) are active galactic nuclei (AGN) recently identified as a new class of $\gamma$-ray sources. The high energy emission is explained by the presence of a relativistic jet observed at small angles, just like in the case of blazars. When the latter are observed at larger angles they appear as radio-galaxies, but an analogue parent population for beamed NLS1s has not yet been determined. In this work we analyze this problem by studying the physical properties of three different samples of parent sources candidates: steep-spectrum radio-loud NLS1s, radio-quiet NLS1s, and disk-hosted radio-galaxies, along with compact steep-spectrum sources. In our approach, we first derived black hole mass and Eddington ratio from the optical spectra, then we investigated the interaction between the jet and the narrow-line region from the [O III] $\lambda\lambda$4959,5007 lines. Finally, the radio luminosity function allowed us to compare their jet luminosity and hence determine the relations between the samples.Comment: 6 pages, no figures. Proceedings of the 28th Texas Symposium, Geneva, December 13-18, 201

Surveys at Bagan Percut, Sumatra, reveal its international importance to migratory shorebirds and breeding herons

The Bagan Percut region of north-eastern Sumatra, Indonesia, is becoming well known for its large concentrations of migratory shorebirds. From January to June 2011 we made monthly counts of shorebirds and waterbirds at four mudflats and one heron rookery. Fifty-one species were recorded, including 35 migratory species, and eight breeding species in the rookery. We counted 20,114 migratory shorebirds (mudflats) and 45,648 breeding waterbirds (rookery) over six months of surveys. We observed &gt;1% of the East Asian-Australasian flyway population of five species of migratory shorebirds: Nordmann&rsquo;s Greenshank Tringa guttifer (globally Endangered), Lesser Sand Plover Charadrius mongolus, Pacific Golden Plover Pluvialis fulva, Eurasian Curlew Numenius arquata, and Ruddy Turnstone Arenaria interpres. Our results support the work of others that indicate that Bagan Percut is an important habitat for wintering, migrating, and summering shorebirds. We recommend that Bagan Percut be added to the East Asian-Australasian Flyway Partnership list of internationally important wetlands because the area meets all three criteria for inclusion

Near-infrared morphologies of the host galaxies of narrow-line Seyfert 1 galaxies

We present J-band near-infrared (NIR) imaging of the host galaxies of nine narrow-line Seyfert 1 galaxies (NLS1). Based on highfrequency radio observations at 37 GHz, seven of them could host powerful jets that are most likely relativistic. Host galaxy morphology studies of NLS1 galaxies are scarce, but exceedingly important for understanding the seemingly heterogeneous nature of the NLS1 population as well as their evolution and place in the active galactic nuclei (AGN) scheme. Increasing the sample size is essential for achieving statistically significant results. We determine the morphological types of the host galaxies by performing photometric decomposition of NIR images using a 2D image decomposition algorithm GALFIT. We were able to sufficiently model five of the nine host galaxies. Based on the fitting parameters, mainly the Sersic index, all five are disk-like galaxies. Sources with clearly distinguishable bulge components all have pseudo-bulges, and four out of five sources show a component resembling a bar. A surprisingly large fraction, three out of five, show signs of interaction or disturbed morphology. Our results suggest that spiral galaxies with pseudo-bulges are able to launch and maintain powerful jets. They also imply that interaction - mainly minor mergers - may have a role in initially triggering higher levels of nuclear activity in NLS1 galaxies. Furthermore, our results support the heterogeneous nature of the NLS1 class and indicate that this diversity is caused by different evolutionary stages, possibly due to mergers