Searching for evidence of jet-cloud interaction in radio galaxies. First results for 3C 381

We present results of Gemini spectroscopy and Hubble Space Telescope imaging of the 3C~381 radio galaxy. Possible ionising mechanisms for the Extended Emission-Line Region were studied through state-of-the-art diagnostic analysis employing line-ratios. Photoionisation from the central engine as well as mixed-medium photoionisation models fail in reproducing both the strengths and the behaviour of the highest-excitation lines, such as [NeV]3424, HeII, and [OIII}]5007, which are measured at very large distances from the AGN. Shock-ionisation models provide a better fit to the observation. Expanding shocks with velocities higher than 500 km/s are capable of reaching the observed intensity ratios for lines with different ionisation states and excitation degrees. This model also provide a direct explanation of the mechanical energy input needed to explain the high-velocity line-splitting observed in the velocity field.Comment: 21 pages, 11 figures; to be published in Monthly Notices of the Royal Astronomical Societ

On the origin of X-ray oxygen emission lines in obscured AGN

We present the Catalogue of High Resolution Spectra of Obscured Sources (CHRESOS) from the XMM-Newton Science Archive. It comprises the emission-line luminosities of H- and He-like transitions from C to Si, and the Fe 3C and Fe 3G L-shell ones. Here, we concentrate on the soft X-ray OVII (f) and OVIII Ly alpha emission lines to shed light on to the physical processes with which their formation can be related to active galactic nucleus (AGN) versus star-forming regions. We compare their luminosity with that of two other important oxygen key lines [O III]lambda 5007 angstrom, in the optical, and [O IV] 25.89 mu m, in the infrared (IR). We also test OVII (f) and OVIII Ly alpha luminosities against that of continuum bands in the IR and hard X-rays, which point to different ionization processes. We probe into those processes by analysing photoionization and collisional ionization model predictions upon our lines. We show that both scenarios can explain the formation and observed intensities of OVII (f) and OVIII Ly alpha. By analysing the relationships between OVII (f) and OVIII Ly alpha, and all other observables: [OIII]lambda 5007 angstrom, [O IV] 25.89 mu m emission lines, and mid-infrared (MIR) 12 mu m, far-infrared (FIR) 60 and 100 mu m, 2-10 and 14-195 keV continuum bands, we conclude that the AGN radiation field is mainly responsible of the soft X-ray oxygen excitation

Disentangling the nature of the prototype radio weak BL Lac: Contemporaneous multifrequency observations of WISE J141046.00 + 740511.2

Context. The gamma-ray emitting source WISE J141046.00+740511.2 has been associated with a Fermi-LAT detection by crossmatching with Swift/XRT data. It has shown all the canonical observational characteristics of a BL Lac source, including a power-law, featureless optical spectrum. However, it was only recently detected at radio frequencies and its radio flux is significantly low. Aims. Given that a radio detection is fundamental to associate lower-energy counterparts to Fermi-LAT sources, we aim to unambiguously classify this source by performing a multiwavelength analysis based on contemporaneous data. Methods. By using multifrequency observations at the Jansky Very Large Array, Giant Metrewave Radio Telescope, Gran Telescopio Canarias, Gemini, William Herschel Telescope and Liverpool observatories, together with Fermi-LAT and Swift data, we carried out two kinds of analyses. On one hand, we studied several known parameters that account for the radio loudness or weakness characterization and their application to blazars (in general) and to our source (in particular). And, on the other hand, we built and analyzed the observed spectral energy distribution (SED) of this source to try to explain its peculiar characteristics. Results. The multiwavelength analysis indicates that WISE J141046.00+740511.2 is a blazar of the high-frequency peaked (HBL) type that emits highly polarized light and that is likely located at a low redshift. In addition, the one-zone model parameters that best fit its SED are those of an extreme HBL (EHBL); this blazar type has been extensively predicted in theory to be lacking in the radio emission that is otherwise typical of canonical gamma-ray blazars. Conclusions. We confirm that WISE J141046.00+740511.2 is indeed a highly polarized BL Lac of the HBL type. Further studies will be conducted to explain the atypical low radio flux detected for this source.Comment: accepted for publication in A&A, in pres

Powerful Radio Sources in the Southern Sky. II. A SWIFT X-Ray Perspective

We recently constructed the G4Jy-3CRE, a catalog of extragalactic radio sources based on the GLEAM 4-Jy (G4Jy) sample, with the aim of increasing the number of powerful radio galaxies and quasars with similar selection criteria to those of the revised release of the Third Cambridge catalog (3CR). The G4Jy-3CRE consists of a total of 264 radio sources mainly visible from the Southern Hemisphere. Here, we present an initial X-ray analysis of 89 G4Jy-3CRE radio sources with archival X- ray observations from the Neil Gehrels Swift Observatory. We reduced a total of 615 Swift observations, for about 0.89 Msec of integrated exposure time, we found X-ray counterparts for 61 radio sources belonging to the G4Jy-3CRE, 11 of them showing extended X-ray emission. The remaining 28 sources do not show any X-ray emission associated with their radio cores. Our analysis demonstrates that X-ray snapshot observations, even if lacking uniform exposure times, as those carried out with Swift, allow us to (i) verify and/or re ne the host galaxy identi cation; (ii) discover the extended X-ray emission around radio galaxies of the intracluster medium when harbored in galaxy clusters, as the case of G4Jy 1518 and G4Jy 1664, and (iii) detect X-ray radiation arising from their radio lobes, as for G4Jy 1863.Comment: 35 pages, 17 figures, 2 tables; second paper of a series, pre-proof versio

Powerful Radio Sources in the Southern Sky. I. Optical Identifications

Since the early sixties, our view of radio galaxies and quasars has been drastically shaped by discoveries made thanks to observations of radio sources listed in the Third Cambridge catalog and its revised version (3CR). However, the largest fraction of data collected to date on 3CR sources was performed with relatively old instruments, rarely repeated and/or updated. Importantly, the 3CR contains only objects located in the Northern Hemisphere thus having limited access to new and innovative astronomical facilities. To mitigate these limitations we present a new catalog of powerful radio sources visible from the Southern Hemisphere, extracted from the GLEAM 4-Jy (G4Jy) catalog and based on equivalent selection criteria as the 3CR. This new catalog, named G4Jy- 3CRE, where the E stands for "equivalent", lists a total of 264 sources at declination below -5 degrees and with 9 Jy limiting sensitivity at ~178 MHz. We explored archival radio maps obtained with different surveys and compared then with optical images available in the Pan-STARRS, DES and DSS databases to search for optical counterparts of their radio cores. We compared mid-infrared counterparts, originally associated in the G4Jy, with the optical ones identified here and we present results of a vast literature search carried out to collect redshift estimates for all G4Jy-3CRE sources resulting in a total of 145 reliable z measurements.Comment: 72 pages, 35 figures, 5 Table

The Fornax Cluster through S-PLUS

The Southern Photometric Local Universe Survey (S-PLUS) aims to map ≈ 9300 deg2of the southernsky using the Javalambre filter system of 12 optical bands, 5 Sloan-like filters and 7 narrow-band filters centeredon several prominent stellar features ([OII], Ca H+K, D4000, Hδ, Mgb, Hα and CaT). S-PLUS is carried outwith the T80-South, a new robotic 0.826 m telescope located on CTIO, equipped with a wide field of view camera(2 deg2). In this poster we introduce project #59 of the S-PLUS collaboration aimed at studying the Fornaxgalaxy cluster covering an sky area of ≈ 11 × 7 deg2, and with homogeneous photometry in the 12 optical bandsof S-PLUS (Coordinator: A. Smith Castelli).Fil: Smith Castelli, Analia Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Mendez de Olivera, C.. Universidade do Sao Paulo. Instituto de Astronomia, Geofísica e Ciências Atmosféricas; BrasilFil: Herpic, F.. Universidade do Sao Paulo. Instituto de Astronomia, Geofísica e Ciências Atmosféricas; BrasilFil: Barbosa, C.. Universidade do Sao Paulo. Instituto de Astronomia, Geofísica e Ciências Atmosféricas; BrasilFil: Escudero, Carlos Gabriel. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Grossi, M.. Observatorio de Valongo; BrasilFil: Sodré, L.. Universidade do Sao Paulo. Instituto de Astronomia, Geofísica e Ciências Atmosféricas; BrasilFil: de Bom, .. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Zenocratti, Lucas Jesús. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: de Rossi, Maria Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio(i); ArgentinaFil: Cortesi, A.. Observatorio de Valongo; BrasilFil: Cid Fernandes, R.. Universidade Federal de Santa Catarina; BrasilFil: Lopes, A.. Ministerio de Ciencia, Tecnología E Innovacao. Observatorio Nacional. Departamento Astronomia y Astrofísica; BrasilFil: Telles, E.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Oliveira Schwarz, G. B.. Universidade Anhembi Morumbi; BrasilFil: Dantas, M. L. L.. Nicolaus Copernicus Astronomical Center; PoloniaFil: Faifer, Favio Raúl. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Chies Santos, A.. Universidade Federal de Santa Catarina; BrasilFil: Saponara, Juliana. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Reynaldi, María Victoria. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Andruchow, Ileana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Sesto, Leandro Alberto. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Mestre, M.. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: de Amorim, A. L.. Universidade Federal de Santa Catarina; BrasilFil: de Lima, E. V. R.. Universidade do Sao Paulo. Instituto de Astronomia, Geofísica e Ciências Atmosféricas; BrasilFil: Abboud, J.. Universidade do Sao Paulo. Instituto de Astronomia, Geofísica e Ciências Atmosféricas; BrasilFil: Cernic, V.. Universidade do Sao Paulo. Instituto de Astronomia, Geofísica e Ciências Atmosféricas; BrasilFil: Souza de Almeida Garcia, I.. Universidade do Sao Paulo. Instituto de Astronomia, Geofísica e Ciências Atmosféricas; Brasil62° Reunión Anual de la Asociación Argentina de AstronomíaRosarioArgentinaUniversidad Nacional de RosarioComplejo Astronómico Municipal Galileo Galile

Powerful radio sources in the southern sky: I. optical identifications

Since the early sixties, our view of radio galaxies and quasars has been drastically shaped by discoveries made thanks to observations of radio sources listed in the Third Cambridge Catalog and its revised version (3CR). However, the largest fraction of data collected to date on 3CR sources was performed with relatively old instruments, rarely repeated and/or updated. Importantly, the 3CR contains only objects located in the Northern Hemisphere, thus having limited access to new and innovative astronomical facilities. To mitigate these limitations, we present a new catalog of powerful radio sources visible from the Southern Hemisphere, extracted from the GLEAM 4 Jy (G4Jy) catalog and based on equivalent selection criteria as the 3CR. This new catalog, named G4Jy- 3CRE, where the E stands for “equivalent,” lists a total of 264 sources at decl. below −5° and with 9 Jy limiting sensitivity at ∼178 MHz. We explored archival radio maps obtained with different surveys and compared them with optical images available in the Pan-STARRS, DES, and DSS databases to search for optical counterparts of their radio cores. We compared mid-infrared counterparts, originally associated in the G4Jy, with the optical ones identified here, and we present results of a vast literature search carried out to collect redshift estimates for all G4Jy-3CRE sources resulting in a total of 145 reliable z measurements.Instituto Argentino de RadioastronomíaInstituto de Astrofísica de La Plat

Interspecific competition delays recovery of Daphnia spp. populations from pesticide stress

Xenobiotics alter the balance of competition between species and induce shifts in community composition. However, little is known about how these alterations affect the recovery of sensitive taxa. We exposed zooplankton communities to esfenvalerate (0.03, 0.3, and 3 μg/L) in outdoor microcosms and investigated the long-term effects on populations of Daphnia spp. To cover a broad and realistic range of environmental conditions, we established 96 microcosms with different treatments of shading and periodic harvesting. Populations of Daphnia spp. decreased in abundance for more than 8 weeks after contamination at 0.3 and 3 μg/L esfenvalerate. The period required for recovery at 0.3 and 3 μg/L was more than eight and three times longer, respectively, than the recovery period that was predicted on the basis of the life cycle of Daphnia spp. without considering the environmental context. We found that the recovery of sensitive Daphnia spp. populations depended on the initial pesticide survival and the related increase of less sensitive, competing taxa. We assert that this increase in the abundance of competing species, as well as sub-lethal effects of esfenvalerate, caused the unexpectedly prolonged effects of esfenvalerate on populations of Daphnia spp. We conclude that assessing biotic interactions is essential to understand and hence predict the effects and recovery from toxicant stress in communities